Angel L. Cisneros

Endothelial study of iris-claw phakic lens : Four year follow-up

Purpose: To study quantitative and morphometric endothelial changes in phakic eyes implanted with the Worst iris‐claw lens to correct high myopia. Setting: Department of Ophthalmology, University Hospital “La Fe”, Valencia, Spain. Material and Methods: This retrospective study involved 111 phakic eyes (73 patients) implanted with the Worst iris‐claw lens. Noncontact specular microscopy and computer‐assisted analysis was performed preoperatively and 6 months and 1, 2, 3, and 4 years postoperatively. Results: The mean cell loss was 3.85% at 6 months, 6.59% at 1 year, 9.22% at 2 years, 11.68% at 3 years, and 13.42% at 4 years. At 2 years, the hexagonality and coefficient variation in cell size were close to the preoperative levels. No major complications were seen; early postoperative corneal touch required intraocular lens (IOL) removal in 1 case (0.9%). Four eyes (3.6%) needed a reoperation because of poor IOL fixation (2 eyes), traumatic subluxation of the IOL (1 eye), and miscalculation of the IOL power (1 eye). Conclusions: Although there was a slight, progressive cell loss after IOL implantation, the morphometric changes recovered and were close to the preoperative levels. This suggests that endothelial damage occurred primarily during the surgical procedure.

Iris claw phakic intraocular lens for high myopia.

BACKGROUND The implantation of a Worst-Fechner iris claw intraocular lens (IOL) is one of the surgical procedures used for the correction of high myopia. This technique reduces myopia with stable refractive results; however, its potential long-term risks have not been evaluated. We report results in 94 eyes with a minimum follow-up of 3 years. METHODS We studied 94 eyes of 62 patients with myopia > or = -7.00 diopters (D) who underwent Worst-Fechner IOL implantation. Lens decentration, permeability of the blood-aqueous barrier by iris angiography, and changes in corneal endothelial density were analyzed. RESULTS Mean follow-up time was 48.9 months (range 36 to 72 mo). Three years after surgery, 58 eyes (61%) had an uncorrected visual acuity > or = 20/40, and 77 eyes (82%) gained two or more lines of spectacle-corrected visual acuity with respect to the preoperative value; 75 eyes (79%) were within +/- 1.00 D of emmetropia and 46 eyes (48%) were within +/- 0.50 D of emmetropia. The mean endothelial cell loss was 17.9% at 5 years after surgery, while the percentage of hexagonality and the coefficient of cell variation tended toward preoperative levels. No vision threatening complications were seen. CONCLUSIONS The implantation of a Worst-Fechner iris claw phakic IOL reduced high myopia with a stable refractive outcome. Endothelial cell damage was within acceptable limits. The absence of major complications makes this procedure an acceptable method for correcting high myopia.

Excimer laser photorefractive keratectomy for high myopia

Abstract One hundred and thirty‐three eyes of 103 patients had photorefractive keratectomy with a slit scan mode excimer laser for myopia ranging from −6.00 to −22.00 diopters (D). The epithelium was removed with 20% ethanol, and the ablation was done with a tapered profile surrounding the optical zone. Patients were divided into two groups based on preoperative myopia: Group A, −6.00 D to −12.00 D (88 eyes); Group B, −12.50 D to −22.00 D (45 eyes). In Group A, mean preoperative refraction was −9.59 ± 1.79 D. Mean postoperative refraction was −0.29 ± 1.47 D at one month, −0.85 ± 1.68 D at three months, −1.17 ± 2.04 D at six months, and −0.56 ± 0.74 D at one year. Anterior stromal haze was greatest at the end of the first month; it diminished thereafter. This haze did not reduce the best corrected visual acuity in any eye in Group A. Mean preoperative refraction in Group B was −14.69 ± 5.27 D. Mean postoperative refraction was −1.34 ± 2.02 D at one month, −0.76 ± 2.08 D at three months, −3.88 ± 2.32 D at six months, and −5.50 ± 5.00 D at one year. Three eyes in Group B lost one or two lines of best corrected visual acuity as a result of severe stromal haze and epithelial scarring. Group A’s results were similar to those obtained in eyes with low myopia. In Group B, although a percentage of eyes obtained fairly good results, the lower degree of predictability and large variation in the results suggest that using this technique is unadvisable in eyes with extremely high myopia except in selected cases.

