Comparing microscope light-associated glare and comfort between heads-up 3D digital and conventional microscopes in cataract surgery: a randomised, multicentre, single-blind, controlled trial.

OBJECTIVE: To compare subjective levels of comfort and visual experiences related to microscope light in patients undergoing their first cataract surgery with topical anaesthesia using a digital microscope (the NGENUITY three-dimensional (3D) visualisation system) or a conventional microscope. METHODS AND ANALYSIS: A prospective, randomised, single-blinded, parallel-group, multicentre, interventional study. Patients (n=128) were randomly assigned to one of two treatment groups: the experimental group (n=63) had surgery using the digital microscope and the control group (n=65) had surgery with a conventional microscope. The primary outcome was patients' subjective experience of glare from the microscope light during surgery on a numerical scale from 0 to 10. Key secondary outcomes were patients' subjective levels of comfort and visual experiences related to the microscope light. RESULTS: The experimental group reported significantly lower levels of glare; median levels were 1.0 (0.0-4.0) for the experimental group vs 3.0 (0.0-6.0) for the control group (p=0.027). They also reported higher levels of comfort; median ratings were 8.0 (6.5-10.0) in the experimental group and 7.0 (5.0-9.0) in controls (p=0.026). There were no group differences in ratings of subjective pain or visual disturbances. Median microscope light intensity was lower in the experimental group than controls; 3425.0 (2296.0-4300.0) Lux vs 24 279.0 (16 000.0-26 500.0) Lux (p<0.0001), respectively. CONCLUSION: Compared with conventional microscopes, the NGENUITY 3D visualisation system allows surgeons to operate with lower levels of light exposure, resulting in significantly less glare and improved comfort in patients undergoing cataract surgery. TRIAL REGISTRATION NUMBER: NCT05085314.

Descemet Membrane Endothelial Keratoplasty After Failed Penetrating Keratoplasty.

PURPOSE: To demonstrate the feasibility of Descemet membrane endothelial keratoplasty (DMEK) performed after previous penetrating keratoplasty (PK) failure and to describe primary outcomes. METHODS: Twenty-eight eyes of 28 patients who underwent DMEK after primary PK failure between January 2013 and November 2017 were included in this single-center retrospective study. Best spectacle-corrected visual acuity, endothelial cell density, and the recipient's central corneal thickness were recorded preoperatively and at 1, 3, and 6 months after surgery. RESULTS: The main indications for primary PK were keratoconus (32%), Fuchs dystrophy (18%), and pseudophakic bullous keratopathy (14%). After a 6-month follow-up, best spectacle-corrected visual acuity was significantly improved in 26 patients (93%) with a mean gain of +0.59 ± 0.47 LogMAR (P < 0.0004). Mean pachymetry reduction was 110 ± 108 µm (P < 0.00003) at 6 months. Mean endothelial cell density was 2016 ± 288 cells/mm (P < 0.006), (24% decrease compared with preoperative values). Graft detachment (>1/3) was observed in 14 cases (50%) and rebubbling was needed (100% effective) during the first 2 weeks after surgery. Elevated intraocular pressure was reported in 5 cases. No early graft rejections were reported. CONCLUSIONS: In case of previous PK failure, DMEK is an alternative treatment to re-PK. A longer follow-up to ensure the long-term viability of the graft is needed.

Customized Topography-Guided Corneal Collagen Cross-linking for Keratoconus.

PURPOSE: To compare the efficacy and safety of topography-guided corneal collagen cross-linking (TG-CXL) to conventional corneal CXL (C-CXL) in progressive keratoconus. METHODS: In this prospective, nonrandomized clinical trial, 60 eyes of 60 patients were scheduled to receive either TG-CXL (30 eyes with deepithelialization focused on the cone, riboflavin application for 10 minutes, and 30 mW/cm2 pulsed ultraviolet-A irradiance pattern according to topography) or C-CXL (30 eyes treated in accordance with the Dresden protocol). Patients were observed for 1 year postoperatively. Maximum keratometry (Kmax), mean keratometry in the inferior part of the cornea (I index), corrected distance visual acuity (CDVA), demarcation line observed in optical coherence tomography, and nerves and cell densities analyzed by confocal microscopy were compared preoperatively and at 1 year postoperatively. RESULTS: The difference was significant for both Kmax (P < .01) and I index (P < .01) between the two groups. CDVA improved significantly in the TG-CXL (0.2162 ± 0.2495 logMAR, P < .05) versus the C-CXL (0.2648 ± 0.2574 logMAR, P = .104) group. A stromal demarcation line was observed in both treatment groups, with similar depth at the top of the cone (P = .391), but it was shallower at the surrounding area in the TG-CXL group (P < .0001). Stromal evaluation by confocal microscopy showed less damage and faster healing in the surrounding area than on the cone area in the TG-CXL group. CONCLUSIONS: At 1 year postoperatively, TG-CXL seems to be as safe as C-CXL with stronger flattening in Kmax and I index and better improvement in CDVA. TG-CXL induces a biological gradient between the cone and the surrounding area that facilitates nerve and cell recovery. [J Refract Surg. 2017;33(5):290-297.].