Ayad A. Farjo

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.

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.

Central lamellar keratoplasty for optical indications

PURPOSE This study aims to evaluate the results of lamellar keratoplasty (LKP) for optical (nontectonic) indications over the past 19 years at our institution, noting the advantages and pitfalls of the procedure. METHODS The study is a retrospective review of 52 central LKPs in 37 patients. Snellen visual acuity, preoperative clinical indications, and postoperative status of the cornea (donor graft, graft-host interface, and recipient cornea) were assessed. RESULTS Postoperative follow-up ranged from 3 months to 18 years (median, 3 years). In descending order of frequency, corneal dystrophies, aniridic keratopathy, corneal scars, and keratoconus were the most common indications for surgery. After surgery, 38% of the eyes were able to achieve 20/50 or better visual acuity. The two most common causes of poor visual acuity were (1) opacification and/or blood vessel growth in the graft-host interface or on the graft surface and (2) high astigmatism. Persistent epithelial defects occurred in 21% of the eyes after LKP. CONCLUSION Although LKP provides a safer alternative to penetrating keratoplasty, it is limited by vision-reducing graft-host interface problems, astigmatism, and difficult surgical technique. We postulate that the current results of LKP may be improved by (1) removing as much recipient corneal stroma as possible (e.g., dissecting down to Descemets membrane) or, alternatively, using an automated microkeratome and (2) raising the currently used qualitative eyebank standards for accepting LKP donor tissue.

Femtosecond Lasers for LASIK Flap Creation: A Report by the American Academy of Ophthalmology

OBJECTIVE To review the published literature to assess the safety, efficacy, and predictability of femtosecond lasers for the creation of corneal flaps for LASIK; to assess the reported outcomes of LASIK when femtosecond lasers are used to create corneal flaps; and to compare the differences in outcomes between femtosecond lasers and mechanical microkeratomes. METHODS Literature searches of the PubMed and Cochrane Library databases were last conducted on October 12, 2011, without language or date limitations. The searches retrieved a total of 636 references. Of these, panel members selected 58 articles that they considered to be of high or medium clinical relevance, and the panel methodologist rated each article according to the strength of evidence. Four studies were rated as level I evidence, 14 studies were rated as level II evidence, and the remaining studies were rated as level III evidence. RESULTS The majority of published studies evaluated a single laser platform. Flap reproducibility varied by device and the generation of the device. Standard deviations in flap thicknesses ranged from 4 to 18.4 μm. Visual acuities and complications reported with LASIK flaps created using femtosecond lasers are within Food and Drug Administration safety and efficacy limits. Of all complications, diffuse lamellar keratitis is the most common after surgery but is generally mild and self-limited. Corneal sensation was reported to normalize by 1 year after surgery. Unique complications of femtosecond lasers included transient light-sensitivity syndrome, rainbow glare, opaque bubble layer, epithelial breakthrough of gas bubbles, and gas bubbles within the anterior chamber. CONCLUSIONS Available evidence (levels I and II) indicates that femtosecond lasers are efficacious devices for creating LASIK flaps, with accompanying good visual results. Overall, femtosecond lasers were found to be as good as or better than mechanical microkeratomes for creating LASIK flaps. There are unique complications that can occur with femtosecond lasers, and long-term follow-up is needed to evaluate the technology fully.

Lamellar corneal patch grafts in the management of corneal melting

Purpose. To evaluate the clinical indications and results of reconstructive (tectonic) lamellar keratoplasty in corneal melting. Methods. A nonrandomized, uncontrolled retrospective case series of 64 consecutive patients (80 eyes) who underwent lamellar keratoplasty for corneal melting at our institution over a 17-year period. We reviewed the (a) clinical indications, (b) visual acuities, (c) postoperative corneal clarity, and (d) postoperative complications. Comparisons in visual acuity were made between central and peripheral corneal melts. The statistical influence of patient age, diagnosis, and corneal graft size on pre-and postoperative visual acuity values also was studied. Results. Although reconstructive lamellar keratoplasty for active corneal melting was effective in saving the integrity of the globes in all but four patients, the postoperative visual acuity remained poor in the majority of cases because of the often devastating nature of the underlying ocular diseases. Only 14 patients had best postoperative visual acuities of 20/100 or better. Repeated lamellar keratoplasties were necessitated by corneal opacification, infection, or progressive postoperative corneal dissolution in 14 cases. Subsequent vision-restoring surgeries, consisting of penetrating keratoplasties or cataract extractions, were done in 11 eyes with modest improvement of visual acuity. Postoperative visual acuity was significantly better in peripheral corneal melts than in central melts (p = 0.004). Conclusion. Lamellar keratoplasty is an effective method of restoring the integrity of the eye ravaged by corneal melting. It is less invasive and consequently safer than penetrating keratoplasty in actively inflamed and unstable eyes. The primary purpose for this surgery is to salvage the integrity of the globe during the acute phase of disease and not so much to achieve visual improvement per se. It allows time for systemic immunosuppression to take effect and for the eye to quiet down before possible future vision-restoring surgery.

