Visual Outcome of Patients in Ranibizumab for Edema of the mAcula in Diabetes (READ-3) Study Based on the Characteristics of Edema on Optical Coherence Tomography

Abstract

Purpose : The morphologic subtype/location of diabetic macular edema (DME) may influence the treatment response to ranibizumab (RBZ). In this study, evaluation of visual outcomes among patients enrolled in the Ranibizumab for Edema of the mAcula in Diabetes (READ-3) study based on the location of DME on spectral-domain optical coherence tomography (SD-OCT) was performed.

Methods : In the READ-3 study, patients received monthly intravitreal injections of 0.5 or 2.0mg RBZ. Patients with center-involving DME and central subfield thickness ≥250µm at baseline were enrolled. SD-OCT images (Heidelberg Spectralis® were analyzed at baseline and month 6 (primary endpoint) to identify the location of edema. DME was classified as (1) center-involving DME alone (fluid within 1mm central ETDRS circle); (2) non-center involving DME, and (3) combination of the two. Patients with subretinal fluid (SRF) at baseline and month 6 were identified. Mean change in best-corrected visual acuity (BCVA) (ETDRS letters) among the three groups was compared using one-way ANOVA test.

Results : 152 eyes (152 patients) were randomized. 119 eyes were included (61 eyes in 2mg arm) in the study. At baseline, 7 eyes had only center-involving DME (6 eyes in 2mg arm). All the remaining eyes had combined center + non-center involving DME. At 6 months, 91 eyes (76.47%) had persistent DME (45 eyes in 2mg arm). 14/91 eyes (15.38%) had only center-involving DME (10 eyes in 2mg arm) and 67/45 eyes (73.63%) (28 eyes in 2mg arm) had combined center + non-center involving DME. The median (interquartile range) BCVA gain was 5 (2-12) letters in the center-involved DME group, 12 (6.5-12.75) in the non-center involved group, and 7 (2-13) letters in combined group (p=0.461). Mean BCVA gain was not significantly different between the 2mg and 0.5mg arms for any of the 3 groups (p>0.64). 14 and 19 eyes had SRF on OCT at baseline in 2mg and 0.5mg arms, respectively. At month 6, SRF was observed in 1 eye in both the groups. Mean BCVA gain in these eyes was 10.48±7.60 compared to 7.24±10.13 in eyes with no SRF at baseline (p=0.042).

Conclusions : Among patients treated with RBZ, location of intraretinal DME on OCT, and the treatment dose of intravitreal RBZ does not influence the final BCVA outcome. However, eyes with SRF at baseline show superior visual gains compared to eyes without SRF.

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