FEMTO-LASIK and BEYOND - Carl Zeiss, Inc.

SUPPLEMENT June 2012 

EDUCATIONAL SUPPLEMENT 

JUNE 2012 

Supported by an Educational 

Grant from Carl Zeiss 

2012 Refractive Compendium 

Panelists from the International Refractive User Symposium, in Kuala Lumpur, and 

the ESCRS ReLEx ® smile Satellite Symposium, in Vienna, share their latest clinical 

experiences in the use of VisuMax ® femtosecond system, ReLEx and Keratoplasty. 

FEMTO-LASIK and BEYOND 

A compendium of the latest global perspectives on the 

VisuMax femtosecond system and the promise it holds 

for the future of refractive surgery.

Introduction 

Table Of Contents 

P4 

P6 

P10 

P11 

P15 

P16 

P19 

P20 

P22 

P24 

P26 

A Winning Combination: 

Femtosecond Lasers and Flapless Laser 

Vision Correction 

VisuMax in Conventional 

Femto-LASIK Surgery 

VisuMax: The Femto-only 

Option of Laser Correction 

LASIK in High Myopia 

ReLEx smile: The New Application 

ReLEx smile: All-in-one Correction 

ReLEx Versus Femtosecond LASIK: 

A Comparison 

ReLEx smile: An Outstanding 

Treatment for Low, Moderate 

and High Myopia 

ReLEx smile: My New 

Clinical Standard 

VisuMax in Keratoplasties 

The Importance of ReLEx in Our 

Current Laser Vision Correction 

Business 

At the International Refractive User 

Symposium, in Kuala Lumpur, 

and the ESCRS ReLEx smile 

Satellite Symposium, in Vienna, 

Carl Zeiss gathered key opinion leaders from 

around the world to share their experiences in 

advanced techniques of refractive surgery. The 

subspecialty continues to evolve dramatically, 

not only in terms of advancements in 

LASIK techniques but also in lenticular 

options available to give a patient the best 

possible visual result. Twenty years after 

its advent, LASIK is today the most widely 

done refractive procedure. However, as was 

evident in the discussions in Kuala Lumpur 

and Vienna, refractive surgery steps beyond 

traditional LASIK. 

Three key advancements were discussed 

in detail at the conferences—the VisuMax 

Femtosecond System, ReLEx and the 

femtosecond laser’s role in keratoplasties. 

VisuMax was appreciated for its precision, 

performance and infallible patient satisfaction. 

Many surgeons shared how the laser pulse rate 

of 500 kHz has helped the VisuMax to set new 

standards of efficiency, and hence scores over 

the frequency of 200 kHz. 

ReLEx, meanwhile, marks a strong 

step forward in laser vision correction by 

combining precise refractive femtosecond 

laser technology with lenticule extraction. The 

predictable results which the technique offers 

are a boon to surgeons and patients alike. 

Apart from the role of VisuMax in 

procedural LASIK, speakers acknowledged 

that the femtosecond system presents a 

comprehensive option for keratoplasty and 

enables superior corneal grafting with minimal 

complications. Indeed, one can certainly think 

beyond LASIK with the VisuMax.

The Panelists 

Ekktet Chansue, MD 

Medical Director 

TRSC International LASIK Eye Center 

Bangkok, Thailand. 

Dr Bertram Meyer 

Consultant, Laser Eyecare and Research Centre 

Dubai Healthcare City 

Dubai, UAE 

Prof Osama Ibrahim 

Professor of Ophthalmology, Alexandria University 

Chairman, Roayah Vision Correction Centers 

Egypt 

Dr Burjor P Banaji 

Medical Dirctor, Banaji Eyecare 

Mumbai, India 

Dr Donald Tan 

Medical Director, SNEC 

Chairman, SERI 

Singapore 

Dr Iain Dunlop 

Director, Canberra Eye Hospital 

Canberra, Australia 

Dr Lennard Thean 

Clinical Director, Ophthalmology 

National University Hospital and 

NUH Eye and LASIK Centre 

Quezon City, Philippines 

Dr Ruben Lim Bon Siong 

Clinical Associate Professor 

University of Philippines 

Manila, Philippines 

Prof Dan Z. Reinstein 

Medical Director, 

London Vision Clinic 

London, UK 

Walter Sekundo, MD 

Chairman, Department of Ophthalmology 

Philipps University of Marburg 

Germany 

Dr Khairidzan Mohd Kamal 

Associate Professor 

International Islamic University 

Kuala Lumpur, Malaysia 

Rupal Shah, MD 

Director, New Vision Laser Centers 

Vadodara, India 

Prof Muhaya Mohammad HJ 

Director, PCMC Eye and Lasik Center 

Prince Court Medical Center 


Prof Zhou Xingtao 

Director, Eye and ENT Hospital 

Fudan University 

Shanghai, China 

Dr Patrick Versace 

Medical Director 

Vision Eye Institute 

Bondi, Australia 

Jesper Hjortdal, MD, PhD 

Director of Corneal and Refractive Surgery 

Aarhus University Hospital 

Denmark. 

Dr Cordelia Chan 

Senior Consultant 

Singapore National Eye Center 

Singapore 

Dr Khaled Ben Amor 

Tunisia

4 

Ophthalmology WORLD REPORT 

A Winning Combination: 

Femtosecond Lasers and Flapless 

Laser Vision Correction 

ESCRS ReLEx smile Satellite Symposium Vienna, Austria 

Cataract & Refractive Surgery Today Europe 

With the right candidate, ReLEx provides many advantages over PRK or LASIK. 

Reviewed by Walter Sekundo, MD 

Refractive surgery is still a 

relatively new frontier in 

ophthalmology. It began as 

a radical idea in the late 1980s and 

early 1990s but it quickly transformed 

into a trend that is acceptable 

worldwide and boasts impressive 

postoperative results. 

Today, millions of people undergo elective laser vision 

correction to fix refractive errors in the hopes of achieving 

spectacle independence. LASIK and PRK are exceptional 

procedures with outstanding safety and efficacy, but there 

are now other laser vision correction options for our patients. 

One newer choice in refractive surgery is ReLEx, a less 

invasive, highly precise form of laser vision correction 

that is performed completely inside the intact cornea with 

the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, 

Germany). This innovation allows the surgeon to create a 3-D 

cut within the cornea, intrinsically increasing predictability 

of refractive surgery due to less tissue destruction and better 

ambient conditions. 

Overview: Marcus Blum, MD, of Erfurt, Germany, and I 

belong to a small group of principal investigators for the VisuMax 

femtosecond laser and have been using this platform 

for refractive surgery since 2007. We also helped develop 

the company’s original lenticule extraction technique, femtosecond 

lenticule extraction (ReLEx flex). Now, 

Carl Zeiss Meditec has a successive lenticule extraction 

technique, ReLEx smile, using small incision extraction. This 

method has eliminated the need for flap creation. Instead of a 

corneal flap, the surgeon creates a small incision and manually 

extracts the intrastromal lenticule. For a video demonstration 

of ReLEx smile, visit http://eyetube.net/?v=ginuh. 

The company has branded both techniques under the general 

name of ReLEx. This technique is unique to other laser procedures 

because it uses precise laser cutting patterns instead 

of ablation patterns typical of LASIK and PRK procedures. 

One advantage of ReLEx is that the same laser can be used 

throughout the entire procedure, saving time in the operating 

room and eliminating the need to move the patient between 

two laser platforms. 

Laser Quality: By today’s increasing standards of patient 

care, I feel that the VisuMax is the only machine that can be 

used for full refractive purposes. My initial experience is with 

ReLEx flex. In the beginning, I used the 200-kHz VisuMax 

femtosecond laser for this procedure, which includes creation 

of two cuts, one at the bottom and one at the top of the 

refractive lenticule. Once the lenticule is removed, the flap is 

repositioned and the procedure concludes. 

ReLEx flex treatments with the 200-kHz laser were efficient 

and lasted between 50 and 60 seconds, depending on the 

lenticule and flap diameter. My surgical results were quite 

impressive. Of the more than 100 commercial patients I 

treated with the 200-kHz machine, all achieved a visual acuity 

of 20/40 or better at 1 month and roughly 80% were 20/20 or 

better by the last follow-up at 3 months. 

In March 2011, I upgraded to the 500-kHz VisuMax, which 

has allowed me to achieve even more impressive results for 

my patients. Most notably, virtually all patients treated are 

20/25 at 1 week and 20/20 unaided at the second follow-up 

at 1 month. Surgically, what I am most impressed with is the 

improved quality of the cut within the cornea and the speed of 

the treatment. With the 500-kHz engine, the treatment is done 

within 40 seconds. Thus, I have been able to reduce laser 

energy, leading to faster visual recovery. Now, I can also treat 

patients who I would have previously found unsuitable for 

this procedure with the 200-kHz laser, such as those who I did 

not feel could lay still for 60 seconds. 

The more important issue, however, is that the 500-kHz 

laser also handles the corneal tissue more delicately, which 

combined with the quality of the corneal cut makes it easier to 

extract the lenticule. I performed ReLEx smile as a study pro-

June 2012 Supplement 

5 

Figure 1. At 3-month follow-up after ReLEx smile, only a faint 

superior incision site is detectable at the slit lamp. 

“ReLEx currently has the most advantages for 

moderate and high myopia when compared 

with excimer-based procedures.” 

cedure with the 200-kHz laser, but today it is my procedure of 

choice with the 500-kHz laser, in particular for moderate and 

high myopia. 

Patient comfort: I have found that 

patients are more comfortable during 

and after ReLEx versus femtosecond 

LASIK and surface ablation procedures, 

and I believe this is because 

the cuts made during ReLEx flex, and 

especially ReLEx smile, are smaller 

than the surface manipulation with 

LASIK and PRK. Smaller cuts shorten 

the time it takes for the epithelium 

to heal (Figure 1). While the eye is 

healing, patients typically experience 

foreign body sensations; with ReLEx 

smile procedures, this lasts for no more 

than 2 to 3 hours as a minor discomfort 

in comparison to approximately 4 to 

5 hours with LASIK and 2 to 3 days 

PRK. 

During the entire procedure, the patient 

feels a little pressure. As shown in a 

study by Vetter et al, 1 treatment with the 

VisuMax femtosecond laser leads to the 

lowest increase in intraocular pressure 

as compared with other femtosecond 

lasers. Additionally, there is neither any central artery occlusion 

(ie, blackout of vision) nor the smell of the fumes typically 

created during excimer-based surgery. 

Because of the increased stability of the achieved refractive 

correction, I can also perform ReLEx in patients with up to 

-10.00D of myopia, which otherwise would have received a 

phakic IOL. In fact, this week I saw a patient 3 months after 

ReLEx smile for -9.50D of myopia. He had an impressive 

distance UCVA of 20/12.5 and no night driving problems 

despite a 6.8-mm scotopic pupil. 

Incision size: The nice thing about ReLEx smile is that there is 

no longer a need for the corneal flap. Therefore, this all-in-one 

laser procedure reduces the complications associated with the 

flap cut, including incomplete or irregular corneal flaps, thin 

or small corneal flaps, buttonholes, and free caps. 

ReLEx smile can be performed using either one or two 

incisions. I prefer making two small incisions (3–5 mm) at 

the 12- and 6-o’clock positions. The use of two incisions 

enhances the flow of fluid within the eye when I flush the 

interface. These incisions can alternatively be created at the 

3- and 9-o’clock positions, as is Professor Blum’s technique, 

with the same result. Because the opening incisions are only 

100 to 120 μm deep, they do not induce astigmatism. When 

only one incision is placed, a technique that Rupal Shah, MD, 

of India uses, a small pocket is created to extract the lenticule. 