Phakic intraocular lenses to correct high myopia: Adatomed, Staar, and Artisan

Purpose: To evaluate the feasibility and safety of using phakic intraocular lenses (IOLs) to correct high myopia by comparing 3 IOL models: Adatomed, Staar, and Artisan. Setting: La Fe University Hospital, Department of Ophthalmology, and the Fundación Oftalmológica del Mediterráneo, Valencia, Spain. Methods: In this prospective comparative study, a phakic IOL was implanted in 217 highly myopic eyes (118 patients). Fifty‐nine eyes received an Adatomed IOL, 21 eyes a Staar IOL, and 137 eyes an Artisan IOL. The mean preoperative spherical equivalent was −15.39 diopters (D) ± 2.83 (SD), −16.00 ± 5.05 D, and −16.17 ± 2.75 D in the Adatomed, Staar, and Artisan groups, respectively. The mean follow‐up was 32.4 months (range 19 to 46 months) in the Adatomed group, 18.3 months (range 11 to 21 months) in the Staar group, and 121.4 months (range 38.4 to 154.3 months) in the Artisan group. At the follow‐up examinations, intraocular pressure (IOP), IOL pigment deposits, cataract formation, and visual acuity were evaluated. Results: The best corrected and uncorrected visual acuities improved in all eyes. No significant differences in visual acuity improvement were observed with the 3 materials, although the improvement was somewhat greater in eyes with the Artisan and Staar IOLs. The difference in mean IOP between preoperatively and the last follow‐up examination was 1.5 mm Hg in the Staar group, 1.3 mm Hg in the Adatomed group, and 1.7 mm Hg in the Artisan group (P = .36, P = .26, and P = .32, respectively). The incidence of pigment deposits was similar in the Adatomed and Staar groups, with deposits in 32 eyes (54.23%) and 8 eyes (38.1%), respectively. Anterior cataract formation was higher in the Adatomed group (44.06%) than in the Staar group (9.52%); nuclear cataract developed in 2 Adatomed eyes (1.46%) only. Conclusions: There was a higher incidence of anterior subcapsular cataract formation in the Adatomed group than in the Staar group. Delayed cataract development and the cataract type in patients with Artisan IOLs indicate that age and axial length may be prognostic factors. Factors such as IOL design, material, and placement probably affect cataract formation in eyes with posterior chamber IOLs for high myopia, particularly the Adatomed IOL.

Posterior chamber phakic intraocular lenses to correct high myopia: a comparative study between Staar and Adatomed models.

PURPOSE To determine the feasibility of using posterior chamber phakic intraocular lenses (PIOLs) to treat high myopia, comparing two different models, Staar and Adatomed. METHODS Twenty-four eyes from 12 patients were studied prospectively. A phakic Staar IOL was implanted in one eye of each patient, and the other eye received a phakic Adatomed IOL. Patients with uveitis or ocular trauma prior to ocular surgery, diabetic retinopathy, or capsular pseudoexfoliation were excluded. The mean preoperative spherical equivalent refraction was -16.00 +/- 5.05 D for the Staar group and -15.39 +/- 2.83 D for the Adatomed group. Average follow-up was 32.4 months (range, 19 to 46 mo) for the Adatomed group and 18.3 months (range, 11 to 21 mo) for the Staar group and included evaluation of intraocular pressure, intraocular lens pigment deposits, lens decentration, anterior subcapsular cataract, and visual acuity. RESULTS Spectacle-corrected and uncorrected visual acuity improved in all eyes in both groups. No statistically significant differences in visual acuity gain were observed with the two materials (Student t-test, P = .08 for the Staar group and P = .6 for the Adatomed group), although the gain in visual acuity was somewhat greater with the Staar PIOLs. The difference in mean intraocular pressure before surgery and at last follow-up was 1.5 mmHg for the Staar group and 2.3 mmHg for the Adatomed group (P = .36). The incidence of lens pigment deposits was the same in both groups (41.66%), with deposits in 5 of the 12 eyes in both groups. The incidence of lens decentration was higher in the Adatomed group (5/12; 41.66%) than in the Staar group (2/12; 16.7%). Anterior subcapsular cataract was higher in the Adatomed group (4/12; 33.3%) than in the Staar group (3/12; 25%). CONCLUSIONS There was a higher incidence of lens decentration and anterior subcapsular cataract in the Adatomed group than in the Staar group.

Long-term results of surgical treatment of high myopia with Worst-Fechner intraocular lenses

Abstract This retrospective study evaluated the results in 90 eyes that had a minus‐power anterior chamber intraocular lens implanted to correct high myopia. Preoperative myopia ranged from −7.00 to −24.00 D. Postoperative spherical equivalent was −0.50 D; 80.5% of eyes were within 1.00 D of emmetropia. Two years postoperatively, no cataract formation, retinal detachment, glaucoma, or significant endothelial damage had occurred. We conclude that minus‐power lenses can rapidly, safely, and predictably correct high myopia in phakic patients.

Implantation of iris devices in congenital and traumatic aniridias: surgery solutions and complications.

Purpose To show surgical solutions in patients with traumatic and congenital aniridia, to evaluate the clinical improvement of these patients when iris prosthesis are implanted, and to examine safety and complications of these implants in a long-term follow-up. Methods Eight patients were included in this retrospective noncomparative case series. Nine eyes had an artificial iris implantation for traumatic or congenital aniridia. Three eyes received a black diaphragm intraocular lens (IOL) in capsular bag after phacoemulsification. An aniridia prosthesis, sulcus sutured, in front of a previous IOL was implanted in two eyes. A black diaphragm IOL, sulcus sutured, in two eyes; two iris diaphragm rings, in front of the previous IOL, in one eye; and a sector iris prosthesis in front of an IOL in the last eye were implanted. Mean follow-up was 22.5 months (range 16 to 44 months). Results All patients had improved visual acuity (VA) and visual comfort after surgery. The glare disability was subjectively better in all cases. Two patients developed new ocular hypertension after surgery; one of them was controlled by medical treatment and the other needed cyclodiode. Two of the patients with glaucoma preoperatively also needed cyclodiode procedure and one of them an Ahmed valve. Conclusions Several kinds of artificial iris implants are available. In all our patients with aniridia, iris artificial prostheses improved VA and diminished visual discomfort. Glaucoma is the most important complication after artificial iris implant. It is possible to implant the iris prosthesis in the capsular bag, but this requires a large capsulorrhexis and presents a surgical challenge.

