A review of small incision lenticule extraction complications.

PURPOSE OF REVIEW: As a flapless procedure, SMILE brings benefits to refractive surgery, such as lower corneal biomechanical impact, less dry eye risk and less stromal bed exposure. However, the longer learning curve can be a risk factor for complications. This article aims to discuss SMILE complications and proposes a categorized analysis of occurrences, dividing into two groups: intraoperative and postoperative complications. Among intraoperative, we also suggest a subdivision between those related to the laser (lenticule construction), tissue separation (lenticule dissection) and tissue removal (lenticule extraction). RECENT FINDINGS: The majority of SMILE complications are related to surgeon inexperience and reversible if precociously diagnosed and correctly managed. Intraoperative complications related to lenticule creation such as suction loss, opaque bubble layer and black spots, are correlated with later difficulties during lenticule dissection and removal, and may lead to unwanted situations, such as cap perforation, lenticule tear and cap-lenticule adhesion. Postoperative complications as dry eye, keratitis and ectasia should not be underestimated. SUMMARY: Analyzing what has been reported as major or unique among the complications with SMILE, and dividing them into subgroups, we aim to help refractive surgeons in becoming familiar with the things that can go wrong during SMILE. Early recognition and correct management will be fundamental for optimizing the final visual result.

Role of percent tissue altered on ectasia after LASIK in eyes with suspicious topography.

PURPOSE: To investigate the association of the percent tissue altered (PTA) with the occurrence of ectasia after LASIK in eyes with suspicious preoperative corneal topography. METHODS: This retrospective comparative case-control study compared associations of reported ectasia risk factors in 129 eyes, including 57 eyes with suspicious preoperative Placido-based corneal topography that developed ectasia after LASIK (suspect ectasia group), 32 eyes with suspicious topography that remained stable for at least 3 years after LASIK (suspect control group), and 30 eyes that developed ectasia with bilateral normal topography (normal topography ectasia group). Groups were subdivided based on topographic asymmetry into high- or low-suspect groups. The PTA, preoperative central corneal thickness (CCT), residual stromal bed (RSB), and age (years) were evaluated in univariate and multivariate analyses. RESULTS: Average PTA values for normal topography ectasia (45), low-suspect ectasia (39), high-suspect ectasia (36), low-suspect control (32), and high-suspect control (29) were significantly different from one another in all comparisons (P < .003) except high- and low-suspect ectasia groups (P = .033), and presented the highest discriminative capability of all variables evaluated. Age was only significantly different between the high-suspect ectasia and normal topography ectasia groups, and CCT was not significantly different between any groups. Stepwise logistic regression revealed the PTA as the most significant independent variable (P < .0001), with RSB the next most significant parameter. CONCLUSIONS: There remains a significant correlation between PTA values and ectasia risk after LASIK, even in eyes with suspicious corneal topography. Less tissue alteration, or a lower PTA value, was necessary to induce ectasia in eyes with more remarkable signs of topographic abnormality, and PTA provided better discriminative capabilities than RSB for all study populations.

Interface blood as a new indication for flap lift after LASIK using the WaveLight FS200 femtosecond laser.

PURPOSE: To report a new indication for flap lift of interface blood using the WaveLight FS200 femtosecond laser (Alcon Laboratories, Inc., Fort Worth, TX). METHODS: The unique evacuation canal of the FS200 femtosecond laser allows blood from injured limbal vasculature to accumulate. In rare instances, blood extends from the canal into the flap interface, requiring a flap lift. All flap lifts were performed using the microscope in the laser suite on the FS200 femtosecond laser to remove postoperative flap interface blood in 3 eyes of 3 patients. RESULTS: All interface blood was removed and no patients experienced re-bleeding. Postoperatively, patients achieved an uncorrected visual acuity of 20/20. CONCLUSIONS: When intracanal blood is noted, planned incomplete dissection of the flap to the canal edge may prevent the progression of blood in the interface.

First proposed efficacy study of high versus standard irradiance and fractionated riboflavin/ultraviolet a cross-linking with equivalent energy exposure.