ReLEx currently has the most advantages for moderate and 

high myopia when compared with excimer-based procedures. 

However, I am participating in a second ongoing study to test 

its efficacy for hyperopia. What we do know is that visual 

recovery, higher-order aberrations, and stability are excellent 

for moderate and high myopia, as shown in the comparative 

studies by Gertnere and Hjortdal at a recent Carl Zeiss users’ 

meeting held in Dubai. Hyperopia treatment has always been 

a more challenging terrain than myopia. However, our first 

results on hyperopic ReLEx are encouraging, and once we 

perfect a cut profile we hope to achieve results similar to 

the current excimer standards. 

Conclusion: ReLEx is an exciting new realm in refractive surgery, 

and any reasonably skilled surgeon can achieve successful 

outcomes with this procedure. What I enjoy about ReLEx 

is being able to use the same femtosecond laser workplace 

for the nonrefractive cut and the surgical manipulation itself, 

and my patients enjoy the faster surgery and improved patient 

comfort. 

1. Vetter JM, Schirra A, Garcia-Bardon D, Lorenz K, Weingärtner WE, Sekundo W. 

Comparison of Intraocular Pressure During Corneal Flap Preparation Between a 

Femtosecond Laser and a Mechanical Microkeratome in Porcine Eyes. Cornea. 2011 

Jul 26. [Epub ahead of print.]

6 


VisuMax 

In Conventional 

Femto-LASIK 

Surgery Kuala Lumpur, Malaysia 

International Refractive User Symposium 

Dr Iain Dunlop on the “Australian 

Experience with the ZEISS Femtosecond 

Laser” 

“I am very happy with this 

machine. It is very forgiving, safe 

and accurate.” 

The Australian experience: Discussing the Australian 

experience with VisuMax, Dr Dunlop rightly called it a 

“platform for growth, both refractive and therapeutic”. 

It holds a promise for service excellence and is costeffective. 

“Well you get what you pay for and ideally 

it is worth it,” he added. It is exceptionally stable and 

self-calibrating; “it has an integrated uninterrupted 

power supply and excellent audiovisual capabilities. It 

does not require a stand-by mode and can be installed 

‘out-of-the box’”. 

Configuration: Dr Dunlop spoke about the configuration 

of the VisuMax for the hinge location, flap 

diameter and thickness and the side-cut angle. “You 

can configure your VisuMax however you like. You 

can change the hinge location. Before it is all in the 

software. The flap diameter can be chosen to fit the 

cone you use,” he explained. He shared details of how 

the energy, spot and track distance settings can be chosen 

for standard mode, standard mode enhanced, fast 

mode and fast mode enhanced, which appear on the 

screen of the VisuMax. He then compared the ablation 

patterns in the initial and advanced models. 

LASIK with VisuMax and MEL 80 ® : Dr Dunlop described 

the flap lift using the MEL 80. According to him, there 

is no need to wait till the bubble layer regresses into 

transparency. He then shared the results of 400 cases 

he had done. For the choice of cones, he said “Medium 

cones (n=289) are used about 3 times more than the 

small ones (n=108) and we rarely use the large cones 

(n=3).With the cone comes a license, so you use one 

cone for one eye. This means ZEISS maintains quality 

control and it is, I guess, a reasonable step though it is 

a bit confronting when you first meet it.” He finds the 

machine to be successful as complications are rare. “The 

machine is so pleasant and successful to use that one has 

to look for irregularities or surprises that arise,” said 

Dr Dunlop. He described suction loss as being 

“something that can be dealt with” and shared that the 

VisuMax was very forgiving. He showed videos of cases 

of suction loss and how it can be avoided by using the 

right cone, correct positioning of the head, and reassuring 

the patient. Lastly, he described his experience with 

patients in range of -8.5D to +4.5D. He said, “We have 

had a 100 μm flap thickness with a 110 degrees side cut 

and it is very satisfying and predictable. The patients are 

very comfortable and happy as well. Importantly, there 

has been no machine downtime.” 

Dr Cordelia Chan on “Femto-LASIK with 

VisuMax: The SNEC Experience” 

“Since its inception in November 

2008, SNEC has developed a 

successful Femto-LASIK with 

VisuMax program. Good clinical 

outcomes for myopic LASIK have 

been achieved with excellent safety, 

predictability and efficacy profiles.” 

The VisuMax fits into the Singapore National Eye 

Center practice as it is a part of the major Translational 

Clinical Research (TCR) program, Translational 

Research in Ocular Surgery (TRIOS) conducted by 

the Singapore Eye Research Institute (SERI) and funded 

by the Singapore government. “We started refractive 

surgery in 1993 with PRK and LASIK in 1996. Today, we 

have done over 50,000 procedures and do a 100% clinical 

audit for all our procedures. This year we published our 

10 year audit results of 37,932 cases performed between 

1998 and 2007—the largest published series on LASIK,” 

Dr Chan briefed. 

Sharing the results of the 200 kHz device, she said that 

there was excellent safety, predictability and efficacy 

of VisuMax femtosecond platform for LASIK. She also 

discussed the results of the study done to evaluate the 

impact of the suction breaks upon tissue separation with 

VisuMax 200 kHz done on eye bank corneas (n=10) and 

said that suction loss was much less of concern with 

VisuMax. “In SNEC, we do predominantly aging eyes,


7 

we normally use an S cone if it is a 12-2 or 12-3 mm 

cornea. With an M cone, it is a little easier to get suction 

breaks,” she said. 

VisuMax vs IntraLase LASIK: She discussed the retrospective, 

multi-surgeon study of LASIK performed for myopia 

with or without astigmatism from September 2009 to 

April 2010 at SNEC. According to her, the efficacy index, 

predictability and safety were similar for VisuMax (n=882) 

and IntraLase (n=654). The VisuMax seemed to be much 

better in high myopes (-10D or more) with an efficacy index 

of 0.97 (n=8) as against the IntraLase with an efficacy 

index of 0.84 (n=9). “But the numbers are small and we 

may have confounded the results,” she cautioned. 

VisuMax vs IntraLase, Contralateral Eye Study: The 

prospective randomized study consisted of a bilateral 

simultaneous LASIK with VisuMax 500 kHz femtosecond 

laser for LASIK flap creation in one eye and IntraLase 

femtosecond system in the fellow eye. Excimer laser 

ablation was done with Wavelight® Allegretto 400 kHz 

in both eyes. The patients and surgeons were interviewed 

perioperatively with a standardized questionnaire 

about their operative experiences and preferences. Dr 

Chan shared the results of 24 patients of the 40 target 

population. Despite of the VisuMax being a low pressure 

system, 17% had a loss of light perception during suction 

and during the femtosecond pass. The same was seen 

in around 45% with IntraLase. When questioned about 

the fear factor, 46% of the VisuMax patients and 67% of 

IntraLase patients were frightened during vacuum suction 

or applanation. “Most patients said that the vacuum 

suction for both the systems was the most painful part. 

The pain score for VisuMax was 1.7 and for IntraLase 

was much higher (4.3),” she said. Seventy-five percent 

and 2% of patients preferred the VisuMax and IntraLase, 

respectively. The patients disliked the discomfort and pain 

in IntraLase and the constant stare at green light in the 

VisuMax. According to Dr Chan, she finds the VisuMax 

to be “an easier platform” with lesser subconjunctival 

hemorrhage and suction loss. “About 45% of us felt that 

the IntraLase was easier to lift, 17% found VisuMax was 

easier to lift and 37% are had no preference,” she said. 

Conclusions: Dr Chan concluded that a nice and assuring 

upward trend in predictability has been obtained with the 

VisuMax. She feels that the VisuMax is also a preferred 

choice by patients. Loss of light perception occurred more 

frequently with the IntraLase during flap creation. “Since 

its inception in November 2008, SNEC has developed 

successful Femto-LASIK with VisuMax program. Good 

clinical outcomes for myopic LASIK have been achieved 

with excellent safety, predictability and efficacy profiles,” 

she summarized. 

Dr Patrick Versace on “Registration, 

Alignment and Tracking” 

“ZEISS provides us with a platform 

that effectively has three elements of 

a laser delivery system. It has good 

diagnostic, so we can measure corneal 

shape, we can measure the wavefront 

of the cornea and total eye, and these 

things are integrated into the 

CRS-Master. We can plan treatments 

integrating all the data that we collect.” 

Ablation, rotational alignment and tracking: “Zeiss 

system tracks both the pupil and the limbus. It has 

a sampling speed and a response time,” Dr Versace 

said. He showed the impact of change in tracking speed on 

various parameters. 

Dr Versace specified how it was important to “put the ablation 

where it is meant to be on the cornea and to maintain 

that position throughout the treatment.” He agreed that 

success was in “having the device placed on the visual axis 

not on the pupil center.” 

Talking about an acceptable misalignment he said that a 

translational error of 300 μm to 400 μm and a rotational 

error of 8-10 degrees would still give a 50% reduction in 

higher order aberrations. He said that a workable registration 

would be an XY shift of less than 200 μm and a 

rotational alignment within 5 degrees. He then spoke about 

the wavefront alignment with the Zernicke reference and 

how the pupil was used for wavefront capture. According 

to him, the ZEISS system does compensate for the shift in 

center of the pupil as the pupil dilates or gets smaller. “The 

ZEISS platform has a resolution of 100 μm with pupil 

center shift. That is well within what we need.” 

Angle kappa: Describing how a large angle kappa leads 

to a significant induction of coma, he shared the results 

for angle kappa from a recent study done in Iraq which 

unleashed that the angle kappa was common and the values 

were pretty much the same for all refractive errors, myopia 

and hyperopia. 

Cyclorotation: Referring to rotational alignment and astigmatism, 

Dr Versace spoke about “how much cyclorotation 

occurs when the patient goes from sitting to lying down.” 

“Most patients have less than 5 degrees cyclorotation,” he 

said. Dr Versace showed the WASCA/CRS-Master/MEL 80

8 


tion he said that “the topography treatment automatically 

compensates for angle kappa and has 2 separate points of 

centration.” 

Summary: According to Dr Versace, the ZEISS platform 

compensates for cyclorotation and change in pupil center. 

In the event of visual axis overriding the laser, there is 

ATLAS registration and automatic angle kappa compensation. 

In astigmatism with iris registration, he “overrides the 

laser and sets the pupil center or visual axis”. For WASCA 

ablation, he said that one should consider the higher order 

on center of pupil present at aberrometer, the sphere and 

cylinder on pupil center or visual axis and incorporation of 

second order into Zernike set. What he does is “over ride 

and place cursor on the pupil center”. 

MEL 80 eye tracker (Dr Patrick Versace, Australia) 

He also described the topoguided ablation using ATLAS. 

In presbyopic LASIK ablation he said, “We shift to visual 

axis and compensate the angle kappa and set ablation on 

visual axis prior to flap lift.” He said that the pre-existing 

and induced spherical aberrations should be considered. 

For enhancement, he uses the toporefractive treatment 

when possible. Lastly, he said that the ZEISS system 

integrates topography, refraction, wavefront, patient data, 

flap creation, eye motion, pachymetry, corneal curvature 

and refraction. “We still have to work towards automated 

centration and registration of ablations to avoid all errors 

that we make,” he concluded. 

Zeiss dynamic registration (Dr Patrick Versace, Australia) 

eye registration data for clinical test done on 37 eyes (OD/ 

OS) where the torsion between sitting and supine position 

was less than +15 degrees. He showed graphical 

results for cyclorotation tolerances. “The system is quite 

forgiving and what is great is that the manufacturers have 

the cyclorotation compensations in the platform. This is 

though not as critical as is the XY registration and centering 

on the right point,” he said. “The resolution for the 

ZEISS platform for cyclorotation is only 0.1 degrees. It is 

voluntarily able to compensate within the sensible cut off 

of 5 degrees,” he added. 

