Table of Contents - WOC 2012

WOC2012 Abstract Book
FP-REF-TH 49 (5)
Initial Experience and Refractive Outcomes with Optimized Prolate
Ablation for Myopia and Astigmatism
Abdel Fattah Tarek (1) , El-Danasoury Alaa (1)
1. Magrabi Hospital
Purpose: To present the initial experience, the refractive outcomes and
induction of spherical aberration of the Nidek optimized prolate ablation (OPA).
Method: This study presents 6 months postoperative data from one surgeon
using OPA on 65 eyes. Patients treated for up to - 5.50 D of sphere and up
to - 2.25 D of cylinder were included in the study. Standard refractive data and
wavefront data were analyzed. Postoperative data at 6 months is presented.
Results: Postoperatively, 100 percent of the patients had uncorrected visual
acuity of 20/20 or better after OPA. No patients lost lines of best corrected
visual acuity (BCVA) and 50% of eyes gained one line of BCVA. The mean
manifest refractive spherical equivalent was 0.00 ± 0.20 D (range -0.63 D
to 0.37 D). Sixth order ocular spherical aberration increased by +0.05 µm
postoperatively.
Conclusion: Initial experience with the OPA ablation algorithm indicates that
treatments are efficacious and predictable with minimal increase in spherical
aberration.
FP-REF-TH 49 (6)
NIDEK Optimized Prolate Ablation (OPA) and Presbyopia Optimized
Prolate Ablation (Presby-OPA) Profiles in Lasik Myopic Correction
Salaheldine Mostafa (1) , Salaheldine Yehia (2)
1. Research Institute of Ofthalmology
2. Cairo University
Purpose: To report the ocular and corneal higher order aberrations and corneal
asphericity of optimized prolate ablations for the treatment of myopia.
Methods: 30 myopic patients were treated using myopic ablation for both eyes
using the new ablation profiles, OPA for younger patients and PresbOPA
for those older than 40 years. Predictability, Mean refraction MR,corrected
distance visual acuity (CDVA), uncorrected intermediate Visual Acuity
(UCIVA),uncorrected near Visual Acuity(UCNVA) and corneal and ocular
aberrations were analyzed out to 3 months postoperatively.
Results: Mean preoperative root-mean-square (RMS) averaged 0.41D and
mean preoperative spherical aberration (SA )averaged 0.124 microns. In
presbyopia group, preoperative mean uncorrected near visual acuity (UCNVA)
averaged 0.68 and preoperative mean uncorrected intermediate visual acuity
(UCIVA ) 0.48 . At 3 months postoperatively, (RMS) of the total ocular higher
order aberrations was 0.57 D. Ocular spherical aberration was -0.027 microns
. In presbyopia group, mean UCNVA averaged 0.7 and mean UCIVA 0.5.
Conclusions: Optimized prolate ablation-treated eyes had less induction of
higher order aberrations and spherical aberrations postoperatively and
increases reading glasses independence in the presbyopic group.
74
FP-REF-TH 49 (7)
The Efficacy, Predictability and Safety of Wavefront Guided
Refractive Laser Treatment: A Meta-Analysis
Suleman Hanif (1) , Fares Usama (1) , Al-Aqaba Mouhamed (1) , Otri Ahmed
Muneer (1) , Dua Harminder Singh (1)
1. Division of Ophthalmology and Visual Sciences
Purpose: We compared the efficacy, predictability, safety, and induced higherorder
aberrations (HOAs) between wavefront-guided (WG) and non-wavefrontguided(NWG)
ablations.
Methods: Randomized controlled trials (RCTs) meeting the selection criteria
were quality appraised and data extracted by two independent authors.
Measures of association were pooled quantitatively using meta-analytical
methods. The pooled odds ratio (POR) and 95% confidence interval (CI) were
computed in the domains of efficacy, safety and predictability. The weighted
mean difference (WMD) and 95% confidence interval were used to compare
induced HOAs.
Results: Eight trials involving 955 eyes were included.
Efficacy: The POR of achieving uncorrected visual acuity (UCVA) of 20/20 after
WG was 1.10(CI: 0.66 to 1.83, p=0.72).
Predictability: The POR of achieving a result within ±0.50 dioptres of intended
target with WG was 1.03(CI: 0.60 to 1.75, p=0.92).
Safety: No study reported loss in two or more lines of Snellen acuity in both
modalities. The WMD of induced HOAs with WG was -0.09(CI: -0.17 to -0.01,
p=0.04).
Conclusions: We have found no clear evidence for any benefit of WG over
NWG ablations. However, there is a lack of standardized reporting of levels
of UCVA better than 20/20, which might mask an advantage in WG treatment.
FP-REF-TH 49 (8)
Rolling and Z Movements Measured with the 6D Eye-Tracker of the
SCHWIND AMARIS Total-Tech Laser
Arbelaez Maria Clara (1) , Arba-Mosquera Samual (1)
1. Muscat Eye Laser Center
Purpose: To evaluate intraoperative dynamic eye rolling and z movements with
6D Eye-Tracking using SCHWIND AMARIS.
Setting: Muscat Eye Laser Center, Oman.
Methods: Scleral-tracker images obtained during initial ablation were compared
to late images to determine eye rolling and axial displacements. The difference
between max and min displacement was taken as a metric of movement range.
Mean, STDdev, and range were computed and expressed as % of treatments.
Results: Successful registration occurred in 90% (52/58). Mean rolling was
2±3° horizontally and -3±3° vertically. Mean rolling measurements were within
5° in 78% horizontally and 70% vertically. Mean axial displacement was
-295±455µm Mean axial displacement values were >1mm in 10%. Mean rolling
range during treatment was 4±2° horizontally and 5±2° vertically. Horizontally,
3% rolling ranges were >8°. Mean axial displacement was 460±271µm. 3% of
axial displacements were >1mm.
Conclusions: 6D-eye-tracker is valuable because uncompensated rolling
movements can induce decentrations (comatic aberrations), and
uncompensated axial movements may induce undercorrections. We retrieved
5° for œnatural-rolling, and observed patients push their heads back at the
beginning of the treatment and return to a more level position during treatment.