Correction of Residual Hyperopia After Cataract Surgery ... - Iogen

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$Refractive Cataract Toolset - Iogen$

FIGURE 1. Digital light delivery (DLD) device used to treat patients with light adjustable intraocular lens (IOL) technology. this fashion, we were able to adjust lens power and test whether a “hyperopic surprise” could be corrected in the postoperative period. METHODS A PROSPECTIVE, NONRANDOMIZED, SINGLE-CENTER CLINIcal study was conducted at Codet Vision Institute, Tijuana, Mexico. Subjects who required cataract extraction and IOL implantation and volunteered for this study were screened for eligibility. Subjects with significant anterior segment pathology, uncontrolled glaucoma, previous ocular surgery, macular deceases, current use of Flomax, or 7.0 mm dilated pupil diameter were excluded. Fourteen patients (one eye per patient) were enrolled, 10 females and four males. Preoperative biometry was performed using an immersion biometry unit (Axis II Ophthalmic Echograph; Quantel Medical, Bozeman, Montana, USA), and the light adjustable IOL power was selected to result in a postoperative refractive error of up to 2.0 D of hyperopia. The light adjustable IOL is a foldable posterior chamber, UV absorbing, three-piece photoreactive silicone lens with blue polymethylmethacrylate modified-C haptics, a 6.0 TABLE 1. Preoperative Refraction and Axial Length, and Implanted Light Adjustable Intraocular Lens Power for Patients With Light Adjustable Intraocular Lens Technology Eye Preoperative Sphere Cylinder Axial Length (mm) Implanted Power (D) 1 2.25 1.25 15 22.76 18.0 2 ND a ND a 23.16 20.0 3 0.75 0.75 90 23.43 20.0 4 4.00 1.50 99 22.04 23.5 5 2.75 0.75 80 22.59 21.5 6 2.50 0.00 0 22.63 23.5 7 1.50 0.00 0 22.31 21.5 8 5.00 0.75 100 22.55 23.0 9 3.00 0.75 75 22.85 22.0 10 3.00 0.75 75 22.90 23.0 11 2.00 0.00 0 22.56 22.5 12 3.25 2.00 90 23.58 20.0 13 2.75 0.75 80 22.88 20.5 14 1.75 0.00 0 22.79 22.5 D diopters; ND not determined. a No refraction can be measured attributable to dense cataract. TABLE 2. Distribution of Refractive Adjustments Attempted for 14 Patients With Light Adjustable Intraocular Lens Technology Attempted Sphere n a /N b 0.25 to 0.5 D 3/14 21.4% 0.75 to 1.0 D 6/14 42.9% 1.25 to 1.5 D 4/14 28.6% 1.75 to 2.0 D 1/14 7.1% D diopters. a Number of eyes at each attempted sphere. b Total eyes enrolled. mm biconvex optic with squared posterior edge, and an overall length of 13.0 mm. All patients underwent phacoemulsification using a topical anesthetic, clear corneal incision (3.0 to 3.5 mm) and anterior capsulotomy (5.5 mm). The light adjustable IOL of the appropriate power was implanted in the capsular bag using the Nichamin II Foldable Lens Insertion Forceps (Rhein Medical Inc, Tampa, Florida, USA). The operative eye was patched following surgery. The patch was removed the following day, and patients were instructed to wear Calhoun Vision-supplied UVblocking photochromic spectacles (7EYE, Pleasanton, California, USA) at all times when indoors and outdoors after surgery until the adjustment and lock-in procedures were completed. VOL. 147, NO. 3 PSEUDOPHAKIC HYPEROPIA CORRECTION 393 %
TABLE 3. Accountability of All Patients Enrolled With Light Adjustable Intraocular Lens Technology as a Function of Postoperative Time The light adjustable IOL was adjusted and locked in using a digital light device engineered by Carl Zeiss Meditec (Jena, Germany). 