Alejandro Lichtinger

Accelerated (9-mW/cm2) corneal collagen crosslinking for keratoconus-A 1-year follow-up.

Purpose: The aim of this study was to assess the efficacy of accelerated crosslinking (irradiance of 9 mW/cm2; 10 minutes) in keratoconus-affected eyes through topographical, visual, and refractive end points. Methods: Mild-moderate keratoconus-affected eyes that underwent accelerated corneal collagen crosslinking (CXL) treatment and had 6 and 12 months of follow-up were reviewed retrospectively. Data regarding uncorrected distance visual acuity (UDVA), manifest refraction, corrected distance visual acuity (CDVA), and computerized corneal topography data before surgery and post-CXL treatment were extracted and analyzed. Results: Sixteen eyes of 14 patients were included in the study. The mean patient age was 24.9 ± 5.8 years (range: 17.1–38.3 years). No statistically significant changes were found in the mean CDVA, mean refractive cylinder, or mean manifest refraction spherical equivalent at either time point. There was a gain of 0.13 logarithm of the minimum angle of resolution lines in the mean UDVA (P = 0.012) at 12 months. All corneal parameters including Ksteep, Kflat, average K (Km), corneal astigmatism (Kcyl), and maximal curvature reading at the corneal apex (Kmax) were stable at 6 and 12 months in all patients. No complications were observed during the follow-up period. Conclusions: Accelerated corneal CXL is effective in stabilizing topographic parameters after 12 months of follow-up in mild-moderate keratoconus-affected corneas. Improvement in the UDVA and stabilization of all tested corneal parameters were noted after the treatment. However, a longer follow-up with larger cohorts is necessary to validate these findings.

Intraocular lenses for presbyopia correction: past, present, and future.

Purpose of review To discuss the development of presbyopia-correcting intraocular lenses (IOLs), what we have learned since their introduction a few decades ago, what are the options currently on the market, and where the technology is heading in the future. Recent findings Multifocal and accommodating IOLs have gone through several modifications to improve distance, intermediate and near vision compared to their predecessors. These modifications have also targeted unwanted side-effects such as glare and halos in the multifocal lenses and inconsistent near-vision results in the accommodating IOLs and although the results have improved, they are far from perfect. Therefore, careful patient selection for each of these technologies is crucial for success and patient satisfaction. Summary Presbyopia correction remains a great challenge in cataract and refractive surgery. In this article, we review the development of presbyopia-correcting IOLs, starting from the simple, two-zone, multifocal, refractive models introduced 2 decades ago, the current Food and Drug Administration (FDA) approved multifocal and accommodating lenses as well as those undergoing FDA trials and take a look into developing technologies that may be available to us in the future.

Outcomes of Descemet stripping automated endothelial keratoplasty in patients with previous glaucoma drainage device insertion.

Purpose: To report the outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) in patients with a previously inserted glaucoma drainage device (GDD). Methods: The clinical records of patients who had DSAEK surgery with a history of GDD insertion were reviewed. Results: Eleven eyes of 10 patients (7 men and 3 women) were included. The mean age for DSAEK surgery was 67.2 ± 20.4 years (range, 22–93 years). The mean follow-up after DSAEK surgery was 20.2 ± 10.7 months (range, 3–37 months). Preoperative mean logarithm of the minimum angle of resolution (logMAR)–corrected distance visual acuity was 1.8 ± 0.6 (range, 20/100 to hand motions), and this improved to 0.9 ± 0.8 (range, 20/40 to hand motions) at the final follow-up (P < 0.01). There was no statistical difference in mean pre-DSAEK versus final post-DSAEK intraocular pressure (P = 0.88). Six of 11 eyes (54.5%) had double GDD insertion before DSAEK surgery. GDD tubes were trimmed in 6 eyes (54.5%), and no eyes required further glaucoma surgical intervention after DSAEK surgery. Postoperative complications included early postoperative graft dislocation in 4 eyes (36.4%) that were successfully repositioned. Four eyes (36.4%) had an episode of endothelial rejection, with 2 patients (18.2%) requiring repeat endothelial keratoplasty for endothelial failure. The mean donor endothelial cell count was 2740 cell per square millimeter preoperatively and reduced to 858 cells per square millimeter at the final follow-up, a significant mean reduction of 69%. This was significantly greater than previously reported endothelial cell loss after DSAEK alone at our institution. Conclusions: Although surgery may be more challenging, the presence of GDD is not a contraindication to DSAEK surgery. In this series, there was a high rate of dislocation that was successfully managed with rebubbling. DSAEK seems to be a reasonable alternative to penetrating keratoplasty for corneal decompensation after GDD.

