David J. Tanzer

Phakic Intraocular Lens Implantation for the Correction of Myopia: A Report by the American Academy of Ophthalmology

OBJECTIVE To review the published literature for evaluation of the safety and outcomes of phakic intraocular lens (pIOL) implantation for the correction of myopia and myopic astigmatism. METHODS Literature searches of the PubMed and Cochrane Library databases were conducted on October 7, 2007, and July 14, 2008. The PubMed search was limited to the English language; the Cochrane Library was searched without language limitations. The searches retrieved 261 references. Of these, panel members chose 85 papers that they considered to be of high or medium clinical relevance to this assessment. The panel methodologist rated the articles according to the strength of evidence. RESULTS Two pIOLs have been approved by the US Food and Drug Administration (FDA): one iris-fixated pIOL and one posterior-chamber IOL. In FDA trials of iris-fixated pIOLs, uncorrected visual acuity (UCVA) was >or=20/40 in 84% and >or=20/20 in 31% after 3 years. In FDA trials of posterior-chamber pIOLs, UCVA was >or=20/40 in 81% and >or=20/20 in 41%. Satisfaction with the quality of vision with both types of pIOLs was generally high. Toric anterior- and posterior-chamber pIOLs have shown improved clinical results in European trials compared with spherical pIOLs. Comparative studies showed pIOLs to provide better best spectacle-corrected visual acuity (BSCVA) and refractive predictability and stability compared with LASIK and photorefractive keratectomy and to have a lower risk of retinal detachment compared with refractive lens exchange. Reported complications and long-term safety concerns include endothelial cell loss, cataract formation, secondary glaucoma (pupillary block, pigment dispersion), iris atrophy (pupil ovalization), and traumatic dislocation. CONCLUSIONS Phakic IOL implantation is effective in the correction of myopia and myopic astigmatism. In cases of high myopia of -8 diopters or more, pIOLs may provide a better visual outcome than keratorefractive surgeries and better safety than refractive lens exchange. The short-term rates of complications and loss of BSCVA are acceptable. Comprehensive preoperative evaluation and long-term postoperative follow-up examinations are needed to monitor for and prevent serious complications, and to establish long-term safety.

Pupil size and quality of vision after LASIK.

PURPOSE To evaluate factors related to the quality of vision after LASIK. DESIGN Survey study. PARTICIPANTS One hundred consecutive patients. INTERVENTION LASIK with a 6.0-mm elliptical ablation pattern without transition zone to treat mild to moderate myopia or astigmatism (preoperative manifest spherical equivalent [MSE], -4.79 +/- 1.33 diopters [D]; range, -2.88 to -9.25 D). The second eye was treated 1 month after the first. MAIN OUTCOME MEASURES Completed questionnaires assessing night vision problems (glare, haze, and halo symptoms) before surgery and at 1, 3, and 6 months after surgery in 97, 75, 81, and 66 subjects, respectively. Mesopic pupil size and preoperative and postoperative variables were analyzed with questionnaire data using an analysis of variance (ANOVA) and multivariate regression analysis. RESULTS Patients with large mesopic pupils had significantly more reports of glare, haze, and halo than did those with smaller pupils in the treated eye at 1 month after surgery (P=0.02, P=0.03, and P=0.02, respectively ANOVA) and of glare at 3 months (P=0.05). Significant predictors of symptoms at 6 months, identified through multivariate regression analysis, included preoperative MSE (for glare and haze), preoperative contrast acuity (glare), postoperative uncorrected visual acuity (UCVA; haze), and residual cylinder (haze). Together, these factors accounted for only 19% of the overall variability in glare and 37% of the variability in haze responses. No relationship between pupils and symptoms was noted at 6 months after surgery in either the ANOVA or regression analysis group. CONCLUSIONS Patients with large pupils had more quality of vision symptoms in the early postoperative period, but no correlation was observed 6 months after surgery. Factors related to long-term symptoms include the level of treatment (preoperative myopia), preoperative contrast acuity, postoperative UCVA, and residual cylinder. Most of the variability in visual quality could not be explained by preoperative or clinical outcome measures, including pupil size.