Direct Objective Quantification of Corneal Haze after Excimer Laser Photorefractive Keratectomy for High Myopia

PURPOSE The purpose of the study is to measure regional distribution differences in corneal haze after excimer laser photorefractive keratectomy for high myopia. METHODS The authors developed computerized gradient edge detectors with which were analyzed digitized anterior slit-lamp photographs of 40 eyes, an average of 21.0 plus or minus 14.5 weeks after photorefractive keratectomy for high myopia (-6 to -22 diopters). A treated area an adjacent untreated area on the anterior corneal surface, each containing six regions, were quantified, and the difference was correlated with various parameters. RESULTS Mean differences between scarred and clear areas for haze grade 0.5, 1.0, 2.0, 3.0, and 4.0 were 16.9, 26.6, 42.6, 60.4, and 76.4 gray levels, respectively (rs = 0.96; P = 0.0001). A low but statistically significant correlation between the intended correction and postoperative corneal haze was found (r = 0.33; P = 0.037). The mean coefficient of variation of the amount of opacification within each treated area was 9.4%. This coefficient of variation increased with a longer follow-up time (r = 0.88; P = 0.0001). The difference in the intensity of haze between the center and more peripheral regions over the entrance pupil did not correlate with the attempted correction. However, a strong association between a relatively less severe central corneal haze with respect to more peripheral haze and longer follow-up time was found (r = -0.96; P = 0.0001). CONCLUSION The amount of corneal haze showed a weak positive association with the attempted correction in excimer laser photorefractive keratectomy for high myopia. Corneal haze appeared fairly uniformly distributed within the ablation zone, but a more heterogeneous distribution was found with a longer follow-up time. Furthermore, later postoperative examinations disclosed a clear trend toward diminishing central opacification relative to peripheral regions over the entrance pupil.

Reproducibility of Digital Image Analysis for Measuring Corneal Haze After Myopic Photorefractive Keratectomy

PURPOSE To evaluate the usefulness of digital image analysis for quantifying corneal haze by determining the reproducibility of its measurements at the corneal plane. METHODS In a prospective study, 20 randomly selected eyes that had undergone myopic photorefractive keratectomy were photographed focusing the slit beam on their anterior corneal surface. Each photograph was examined using computer image analysis techniques that detect the edge of the reticular pattern of the image. Quantification of the difference between two areas, treated and adjacent untreated cornea, each containing 3,750 pixels with a resolution of 256 gray levels, was performed. Intra-analyzer variation was determined by evaluating the photographs obtained by two analyzers under standard conditions on four separate visits. Interanalyzer variation was calculated using one measurement and the mean of the four measurements. RESULTS The pooled standard deviation of the measurements for the analyzers was 0.63 and 0.62 gray levels (coefficient of variation, 4.1% and 3.3%). An association between less severe haze measurements and higher reproducibility scores was found (r = .42; P = .007). The mean interanalyzer variation was smaller for the average of four measurements, 0.55 +/- 0.37 gray levels, than for one measurement, 0.94 +/- 0.73 gray levels (P = .014). CONCLUSIONS Good reproducibility for haze measurements by digital image analysis of the differences between the treated and adjacent untreated corneal areas was obtained. When the average of four measurements was used instead of a single measurement, interanalyzer reproducibility increased significantly. This new technique may be used to quantify and analyze corneal haze after myopic photorefractive keratectomy.

Digital System Measurement of Decentration of Worst-Fechner Iris Claw Myopia Intraocular Lens

BACKGROUND Topography measures the centration in refractive and corneal refractive surgery, but until recently there was no effective method to measure decentration in intraocular lens (IOL) implantation. PATIENTS AND METHODS We measured the decentration of 22 phakic eyes, in 14 high myopic patients, based upon photographs of the anterior segment using a digital analysis system (IMAGEnet Topcon Corporation 1988, Tokyo, Japan). These eyes had undergone IOL implantation for the correction of myopia with Worst-Fechner iris claw lenses. Decentration was measured with respect to the centers of both the cornea and pupil. RESULTS Mean decentration of the IOL center from the cornea center was 0.51 +/- 0.25 mm (range, 0 to 0.8374 mm). When measured with respect to the center of the pupil, the average decentration was 0.47 +/- 0.29 mm (range, 0.182 to 0.9341 mm). A positive correlation between the decentration measurements of the two methods was found (p < .01 indicated statistical significance). CONCLUSIONS This digital imaging system (IMAGEnet) accurately measured decentration of IOLs in myopic eyes.