PURPOSE: To document the first presented report in December 2008 of high irradiance riboflavin/ultraviolet A (UVA) corneal cross-linking in comparison with that of standard irradiance and of fractionated exposure to increase the time for oxygen diffusion into the cornea. METHODS: After in vitro studies of oxygen depletion and cross-linking density using type 1 human collagen gels, 36 ex vivo porcine globes were deepithelialized and exposed to 0.1% riboflavin drops in carboxymethylcellulose solution every 5 min for 3 initial doses and then throughout irradiation afterward. Six eyes each were irradiated with 370-nm UVA light at 2, 3, 9, and 15 mW/cm continuously and 15 mW/cm fractionated (with alternate cycles of 30 s "ON" and 30 s "OFF" exposure) using an equivalent radiant exposure of 5.4 mJ/cm. The final six eyes received no UVA exposure as a control. The exposed corneas were then dissected and subjected to extensiometry. Analysis of variance with Bonferroni post hoc test was performed between groups. RESULTS: The stress required to induce a 10% strain for the control eyes (no UVA) was 100.6±20.9×10 N/m in comparison with the stress of 3 mW/cm (standard irradiation) at 146.7±17.6×10 N/m (P=0.009). The stress at the other equidose irradiances of 2, 9, 15 continuously, and 15 mW/cm fractionated were 140±21.9, 162.8±70, 154.1±70, and 163.0±64×10 N/m, respectively. When comparing the irradiances of 15 mW/cm continuously and fractionated to the standard irradiation, the stress was not statistically different (P=0.799 and 0.643), respectively. CONCLUSION: High irradiance riboflavin/UVA cross-linking with equivalent energy exposure demonstrates comparable efficacy in stiffening corneal collagen with standard irradiance, but with considerably less exposure time. Over the past 6 years, since this report was first presented, the use of high irradiance cross-linking has been gaining popularity.

Corneal higher order aberrations after myopic wavefront-optimized ablation.

PURPOSE: To analyze the induced corneal higher order aberrations (HOAs) after wavefront-optimized ablation. METHODS: Sixty-four myopic eyes that underwent wavefront-optimized myopic LASIK were divided into three groups based on spherical equivalent (SE): low myopia group (23 eyes with SE <-3.00 diopters [D]); moderate myopia group (27 eyes with SE between -3.00 and -6.00 D); and high myopia group (14 eyes with SE >-6.00 D). Total corneal HOA, corneal spherical aberrations, corneal coma through a 6-mm pupil size, and corneal eccentricity were measured with a dual Scheimpflug imaging device preoperatively and 3 months after surgery. RESULTS: An overall increase in total corneal HOA was observed with a mean of 0.18±0.18 µm (P<.01), although this induction was not statistically significant in the low myopic group with a mean of 0.006±0.15 µm (P=.85). Root-mean-square spherical aberration varied the most after myopic ablation, with an overall induction of positive spherical aberration of 0.27±0.25 µm (P<.001). CONCLUSIONS: Although the wavefront-optimized profile was designed to preserve the preoperative HOAs of the total eye, a significant induction of the corneal HOAs after myopic treatment was observed. The magnitude of the induced corneal HOA was related to the amount of intended correction. Corneal wavefront profiles do not reflect the visual performance; however, they provide relevant information, which may help in optimizing new laser treatment algorithms.

Influence of the reference surface shape for discriminating between normal corneas, subclinical keratoconus, and keratoconus.

PURPOSE: To compare the discriminating ability of corneal elevation generated by a dual Scheimpflug analyzer calculated with different reference surfaces for distinguishing normal corneas from those with keratoconus and subclinical keratoconus. METHODS: A total of 391 eyes of 208 patients were prospectively enrolled in the study and divided into three groups: 167 eyes of 113 patients with keratoconus, 47 contralateral topographically normal eyes of patients with clinically evident keratoconus in the fellow eye, and 177 eyes of 95 refractive surgery candidates with normal corneas. All eyes were measured with a dual Scheimpflug analyzer (GALILEI Analyzer; Ziemer Ophthalmic Systems AG, Port, Switzerland). Maximum elevation values were recorded within the central 5-mm diameter in both anterior and posterior elevation maps. Discriminating ability of corneal elevation measurements obtained by best-fit toric and aspheric (BFTA) and best-fit sphere (BFS) reference surfaces were compared by receiver operator characteristic (ROC) curves. RESULTS: ROC curve analysis showed that corneal elevation measured by BFTA had a significantly better ability than with BFS for distinguishing normal corneas from those with keratoconus and forme fruste keratoconus (P = .01). Posterior elevation measured by BFTA had a significantly higher predictive accuracy for forme fruste keratoconus than anterior elevation with an area under ROC curves of 0.88 and 0.80, respectively (P = .01). The sensitivity and specificity achieved with the maximum posterior elevation for detecting keratoconus and forme fruste keratoconus were 99% and 99% for keratoconus and 82% and 80% for forme fruste keratoconus with the cut-off value at 16 and 13 µm, respectively. CONCLUSIONS: The ability to discriminate between normal cornea and forme fruste keratoconus with elevation parameters was significantly improved by using BFTA instead of BFS reference surface.