Wavefront-Guided LASIK for the Correction of Primary Myopia and Astigmatism A Report by the American Academy of Ophthalmology

OBJECTIVE To describe wavefront-guided (WFG) LASIK for the primary treatment of low to moderate levels of myopia and astigmatism and to examine the evidence on the safety and effectiveness of the procedure in comparison with conventional LASIK. METHODS Literature searches conducted in 2004, 2005, 2006, and 2007 retrieved 209 unique references from the PubMed and Cochrane Library databases. The panel selected 65 articles to review, and of these, chose 45 articles that they considered to be of sufficient clinical relevance to submit to the panel methodologist for review. During the review and preparation of this assessment, an additional 2 articles were included. A level I rating was assigned to properly conducted, well-designed, randomized clinical trials; a level II rating was assigned to well-designed cohort and case-controlled studies; and a level III rating was assigned to case series, case reports, and poorly designed prospective and retrospective studies. In addition, studies that were conducted by laser manufacturers before device approval (premarket approval) were reviewed as a separate category of evidence. RESULTS The assessment describes studies reporting results of WFG LASIK clinical trials, comparative trials, or both of WFG and conventional LASIK that were rated level II and level III. There were no studies rated as level I evidence. Four premarket approval studies conducted by 4 laser manufacturers were included in the assessment. The assessment did not compare study results or laser platforms because there were many variables, including the amount of follow-up, the use of different microkeratomes, and the level of preoperative myopia and astigmatism. CONCLUSIONS There is substantial level II and level III evidence that WFG LASIK is safe and effective for the correction of primary myopia or primary myopia and astigmatism and that there is a high level of patient satisfaction. Microkeratome and flap-related complications are not common but can occur with WFG LASIK, just as with conventional LASIK. The WFG procedure seems to have similar or better refractive accuracy and uncorrected visual acuity outcomes compared with conventional LASIK. Likewise, there is evidence of improved contrast sensitivity and fewer visual symptoms, such as glare and halos at night, compared with conventional LASIK. Even though the procedure is designed to measure and treat both lower- and higher-order aberrations (HOAs), the latter are generally increased after WFG LASIK. The reasons for the increase in HOA are likely multifactorial, but the increase typically is less than that induced by conventional LASIK. No long-term assessment of WFG LASIK was possible because of the relatively short follow-up (12 months or fewer) of most of the studies reviewed.

Randomized Prospective Comparison of Visian Toric Implantable Collamer Lens and Conventional Photorefractive Keratectomy for Moderate to High Myopic Astigmatism

PURPOSE To compare the Visian Toric Implantable Collamer Lens (TICL), a toric phakic intraocular lens (IOL), and photorefractive keratectomy (PRK) in the correction of moderate to high myopic astigmatism. METHODS This prospective, randomized study consisted of 43 eyes implanted with the TICL (20 bilateral cases) and 45 eyes receiving PRK with mitomycin C (22 bilateral cases) with moderate to high myopia (-6.00 to -20.00 diopters [D] sphere) measured at the spectacle plane and 1.00 to 4.00 D of astigmatism. All patient treatment and follow-up occurred at the Naval Medical Center San Diego. Study follow-up was 1 day, 1 week, 1, 3, 6, and 12 months postoperative. RESULTS Mean best spectacle-corrected visual acuity (BSCVA), change in BSCVA, proportion of cases with improvement of 1 or more lines of BSCVA, proportion of cases with BSCVA and uncorrected visual acuity (UCVA) 20/12.5 or better, proportion of cases with BSCVA and UCVA 20/16 or better (6 months, 88% vs 54%, P=.002), and predictability +/-1.00 D (6 months, 100% vs 67%, P<.001) were all significantly better in the TICL group than the PRK group at all time periods studied postoperatively. Similarly, contrast sensitivity, tested at both the 5% photopic level and the 25% mesopic level, was significantly better at all postoperative time points in the TICL group. Mean spherical equivalent refraction was closer to emmetropia (0.28+/-0.41 vs 0.76+/-0.86, P=.005), and predictability +/-0.50 D and stability of manifest refraction (+/-0.50 D and +/-1.00 D) were significantly better in the TICL group at all postoperative visits through 6 months. Mean astigmatism correction at 6 months was not significantly different between the two groups (0.52+/-0.33 vs 0.46+/-0.35, P=.450). CONCLUSIONS The TICL performed better than PRK in all measures of safety (BSCVA), efficacy (UCVA), predictability, and stability in this comparison, supporting the TICL as a viable alternative to existing refractive surgical treatments.