OcuLight eye registration: Talking about the compensation 

for cyclotorsion and pupil size, Dr Versace elaborated 

on the advantages offered by the OcuLign like the wavefront 

measurements, use of limbus margin rather than 

pupil for centration, limbus position being independent of 

pupil size and utilization of iris and scleral vessels as reference. 

He next spoke about the ZEISS topography-based 

ablation and described how the two treatments were integrated 

and superimposed. Regarding topographic registra- 

Dr Lennard Thean on “Why I Switched to 

ZEISS Refractive Laser Platform?” 

“Personally for me, it is a real 

workhorse excimer laser system. 

We have treated over 500 soldiers, 

fighter pilots, commandoes and 

naval divers.” 

MEL 80: Dr Thean discussed the benefits with 

MEL 80, i.e. accuracy, faster recovery due to 

shorter exposure time, and excellent eye tracker 

response time. It has a tracking system: pupil tracking, 

limbus tracking and iris registration. He discussed the 

special application of this technique for people engaged 

in military and other armed services where spectacles and 

contact lenses are not appropriate, where refractive surgery 

has helped to increase the talent pool. Discussing the 

results in candidates chosen for the Republic of Singapore 

Air Force (RSAF) PRK Programme, he said that the 

MEL 80 was a benchmark in refractive surgery success.


9 

There was a 95% of UCVA of 6/6 or better (6/12 was not 

used as it would not have been compatible with a flying 

vocation), and 95% within + 1D of intended correction 

and 95% preservation of BSCVA (

10 


VisuMax: 

The Femto-only 

Option of Laser 

Correction 



Prof Dan Z. Reinstein on “Laser Blended 

Vision” 

Flap centration on corneal vertex. (Prof Dan Z. Reinstein, the United 

Kingdom) 

we have a very new ablation profile algorithm via this 

topographic mode,” he added. He further explained that the 

ablation depth is minimal and there are considerations of 

biomechanical effects of the cornea. “It is safe in tissues. 

There is 25-30% less tissue waste when using this profile,” 

he added. 

Clinical experiences: He shared the results of 84 eyes with 

hyperopia or mixed astigmatism where the mean sphere 

was +2.67D and the mean cylinder was -2.51D. “The 

astigmatic corrections are very reliable. Even in higher 

astigmatic cylinders we have good results,” he said. 

Further he showed the results of VisuMax femtosecond 

flap cut of 514 myopic eyes where the mean sphere was 

-4.48D and the mean cylinder was -1.14D. According to 

him, there were “marvelous outcomes” with no technical 

complications intraoperatively and no significant side effects. 

He showed the case reports for topographic findings 

in myopic (-4.25D and -2D cylinder) and hyperopic (+4D 

and -0.25D cylinder) eyes. These had a well centered very 

large and homogenous optical zone postoperatively. He 

then shared an exceptional case with +6.5D sph combined 

with a -7D cylinder,which according to him “nobody will 

do”. Even in this case he said, “We had a very nice refractive 

outcome.” 

Conclusions: He concluded that the VisuMax and MEL 80 

is an “all-laser procedure,” which allowed an easy and safe 

handling of VisuMax, MEL 80 and CRS-Master. According 

to him the refractive outcomes were excellent: safe, 

predictable and effective with long-term stability. Minimal 

induction of high order aberrations (HOA), large optical 

zones and a reduced ablation depth were other positive 

attributes. 

“We are able to make a 80 µm flap 

now and we hardly ever do a PRK 

now as we have the limits set by the 

corneal thickness and not by the 

resultant stroma.” 

Prof Reinstein spoke on the accuracy of the femtosecond 

laser and how it could replace the much-used 

microkeratome. According to him, the short procedure 

time, easy flap lift and excellent cut quality together 

helped to produce the best results. “Now we are at 0.1 μJ 

with VisuMax. We are dealing with 1/10th of the power of 

the IntraLase. Spot size is much smaller and pulse repetition 

rate was much higher. Optimization was much better 

with the VisuMax as it wasn’t intended to be a flap cutter. 

It was intended to be a refractive surgery machine,” he 

added. 

Accuracy in VisuMax: The VisuMax makes possible an 

ultra-thin flap and the flap can be made-to-measure. There 

is high flap thickness reproducibility and flap scan be done 

even in difficult eyes. Besides these, there is low corneal 

suction and centration on corneal vertex. According to 

him, there is great future potential in the VisuMax and it is 

an all-in-one option. He explained repeatability, reproducibility 

and how validation of the measurement instrument 

influences the accuracy measurements. 

Flap Thickness Study: He discussed the results of a study 

published in the Journal of Refractive Surgery for 24 eyes, 

which included an intended flap thickness of 110 μm and 

average flap thickness of 112.3 μm with an accuracy of 

2.31. Precision was just under 8 μm. Artemis very high 

frequency digital ultrasound arc-scanner was used to 

measure the flap thickness. The central flap thickness was 

essentially the thickness of the stromal component of the 

flap measured 3 months after surgery. Reiterating how the 

VisuMax is so accurate he said that it was because “the


11 

cornea is not being applanated but is effectively being accurvated”. 

In other words, there is minimal distortion of the 

lamellae. 

Comparing the intraocular pressures, he said that it was 300 

mm Hg with the IntraLase and that with the VisuMax was 

much less, being lower than even 100 mm Hg. Elaborating 

on the flap centration on corneal vertex he said, “The centration 

is very important for accuracy as the flaps automatically 

center during refractive surgical procedures on the vertex of 

the cornea. VisuMax gives the best approximation.” 

VisuMax in diverse eyes: Prof Reinstein said the VisuMax 

was a preferred option where the Hansatome was not possible. 

He then went on to discuss the VisuMax in a RK patient 

in whom they measured the epithelial thickness, added 

three standard deviations and produced a femtosecond flap. 

Next, he shared an example of a VisuMax flap deep lamellar 

keratoplasty. Finally, he showed the visual outcomes in the 

series of 232 eyes in 131 patients with a median age of 38 

years and a mean spherical equivalent of -4D and a mean 

cylinder of -0.72D. All had BCVA of 20/20 and 59% had 

a BCVA of 20/16. “Stability was reached at 3 months,” he 

added. Lastly, he shared his experiences with the ReLEx 

flex cut in a patient with coloboma.“I argued with her that 

eye tracking is very tricky in a coloboma, so I did a ReLEx 

and worked through a small incision,” he said. 

LASIK in High Myopia 

Prof Dan Z. Reinstein 

Very High Myopic LASIK Using New 

Aspheric Hybrid Profiles 

Spherical aberration: Prof Reinstein explained the spherical 

aberrations being due to the excimer laser beam landing 

on the cornea at an angle which lead to a projection error 

causing the lower fluence and hence less ablation as one went up 

towards the periphery. He explained the biomechanics of how on 

the pachymetric topography of LASIK, the stroma was actually 

thickening and showed examples for the same. He discussed the 

option for precompensation of spherical aberration and shared 

more examples. 

New hybrid profile: Prof Reinstein then discussed the new 

profile for high myopes. According to him, the non-linear 

aspheric ablation profile increased peripheral ablation (not more 

than z(4,0)) and reduced induction of spherical aberration. In 

the process, some myopia can be corrected due to the central 

flattening. “In the new ‘free lunch’ profile, the patients were 

overcorrected by half a diopter. This is because we were 

Laser Blended Vision: Prof Reinstein elaborated on the components 

for Laser Blended Vision relating to surgical planning, 

the patients themselves and most importantly residual 

accommodation. He described how the eye has an inherent 

spherical aberration that increases as the accommodation 

decreases with aging. This, however, is not accompanied 

by a loss of miosis, hence increasing the depth of field. He 

then discussed the reduction of anisometropia in monovision 

because of increased depth of field. He then shared an 

elegant study to explain the blur adaptation that happens in 

the brain. He explained how visual anisometopia decreases 

as the day goes on. Finally, he spoke of the neural suppression 

and the problems with multifocality. “The brain is not 

wired for a monocular diplopia,” he said when referring to 

the problem of obtaining two images. He specified that the 

eye should have the “right amount of spherical aberration” 

as too much of it would give disturbances in nightvision and 

contrast and too little of it would leave no depth of field. 

Night vision disturbances and centration: Elaborating on 

the causes and treatment of night vision disturbances, Prof 

Reinstein shared the results of a study titled “A new night 

vision disturbance parameter and contrast sensitivity as indicators 

of success in wavefront-guided enhancement”, which 

has been published in the Journal of Refractive Surgery in 

2005. Prof Reinstein said that unlike the IOLs it was easier 

to center with the excimer laser. He shared an example of 

MEL 80 in high myopia: Accuracy 

Continued on P13 >>

12 


a patient where the measured wavefronts revealed an angle 

kappa and showed the calculated point spread function from 

the vertex of centered wavefront. “Subjective point spread 

function correlates with the vertex point spread function and 

not pupil point spread function,” he said. “In clinical practice, 

patients see aberration relative to the vertex which is in approximation 

to the visual axis,” he added. He showed the 

published myopic, hyperopic, and emmetropic results where 

a Hansatome was used for treatment and the results were not 

as good as with the femtosecond laser. 

Safety and efficacy: “On the safety front, shockingly we 

found that patients who started with very high stereo, only 1 

in 20 lost one patch,” he said, to show that there was a statistically 

significant change in stereo acuity by this procedure. 

For efficacy he said, “About two-thirds of the patients had 

100 seconds of stereo and 90% of them had 200 seconds of 

stereo uncorrected.” The post-op uncorrected stereo acuity 

was thus lower than the pre-op near-corrected. 

Summary: He summarized the non-linear aspheric micromonovision. 

“We have a procedure which is based on 

LASIK, which corrects pure presbyopia, wide range of 

refractive errors (+5D to -9D), does a simultaneous accurate 

correction of cylinder, is centered perfectly by an eye tracker, 

allows a minimal compromise to contrast sensitivity and 

night vision disturbances, is well tolerated by more than 

95% patients, maintains a functional stereo acuity and is 

performed as a 10 minute bilateral procedure that heals in 

3 hours,” he said. This according to him was actually the 

solution. 

Future of VisuMax: Prof Reinstein spoke about the unsurpassed 

future potential of VisuMax which he referred to as 

“the new horizon of femtosecond technology in ophthalmology”. 

According to him, the VisuMax is designed to become 

the corneal surgery workstation for a large spectrum of 

procedures. ReLEx flex and ReLEx smile have undoubtedly 

added unprecedented accuracy in corneal incision. 

Prof Zhou Xingtau on “Clinical and Research 

Experience of Femto-LASIK and ReLEx using 

VisuMax in China” 

“ReLEx appears to be a safe and 

promising corneal refractive 

procedure for correcting high myopia.” 

Experience with ReLEx: Prof Zhou has been doing 

Femto-LASIK procedures since 2008. He presented 

the preliminary 5-month results of a recent prospective 

study for femtosecond lenticule extraction in correction 

of high myopia. He then discussed his clinical experiences 

with patients ranging from 32 to more than 45 years of age. 

“ReLEx recovery may be slower than the excimer laser 

LASIK but the outcome in general is very good,” he said. 

VisuMax Femto-LASIK: Prof Zhou showed the results of the 

first 60 cases of high myopia (SE of -8.05D) who underwent 

Femto-LASIK with VisuMax femtosecond laser. He then 

showed comparative results of the femtosecond flap to the 

microkeratome, where the predictability of femtosecond was 

much better. According to him, the patients were satisfied 

with -0.34D and the cylinder was -0.3D. He also showed the 

good topography outcomes in cases of hyperopic patients. 