Salzmann's Nodular Corneal Degeneration Clinical Characteristics and Surgical Outcomes

Purpose: To characterize the clinical characteristics and surgical outcomes for Salzmanns nodular corneal degeneration (SNCD). Methods: In this retrospective, noncomparative, observational case series, all patients coded with a diagnosis of SNCD between January 1, 1996, and April 30, 2002 were included. Cases whose clinical description did not match the classic description of this disorder were excluded. Clinical characteristics, surgical procedures, and qualitative outcomes were recorded. Results: Among 103 patients diagnosed with SNCD, 93 (152 eyes) met inclusion criteria. Eighty-three patients (89.2%) were women (P < 0.00001), and 59 patients (63.4%) had bilateral disease. A normal age distribution was noted, with a mean age of 54.3 years (median, 53 years; standard deviation = 16.9). Meibomian gland dysfunction was noted in 51 patients (54.8%), contact lens wear in 31 patients (33.3%), peripheral vascularization in 29 patients (31.2%), pterygium in 15 patients (16.1%), keratoconjunctivitis sicca in 9 patients (9.7%), and exposure keratitis in 4 patients (4.3%). Forty-nine eyes (32.2%) of 37 patients (39.8%) required a total of 62 surgical procedures. Impaired vision led to 53 (85.5%) of these procedures and resulted in improved vision in 42 (79.2%) of these cases. Seven eyes (4.6%) underwent surgical intervention for subjective discomfort or contact lens intolerance, and all had improved symptoms at last follow-up. Conclusions: SNCD appears to be a disorder that occurs predominantly in middle-aged women and may be associated with chronic ocular surface inflammation and/or irritation. It is important to diagnose properly because of the good prognosis with medical and surgical therapy.

Femtosecond Lasers for LASIK Flap Creation

OBJECTIVE To review the published literature to assess the safety, efficacy, and predictability of femtosecond lasers for the creation of corneal flaps for LASIK; to assess the reported outcomes of LASIK when femtosecond lasers are used to create corneal flaps; and to compare the differences in outcomes between femtosecond lasers and mechanical microkeratomes. METHODS Literature searches of the PubMed and Cochrane Library databases were last conducted on October 12, 2011, without language or date limitations. The searches retrieved a total of 636 references. Of these, panel members selected 58 articles that they considered to be of high or medium clinical relevance, and the panel methodologist rated each article according to the strength of evidence. Four studies were rated as level I evidence, 14 studies were rated as level II evidence, and the remaining studies were rated as level III evidence. RESULTS The majority of published studies evaluated a single laser platform. Flap reproducibility varied by device and the generation of the device. Standard deviations in flap thicknesses ranged from 4 to 18.4 μm. Visual acuities and complications reported with LASIK flaps created using femtosecond lasers are within Food and Drug Administration safety and efficacy limits. Of all complications, diffuse lamellar keratitis is the most common after surgery but is generally mild and self-limited. Corneal sensation was reported to normalize by 1 year after surgery. Unique complications of femtosecond lasers included transient light-sensitivity syndrome, rainbow glare, opaque bubble layer, epithelial breakthrough of gas bubbles, and gas bubbles within the anterior chamber. CONCLUSIONS Available evidence (levels I and II) indicates that femtosecond lasers are efficacious devices for creating LASIK flaps, with accompanying good visual results. Overall, femtosecond lasers were found to be as good as or better than mechanical microkeratomes for creating LASIK flaps. There are unique complications that can occur with femtosecond lasers, and long-term follow-up is needed to evaluate the technology fully.