Corneal collagen cross-linking using riboflavin and ultraviolet A for the treatment of mild to moderate keratoconus: 2-year follow-up

OBJECTIVE To evaluate the safety and efficacy of corneal ultraviolet A/riboflavin collagen cross-linking (CXL) in patients with mild-to-moderate keratoconus. DESIGN Retrospective cohort study. PARTICIPANTS Thirty-nine eyes from 30 patients who underwent CXL for progressive mild and moderate keratoconus were included. METHODS Clinical charts for keratoconus patients who had undergone CXL alone from November 2008 to February 2011 were reviewed for preoperative and postoperative uncorrected and best corrected distance visual acuity (UDVA and BDVA, respectively), manifest refraction, topographical and Scheimpflug imaging, as well as ultrasound pachymetry and haze. Mean and steepest keratometry, central corneal thickness, and root mean-square from corneal aberrations were extracted from the topography. Central and thinnest corneal thicknesses were extracted from the Scheimpflug imaging RESULTS A significant improvement in UDVA was seen at 3, 6 and 24 months with an average change in logMAR of 0.39 (p = 0.003) at 24 months compared with baseline. Change in BDVA failed to reach significance, but subgroup analysis showed that a baseline BDVA worse than 0.1 logMAR was associated with better improvement. Stability of refraction, keratometry, and aberrations was demonstrated. Presence of haze was statistically significant up to 12 months (p≤0.001), being maximal at 3 months, then insignificant by 24 months. No complications were observed during the follow-up period. CONCLUSIONS CXL is a safe and effective stabilizing strategy for progressive mild-to-moderate keratoconus with significant improvement of the UDVA. There was a trend toward improvement of BDVA in patients with lower preoperative BDVA value.

Combined use of subconjunctival and intracorneal bevacizumab injection for corneal neovascularization.

Purpose: To report on the safety and clinical use of combined subconjunctival and intracorneal bevacizumab for corneal neovascularization. Methods: The charts of 12 consecutive patients with corneal neovascularization who received combined subconjunctival and intracorneal injections of bevacizumab (2.5 mg/0.1 mL) were reviewed. Patients received 1 to 3 injections of 2.5 mg of bevacizumab (1.25 mg/0.05 mL subconjunctival and 1.25 mg/0.05 mL intrastromal). Morphological changes were assessed clinically by 1 investigator. Results: Combined subconjunctival and intracorneal injections of bevacizumab were effective and well-tolerated. No significant ocular or systemic adverse events were observed during 6.4 months (range, 0.25-22 months) of follow-up. All patients showed a reduction in the neovascularized area. Conclusions: Short-term results suggest that combined subconjunctival and intracorneal injections of bevacizumab are an effective method for reducing corneal neovascularization. It may be a useful option or adjunct to other treatments in stabilizing or improving vision.

Gabapentin for Postoperative Pain After Photorefractive Keratectomy: A Prospective, Randomized, Double-blind, Placebo-controlled Trial

PURPOSE To determine whether treatment with oral gabapentin reduces postoperative pain after photorefractive keratectomy (PRK). METHODS This prospective, randomized, double-blind, placebo-controlled study comprised 40 patients scheduled for bilateral PRK. Exclusion criteria were previous refractive surgery; diseases that could affect epithelial healing; use of antihistamines, nonsteroidal anti-inflammatory drugs, or steroids; and use of mitomycin C during PRK. Patients were divided into two groups: 20 patients received gabapentin capsules (300 mg) and 20 patients received identical placebo capsules. Visual acuity, slit-lamp examination, and a 12-question, 10-point visual numerical scale questionnaire were evaluated at each postoperative follow-up. Main outcome measures were the severity of pain at each follow-up and during the previous 24 hours. Secondary outcome measures were maximum and minimum severity of pain, healing time, uncorrected distance visual acuity, and the rating of other symptoms and potential side effects. RESULTS The gabapentin group had less pain during the first 72 hours (P=.024 to .001). A significant difference in favor of gabapentin was found for the first 48 hours regarding minimum pain severity (P=.005 and .01 for 24 and 48 hours, respectively) and for the first 72 hours for maximum pain severity (P=.014, .007, and .001 for 24, 48, and 72 hours, respectively). No significant differences were observed for side effects, symptoms, or healing time except discomfort in favor of gabapentin during the first 24 hours (P=.043). CONCLUSIONS Gabapentin significantly reduced postoperative pain after PRK compared to placebo, with no increase in reported side effects.

Correction of Astigmatism After Cataract Surgery Using the Light Adjustable Lens: A 1-year Follow-up Pilot Study

PURPOSE The management of preoperative and residual astigmatism is critical to obtain optimized uncorrected visual acuity. The aim of this study was to determine whether residual astigmatism could be precisely corrected postoperatively using the Light Adjustable Lens (LAL, Calhoun Vision Inc) and to determine the stability of the adjusted refraction. METHODS Ten eyes of 10 patients with cataract and corneal astigmatism between 1.00 and 2.00 diopters (D) were included. After standard phacoemulsification and implantation of the LAL, adjustment and lock-in procedures were completed. Before adjustment and 2 weeks, 6 months, and 1 year after lock-in, a full ophthalmic examination including uncorrected distance acuity (UDVA) and corrected distance visual acuity (CDVA), autorefraction, and manifest refraction was performed. RESULTS All surgeries, adjustments, and lock-in procedures were performed with no complications. All eyes achieved ±0.50 D of the targeted cylindrical adjustment. Mean spherical equivalent refraction was 0.03±0.84 D before adjustment and -0.06±0.25 D at final follow-up. The cylinder axis remained the same in 60% of eyes and all eyes were stable within 10° rotation at 12-month follow-up. Seven of 10 eyes achieved UDVA of 20/25 or better whereas all eyes achieved UDVA of 20/32 or better. Corrected distance visual acuity remained stable in all eyes. CONCLUSIONS In this pilot study, the LAL proved to be an efficient, predictable, and stable method of managing astigmatism in cataract patients.