Intraoperative, real-time aberrometry during refractive cataract surgery with a sequentially shifting wavefront device.

PURPOSE: To introduce a new sequential wavefront device with rapid sampling that can be used as an intraoperative, real-time aberrometer/refractometer for immediate diagnosis and management of refractive outcomes during cataract surgery. METHODS: A unique wavefront device uses a rotating prismatic mirror to rapidly shift the incident wavefront emanating from the eye through an aperture for analysis of a sequentially sampled wavefront segment. The sampled segment is then focused onto a quad detector that localizes its angular displacement of the sampled segment's wavefront gradient. Although the device's capability is higher for other applications, the wavefront is herein rapidly sampled at 200 Hz (frames/second), with a 2-mm aperture that moves along a 5-mm outer diameter annulus to capture a real-time analysis of refractive error for intraoperative application (ie, an intraoperative wavefront movie). The prototype wavefront device has been miniaturized into a narrow profile attachment that can be fixed to an operating microscope. In pilot analysis, several eyes undergoing cataract surgery were analyzed to determine both the qualitative and quantitative change in refraction with surgical intervention in an effort to document and improve outcomes intraoperatively. RESULTS: Clinical application of the device was easily implemented without changing or limiting the working distance, magnification, or illumination of the surgeon's ergonomics intraoperatively. The real-time wavefront outcome was visualized overlaying a live eye image, presenting the refractive error both qualitatively and quantitatively. Qualitative representation of spherical refractive error was seen as a circle, cylinder as a thin ellipse, and emmetropia as a dot. Localization of lower-order aberrations with a practical sample rate of 200 frames/ second enables a real-time visualization of qualitative refractive data coaxially aligned with the eye image and quantitatively as sphere, cylinder, and axis at the bottom of the screen. Practical evaluation of residual cylinder prior to and during limbal relaxing incision placement, rotational accuracy during toric intraocular lens alignment, and refractive effect of subtle surgical maneuvers were all achieved with this device. CONCLUSION: Real-time, intraoperative refraction and visualization is possible with a new sequential wavefront device attached to the operating microscope. The precision and accuracy of intraoperative documentation and refinement of outcomes is likely to be enhanced, making this an important future tool for optimizing cataract surgery outcomes.

Comparison of keratometric changes after myopic ablation: ray tracing versus simulated keratometry.

PURPOSE: To compare the changes in corneal power (ΔK) induced by myopic ablations estimated by Placido-disk and total corneal power (TCP) ray tracing methods to the refractive change (ΔSE). METHODS: Manifest refraction, simulated keratometry from a Placido-disk based system, and TCP from a dual-Scheimpflug analyzer were obtained from 35 patients (58 eyes) before and 3 months after a myopic ablation. The change in the manifest refraction that occurred after surgery was then vertex distance corrected and compared to the changes observed in corneal power with the various systems analyzed. RESULTS: The Placido-based simulated keratometry overestimated the corneal power after the procedure by 0.50 ± 0.53 diopters (D) when compared to refractive change in the corneal plane induced by the laser surgery (ΔSE-ΔK). The ray tracing method showed the opposite trend, with the TCP simulated keratometry showing an underestimation of the corneal power of -0.25 ± 0.48 D. The Placido system showed a direct correlation between the overestimation of the corneal power and the level of myopia, whereas the ray tracing method showed an underestimation, which was more pronounced in higher levels of myopia. CONCLUSIONS: Ray tracing methods underestimate corneal power as opposed to the overestimation in corneal power after refractive surgery, directly related to the level of myopia, observed in Placido-based systems. They have the potential to overcome the errors in calculations based on anterior curvature alone. However, ray tracing methods need to be validated and optimized before it can be used routinely in IOL calculation.

The association between femtosecond laser flap parameters and ocular aberrations after uncomplicated custom myopic LASIK.