He shared that recently he has been choosing to do flaps of 

only 85-90 μm and discussed the results of the post-corneal 

aberration of Femto-LASIK for high myopia. 

CXL Research with VisuMax: “With VisuMax, we not 

only do Femto-LASIK, not only do ReLEx, but we can 

also do some research,” he said, and shared the procedure 

of intrastromal pocket creation in animal eyes. The 

stromal pocket was apparently visible shortly after the 

operation and disappeared within 2 weeks normally. 

In 8 of 10 cases, a demarcation line-like change in the 

stroma, indicating the cross linking was visible as early 

as 2 weeks after crosslinking treatment. The reflection 

density of the crosslinking stroma slightly decreased at 1 

month postoperatively.“Crosslinking with femtosecond 

laser appears to be a safe approach. The demarcation line 

may be a potential tool to monitor the depth of effective 

crosslinking with the femtosecond laser in the early phase 

postoperatively,” he concluded. 

Prof Muhaya Mohammad on “LASIK and 

Character Building” 

“The VisuMax femto energy is regular 

and smooth. Every step is smooth. 

Post-LASIK discomfort is less.” 

LASIK and Character Building: Prof Mohammad shared 

her observations about the use of VisuMax. According 

to her the VisuMax femtosecond energy is very 

regular and smooth and the post-LASIK discomfort is less. 

Every step is gorgeous. She believes in deep breathing and 

meditation and reassures her patients through talking. She 

specified that intention, attention and no tension were the 

secrets of attaining the desired results. She then supported a 

positive mental attitude as a prerequisite to success. She has 

even done VisuMax Femto-LASIK on her daughter.



13 

Continued from P11 >> 

Dr Donald Tan on “Preliminary Results of 

ReLEx in SNEC: As good as LASIK, or better?” 

“The future of this technology lies 

in ReLEx smile, which is a major 

advance over LASIK with no flap, 

minimal ocular surface disturbance, 

or dry eye. It is a quantum leap. 

Another advantage is the potential 

reversibility of ReLEx, which is a 

new concept of long-term lenticule 

storage for patients. Lenticules 

may be re-implanted back at a later 

stage, in the event of keratectasia, 

refractive shift or even to restore 

myopia for presbyopic correction.” 

taking more of peripheral tissue out and creating a mechanical 

flattening at the center of the cornea in these highly myopic 

eyes.” Explaining the ablation depth for the new profile, he 

said that “we are taking it much more efficiently from where it 

has to go.” And where it has to go from is actually measured 

at the stromal level with ultrasound. Sharing an example of 

RST planning, he spoke of how in a -11D, with 509 μm in 

pachymetry, treating with VisuMax with flap thickness of 80 μm 

and an ablation depth of 135 μm, one can still leave around 

300 μm residual stromal thickness. 

Outcomes: “I am sure femtosecond lasers will take over in 

high myopic treatments,” said Prof Reinstein. He discussed the 

results in 220 eyes with a 1-year follow-up and myopic spherical 

equivalent of up to -14.5D. The myopia maximum meridian 

was -10.18 ± 1.48D -8D, up to -16D and the cylinder went up to 

-6.25D. Around 45% eyes were treated with staged procedures. 

The enhancement rate for the non two-stage was 35%. According 

to him, the advantages of the two-stage procedure were an 

increased safety, more accurate results, and lower patient expectations. 

“If after the first stage, someone had a main issue of 

night vision disturbances, we had the option of using the remaining 

tissue for topography-guided expansion instead of further 

myopic corrections.” 

Femtosecond lasers: Dr Tan enlisted the 

femtosecond lasers currently available. He then 

discussed the results of femtosecond laser-assisted 

sutureless ALK in 12 eyes with anterior corneal scarring 

using the IntraLase.“Only 58% improved visual acuity 

and about 33% had 20/50 or better,” he said. Further, he 

shared results of a study published in 2009 for DALK 

with femtosecond laser (IntraLase ALK with zigzag 

incisions) where a poor stromal bed quality was reported 

and good lenticules were not obtained. 

Dr Tan presented the results of their 2008 study comparing 

the ALTK microkeratome (R2=0.24, with a wide 

scatter) with the femtosecond laser (R2=0.93, more statistically 

significant). “So we know that the femtosecond 

laser is much more predictable than the microkeratome 

for depth,” he confirmed. Showing pictures of the rim 

cuts, he said, “There is not much collateral damage.” 

He also specified the minimal morphological damage to 

endothelium. 

VisuMax: Dr Tan discussed the “very precise vertical 

ablations” with “minimal collateral endothelial damage” 

and “reasonably smooth lamellar bed” with VisuMax 

200 kHz and showed how the atomic force microscopy 

pictures with deep stromal lamellar dissection (400 μm) 

improved with the 500 kHz VisuMax than with the 200 

kHz VisuMax and the 40 kHz FEMTEC. He shared pic- 

Monocular efficacy (Excluding eyes not intended plano) 

MEL 80 High myopia: Safety - BSCVA 

Continued on P15 >>

14 


tures of Femto-DALK and Femto-DSEK procedures and 

showed results for the VisuMax-ALK done for a post- 

PRK scarring. Post-op a 20/40 was obtained. 

He then showed a second patient with granular dystrophy 

and previous PRK with 20/60. The patient attained 20/40 

unaided on postop day 1. In the view of Dr Tan, stromal bed 

quality, rim cut quality and accuracy of depth with femtosecond 

can exceed microkeratome quality but further optimization 

is needed. The endothelial morphology appears 

unaffected in the presence of laser ablation 150 microns 

from Descemet’s membrane. “Femtosecond laser ablation 

of the deep corneal stroma is close to being a viable alternative 

to microkeratome for donor preparation for DSEK and 

DALK. The next major advance we would like to see is to 

have a topographic link-up using anterior segment optical 

coherence tomography (AS-OCT) for accurate ablation 

profiles in reference to the posterior corneal surface. I think 

the femtosecond laser for DSEK and DALK are currently 

on horizon now,” he said. 

Singapore ReLEx Study: Dr Tan discussed the results of 

30 ReLEx flex and 10 ReLEx smile cases of which 17 were 

analyzed. There was no algorithm adjustment. All cases 

were followed up for at least 1 month and 33 for 3 months. 

Speaking about the wide range of myopia, he said, “We 

went up to -10D and the average mean spherical equivalent 

was about -5.5D. The range was up to -9.75D and cylinder 

went up to -2.75D.” 

At 1 month postoperative, the mean spherical equivalent 

was 0.33. This hyperopic mean was good as most patients 

were young. And at 3 months postoperatively (33 eyes), the 

mean spherical equivalent was 0.22 (1.75 to -0.63). There 

was a case of hyperopic surprise and there wasn’t much 

myopic regression. Speaking about safety, he said that there 

does occur loss of lines. The results though are far better at 

3 months. He shared his learning experience about suction 

loss in a 30 year old female, -8.75D/-1.25D. According to 

him, the ReLEx was stable and predictable without nomogram 

adjustments unlike the excimer laser nomograms. 

Talking about the reasonable efficacy he said that the results 

at 3 months were appreciable with 95% at 1D visual acuity. 

ReLEx smile results (6 eyes): These had a full ReLEx 

ablation profile, but the flap was only partially opened 

(about 1/3) and the lenticule extracted. According to him, 

“Enhancement could be done and it was easier.” The 

encouraging results seemed better than ReLEx. He further 

explained that the advantage of ReLEx smile was the 

easier enhancement.“I shifted the hinge to 160 degrees, as 

I am a right-handed surgeon,” he said. Comparing these 

with ReLEx, he said that ReLEx smile is a bit more challenging. 

He feels that ReLEx smile is good in the hands 

of surgeons who are experienced. For an average surgeon, 

who has not done many cases, there is a learning curve. He 

showed the various dissectors they have used in lamellar 

surgery and his favored DSAEK forceps. He shared a video 

of the ReLEx smile procedure and showed how centration 

is the key to visual acuity. 

ReLEx experiences and research at SERI: According to 

Dr Tan, ReLEx seems to be a promising new modality 

which may well challenge the superiority of LASIK, further 

clinical studies including direct comparison with LASIK 

are underway. Early clinical results with no nomogram 

adjustment appear to confirm good refractive efficacy, 

predictability, stability and safety though more cases need 

to be done. Preliminary results of ReLEx smile are also 

highly promising, with major advantages of better tectonic 

strength and possibly less dry eye and ocular surface 

disturbance. Lastly, the potential reversibility of ReLEx 

procedures may be a reality. “We have a cornea wound 

healing laboratory at the Singapore Eye Research Institute 

and the main role is to explore new surgical and therapeutic 

modalities for selective lamellar keratoplasty and corneal 

lamellar laser refractive surgery. We do have facilities for 

small and large animal primates with dedicated ophthalmic 

theatres, surgical microscopes, confocal microscopy, AS- 

OCT, immunohistochemistry, range of methodologies like 

EM, microkeratome, femtosecond laser and excimer laser 

platforms. He also said that the VisuMax platform is a part 

of the Translational Clinical Research (TCR) Flagship 

Program (TRIOS) funded by Government National 

Research Foundation Grant in collaboration with Carl Zeiss 

Meditec and discussed the changing trends of selective 

lamellar keratoplasty at SNEC. 

Storage of lenticules: He discussed the potential of 

reversibility of ReLEx and shared that SERI has filed 

a patent (#61/382,037) for the technique of storage of 

lenticules following femtosecond refractive lenticule 

procedures. 

SERI studies in rabbit eyes: SERI is experimenting in 

rabbit eyes for Femto-LASIK and ReLEx. Dr Tan showed 

the comparable results of in-vivo confocal microscopy 

for lamellar interface and anterior stroma in LASIK 

and ReLEx. He then discussed the ongoing studies to 

investigate the various markers for inflammation (CD 

11b), cell proliferation (Ki-67), wound healing response 

(Fibronectin) and cell death. He showed the ReLExlenticule 

re-implantation technique wherein the lenticule 

placed on RGP CL and stored at -80 degree centigrade was 

replaced in correct anatomical orientation at 1 month after 

a flap relift. “We have tested the proof of concept that we 

can re-implant at least in rabbits,” he affirmed. He showed 

the topographies before ReLEx, 3 days after ReLEx and 

3 days and 7 days after re-implantation of lenticule. He 

showed the AS-OCT imaging obtained after reimplantation


15 

Continued from P13 >> 

and the results of in-vivo confocal at the anterior flap 

interface, lenticule lamellae and the posterior flap interface, 

3 days and 7 days after re-implantation of the lenticule. 

Non-human primate model: Dr Tan said that ReLEx 

study had been initiated in monkeys at SERI and these 

should now prove the proof of concept of reversibility of 

ReLEx. He then showed the averaged topographies from 3 

non-human primates (-6D treatment) before ReLEx and 3 

days and 7 days after ReLEx. 



In 2009, Prof Reinstein published the results for the combined 

corneal topography and corneal wavefront in treatment of corneal 

irregularity and refractive error in LASIK or PRK using MEL 80 

and CRS-Master. Here, he reported a 41% decrease in spherical 

aberration and a 21% reduction in HORMS. Sharing the graphical 

record of attempted vs achieved spherical equivalent, he elaborated 

on the accuracy of the MEL 80 in high myopia. Seventy-one 

percent of the eyes were within +/- 0.5D and 94% within +/-1D. 

He shared the results of monocular efficacy in 127 eyes (excluding 

eyes not intending plano). Pre-op only 83% had 20/20 and postop 

uncorrected 90% had 20/20. “That is excellent,” he said. Then 

talking about safety (BSCVA) in 220 eyes, he said, “No loss of two 

lines. Very little loss of one line.” There was no change in 40% and 

52% gained one line. According to him, the contrast sensitivity 

increased statistically significantly for only the higher frequencies. 