Masked comparison of silicone hydrogel lotrafilcon A and etafilcon A extended-wear bandage contact lenses after photorefractive keratectomy

Purpose: To compare the efficacy of 2 types of bandage contact lenses (BCLs) after photorefractive keratectomy (PRK). Setting: Navy Refractive Surgery Center, Naval Medical Center San Diego, San Diego, California, USA. Methods: In this prospective study, 100 patients received PRK in both eyes. Each patient received a BCL composed of etafilcon A (Acuvue [ACV], Vistakon Inc.) (14.0 diameter, 8.4/8.8 base curve) in 1 eye and lotrafilcon A (Focus Night & Day [N&D], Ciba Vision) (13.8 diameter, 8.4/8.6 base curve) in the fellow eye. The patient was masked to the lens type in each eye. The postoperative medication regimen was the same with both lenses. The epithelial defect size and subjective level of discomfort were measured at surgery and daily after surgery until both eyes had reepithelialized and the lenses were removed. Results: The mean epithelial defect size at surgery was similar with both BCLs (ACV 57.07 mm2 and N&D 57.53 mm2; P = .422). On postoperative days 1 and 2, the mean defect size was significantly smaller in eyes with the N&D lens (day 1, ACV 21.53 and N&D 18.74; day 2, ACV 3.62 and N&D 2.12) (paired t test, P<.001). On day 1, no eye had completely reepithelialized; on day 2, 20 eyes with N&D lenses and 13 eyes with ACV lenses had. On day 3, 70 eyes with N&D lenses and 66 eyes with ACV lenses had reepithelialized. The mean discomfort index was significantly higher in the eyes with ACV lenses on days 1 and 2 (paired t test, P<.001 and P<.002, respectively). Topical nonpreserved tetracaine was used significantly more often in eyes with ACV lenses on days 1, 2, and 3 (paired t test, P<.001, P<.008, P<.003, respectively). No correlation between the use of tetracaine in the first 24 hours and the rate of reepithelialization was noted (R2 = 0.0025 for ACV and R2 = 0.0003 for N&D). Conclusion: The lotrafilcon A lens resulted in significantly faster corneal reepithelialization and reduced patient discomfort in most patients during the first 48 hours after PRK.

Laser refractive surgery in the United States Navy.

Purpose of review The aim of this article is to highlight the numerous contributions the US Navy has made to the field of laser refractive surgery. It summarizes and draws together published papers, national meeting presentations, and unpublished data of clinical and laboratory studies involving the excimer laser and the laser-assisted in-situ keratomileusis (LASIK) flap. Recent findings Photorefractive keratectomy (PRK) is the most widely performed refractive procedure in the US Navy, but this trend is slowly changing as femtosecond laser-assisted LASIK becomes more widely performed. Based on the results of recent studies, PRK is approved for designated Naval aviators and flight officers; post-PRK students are now allowed into flight training. Wavefront-guided PRK and LASIK are more predictable and provided better results than conventional PRK and LASIK. Femtosecond laser-assisted LASIK is now a waiverable procedure for US military personnel and US Astronauts (excluding Naval aviators, as of this writing). Summary Since its personnel must meet strict visual requirements to accomplish their mission in a variety of environments, the US Navy places particular emphasis on safety and quality of vision after laser refractive surgery. The US Navy has been evaluating the safety and efficacy of laser refractive surgery since 1993 and will continue to do so.

Laser in situ keratomileusis in United States Naval aviators.

Purpose To evaluate the safety and efficacy of femtosecond‐assisted wavefront‐guided laser in situ keratomileusis (LASIK) as well as higher‐order aberrometric changes in a population of active‐duty United States Naval aviators. Setting Navy Refractive Surgery Centers, San Diego, California, and Portsmouth, Virginia, USA. Design Prospective noncomparative 2‐site study. Methods In this study of femtosecond‐assisted wavefront‐guided LASIK, 3 groups were differentiated according to the refractive status: myopia, mixed astigmatism, and hyperopia. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, mesopic low‐contrast CDVA, higher‐order aberrations (HOAs), and patient satisfaction were evaluated during a 3‐month follow‐up. Results The study enrolled, treated, and included for analysis 548 eyes with myopia, 60 eyes with mixed astigmatism, and 25 eyes with hyperopia. The UDVA was 20/20 or better in 98.3% of eyes with myopia and mixed astigmatism at all postoperative visits and in 95.7% of hyperopic eyes 3 months postoperatively. The gain in CDVA was 1 or more lines in 39.2%, 41.1%, and 30.4% of myopic, mixed astigmatic and hyperopic eyes, respectively. Loss of 2 lines of CDVA after surgery occurred in 2 myopic eyes (0.4%). At 3 months, a mean change of +0.03 &mgr;m ± 0.10 (SD) and +0.05 ± 0.08 &mgr;m was observed in higher‐order root mean square and primary spherical aberration, respectively. Of the patients, 95.9% said they believed that LASIK had helped their effectiveness as Naval aviators and 99.6% would recommend the same treatment to others. Conclusion Femtosecond‐assisted wavefront‐guided LASIK was an efficacious and safe option for refractive correction in Naval aviators, enabling a quick return to flight status. Financial Disclosure Drs. Tanzer and Schallhorn are consultants to Abbott Medical Optics, Inc. No author has a financial or proprietary interest in any material or method mentioned.