BACKGROUND: To investigate the association between femtosecond laser flap parameters, uncorrected distance visual acuity, and higher-order aberrations (HOA) after customized myopic LASIK. METHODS: Retrospective review of the charts of patients who underwent uncomplicated wavefront-guided customized myopic LASIK with flap creation using the femtosecond laser. Patients were stratified by intended flap thickness, and the change in HOA from preoperative to 3 months postoperative was compared. Multivariate linear models were performed to assess the association between calculated flap thickness, intended flap diameter, HOA, and uncorrected visual acuity. RESULTS: One hundred seventy-one eyes of 171 patients were included. There was no statistically significant difference in the induction of HOA between eyes with thin (90 µm) or thick (100 or 110 µm) intended flaps. In a multivariate model, the level of myopic correction was highly associated with the induction of total HOA, coma, and spherical aberration. There was no correlation between calculated flap thickness, uncorrected visual acuity, or HOAs. Intended flap diameter was not associated with coma or spherical aberration, but larger flap diameter was associated with better uncorrected visual acuity. CONCLUSIONS: Femtosecond laser flap thickness in the range of 90-110 µm was not associated with uncorrected visual acuity or the induction of HOA after uncomplicated customized myopic LASIK. The level of myopic correction was the largest determinant of the induction of HOA.

Hydralazine Revives Cellular and Ocular Lens Health-Span by Ameliorating the Aging and Oxidative-Dependent Loss of the Nrf2-Activated Cellular Stress Response.

A major hallmark of aging-associated diseases is the inability to evoke cellular defense responses. Transcriptional protein Nrf2 (nuclear factor erythroid-derived 2-related factor) plays a pivotal role in the oxidative stress response, cellular homeostasis, and health span. Nrf2's activation has been identified as a therapeutic target to restore antioxidant defense in aging. Here, we demonstrated that FDA-approved drug, hydralazine (Hyd), was a reactivator of the Nrf2/ARE (antioxidant response element) pathway in various ages and types of mouse (m) or human (h) lens epithelial cells (LECs) and mice lenses in-vitro/in-vivo. This led to Hyd-driven abatement of carbonyls, reduced reactive oxygen species (ROS), and reduced 4-HNE/MDA-adducts with cytoprotection, and extended lens healthspan by delaying/preventing lens opacity against aging/oxidative stress. We elucidated that Hyd activated the protective signaling by inducing Nrf2 to traverse from the cytoplasm to the nucleus and potentiated the ARE response by direct interaction of Nrf2 and ARE sequences of the promoter. Loss-of-function study and cotreatment of Hyd and antioxidant, N-acetyl cysteine (NAC) or Peroxiredoxin (Prdx)6, specified that Nrf2/ARE-driven increase in the promoter activity was Hyd-dependent. Our study provides proof-of concept evidence and, thereby, paves the way to repurposing Hyd as a therapeutic agent to delay/prevent aging and oxidative-related disorders.

Vision health perspectives on Breaking Bad: Ophthalmic sequelae of methamphetamine use disorder.

Methamphetamine use has become a rampant public health issue that not only causes devastating consequences to the user but also poses a burden to surrounding communities. A spectrum of ophthalmic sequelae is associated with methamphetamine use and includes episcleritis, scleritis, corneal ulceration, panophthalmitis, endophthalmitis, retinal vasculitis, and retinopathy. In many instances, prompt recognition of the condition and associated infectious process and early initiation of antimicrobial therapy are crucial steps to preventing vision loss. In this review, we summarize the reported ocular complications that may result from methamphetamine use in addition to several postulated mechanisms regarding the ocular toxicity of methamphetamine. The increasing prevalence of methamphetamine use as a public health threat highlights the need for continued investigation of this ophthalmologic issue.

Optimized Artificial Intelligence for Enhanced Ectasia Detection Using Scheimpflug-Based Corneal Tomography and Biomechanical Data.