The stability was also maintained at 24 months. 

ReLEx smile: 

The New Application 

Prof Osama Ibrahim on “ReLEx: Clinical 

Update (ReLEx flex and ReLEx smile). My 

Experience with VisuMax” 

“ReLEx smile is a real innovation 

and a real challenge. It maintains 

the biomechanical integrity of the 

cornea in the anterior surface which 

actually is most important.” 

High myopia: Contrast Sensitivity 

Experience with VisuMax: Prof Ibrahim shared 

videos of the ReLEx flex and ReLEx smile procedures 

and said that “the VisuMax procedure was 

simply tissue removal rather than tissue ablation”. He 

specified the direction of scanning and how it is best 

to remain above the lenticule when making the flap. 

Sharing a video for ReLEx smile and explaining the 

correction of higher errors, he said that the technique 

is very simple and he ensures that he “remains anterior 

all the time”. “I go to one part and leave the other part 

as a counterpart. I use a very thin flap and can go up to 

90µm,” he added. 

Study results: He shared the results of analysis of 189 

eligible eyes (120 female and 69 males) that were mostly 

cases with high errors, higher even than -10D. The mean 

High myopia: Stability 

Summary: According to Prof Reinstein, one should know the 

spherical aberration induction per diopter, measure pre-op spherical 

aberration and know if the spherical aberration may cross the 

threshold. If crossing the threshold, one can do a spherical aberration 

pre-compensation or use a two-stage procedure, i.e. the 

wavefront-topograph-guided repair if necessary as second treatment. 

He cautioned with predicting the RST. “Pachymetry is best 

done with a high repeatability instrument. It is best to use a high 

reproducibility flap creation technique and always include the flap 

thickness bias,” Prof Reinstein concluded.

16 


age was 27 years and the mean spherical equivalent was 

-5.65D ± 2.91D. Next he showed the collective results 

for both ReLEx flex and ReLEx smile at 1 week for 175 

eyes. “The mean spherical equivalent is less than a quarter 

(-0.27D± 0.57D), though some cases called the outliers 

were not corrected fully. Ammetropia was not our aim in 

all cases both for sphere and cylinder. The range for sphere 

went from +1.75D to -2D,” he said. The results were better 

still for 136 eyes followed at 1 month postoperatively with 

the mean spherical equivalent being -0.25D ± 0.63D. “The 

sphere is perfect, as good as the excimer laser except for 

the few outliers,” he said. The correction remained better 

at 3 months postoperatively for 93 eyes that were followed. 

Explaining the results further at 1 year after procedure, he 

said, “This is a very stable procedure as we do not see a regression 

that we see in high myopes. The stability was very 

good at 1 year.” He then explained the challenges, saying 

that in the initial series there were patients who lost lines. 

“These were cases where we had used a very high energy, 

the section was very clumpsy, or had taken us a longer 

time,” he elaborated. But these cases where someone lost 

one or two lines decreased over a period of time as the 

learning curve improved. According to him the visual recovery 

was excellent. “At 1 day or at 1 week, almost 95% 

of cases were able to achieve the legal driving vision. As 

time goes by, the number of patients who are 20/20 or better 

improves. For high myopes, the results are very good, 

very comparable and even better than excimer laser.” 

200 kHz vs 500 kHz: He discussed a comparison of 200 kHz 

(97 eyes) and 500 kHz (78 eyes). “The refractive outcome 

was not much of a difference,” he said. However at 3 

months, the results were better with the 500 kHz. Similarly, 

better results were seen with the 500 kHz for the 

spherical equivalent percentage. According to him, the real 

difference was in the visual recovery. 

Conclusion: He concluded that ReLEx was effective, 

predictable, safe and stable. He thinks ReLEx is definitely 

“as effective as the excimer laser”. He said that improvement 

in customization can certainly make it better. “It 

is definitely as predictable. Safety is very good and it 

has improved. Stability is beyond doubt and even better 

than the excimer laser ablation,” he added. He shared 

the results for some clinical cases like -8.00D and also 

cases with high astigmatism. He said that future may hold 

promise of going down to use smaller lenticules of even 

5 mm. “This opens a new horizon for the correction of 

higher errors even if you use smaller lenticules.” 



ReLEx smile: 

All-In-One Correction 

Dr Ekktet Chansue on “ReLEx smile in Low and 

Moderate Myopia” 

“The procedure is highly accurate 

and very neutral in terms of spherical 

aberration and independent of the 

amount of correction.” 

ReLEx: Dr Chansue described ReLEx as “a procedure 

where the femtosecond laser is used to create an intrastromal 

lenticule” which is then removed manually 

in a single piece. He then showed how the side and anterior 

cuts are made in steps. He also shared his opinion about and 

showed videos for ReLEx smile along with the instruments 

used for the procedure and added that “there is nothing that 

can inhibit the surgeon from doing a small incision surgery”. 

Speaking about his experiences with the ReLEx smile technique 

in the last 100 cases, he said, “We did a range of -1.13D 

to -9.75D, with spherical mean of about 5D and cylinder 

anything between zero and 4D.” 

ReLEx smile: Dr Chansue said that the efficacy was mostly 

20/25 or better at 1 week. “At 3 months, we had only 12 

eyes. All the eyes are seeing 20/20 or better,” he added. He 

then spoke of accuracy being very high (R2 being 98%). “It 

does not lose any accuracy at the higher end (up to -10). It 

takes the same amount of time to do a -1D or -10D. It cuts 

the two planes following a basic geometry and without being 

influenced by other elements around the field.” He explained 

ReLEx Technique (Dr Ekktet Chansue, Thailand)


17 

The TRSC experience (Dr Ekktet Chansue, Thailand) with this figure we can add the section in pink above 

a) ReLEx smile at TRSC: Efficacy 

b) ReLEx smile at TRSC: Accuracy c) ReLEx smile at TRSC: Safety 

d) Topographical changes: -2.75D correction e) Topographical changes: -7D correction f) ReLEx smile at TRSC: Spherical aberration 

how ReLEx smile attained 

a “wide optical 

zone”. “We don’t 

have any correlation 

between the amount 

of correction and the 

spherical aberration,” 

he said. The same 

large optical zone 

was maintained even 

at -7D correction. 

Talking about safety, 

he said, “We did lose 

lines at some times 

and at 3 months no 

one lost more than 

ReLEx smile: Instrumentation 

one line.” Complications 

in the procedure were minimal. There was a failure 

to dock in one case which had a very small cornea, a case of 

suction loss during anterior cut in the lenticule, some epithelial 

problems and a lenticular tear which according to him “occurred 

in a thin lenticule in a low myope with 1D”. 

Conclusion: He concluded that the procedure gives potentially 

better corneal strength than LASIK. The peripheral cornea 

needs minimal dissection. “If you look at the eye, you appreciate 

that there is incision only on the top, actually completely 

covered by the lid, so there is no wound actually. Then you 

dissect the cornea only enough to get the lenticule out,” he 

explained. According to him, ReLEx is a procedural breakthrough. 

“Technology has enabled us to do what we have been 

wanting to do,” he added. 

The path ahead: He shared valuable suggestions for further 

improvement. The illuminator according to him is too bright 

and should not be coaxial. Another concern is the lack of a 

real fixation target in the microscope. He wished there was an 

assistant’s joystick. He then spoke about the need for optimal 

enhancement strategies. “In any refractive procedure success 

depends on enhancement strategies,” he said. According to 

him adjustments are a little difficult with ReLEx as compared 

to LASIK and will need to be improved upon. “This is important 

because the patient needs change with time as the refractive 

status is likely to change. For someone who has been 

doing refractive surgeries for 20 years, patients do come back 

and say after 10 years that they are willing to get corrected 

for whatever progression they have had,” he said. Lastly, he 

questioned if “ReLEx is the beginning of the end of LASIK.” 

Dr Rupal Shah on “ReLEx: An Update of the 

Results” 

“ReLEx is an interesting procedure 

and an exciting paradigm shift in 

refractive surgery that we are very 

proud to be able to be a part of.” 

Dr Shah shared a video for ReLEx smile and emphasized 

how she checks centration. She currently is using a 3 

mm incision in the ReLEx smile procedure and said 

that perhaps even smaller incisions would be possible in future.

18 


VisuMax Femtosecond Laser System (Dr Rupal Shah) 

a) Change in CDVA: Safety 

b) Achieved correction (MR SEQ) over time 

c) Refractive outcome (MR SEQ percent within attempted @ 1m and @ 3m) 

d) pre-op CDVA vs. post-op UDVA – 500 kHz (Only full-correction cases) 

She then said that “the tissue separation is very simple and you do 

not need any fancy instruments”. 

Experience with ReLEx: Dr Shah described ReLEx smile as 

a preferred procedure to Femto-LASIK for the treatment of 

myopia and myopic astigmatism. They are also looking at 

ReLEx flex for investigating the possibility for hyperopia treatment. 

She shared the results of 860 eligible myopic eyes (427 OD, 433 

OS) in 518 female patients and 342 males with a mean age of 25 

years. Preoperatively, the mean spherical equivalent was -4.53D 

with a range of up to -10D and the mean cylinder was -0.67D and 

ranged up to -4.5D. 1 month postoperatively, the procedure showed 

impressive predictability. The mean spherical equivalent (827 

eyes) was very close to zero and the range was 1.63D to -1.25D. 

The trend continued at 3, 6 and 12 months. The refractive outcome 

was particularly encouraging because there were no nomogram 

adjustments. The treatment of myopic astigmatism was equally 

impressive. 

Taking about complications, she said that there was a suction 

loss in 13 eyes. In 12 of the eyes, the procedure was immediately 

repeated with excellent post-operative outcome. The only 

case which was aborted was the 1st eye which suffered from a 

suction loss. 5 eyes suffered from deep lamellar keratisis postoperatively. 

These were either related to the use of high energy 

settings or due to the use of a new type of instrument. There 

were few cases of lenticule being stuck on the undersurface 

of the flap and these could be removed without any incident. 

Besides these, there were 14 cases of visually non-significant 

haze that responded to stepping up of steroids and a case of stationary 

epithelial ingrowth at the flap edge. Two of the ReLEx 

procedures needed a retreatment and in these an excimer laser 

ablation was done. She showed topography of a patient with 

- 4.5D and -1.75D cylinder. “The cylinder gets treated very 

satisfactorily and there is a nice big zone of flattening,” she said. 

Hyperopic cases: Dr Shah shared the results of the first 38 

hyperopic eyes they have done. “We have treated up to 7.5D 

of spherical equivalent with some amount of cylinder,” she 

said in introduction. Explaining the outcome at 1 month, 

she said, “At 1 month, we have results from 30 eyes, again 

a mean very close to zero (spherical equivalent of 0.15D ± 

0.75D), so the predictability of the instrument is not an issue. 

The visual recovery is still something to be refined on.” She 

wasn’t really positive for the CDVA. “We are getting some 

losses in best corrected visual acuity. Of course, this is getting 

offset by some gains also in best corrected visual acuity. But, 

today, Hyperopic ReLEx is a work in progress. ” she said. The 

stability was also not as encouraging as in myopia. 

Conclusion: Dr Shah concluded that ReLEx is a promising new 

modality for laser vision correction. Treatment for 

myopia and myopic astigmatism has been revolutionized 

and hyperopic trials have already begun. “This is a work in 

progress and the results are much better than the initial results 

that we saw with excimer laser,” she said.


19 



ReLEx Versus 

Femtosecond LASIK: 

A Comparison 

As a new technique for laser vision correction, 

ReLEx is a single-step, single instrument 

operation. 