15,16 The digital light device uses a mercury (Hg) arc lamp fitted with a narrow bandpass interference filter producing a beam at 365 nm ( 4nm full width half maximum). The digital light device generates and projects a spatial irradiance pattern onto the light adjustable IOL using a digital mirror device. The digital mirror device is a pixelated, micromechanical spatial light modulator formed monolithically on a silicon substrate. The digital mirror device chip enables customization of the irradiation profile to correct not only spherical and astigmatic errors but also HOAs. The surgeon centers and focuses the treatment beam on the light adjustable lens using an alignment reticle while patient alignment is achieved using a fixation target, parcentral to the delivery beam. The digital light device is shown in Figure 1. At one to two weeks postimplantation, best-corrected and uncorrected visual acuity (VA) and residual hyperopic refractive error were measured. VA assessment and manifest refraction were performed by an optometrist who was masked to the patient’s targeted refractive outcome and light adjustable IOL power. The digital light device was then used to adjust the light adjustable IOL power to correct the hyperopic error. Refractive power adjustments are defined at the spectacle plane. A second irradiation treatment was given a minimum of 20 hours after adjustment to lock-in the lens. The following study endpoints were evaluated: 1. Attempted vs achieved lens power change (manifest refraction). 2. VA (best-corrected and uncorrected distance VA). 3. Stability of adjusted lens power (manifest refraction). 4. Complications and adverse events. RESULTS A TOTAL OF 14 EYES WERE TREATED FOR REFRACTIVE ADjustments in the range of 0.25 to 2.0 D and were followed for one to six months postoperatively. Of the 14 patients, 10 were female and four were male. The average One Month Three Months Six Months Available for analysis n/N (%) 14/14 100.0% 14/14 100.0% 9/14 64.3% Discontinued n/N (%) 0/14 0.0% 0/14 0.0% 0/14 0.0% Missed visit n/N (%) 0/14 0.0% 0/14 0.0% 0/14 0.0% Not yet eligible for the interval n/N (%) 0/14 0.0% 0/14 0.0% 5/14 35.7% Lost to follow-up n/N (%) 0/14 0.0% 0/14 0.0% 0/14 0.0% % Accountability Availability for Analysis (Enrolled Discounted Notyeteligible) 14/14 100% 14/14 100% 9/9 100% FIGURE 2. Scattergram of target vs achieved hyperopic corrections in patients with light adjustable IOL technology. The solid line represents achieved refractive adjustments in diopters (D) equal to the targeted power. Of 14 eyes adjusted, 13 (93%) achieved 0.25 D of the targeted refractive adjustment in the range of 0.25 to 2.0 D. The remaining one eye was within 0.50 D of the targeted refraction. age of the study participants was 68 7 years. The power of implanted light adjustable IOL as well as preoperative refractive errors and axial length are presented in Table 1. The distribution of refractive adjustments attempted can be found in Table 2. All eyes were accounted for at the one, three, and six month postoperative visits in Table 3. There were no missed visits or any patients lost to follow-up during the study period. An additional 14 patients were implanted with the light adjustable lens and treated for refractive adjustments in the range of 2.0Dto plano; these will be detailed in a separate report. ● TARGET VS ACHIEVED HYPEROPIC CORRECTIONS: The accuracy of the achieved sphere to the targeted refractive adjustment is demonstrated in the scattergram presented in Figure 2 and data in Table 4. Thirteen of the 14 eyes (92.9%) treated were within 0.25 D of the target refraction at one day post lock-in follow up visit with 100% of the eyes achieving 0.50 D of the targeted refractive adjustment at one day post lock-in, three and six months postoperative visits. Similar results were demonstrated in the analysis of accuracy of the achieved manifest 394 AMERICAN JOURNAL OF OPHTHALMOLOGY MARCH 2009
Page 1: Correction of Residual Hyperopia Af
Page 5 and 6: FIGURE 3. Bar graph of uncorrected
Page 7: Biosketch Artura Chayet, MD, is the

Correction of Residual Hyperopia After Cataract Surgery ... - Iogen

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