Mitomycin-C in Corneal Surface Excimer Laser Ablation Techniques: A Report by the American Academy of Ophthalmology

OBJECTIVE To review the published literature assessing the efficacy and safety of mitomycin-C (MMC) as an adjunctive treatment in corneal surface excimer laser ablation procedures. METHODS Literature searches of the PubMed and Cochrane Library databases were last conducted on August 19, 2014, without language or date limitations. The searches retrieved a total of 239 references. Of these, members of the Ophthalmic Technology Assessment Committee Refractive Management/Intervention Panel selected 26 articles that were considered to be of high or medium clinical relevance, and the panel methodologist rated each article according to the strength of evidence. Ten studies were rated as level I evidence, 5 studies were rated as level II evidence, and the remaining 11 studies were rated as level III evidence. RESULTS The majority of the articles surveyed in this report support the role of MMC as an adjunctive treatment in surface ablation procedures. When MMC is applied in the appropriate concentration and confined to the central cornea, the incidence of post-surface ablation haze is decreased. Although a minority of studies that evaluated endothelial cell density (ECD) reported an MMC-related decrease in ECD, no clinical adverse outcomes were reported. CONCLUSIONS Over the past 15 years, the use of MMC during surgery in surface ablation has become widespread. There is good evidence of the effectiveness of MMC when used intraoperatively as prophylaxis against haze in higher myopic ablations. Although there are reports of decreased endothelial counts after the administration of MMC during surgery, the clinical significance of this finding remains uncertain, because no adverse outcomes were reported with as much as 5 years of follow-up. Optimal dosage, effectiveness as prophylaxis in lower myopic and hyperopic ablations, and long-term safety, particularly in eyes with reduced corneal endothelial cell counts from prior intraocular surgery, have yet to be established.

Scytalidium keratitis: case report in a human eye.

Purpose: To describe the presentation and treatment of a case of an atypical reticular corneal infiltrate with surrounding immune-like ring in a young woman caused by Scytalidium fungal species. Methods: Interventional case report describing the clinical appearance, course, and treatment of Scytalidium keratitis. Results: A 21-year-old female equestrian with a history of soft contact lens wear was noted to have persistent keratitis and photophobia of the right eye after an injury with a volleyball. Although initially culture negative and responsive to topical steroids, the keratitis persisted, and repeat corneal scrapings and cultures revealed Scytalidium species. Treatment with topical amphotericin B 0.15% and oral fluconazole 200 mg twice daily eradicated the infection, and the patient had a final best-corrected visual acuity of 20/20. Conclusion: Scytalidium species fungal organisms can cause an indolent keratitis. Intensive oral and topical antifungal therapy was successful in eradicating the infection.

Online-only articleFemtosecond Lasers for LASIK Flap Creation: A Report by the American Academy of Ophthalmology

OBJECTIVE To review the published literature to assess the safety, efficacy, and predictability of femtosecond lasers for the creation of corneal flaps for LASIK; to assess the reported outcomes of LASIK when femtosecond lasers are used to create corneal flaps; and to compare the differences in outcomes between femtosecond lasers and mechanical microkeratomes. METHODS Literature searches of the PubMed and Cochrane Library databases were last conducted on October 12, 2011, without language or date limitations. The searches retrieved a total of 636 references. Of these, panel members selected 58 articles that they considered to be of high or medium clinical relevance, and the panel methodologist rated each article according to the strength of evidence. Four studies were rated as level I evidence, 14 studies were rated as level II evidence, and the remaining studies were rated as level III evidence. RESULTS The majority of published studies evaluated a single laser platform. Flap reproducibility varied by device and the generation of the device. Standard deviations in flap thicknesses ranged from 4 to 18.4 μm. Visual acuities and complications reported with LASIK flaps created using femtosecond lasers are within Food and Drug Administration safety and efficacy limits. Of all complications, diffuse lamellar keratitis is the most common after surgery but is generally mild and self-limited. Corneal sensation was reported to normalize by 1 year after surgery. Unique complications of femtosecond lasers included transient light-sensitivity syndrome, rainbow glare, opaque bubble layer, epithelial breakthrough of gas bubbles, and gas bubbles within the anterior chamber. CONCLUSIONS Available evidence (levels I and II) indicates that femtosecond lasers are efficacious devices for creating LASIK flaps, with accompanying good visual results. Overall, femtosecond lasers were found to be as good as or better than mechanical microkeratomes for creating LASIK flaps. There are unique complications that can occur with femtosecond lasers, and long-term follow-up is needed to evaluate the technology fully.