By Osama Ibrahim, MD 

ReLEx smile is a minimally invasive approach to laser 

vision correction. Instead of a corneal flap, which is 

mandatory for the execution of LASIK, an intrastromal 

lenticule is created with the femtosecond laser. The size 

and shape of the lenticule corresponds to the desired refractive 

correction in the intact cornea, and the incision is subsequently 

prolonged to the anterior corneal surface with a very 

small opening incision. ReLEx uses tissue removal instead 

of tissue ablation (Figure 1); it achieves a high precision of 

cutting that contributes to the predictability of the procedure. 

Comparing results: I have been using femtosecond LASIK 

for 5 years and ReLEx for 2 years now. In this time, we have 

performed ReLEx flex and ReLEx smile in approximately 

200 eyes and 400 eyes, respectively. Similar to LASIK, 

ReLEx flex is performed with a corneal flap-like access cut; 

however, the flap created for ReLEx flex is smaller than 

the LASIK flap (Figure 2). Another difference is that, for 

ReLEx flex, after the flap is lifted, the lenticule is peeled 

off of the corneal bed rather than ablated. ReLEx smile is 

entirely different from LASIK, as there is no longer need to 

create a corneal flap. Instead, a small incision is made in the 

cornea and the lenticule is dissected and extracted through 

the incision. 

As our experience with ReLEx grew over the course of the 

clinical study, we were able to titrate the energy levels of 

the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, 

Germany) as well as its spot distance and size to make the 

system more case specific. These adjustments have provided 

us with more repeatable and reproducible study results. 

Since then, we have also fine-tuned the lenticule geometry, 

resulting in more accurate astigmatic correction. 

Comparing ReLEx smile to femtosecond LASIK, 

ReLEx smile has a slightly steeper learning curve, yet 

after mastering it, ReLEx smile became a much easier and 

shorter procedure. It is a single-step, single instrument 

operation, and therefore there is no need to move the 

patient between two lasers as there is during femtosecond 

LASIK. Additionally, laser treatment time (ie, time to create 

the lenticule) is nearly the same for all levels of myopic 

correction. For instance, I can treat -10.00D of myopia 

in the same amount of time it takes me to treat -1.00D of 

myopia, provided the eyes have the same cap diameter and 

optical zone. 

The long-term results after ReLEx smile and LASIK are 

similar, but visual recovery can take a bit longer after 

ReLEx smile in some eyes. However, there is less incidence 

of dry eye after ReLEx smile compared with LASIK. One 

more important advantage for the use of ReLEx smile is that 

the incidence of straie and other flap complications have 

vanished. 

Surgical advantages: The major advantage of ReLEx 

smile is that there is no flap cutting involved, which we 

believe minimizes the induction of spherical aberration. 

Without the thread of spherical aberration, ReLEx smile 

patients are more likely to achieve better quality of vision 

than patients treated with an excimer laser, which is 

especially true for those with high myopia. We also believe 

that ReLEx smile offers better biomechanical stability than 

procedures employing flap creation, going along with less 

postoperative discomfort and less cases of dry eye. With 

no flap displacement, even after trauma, ReLEx smile is 

the best procedure for those who are involved in contact 

sports. 

Figure 1. ReLEx uses tissue removal instead of tissue ablation. 

Unlike excimer-laser-based procedures, ReLEx smile 

uses a solid-state laser, and therefore there is no need for 

consumable gases or tight environmental humidity control. 

The VisuMax is a silent, soft, and gentle laser. It does not 

produce any smell, there is no vision blackout during the 

procedure, and the cornea is not forced into a nonphysiological 

planar shape. Thus, deformation and artifacts can 

be avoided in the cutting results, as well as unnecessarily 

high intraocular pressure (IOP). 

The procedure: The first step for ReLEx smile is to attach 

a disposable curved contact glass onto the laser aperture

20 


Figure 2. (A,B) The flap-like cut for ReLEx flex is smaller than the flap 

created for LASIK. 

cone of the VisuMax femtosecond laser. The curved surface 

of the contact glass is designed to couple with the cornea 

after the VisuMax system self calibrates the contact glass. 

Keratometry data can then be entered into the VisuMax 

software to account for the difference between the relaxed 

cornea and the contact glass curvature. This calculation allows 

the system to determine the ratio between the intended 

clinical treatment and the cap diameter on the relaxed eye as 

well as the incision diameter when cutting the eye coupled 

to the contact glass. 

With the patient fixating on a flashing green light, the 

patient bed is repositioned so that the cornea comes into 

contact with the contact glass. At this time, the patient will 

notice a flashing fixation target in clear focus. This target 

uses the manifest refraction of each individual eye to align 

the target visibility. The bed is raised vertically while the 

surgeon observes the alignment of the contact glass application 

through the operating microscope and the side screen. 

The cornea slightly applanates and centers, aiming for 

the corneal vertex, and suction is applied. The eye is then 

immobilized with low corneal suction. The increase in 

IOP with the VisuMax is low enough for the patient to see 

throughout the procedure. The laser is activated when the 

surgeon presses on the foot pedal. After the lenticule and 

a small incision are created with the laser, the patient is 

moved to the observation microscope, where manual dissection 

is performed. This process starts with dissection of 

the upper surface (ie, cap) from the intrastromal lenticule. 

The lenticule is then dissected from the stromal bed and 

removed with a forceps through a 3- or 4-mm incision. 

Conclusion: The evolution of refractive surgery is heading 

closer to preservation of corneal biomechanics. Increased 

safety was first achieved by creating thinner flaps; now, it 

goes one step further by using small incisions. ReLEx smile 

is the latest technique to follow this pattern of preserving 

corneal biomechanics. The most important point that refractive 

surgeons are aiming to achieve is aberration-free treatments. 

ReLEx smile is one step closer to this quest. 

ReLEx smile: 

An Outstanding 

Treatment for Low, 

Moderate and High 

Myopia 

I have treated more than 600 eyes with this 

minimally invasive technique. 

By Rupal Shah, MD 



Of all the surgeons currently using ReLEx smile 

(Figure 1), I have completed the most cases to 

date. The reason that I choose this procedure time 

and time again is threefold. First, I feel it offers the most 

advantages to my patients in terms of the accuracy of 

refractive outcomes and safety. In fact, 99% of all eyes 

treated for myopia at our center are within ±0.50D of intended 

correction. While 30% of patients gain visual acuity 

after the procedure, less than 3% lose 1 or more lines of 

visual acuity. The advantages are particularly stark for high 

myopia. Second, ReLEx is a very time-efficient procedure, 

meaning that I am able to perform more procedures each 

day with the reassurance that I am selecting the best possible 

solution for my patients’ refractive errors. Third, it is 

a unique procedure that is easily distinguishable from other 

laser vision techniques (no flap), which allows me to use a 

unique marketing strategy. 

My experience with ReLEx totals more than 2,000 

procedures for the treatment of low, moderate, and high 

myopia (up to -10.00D). There are two ReLEx techniques, 

femtosecond lamellar extraction (ReLEx flex) and small 

incision lamellar extraction (ReLEx smile), which are both 

minimally invasive and are performed with the VisuMax 

femtosecond laser (Carl Zeiss Meditec, Jena, Germany). 

The major difference between ReLEx flex and 

ReLEx smile is that a corneal flap is created prior to 

lenticule extraction in ReLEx flex only. I prefer ReLEx 

smile, because I no longer have to create and lift a flap in 

the cornea but rather just make a small corneal incision to 

excise the refractive lenticule. 

Advantages : ReLEx smile offers many advantages: 

• Postoperative discomfort for the patient is significantly less. 

• The lack of a corneal flap eliminates the risk of a flap 

displacement, and so the amount of care that patients need 

to exercise is significantly less.


21 

• Use of a small incision means that fewer corneal nerves 

are severed. This also leads to fewer issues after surgery, 

including dry eye. 

in the ablation rate. This causes the commonly observed increased 

scatter in the results of excimer laser LASIK once you 

start treating high myopia. Such increase in scatter is much 

less in ReLEx. 

Within each of the three groups—low myopia, moderate 

myopia, and high myopia—at 3 months, 97%, 97%, and 

90%, respectively, were within ±0.50 D of intended correction 

(Figure 2). At 1 year, approximately 2% of eyes in the 

low myopia group and approximately 4% of eyes in the other 

two groups lost 1 or more lines of BCVA, but 25%, 29%, 

and 49%, respectively, gained 1 or more lines of visual acuity 

(Figure 3). 

Figure 1. Schematic representation of the ReLEx smile procedure. 

Patient selection: I am happy that ReLEx smile is 

available for commercial purposes since I can now use this 

technique for all suitable patients independent from study 

participation. Before it was commercially available, I only 

performed ReLEx smile if patients agreed to participate in 

our current study, which precluded them to be available for 

at least 1 year of follow-up visits. 

There are certain cases for which special attention must be 

given to patient selection for ReLEx, including if patients 

are too anxious; if they have astigmatism higher than the 

spherical component of myopia; or if they have more than 

-10.00D of myopia, as this is still under investigation. 

In these patients, I typically perform LASIK, creating a 

flap with the femtosecond laser and ablating the corneal 

tissue with the excimer laser. However, the disadvantage 

with this treatment is that it takes more time, because I am 

moving the patients between two lasers. 

Treatment results: As I said previously, I have extensive 

experience performing ReLEx treatments. Of the nearly 1,200 

eyes for which I have at least 3-month follow-up, 29% have 

been for the treatment of low myopia, 50% for moderate 

myopia, and 21% for high myopia. 

If I had to provide a quick snapshot of my results to date, 

I would say that visual outcomes after ReLEx have been 

equivalent to visual outcomes after LASIK in eyes with low 

myopia. Therefore, even if I have a -1.00D treatment, I am 

not hesitant to perform a ReLEx procedure. 

For eyes with moderate or high myopia, ReLEx has an edge 

over excimer laser treatments. Because the technique involves 

cutting a lenticule instead of ablating it, the results are 

less dependent on environmental factors including humidity 

and organic vapors. During ablation for high myopia, there is 

considerable drying of the corneal bed, with resultant scatter 

Added benefits: As I see it, there are three distinct benefits 

that I have achieved by incorporating ReLEx into my surgical 

armamentarium: patient benefits, surgeon benefits, and 

marketing benefits. 

Patient benefits. The beauty of ReLEx smile is that it builds 

on existing—and successful—laser vision techniques, and 

our results reflect that. In all three groups, more than 90% 

of eyes had a UCVA of 20/30 or better. Additionally, patient 

discomfort was minimized, and, in the majority of cases, pain 

was gone within the first few hours after surgery. Another 

benefit to ReLEx smile is that there is no risk of possible flap 

displacement from eye trauma or surgery at a later date. This 

is especially important for those patients who are involved in 

contact sports or jobs in which eye trauma is more likely. 

Surgeon benefits. For me, two important surgical benefits of 

performing ReLEx smile are as follows. First, I can better 

maintain biomechanical stability. Second, this procedure 

causes fewer cases of dry eye. I make only a small incision in 

the cornea, and even the cap separation extends only up to 7 

mm from the center of the cornea. 

Both of these reasons should ensure that biomechanical 

stability is better maintained and that there are fewer cases of 

dry eye. Additionally, I save significant amount of time when 

performing ReLEx smile compared with Femto-LASIK—approximately 

10 minutes per patient. I treat more than 1,000 

patients a year, which means that I can conceivably save about 

45 minutes on every working day. 

