Michael R. Deitz

Implantable contact lens for moderate to high myopia: Phase 1 FDA clinical study with 6 month follow-up

Purpose: To assess the short‐term safety and efficacy of the implantable contact lens (ICL™) to treat, moderate to high myopia, Setting: Phase 1 U.S. Food and Drug Administration clinical study of the ICL conducted at four sites in the United States. Methods: Ten patients with myopia of 7,00 diopters (D) or greater had implantation of a Staar Surgical ICL and were examined preoperatively (baseline) and 1 day, 1 week, and 1, 3, and 6 months postoperatively. Mean preoperative myopia was 7.75 D (range 7.25 to 9.37 D): Results: Six months postoperatively, 5 of 10 eyes (50%) had an uncorrected visual acuity (UCVA) of 20/20 or better, and all eyes had a UCVA of 20/30 or better. All eyes had a best spectacle‐corrected visual acuity (BSCVA), of 20/20 or better and 6 eyes (60%), of 20/15 or better. Six eyes (60%) had an improvement of one or more lines of BSCVA. Mean postoperative spherical equivalent was −0.025 D ± 0.47 (SD). Eight eyes (80%) were within ±0.250 D of emmetropia, and all were within ±1.125 D. No intraoperative or postoperative complications or adverse reactions were observed. Conclusions: The results support the short‐term safety, efficacy; and predictability of ICL implantation to treat moderate to high myopia.

Photorefractive keratectomy for low-to-moderate myopia and astigmatism with a small-beam, tracker-directed excimer laser.

OBJECTIVE To assess the safety and effectiveness of the Autonomous Technologies Corporation LADARVision excimer laser system for photorefractive keratectomy correction of myopia and astigmatism. DESIGN A multicenter, prospective, noncomparative case series. PARTICIPANTS The cohort consisted of 467 eyes corrected for spherical myopia and 211 eyes corrected for myopia with astigmatism. INTERVENTION Treatments were performed at six sites in the United States using a 6-mm ablation zone for spherical myopes and a 5.5-mm zone with a 1.0-mm blend for astigmats. MAIN OUTCOME MEASURES Visual acuity, subjective refraction, corneal haze, intraocular pressure, complications, adverse reactions, patient satisfaction, and corneal endothelial changes. RESULTS Twelve-month follow-up was available on 414 spherical eyes and 175 astigmatic eyes. The results for spherical eyes with correction between -1 and -5.99 diopters (D) were: uncorrected visual acuity (UCVA) of 20/40 or better achieved by 98.1%, 20/20 or better by 72%, 1.8% lost 2 lines and 0.3% lost greater than 2 lines of best spectacle-corrected visual acuity (BSCVA); 76.4% were within 0.50 D of the target correction and 94.4% were within 1.00 D. The results for myopia with astigmatism with spherical equivalent correction between -1 and -5.99 D were: UCVA of 20/40 or better in 97.4%, 20/20 or better in 61.7%, 2.5% lost 2 lines and no eyes lost greater than 2 lines BSCVA; 73.9% were within 0.50 D of the target correction and 95% were within 1.00 D. For spherical myopes combined with myopic astigmats corrected for 6 to 10 D, results were: UCVA of 20/40 or better in 93.4%, 20/20 or better in 61.2%, 2.3% lost 2 lines and no eyes lost greater than 2 lines of BSCVA; 67.2% were within 0.50 D of the desired correction and 87.8% were within 1.00 D. Refractive stability was achieved between 3 and 6 months for the spherical and astigmatic groups. No eyes had corneal haze graded as moderate or greater, and there was no significant decrease in endothelial cell density. CONCLUSIONS Patients treated for 1 to 10 D of spherical equivalent myopia, with or without astigmatism, showed early refractive stability, excellent UCVA, no significant loss of BSCVA, no loss of endothelial cell density, and very low levels of corneal haze to 12 months after surgery.

Progressive Hyperopia in Radial Keratotomy: Long-Term Follow-Up of Diamond-Knife and Metal-Blade Series

In an earlier report, the authors demonstrated a trend toward progressive hyperopia in radial keratotomy (RK) patients examined between one and three to four years postoperatively. In those 109 cases, the surgeries were performed using a metal-blade instrument. In the following study, the metal-blade series was updated to a total of 225 procedures, and a more recent series of 300 procedures performed on 228 patients was examined in which a diamond-knife cutting instrument was used. Patients had uncorrected visual acuity determination, cycloplegic refractions with best corrected visual acuity measurements and keratometry measurements. The authors demonstrated a hyperopic shift in the distribution of postoperative spherical equivalent (SE) values across time such that higher proportions of cases in both metal-blade and diamond-knife series were at least 1.0 diopter (D) away from emmetropia at 24 and 48 months than was the case at 12 months after surgery. Regression analysis determined that none of the preoperative or surgical variables known to affect refractive outcome of RK (alone or in combination) could account for the changes in refraction seen during the course of postoperative time. In general, changes in keratometry paralleled refractive changes, but were somewhat smaller in magnitude.