PURPOSE: To optimize artificial intelligence (AI) algorithms to integrate Scheimpflug-based corneal tomography and biomechanics to enhance ectasia detection. DESIGN: Multicenter cross-sectional case-control retrospective study. METHODS: A total of 3886 unoperated eyes from 3412 patients had Pentacam and Corvis ST (Oculus Optikgeräte GmbH) examinations. The database included 1 eye randomly selected from 1680 normal patients (N) and from 1181 "bilateral" keratoconus (KC) patients, along with 551 normal topography eyes from patients with very asymmetric ectasia (VAE-NT), and their 474 unoperated ectatic (VAE-E) eyes. The current TBIv1 (tomographic-biomechanical index) was tested, and an optimized AI algorithm was developed for augmenting accuracy. RESULTS: The area under the receiver operating characteristic curve (AUC) of the TBIv1 for discriminating clinical ectasia (KC and VAE-E) was 0.999 (98.5% sensitivity; 98.6% specificity [cutoff: 0.5]), and for VAE-NT, 0.899 (76% sensitivity; 89.1% specificity [cutoff: 0.29]). A novel random forest algorithm (TBIv2), developed with 18 features in 156 trees using 10-fold cross-validation, had a significantly higher AUC (0.945; DeLong, P < .0001) for detecting VAE-NT (84.4% sensitivity and 90.1% specificity; cutoff: 0.43; DeLong, P < .0001) and a similar AUC for clinical ectasia (0.999; DeLong, P = .818; 98.7% sensitivity; 99.2% specificity [cutoff: 0.8]). Considering all cases, the TBIv2 had a higher AUC (0.985) than TBIv1 (0.974; DeLong, P < .0001). CONCLUSIONS: AI optimization to integrate Scheimpflug-based corneal tomography and biomechanical assessments augments accuracy for ectasia detection, characterizing ectasia susceptibility in the diverse VAE-NT group. Some patients with VAE may have true unilateral ectasia. Machine learning considering additional data, including epithelial thickness or other parameters from multimodal refractive imaging, will continuously enhance accuracy. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Optimized femto-LASIK maintains preexisting spherical aberration independent of refractive error.

PURPOSE: To report the visual outcomes and change in spherical aberration in the first cohort of eyes treated at the Cole Eye Institute using the FS200 laser (Alcon Laboratories Inc). METHODS: A chart review was performed on 100 eyes targeted for emmetropia with wavefront-optimized femto-LASIK using the WaveLight Allegretto Wave Eye-Q (Alcon Laboratories Inc) and FS200 lasers. Patients were subdivided into low (< -3.00 D, n = 23), moderate (-3.00 to -6.00 D, n = 45), and high myopia (> -6.00 D, n = 2). Pre- and 3- to 9-month postoperative wavefront aberrometry and uncorrected distance visual acuity (UDVA) were compared. RESULTS: An increase was found in spherical aberration of 0.03 +/- 0.02 microm (P = .14) for low myopia, but decreases were found of 0.01 +/- 0.01 microm (P = .45) for moderate myopia and 0.02 +/- 0.04 microm (P = .48) for high myopia. An increase in coma was noted of 0.02 +/- 0.02 microm (P = .37), 0.04 +/- 0.02 microm (P = .02), and 0.11 +/- 0.04 microm (P = .01) for low, moderate, and high myopes, respectively. An increase was found in total higher order aberrations of 0.05 +/- 0.04 microm (P = .17), 0.04 +/- 0.01 microm (P = .01), and 0.11-0.03 microm (P = .01) for low, moderate, and high myopes, respectively. Uncorrected distance visual acuity of 20/15 and 20/20 was achieved in 70% and 91% of low myopes, 58% and 93% of moderate myopes, and 34% and 78% of high myopes, respectively. CONCLUSIONS: Wavefront-optimized femto-LASIK with the WaveLight Allegretto Wave Eye-Q and FS200 lasers achieved excellent postoperative UDVA outcomes, with no significant induction of spherical aberration at all refractive errors.

Wavefront ablation profiles in refractive surgery: description, results, and limitations.

PURPOSE: To provide an overview of the clinical results of different ablation profiles based on wavefront technology and discuss their characteristics and limitations. METHODS: Literature review of studies reporting results of ablation profiles based on wavefront technology in virgin healthy eyes. RESULTS: Over the past 10 years, a large number of studies comparing different treatment algorithms and newer excimer laser platforms have been published. Thirty-six clinical studies including 3637 eyes analyzing the clinical results obtained after wavefront-guided, wavefront-optimized, and Q-factor profiles have been reviewed. Although wavefront-driven profiles allowed reduction of the amount of induced optical aberrations with conventional ablations, thereby improving the quality of vision, it appears that no algorithm of treatment or excimer laser platform has demonstrated a clear superiority over another. Wound healing and unexpected biomechanical response to surgery affect the accuracy of customized treatments and produce variable results. In addition, it is difficult to rigorously analyze and compare findings among different studies because of the diverse variety in which the data are reported. CONCLUSIONS: Despite several technological improvements over the years, wavefront ablation profiles have not consistently demonstrated superiority in terms of visual acuity and lower order aberrations compared to the standard procedure, although the induction of higher order aberrations has been reduced. The concept of an individualized eye model has emerged recently, based on the optical ray tracing algorithm, and could theoretically provide a higher level of customization, thus fulfilling the promise of "super vision."