Another aspect that I find beneficial is that I only have to 

purchase and maintain one laser instead of the two lasers that 

are needed for PRK or LASIK. Economically, this is the better 

set-up, because here in India we cannot up-charge the patient 

as much as what can be done in other countries, and it is hard 

for us to afford the maintenance and capital costs on two different 

laser systems. 

Marketing benefits. We are in a very unique position, because we 

are one of the only centers that can offer blade-free, flap-free laser

22 


ReLEx smile: 

My New Clinical 

Standard 



Using this procedure in a high-volume clinic 

saves us from having to create a corneal flap. 

By Jesper Hjortdal, MD, PHD 

Figure 2. Refractive outcome after ReLEx for treatment of myopia and 

myopic astigmatism up to -10.00 D. 

Figure 3. Safety of the ReLEx procedure, as expressed in the change in 

the numbers of lines of BCVA. 

vision correction. This has provided patients with incentive to 

come into our center and find out more about ReLEx flex and 

ReLEx smile. Of course we still offer LASIK and PRK, as it is 

very important that the patient selects the treatment that is right 

for him or her specifically, but I have noticed that more often 

patients prefer one of the two ReLEx techniques. 

Conclusion: In the future, ReLEx procedures will be able 

to be performed through even smaller incisions than we use 

today. I have already attempted the use of 3-mm incisions in 

a number of ReLEx smile cases, and the results have been 

promising. The limiting factor at this point is the instruments 

we have to separate the lenticule in situ, which at this time are 

too large for smaller incision sizes. One solution may be the 

use of hydrodissection to separate the lenticule. 

I feel very lucky to be among the first surgeons to use ReLEx 

in a large patient population. To date, I have noticed a surge 

in the number of patients who ask for ReLEx by name, and I 

look forward to growing my number of treated patients even 

more. It is truly an exciting time to be a refractive surgeon. 

Iwork in an extremely high-volume, hospital-based clinic. 

In a typical day, I see up to 40 patients, treat a multitude of 

conditions, and correct various forms of refractive errors. My 

work is extremely rewarding—I find great joy in helping patients 

achieve better visual quality and in most cases spectacle 

independence—but it is also time-consuming, and anything I 

can do to safely reduce procedural times is helpful. 

Approximately 16 months ago, we switched from using LASIK 

to lenticule extraction with ReLEx in the majority of my 

patients. We have performed approximately 900 procedures in 

this period. I have noticed a significant time-saving benefit. Of 

the two available ReLEx procedures, femtosecond lamellar 

extraction (ReLEx flex) and small incision lamellar extraction 

(ReLEx smile), I prefer the latter because I no longer need to 

create a corneal flap to perform the refractive correction. For 

the past 4 months, I have been using ReLEx smile whenever 

possible, promoting it as my new clinical standard for refractive 

surgery. We have thus far performed approximately 400 

ReLEx smile procedures. 

Differences: ReLEx is a simplistic but effective procedure that 

can today only be performed with the VisuMax femtosecond 

laser (Carl Zeiss Meditec, Jena, Germany); it is the only laser 

vision correction technique that uses a femtosecond laser to 

create a cut in the cornea and perform the refractive correction. 

With this technique, I am able to create the lenticule 

without ever having to break through the corneal surface. I 

typically use ReLEx for the treatment of high myopia, as this 

is the majority of patients who elect treatment due to reimbursement 

by the public health service. I treat patients with as 

much as -10.00D. Below I describe the differences between 

both ReLEx procedures. 

ReLEx flex. In the initial steps of the procedure, ReLEx flex is 

similar to LASIK in that a corneal flap is created and lifted; 

however, instead of ablating the tissue underneath the flap, the 

surgeon peels off a small refractive lenticule to provide the 

refractive correction. This is extremely easy to do, and after 

about 10 procedures I was comfortable with this technique.


23 

I have seen less cases of patient discomfort, including dry 

eyes and foreign body sensation, and so far in my clinical 

experience with ReLEx smile I expect even less risk of 

corneal ectasia compared with LASIK. Regarding procedure 

time, I no longer have to move the patient from the 

femtosecond laser to the excimer laser, but rather I simply 

perform the cut and the refractive correction on the same 

patient bed at the VisuMax laser. There was a slight learning 

curve in which the procedure time was longer than it 

is for LASIK, but after I understood the ins and outs of the 

technique the surgical time decreased. 

Figure 1. View through the operating microscope immediately before 

completion of a ReLEx smile laser treatment using the VisuMax femtosecond 

laser. 

ReLEx smile. The main difference between ReLEx flex and 

ReLEx smile is that there is no longer a need for a corneal 

flap. Instead, a small tunnel incision is created and the 

refractive lenticule is extracted through the incision using 

a spatula. The learning curve is slightly longer with ReLEx 

smile, but by 20 cases I had the technique perfected. 

Procedural advantages: My typical ReLEx smile procedure, 

which lasts approximately 10 minutes, is outlined 

below: 

• The patient is prepped for surgery by two drops of topical 

anesthesia and a lid speculum is inserted; 

• Using the VisuMax femtosecond laser, an intrastromal 

lenticule is cut and a 3-mm incision is created at the 

12-o’clock position. With a length of 500 μm, this small 

channel-like incision produces an entryway to the refractive 

lenticule (Figure 1); and 

• The lenticule is loosened with a spatula and is manually 

extracted through the tunnel using a small forceps (Figure 

2). 

Surgically speaking, the ReLEx smile procedure has 

several advantages over excimer ablation techniques such 

as LASIK and PRK. Perhaps the largest is that I no longer 

have to create a preflap on the surface of the eye, meaning 

that I no longer have to worry about the complications 

associated with a corneal flap, such as buttonholes and 

later flap dislocation. Additionally, there is minimal risk of 

epithelial growth under the flap, as only one small incision 

replaces the need for a flap, and there is more intact 

cornea compared with surface ablation procedures, which 

increases corneal stability. 

Clinically speaking, the main advantages are that the 

procedure is shorter and follow-up shows less variations. 

Higher-order aberrations: We have begun to analyze 

higher-order aberrations before and after ReLEx and 

LASIK. Thus far, we have studied 3-month results for 100 

patients, 50 of whom underwent femtosecond LASIK and 

50 of whom underwent ReLEx flex. Patients in the ReLEx 

flex group had fewer higher-order aberrations after surgery 

compared with femtosecond LASIK patients. Once we have 

longer-term results, we will repeat the same study using 

ReLEx smile patients. Since the process is similar to ReLEx 

flex, whereby the refractive lenticule is removed, we expect 

that the higher-order aberrations after ReLEx smile will be 

similar or even better than those after ReLEx flex. 

Figure 2. Lenticule removal is completed through a small 

incision in the ReLEx smile procedure. 

How can this difference in higher-order aberrations after 

ReLEx flex and femtosecond LASIK be explained? We 

postulate that, with LASIK, once the flap is cut and following 

the excimer laser ablation, there tend to be small 

decentrations that can lead to coma. However, with the 

ReLEx procedures this is avoided because any and all cutting 

is done within the cornea. More research is needed to 

confirm this hypothesis. 

Conclusion: ReLEx, and most specifically ReLEx smile, 

has become the new standard of care at our clinic for 

patients with high myopia. This treatment has many advantages 

over excimer ablation techniques, the most important 

two being a decreased number of higher-order aberrations 

after surgery compared with LASIK and the time it saves 

me in the operating room.

24 




VisuMax 

in Keratoplasties 

Dr Khaled Ben Amor on “Keratoplasties 

with VisuMax” 

“Even in DLK, the results of 

femtosecond laser are very nice 

optically and we have much more 

success rate with the technique.” 

Keratoplasties with VisuMax: : Dr Ben Amor shared his 

experiences about the keratoplasty with VisuMax which 

according to him is “the obligation of the VisuMax, 

much beyond refractive surgery”. Discussing the advantages 

of the VisuMax he said that it offered a curved corneal interface 

and a planar cut. He then showed the high performance 

optics in ZEISS that was the key to optimum cut. He shared 

videos showing how it was easy to lift a donor graft and those 

for keratoconus hydrops, corneal scarring, bullous keratopathy 

and adherent leucoma. Dr Ben Amor also discussed the 

advantages of the femto penetrating keratoplasty due to the 

regular side cut. “Better centration and better donor recipient 

fit give a nice optical result better than that with a manual 

keratoplasty,” he said. 

Deep lamellar keratoplasty (DLK): He explained the principle 

approach in a DLK which required the separation of 

the endothelium from the stroma by injecting a bubble. In 

manual DLK, the bubble layer is seen in around 52% cases 

which necessitate desiccation of the rest of the stroma. According 

to him, Femto DLK ensures precision during surgery. 

Dpt 

Dense central corneal scarring (Dr. Burjor P. Banaji, India) 

“The cut can easily be lifted and then a big bubble is injected 

which works in 75% of cases. It is much easier to take off the 

remaining stroma. So, you have a complete Descemet barring 

which is very important. This happens in 90% of the 

Femto DLK cases versus 60% in manual DLK,” Dr Ben 

Amor added. 

Dr Burjor P. Banaji on “Challenging Cases 

Corrected with Topography-Linked LASIK” 

Clinical experiences: Dr Banaji shared his experiences 

with topography-guided LASIK in some “weird” 

cases he has done over the past few years, which 

otherwise would be very difficult if not impossible to treat 

with the standard modalities of LASIK. He showed the 

topographical picture of a corneal central island. He shared 

another case of multiple prior corneal surgeries. He then 

shared interesting results in a patient who had dense corneal 

scarring after a lacerating full thickness injury to the cornea 

many years ago and was complaining of haloes, scatter and 

distortion of images. The refraction was -8D spherical with 

-5D cylindrical and BCVA was approximately 6/36. The scar 

was right in the center of the pupil and the corneal thickness 

was almost 600μm. “We smoothened the bed and about 4-5 

months later lifted the flap and corrected the residual error 

again with a topography guided treatment,” he specified. He 

showed the large 10D shift in the center of the pupil that was 

causing debilitating symptoms and how just smoothing it 

with topography brought down the dioptric shift by 6D, thus 

abating the symptoms. LASIK was planned as the patient was 

still severely myopic. The pre-op refraction was -8D/-5D and 

post-op it miraculously was -0.75D. “I could not have done 

it with anything other than a topography-guided treatment,” 

added Dr Banaji. 

Further, he discussed a post-op cataract case, which was 

referred to him in not very distant past. A well-centered 

multifocal IOL was given and there was a residual 

astigmatism.“Confirm that your central rim 

and the lights are like a bull’s eye, one within 

the other when the patient is asked to look into 

the microscope after the procedure. Then you 

see that your lens is centered properly. You 

will often need to decenter your lens nasally 

for that to happen. When you look at your eye 

postoperatively, that ring should, if you have 

done your job properly, never be in the center 

of our pupil,” he explained. He attributed the 

astigmatism to an LRI that “had done something 

very naughty to the cornea”. The patient 

was not only having an asymmetrical astigmatism, 

it was non-orthogonal. “Post-op the 

patient was very happy and the topography has 

worked very well,” he said in delight.


25 

Conclusion: Dr Banaji supported that ZEISS had the best 

refractive outcome among all topography-guided systems. 

He referred to the topography-guided treatment as 

“ZEISS’ hidden jewel” and called it an “Optical success 

for Carl Zeiss”. 

Topography assisted ablation with Carl Zeiss Meditec MEL 80 and 

CRS-Master (Dr Ruben Lim-Bon-Siong, Philippines) 

Dr Ruben Lim Bon Siong on “Topography- 

Guided Refractive Surgery: For the Sins of 

Our Past and Present” 

“It is not the end of the road when a 

flap complication occurs. There are 

topography-guided procedures that 

can help these kinds of problems.” 

a) Change in Snellen lines of BCVA (N=48) 

Topography-guided refractive surgery: Dr Lim Bon 

Siong spoke of the topographically customized systems 

that aim to correct an irregular corneal surface. 

