Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) in Patients with Central Retinal Vein Occlusion (CRVO) and Cystoid Macular Edema (CME): A SCORE2 Ancillary Study

Abstract

Purpose : To study photoreceptor structure using high resolution imaging techniques in patients with CRVO and CME who enrolled in the Study of COmparative Treatments for REtinal Vein Occlusion 2 (SCORE 2).

Methods : Patients were evaluated with AOSLO at one of five study sites. Inclusion criteria included clear natural lenses, pupils that dilate to at least 7 mm in both eyes, 6 diopters myopia or less in both eyes, and reproducible baseline AOSLO images at 2 baseline imaging sessions performed no more than 15 days after the baseline SCORE2 study visit, at which the study eye was randomized to receive a single intravitreal injection of either aflibercept 2mg or bevacizumab 1.25mg. Exclusion criteria included corneal opacification or lack of optical clarity in either eye, refractive surgery in either eye, unstable fixation in either eye, severe hearing disabilities in both ears, dry eye in either eye, and pseudophakia in the diseased eye precluding successful AOSLO baseline imaging. For each baseline montage, 10 regions of interest (ROI) were selected by a single investigator (AR) where at least 50 cones could be counted reliably. Cone spacing, cone density, and cone packing will be assessed at each of the ROIs by 5 independent graders (one from each of the 5 sites). Additional AOSLO imaging is planned at 6 months and 12 months after the baseline imaging date.

Results : CME posed significant challenges to AOSLO image acquisition during baseline imaging sessions. Of the 8 SCORE2 participants evaluated, AOSLO montages showed at least 10 ROIs at both baseline imaging sessions in only 3 patients. In these 3 patients, baseline images showed edema with fluid obscuring photoreceptor detail in many locations within 2.5 degrees of the foveal center, but at least 10 ROIs were identified with quantifiable cones in both baseline montages. Low image quality resulted in 5 screen failures where no cone structure could be discriminated.

Conclusions : CME obscures photoreceptor details in many locations in images acquired using AOSLO after a single intravitreal anti-VEGF treatment in eyes with CRVO. However, cone structures were visualized in a subset of imaged patients, enabling assessment of cone photoreceptor structure in response to anti-VEGF treatment of CME longitudinally.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.