The Dynamic History of the Ophthalmology Residency Matching Program.

Background The ophthalmology residency matching program is the first successful medical specialty match, dating back to 1979. This article reviews the impetus for starting the match and the roles that ophthalmologists Bruce Spivey, MD, and August Colenbrander, MD, PhD, played in establishing the match and developing the machinery to make it possible. Challenges to the match's operations over the years have improved the process. Objective This article aims to research the roles of key individuals and institutions in establishing and maintaining the ophthalmology residency matching program. Methods Oral and written interviews with key participants in establishing and maintaining the match were conducted. Primary and secondary written materials were reviewed. Results Two physicians played key roles in establishing the ophthalmology residency matching program. Bruce Spivey, MD, spearheaded the drive to persuade the Association of University Professors of Ophthalmology (AUPO) to support and sponsor the match. August Colenbrander, MD, PhD, created the original match algorithm and single-handedly ran the match process in the early years. Obstacles were overcome, including resistance from the Association of American Medical College's National Resident Matching Program, a challenge to the validity of the algorithm, and the threat that antitrust laws might prohibit all graduate medical education residency match programs. The ophthalmology match evolved over time to become a more formal entity, the San Francisco Matching Program (SF Match). With continued support of the AUPO, the process of matching applicants to residency programs has flourished despite contemporary challenges related to electronic applications and social media. Conclusion The ophthalmology residency matching program has benefited applicants and teaching programs for more than four decades due to visionary founders, ongoing support of the AUPO, and strong leadership within SF Match.

Ophthalmic complications associated with methamphetamine use disorder.

Purpose: To describe the devastating ophthalmic sequelae of methamphetamine use disorder in two patients who developed vision loss from ocular complications, including keratitis and endophthalmitis. Observations: Case 1 is a 26-year-old male with hepatitis C, poorly controlled type 1 diabetes, and chronic methamphetamine use who presented with a corneal ulcer in the left eye. Corneal culture grew Staphylococcus aureus and Streptococcus viridans, prompting antibiotic therapy. Follow-up exam showed peripheral corneal ulceration OD and diffusely vascularized and scarred cornea OS, although nonadherence was reported. Vision eventually worsened to hand motions OD and light perception OS.Case 2 is a 44-year-old woman with hepatitis C, acute myeloid leukemia, dry eye syndrome secondary to chronic graft-versus-host disease (GVHD), and chronic methamphetamine use who presented with a diffuse corneal infiltrate and hypopyon. She underwent emergent corneal transplantation, vitrectomy, and broad-spectrum intravitreal and intravenous antibiotics. Vitreous cultures were positive for Streptococcus pyogenes. However, progressive disease eventually required enucleation despite initial globe salvaging measures. Conclusions and importance: These two patient cases highlight the risk of vision loss or blindness due to the detrimental effects of chronic methamphetamine use on the eye, including the potential for keratitis and endophthalmitis. Given the increasing prevalence of methamphetamine use disorder in the United States, further understanding of these toxicities and preventive strategies are needed.

Stability of simultaneous topography-guided photorefractive keratectomy and riboflavin/UVA cross-linking for progressive keratoconus: case reports.