He shared the published results of topography-guided 

ablation with MEL 80 and CRS-Master by Dan Reinstein. 

The results were of 48 eyes in 32 patients who underwent 

the procedure for small optic zones, decentered ablations, 

decentration after radial keratotomy, high myopia after 

deep lamellar keratoplasty, irregular astigmatism due 

to wound gape following cataract surgery and irregular 

astigmatism due to scars. The median follow-up was 7.7 

months (1 month to more than 1 year) and the mean preop 

spherical equivalent was -1.12D ± 1.97D with a mean 

preoperative cylinder of -1.34D ± 1.65D. “All patients 

had good topographies. LASIK, LASIK-enhancements, 

or PRK were done and treatments were centered on the 

corneal vertex. “It is a very safe procedure. None of 

the patients lost more than 2 lines after the procedure.” 

Speaking about the accuracy, he said, “79% of patients 

were within +/- 1D and 63% within +/- 0.5D. All these 

patients had an improvement of least 2 lines or more. 

This was very significant compared to the pre-op. It is 

very stable. All patients had improved contrast sensitivity.” 

Clinical cases: Dr Lim Bon Siong discussed clinical experiences 

including cases of a central island, post-LASEK 

corneal scar, lost cap and incomplete flap. Additionally, 

he discussed a case of a 22-year-old male Filipino who 

underwent LASIK with XP microkeratome and ended in 

an incomplete flap with subsequent haze in the left eye. 

The preoperative refraction of OS was -3.25-0.50 x 170 

(20/20). Three months after the the flap complication, the 

UCVA was 20/200 with refraction of +6.50 -2.00 x 170 

and BCVA 20/30. In this patient a transepithelial PTK was 

done with ablation depth of 50µm and a diameter of 8mm 

b) Accuracy 

c) UCVA improvement 

d) Stability

26 


The Importance 

of ReLEx in Our 

Current Laser 

Vision Correction 

Business 



e) Contrast Sensitivity 

followed by topographic smoothing to a depth of 58µm. 

At 7 months after the topo smoothing, UCVA was 20/100, 

refraction +4.25-4.25x180 (20/30). Corneal topographyguided 

PRK was done and at one and a half months post 

PRK, UCVA was 20/25, refraction +0.75D sphere (20/20). 

Summary: Dr Lim Bon Siong summarized that 

topography-guided ablations with the MEL 80 and 

CRS-Master allowed regularization of corneas with 

irregular astigmatism resulting in the improvement of 

quality of vision. 

Dr Donald Tan, Medical Director, SNEC, 

Singapore, Chairman, Singapore Eye 

Research Institute 

Femtosecond laser assisted penetrating 

keratoplasty: Dr Tan shared the outcomes in a small 

series of 8 eyes (bullous keratopathy, Fuchs herpetic 

keratopathy, regraft) done at their center. The donor and 

recipient trephined with femtolaser had a mean follow-up 

of 9.5 months and mean post-graft astigmatism of 2.56D. 

The mean endothelial cell count was 1.753 mm 2 and there 

weren’t any complications. “The potential of femtosecond 

lasers to perform deep stromal ablation will allow us to 

perform Femto-DSEK and Femto-DALK. Advantages, 

there is ease of surgery, improved bed quality and better 

accuracy in terms of depth of ablation. There should be 

better donor edge quality with no restriction to shape and 

edge profiles and better lenticule profiles,” he said. Talking 

further he said that the disadvantages were “cost and 

poor laser penetration of corneal scars. Arcus senilis is an 

issue. Many femtosecond lasers do not reach the good bed 

quality that we need. There are limitations because we are 

relying on the anterior corneal surface”. This in his view 

could be solved by linking with AS-OCT technology. 

Gradual Incorporation of This Technique 

Has Led to Steady Growth. 

By Ekktet Chansue, MD 

ReLEx combines the latest femtosecond laser technology 

with an exact method for lenticule extraction within the 

intact cornea to achieve precise, accurate, and gentle 

vision correction. This procedure not only provides an easier 

approach to refractive correction, but it does so using just one 

device, the VisuMax femtosecond laser (Carl Zeiss Meditec, 

Jena, Germany). I transitioned to using ReLEx in July 2010 

and have since performed approximately 600 procedures. 

This article reviews my personal motivation behind the 

switch to ReLEx, demonstrates the benefits of transitioning to 

ReLEx flex and subsequently ReLEx smile, and lastly offers 

my unique perspective of marketing the procedure. 

Personal motivation: I am continually striving to achieve 

better refractive results for my patients. Part of this equation 

is the willingness to consider incorporating new procedures 

into daily practice. Throughout my career as a refractive 

surgeon, I have made a habit of objectively analyzing any 

new procedure that I am curious about, and if it makes sense, 

I consider adopting it. For instance, in 1994, I was the first 

surgeon in Thailand to perform LASIK. Looking back to that 

period, the procedure was being performed by only a handful 

of surgeons around the world—it was even considered an 

aggressive approach by a lot of ophthalmologists. But my 

objective analysis of LASIK told me that it would help me to 

achieve better postoperative outcomes compared with radial 

keratotomy, PRK (with first-generation excimer lasers), and 

automated lamellar keratoplasty. 

LASIK is commonplace today, but I believe that laser vision 

correction is evolving from excimer laser-based ablation 

procedures to microincision surgery procedures like ReLEx 

smile. Like any other procedure I have considered for routine 

use, I performed an objective analysis of ReLEx and determined 

it may perhaps be the most ideal way to perform laser 

vision correction.


27 

The basis for the ReLEx procedure is the Law of Thickness, 

which was introduced by the late Jose Ignacio Barraquer, of 

Bogotá, Colombia, in 1949. 1 This is also the same principle 

for which numerous methods of laser vision correction— 

LASIK included—are based. However, ReLEx is unique to 

these other laser vision correction procedures because of the 

elegance with which the Law of Thickness is implemented. 

The beauty of ReLEx is its minimalistic approach to surgical 

correction. My incision size is now routinely between 2.0 and 

2.5 mm long (Figure 1). You can say it is the cutting edge of 

refractive surgery because there is almost no cut edge. 

Benefits: I gradually incorporated ReLEx into my practice 

over the past year, with a steady growth in the number of 

procedures I was performing. Currently, approximately half 

of my procedures are ReLEx surgeries. My initial experience 

(six eyes) was with ReLEx flex. I then transitioned to performing 

ReLEx with a continuously smaller incision size, still 

using the flex program on the VisuMax femtosecond laser. 

This is a helpful transition procedure based on ReLEx flex. 

In July 2011, the ReLEx smile program was installed on 

our laser, and since then almost all of my cases have been 

done with this program. I have always been a firm believer 

in Dr. Barraquer’s Law of Thickness, but only when I saw 

Rupal Shah, MD, of India, perform ReLEx smile did I 

realize that this is what LASIK wants to be when it grows 

up. ReLEx smile does what LASIK does—only better. There 

are minimal disturbances to the cornea, both structurally and 

physiologically. I see this procedure as the ultimate homage to 

Dr. Barraquer. 

ReLEx flex and ReLEx smile procedures both have advantages. 

I prefer ReLEx smile, because I have found that, after 

surgery, these eyes tend to be more comfortable during the 

first night postoperative. Additionally, ReLEx smile eyes have 

the potential to be structurally stronger than ReLEx flex eyes, 

as there is no flap-edge cut by the laser. The benefit of such 

cut, however, is the ease with which you can go back and do 

enhancement surgery much in the same way as after LASIK. 

Stepping stone: I use ReLEx smile whenever I can. When 

I do use ReLEx flex, I perform this technique with a small 

incision size while still using the flex program. ReLEx flex 

is a steppingstone, albeit an important one, to ReLEx smile. 

This procedure is a helpful step to optimize laser settings and 

to gain valuable experience learning the techniques required 

for this type of surgery. The ReLEx flex software also allows 

the surgeon to start performing a small-incision technique 

as described above by only making a small access cut even 

when the laser has created LASIK flap-like cuts. This serves 

as a training step for the surgeon to gain the confidence for 

progressing to ReLEx smile. 

I can use the same preoperative process with ReLEx smile 

Figure 1. (A) During ReLEx smile, the lenticule is removed through a 

2-mm incision. (B) ReLEx smile: Postoperative day 1. 

as we did for ReLEx flex and also for LASIK. We carefully 

explain the risks and benefits of each surgical option, and the 

patient has the freedom to make an informed decision. ReLEx 

has expanded the range of myopic treatment we can offer to 

patients. Historically, we have limited our myopic treatment 

to -10.00D with LASIK, more from an optical quality standpoint. 

Now, with the superior optics that we see with ReLEx, 

we are treating cases above -10.00D in the course of our clinical 

study, if pachymetry allows, with great results. Therefore, 

having ReLEx as a surgical option may increase the number 

of potential candidates for the future. 

Marketing services: As with any service I offer my patients, 

I truly believe in the ReLEx procedure. This is the first 

message that I tell patients. After that, it is mostly about 

providing clinical data and describing the procedure to the 

patient. I offer ReLEx to all patients who are candidates 

for the procedure, but it is important to let them choose the 

procedure that they feel is best suited. I do not like to think of 

it as marketing, but rather information gathering. I am able 

to offer a wider range of procedures to my patients. In the 

beginning, when there was not a lot of data on ReLEx, I made 

sure to point that fact out to the patient. Today, I feel very 

comfortable offering ReLEx to my patients. 

It is not always easy to explain the procedure and make the 

patient understand completely, but one of the things patients 

like about ReLEx smile is that it uses a microincision and the 

vision correction cut is performed inside the intact cornea. 

Most people can identify with the benefits of minimally 

invasive procedures, as the whole of medical practice seems 

to be progressing. An analogy such as endoscopic surgery as 

opposed to laparotomy (in cholecystectomy, for example) is 

helpful. 

Conclusion: Using ReLEx flex and ReLEx smile, I have been 

able to provide patients with a minimally invasive approach 

to laser vision correction that affords short treatment times 

and inherent accuracy, even in cases of high myopia. I have 

been able to expand my treatment range within the scope of 

the study well past the -10.00D of myopia I could treat with 

LASIK, and I have done so safely and accurately using these 

techniques. 

1. Barraquer JI. Queratoplastia refractiva. Estudios Inform Oftalmol Inst 

Barraquer.1949;10:2-21.

This is the moment we work for. 

The moment flapless surgery 

becomes clearly visible: in a smile. 

This is the moment we work for. 

// ReLEx 

MadE By CaRL ZEiss 

// ReLEx 

MadE By CaRL ZEiss 

Flapless. All-femto. Single-step. For the first time ever, advanced femtosecond technology and highly 

precise lenticule extraction are combined to perform minimally invasive corrections – with a single system: 

the VisuMax ® from Carl Zeiss. Thereby, a refractive lenticule is created within the intact cornea and extracted 

through a small incision. The new flapless procedure offers clear advantages: minimal surgical impact on the 

corneal stability and excellent predictability of the refractive outcomes. 

Flapless. All-femto. Single-step. For the first time ever, advanced femtosecond technology and highly 

www.meditec.zeiss.com/ReLEx 

precise lenticule extraction are combined to perform minimally invasive corrections – with a single system: 

the VisuMax ® from Carl Zeiss. Thereby, a refractive lenticule is created within the intact cornea and extracted 

through a small incision. The new flapless procedure offers clear advantages: minimal surgical impact on the 

000000-1839-885 

corneal stability and excellent predictability of the refractive outcomes.

FEMTO-LASIK and BEYOND - Carl Zeiss, Inc.

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