Posterior Chamber Phakic Intraocular Lens For Hyperopia

PURPOSE A Phase I U.S. FDA clinical study of a plate haptic posterior chamber phakic intraocular lens (STAAR Surgical Implantable Contact Lens) for treatment of hyperopia was conducted at 4 sites in the United States. The purpose of this report is to assess the short-term safety and efficacy. METHODS Ten patients with hyperopia between +2.50 and +10.875 D were implanted in one eye each with the posterior chamber plate phakic intraocular lens and were examined at baseline and 1 day, 1 week, 1, 3, and 6 months after surgery. Mean baseline hyperopia was +6.63 D. RESULTS At 6 months postoperatively, 7 of 10 eyes (70%) had an uncorrected visual acuity of 20/20 or better and 10 of 10 (100%) had 20/40 or better. Eight of ten eyes (80%) had a spectacle-corrected visual acuity within 1 line of baseline; the other two eyes (20%) had an improvement of 3 lines. Mean 6-month postoperative spherical equivalent refraction was +0.20 +/- 0.61D (range, -0.50 to +1.50 D), a reduction of 6.025 D from baseline. Eight of 10 eyes (80%) were within +/-0.50 D of emmetropia, 9 eyes (90%) were within +/-1.00 D, and all eyes (100%) were within +/-1.50 D. No operative or postoperative complications or adverse reactions were observed. CONCLUSIONS Results support the short-term safety, efficacy, and predictability of the STAAR Surgical Implantable Contact Lens (plate haptic posterior chamber phakic intraocular lens) in the treatment of hyperopia.

Factors Affecting Predictability of Radial Keratotomy

A major criticism of radial keratotomy (RK) has been its lack of predictability, a lack due in large measure to the use of simple correlational statistics assessing the relationship between refractive result and each predictor-variable being evaluated separately. This report utilizes multivariate analysis in an attempt to account for the effects of a number of predictor-variables simultaneously. Variables studied are patient age, optical zone size, number of incisions, mean incision depth, preoperative average keratometry, preoperative average applanation tension, patient sex, and age-sex interrelationship. The area of the optical clear zone selected by the surgeon was found to be the most important factor determining refractive change as a result of RK, explaining one-quarter to one-half of the variability of the procedure. The effects of the other factors and the limitations of the method are discussed. Although this method cannot produce a fully predictive equation, we believe this analysis can serve as a good starting point for beginning RK surgeons and a method by which experienced RK surgeons can improve their techniques.

A Consecutive Series (1982-1985) of Radial Keratotomies Performed with the Diamond Blade

The refractive and visual results of a consecutive series of diamond knife radial keratotomy procedures were evaluated at one year after surgery as part of an ongoing prospective study of radial keratotomy. Of the 972 procedures performed, 656 eyes (67.5%) were examined one year or more after surgery. The average amount of preoperative myopia was 4.4 diopters with a range of 0.6 to 11.9 diopters; 638 (97%) of the eyes had a preoperative uncorrected visual acuity of 20/100 or worse. The mean change in spherical equivalent after one year was 4.5 diopters. One year after surgery, 496 (76%) of the eyes were within 1 diopter of emmetropia; 310 (47%) had uncorrected distance visual acuity of 20/20 or better, 579 (88%) were 20/40 or better, and all but one eye had uncorrected visual acuity improved by at least two Snellen lines. Evaluation of refractive and visual results at the final available examination of those eyes not examined one year after surgery showed that 256 (81%) of the eyes were within 1 diopter of emmetropia; 176 (56%) had uncorrected distance visual acuity of 20/20 or better, and 287 (91%) were 20/40 or better.

Five and three year follow-up of photorefractive keratectomy for myopia of -1 to -6 diopters.

BACKGROUND To report the 5 and 3 year results of photorefractive keratectomy for -1 to -6 D of myopia and less than 1.50 D astigmatism. METHODS All eyes were treated with a VISX 20/20 excimer laser with an ablation diameter of 5 mm. Our initial series of 133 eyes were treated in four groups: IIA, IIB, III and III No Nitrogen and reported on previously with follow-up from 6 to 36 months. The present report extends the observation period to 3 and 5 years for 114 eyes. RESULTS Groups IIA and IIB were followed for 5 years and Groups III and III No Nitrogen for 3 years. Group IIA achieved 77% (10 of 13 eyes) +/-1.00 D (54% within +/-0.50 D) of emmetropia with stability from 6 months and 54% (seven of 13 eyes) had visual acuity of 20/20 or better. In Group IIB, 35% (six of 17 eyes) were +/-1.00 D (18% within +/-0.50 D) of emmetropia and stable from 18 months. Two of 17 eyes (12%) had 20/20 or better visual acuity. Group III had 76% (42 of 55 eyes) within +/-1.00 D (51% within +/-0.50 D) of emmetropia with stability after 12 months; 60% (33 of 55 eyes) had 20/20 or better visual acuity. Group III No Nitrogen had 73% (11 of 15 eyes) within +/-1.00 D (60% within +/-0.50 D) of emmetropia and were stable after 6 months; 47% (seven of 15 eyes) had 20/20 or better visual acuity. There was no hyperopic refractive shift. No correlation was found between the percent of correction achieved and preoperative amount of myopia, age, or sex. CONCLUSION Refractive stability was achieved from 6 to 12 months in most eyes; a few required 18 months to stabilize. Groups IIA and III continued to be stable; Groups HB and III No Nitrogen showed mild regression that was not statistically significant.