Intracorneal ring segment explantation after intracorneal ring segment implantation combined with same-day corneal collagen crosslinking in keratoconus.

Purpose: To report the outcome and the reversibility of refractive outcomes after intrastromal corneal ring segment (ICRS) explantation in patients with keratoconus treated with ICRS implantation and same-day collagen crosslinking (CXL). Methods: This is a retrospective review of ICRS explantation in 3 eyes of 3 patients with keratoconus that had undergone femtosecond laser–enabled placement of paired ICRS (Intacs) with same-day CXL by a single surgeon between 2008 and 2011. The main outcome measures included baseline/preexplantation/postexplantation visual acuity, refractive error, keratometry, and higher order aberrations. Results: None of the patients lost best-corrected distance visual acuity lines. ICRS can be safely and easily explanted from keratoconic eyes with previous CXL. Some of the topographic benefits gained from ICRS implantation may persist after explantation. Conclusions: Despite the reversal of refractive outcomes, the preservation of topographic changes may occur in some cases after the explantation of 1 or both the segments in patients with keratoconus treated with ICRS implantation with same-day CXL.

Accelerated versus standard corneal collagen crosslinking combined with same day phototherapeutic keratectomy and single intrastromal ring segment implantation for keratoconus

Aim To compare the results of same day transepithelial phototherapeutic keratectomy (t-PTK) and single inferior intracorneal ring segment (ICRS) combined with standard versus accelerated corneal collagen crosslinking (CXL) for keratoconus. Methods All consecutive progressive keratoconus eyes that underwent standard or accelerated CXL treatment preceded by same day t-PTK and placement of a single inferior ICRS and had 6  and 12 months of follow-up were reviewed retrospectively. Eyes were classified into two groups, the ‘standard’ and the ‘accelerated’ group, accordingly. Visual, refractive and topographic data prior to surgery and at 6 and 12 months post-treatment were analysed. Results Sixteen eyes were included in each of the standard and the accelerated groups. Mean patient age was 27.5±8.5 years and 30.5±10.7 years (p=0.38) in the standard and accelerated groups, respectively. There was a significant improvement in uncorrected distance visual acuity, refractive cylinder and all examined corneal parameters in both groups 12 months postsurgery. The corrected distance visual acuity and manifest refraction spherical equivalent showed a significant improvement after 12 months of follow-up only in the accelerated group. However, mean changes in all evaluated parameters did not differ significantly between the two groups. Conclusions A combined treatment of accelerated CXL preceded by same day t-PTK and single ICRS is as effective as the combined treatment using standard CXL for visual rehabilitation in progressive keratoconus.

Corneal endothelial safety after ultraviolet light treatment of the light-adjustable intraocular lens

PURPOSE: To assess the safety to the corneal endothelium of ultraviolet (UV) light treatment to a light‐adjustable intraocular lens (IOL). SETTING: Codet Vision Institute, Tijuana, Mexico. DESIGN: Cohort study. METHODS: The study evaluated consecutive patients scheduled for phacoemulsification cataract surgery with implantation of a light‐adjustable IOL. Endothelial cell density (ECD), variation in the size of endothelial cells, and the percentage of hexagonal cells were determined centrally with a specular microscope preoperatively, 1 week postoperatively (before UV treatment), and 6 months postoperatively. Two adjustments and 2 lock‐in procedures were performed with a light‐delivery system between 2 weeks and 4 weeks postoperatively. RESULTS: The study enrolled 10 patients. Specular microscopy showed a mean ECD of 2344 cells/mm2 preoperatively. The mean overall central ECD was 2047 cells/mm2 1 week postoperatively and 2130 cells/mm2 at 6 months, representing an endothelial cell loss of 12.6% and 9.1%, respectively, from preoperative values. There was no statistically significant difference in the coefficient of variation or percentage of hexagonal cells at either postoperative evaluation. CONCLUSIONS: The endothelial cell loss at 6 months correlated well with previous reports of endothelial damage after phacoemulsification with IOL implantation. The light‐adjustable IOL irradiation protocol for adjustment and lock‐in procedures did not seem to add to the endothelial damage caused by the cataract surgery, indicating the protocol is safe to the corneal endothelium. Financial Disclosure: Drs. Lichtinger and Padilla have no financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.