Role of depressive symptoms in patient satisfaction with visual quality after laser in situ keratomileusis.

PURPOSE: To assess the role of depressive symptoms in patient satisfaction with visual quality after laser in situ keratomileusis (LASIK). SETTING: Navy Refractive Surgery Center, Ophthalmology Department, Naval Medical Center, San Diego, California, USA. METHODS: This was a prospective study of active‐duty military patients having bilateral conventional LASIK to treat low to moderate myopia with or without astigmatism. Patients completed the Armstrong Laboratory Personality Survey Depression scale preoperatively. Patients were also given a 10‐point Navy questionnaire that included an assessment of patient satisfaction with visual quality at the 1‐ and 6‐month follow‐up examinations. Patients were stratified by their visual quality rating after LASIK as highly satisfied, satisfied, and less satisfied and by their depression scale score into low, medium, and high groups. A proportional odds model was developed to compare the visual quality rating between the 3 depression groups 1 and 6 months post LASIK. RESULTS: The study comprised 370 patients. An uncorrected visual acuity of at least 20/20 was achieved in 88.6% of eyes. Patients with higher levels of depressive symptoms had 3.0 times higher odds (95% confidence interval [CI], 1.2 to 7.4) of being less satisfied than those with low levels of depressive symptoms 1 month after LASIK (P≤.02) and 2.5 times higher odds (95% CI, 1.0 to 6.5) of being less satisfied at 6 months (P≤.06). CONCLUSION: Preoperative depressive symptoms were a significant contributor to patient satisfaction with visual quality after LASIK.

Stability of the laser in situ keratomileusis corneal flap in rabbit eyes

PURPOSE: To quantify the force required to dislodge a laser in situ keratomileusis (LASIK) corneal flap in rabbits and correlate that force with sources of injury to LASIK corneal flaps in humans. SETTING: Animal Vivarium and Department of Ophthalmology, Naval Medical Center, San Diego, California, USA. METHODS: Corneal flaps were cut in 56 eyes of 30 rabbits. A −8.00 diopter excimer ablation was also performed in 32 of the eyes. Injury testing, using a burst of CO2 from a modified paintball gun, was conducted from 1 to 9 days postoperatively. Impact force was compared to that generated by mechanical trauma (fingers and a small tree branch) striking a force gauge. RESULTS: Of 43 eyes tested for injury, flaps could not be dislocated in 11 eyes (26%). There was no significant difference between eyes treated with flap only and those that also had ablation. When flaps were dislodged, the required force generally resulted in extensive intraocular injury. There was no significant difference between the force required for flap dislocation on postoperative days 1 and 9. CONCLUSIONS: In rabbits, LASIK corneal flaps were very resistant to high‐speed wind trauma as early as 24 hours postoperatively. Flap stability was robust prior to the formation of collagen scar tissue, probably due to epithelial bridging at the edge of the flap and an osmotic gradient across the flap–stromal bed interface. Although this study used a rabbit model, it seems likely that both these flap adhesion mechanisms would also provide stability to the LASIK flap in humans.

Topical cyclosporine A for postoperative photorefractive keratectomy and laser in situ keratomileusis

Purpose To compare the stability and predictability of the refractive outcomes in eyes treated with photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) with and without postoperative use of topical cyclosporine A emulsion. Setting Naval Medical Center San Diego Refractive Surgery Center, San Diego, California, USA. Design Randomized clinical trial. Methods Patients had PRK or LASIK and were randomized, pairwise, to a standard postoperative treatment regimen with or without the addition of topical cyclosporine A 0.05% emulsion twice daily for 3 months postoperatively. Visual acuity, mesopic contrast acuity, refractions, and ocular symptoms were assessed through the 3‐month examination. Tear‐film samples (cytokines and chemokines) were analyzed preoperatively and 1 week and 1 and 3 months postoperatively. Results The PRK group comprised 70 patients and the LASIK group, 54 patients. The addition of topical cyclosporine A twice a day after PRK or LASIK did not confer special benefits in terms of achievement of target refraction, final uncorrected distance visual acuity (UDVA), or rate of visual recovery (all P>.05, multivariate analysis of variance [MANOVA]). There was no significant difference in tear‐film composition based on measurement of matrix metalloproteinase‐9, interleukin (IL)‐6, or IL‐8 recovery (all P>.05, MANOVA). Conclusion The addition of topical cyclosporine A twice daily for 3 months after PRK or LASIK did not provide a significant benefit in the rate of visual recovery, final UDVA, or patient symptoms, nor did it significantly change measured inflammatory mediators (cytokines) present in the tear film. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.