PURPOSE: To follow the stability of a simultaneously delivered therapy that corrects aberrations and stiffens the corneal collagen of eyes with progressive keratoconus. METHODS: Two patients with progressive keratoconus underwent partial treatment (70% cylinder and sphere up to 50-µm central depth) with topographic customized photorefractive keratectomy (PRK) using the T-CAT module of the ALLEGRETTO WAVE Eye-Q excimer laser (Alcon Laboratories Inc), and then immediate corneal collagen cross-linking (CXL) with riboflavin 0.1% drops every 2 minutes while exposed to mean 365-nm ultraviolet A (UVA) light at 3.0 mW/cm² for 30 minutes (the Athens Protocol). Pre- and postoperative evaluations included manifest and cycloplegic refraction, Scheimpflug corneal tomography and pachymetry, and slit-lamp examination of corneal clarity with a minimum follow-up of 30 months. RESULTS: Both treated eyes experienced rapid healing of the epithelial surface within 5 days and progressive improvement of vision. In the first case, partial treatment reduced the astigmatism and aberrations, allowing for successful soft contact lens wear at 3 months. Follow-up at 13, 19, 30, and 36 months showed progressive reduction of refractive myopia and keratometric power. In the second case, laser treatment led to a near emmetropic refraction with an uncorrected visual acuity of 20/20 at 3 months, which remained unchanged at 21 and 30 months postoperative. CONCLUSIONS: Partial topography-guided PRK followed by riboflavin/UVA CXL is a safe and effective therapy that halts the progression of keratoectasia and reduces the spherocylindrical refraction and aberrations to improve the visual function of patients with progressive keratoconus. Stability and progressive improvement over time is observed, although limitations may exist for steeper and thinner corneas.

Enhanced visual acuity and image perception following correction of highly aberrated eyes using an adaptive optics visual simulator.

PURPOSE: To evaluate the changes in visual acuity and visual perception generated by correcting higher order aberrations in highly aberrated eyes using a large-stroke adaptive optics visual simulator. METHODS: A crx1 Adaptive Optics Visual Simulator (Imagine Eyes) was used to correct and modify the wavefront aberrations in 12 keratoconic eyes and 8 symptomatic postoperative refractive surgery (LASIK) eyes. After measuring ocular aberrations, the device was programmed to compensate for the eye's wavefront error from the second order to the fifth order (6-mm pupil). Visual acuity was assessed through the adaptive optics system using computer-generated ETDRS opto-types and the Freiburg Visual Acuity and Contrast Test. RESULTS: Mean higher order aberration root-mean-square (RMS) errors in the keratoconus and symptomatic LASIK eyes were 1.88+/-0.99 microm and 1.62+/-0.79 microm (6-mm pupil), respectively. The visual simulator correction of the higher order aberrations present in the keratoconus eyes improved their visual acuity by a mean of 2 lines when compared to their best spherocylinder correction (mean decimal visual acuity with spherocylindrical correction was 0.31+/-0.18 and improved to 0.44+/-0.23 with higher order aberration correction). In the symptomatic LASIK eyes, the mean decimal visual acuity with spherocylindrical correction improved from 0.54+/-0.16 to 0.71+/-0.13 with higher order aberration correction. The visual perception of ETDRS letters was improved when correcting higher order aberrations. CONCLUSIONS: The adaptive optics visual simulator can effectively measure and compensate for higher order aberrations (second to fifth order), which are associated with diminished visual acuity and perception in highly aberrated eyes. The adaptive optics technology may be of clinical benefit when counseling patients with highly aberrated eyes regarding their maximum subjective potential for vision correction.

Transitioning to optimized correction with the WaveLight ALLEGRETTO WAVE: case distribution, visual outcomes, and wavefront aberrations.

PURPOSE: To describe the outcomes of the first 285 eyes receiving LASIK or photorefractive keratectomy (PRK) using an optimized ablation profile at a refractive surgery practice experienced with customized ablation. METHODS: A retrospective chart review was performed on all patients who underwent refractive treatments using the ALLEGRETTO WAVE Eye-Q platform (Alcon Laboratories Inc) between September 2008 and July 2009. Patients were divided into LASIK and PRK treatments, then further subdivided based on pre- and targeted postoperative refraction. Pre- and postoperative measures of uncorrected distance visual acuity (UDVA), corrected distance visual acuity, manifest refraction, keratometry, and wavefront values were taken and compared, and the average changes in keratometry and higher order aberrations were calculated. RESULTS: At 3 months postoperative, 92% of myopes and 63% of hyperopes undergoing LASIK with a target of emmetropia achieved UDVA of 20/20. Of PRK eyes targeted for emmetropia, 80% of myopic eyes achieved UDVA of 20/20 (the hyperopic subgroup was too small to analyze). In both LASIK and PRK subgroups, total wavefront aberrations decreased, as did some higher order aberrations. CONCLUSIONS: This group of patients, who all achieved excellent postoperative UDVA, represents our initial surgical experience with the ALLEGRETTO WAVE, using only a standard (global surgeon) nomogram. These results may serve as an estimate of what a practice could expect in terms of initial outcomes with this system.