Effects of Two Different Doses of Ranibizumab on the Resolution and Recurrence of Diabetic Macular Edema in the Ranibizumab for Edema of the Macula in Diabetes (READ-3) Study

Abstract

Purpose : To determine the number of intravitreal injections of ranibizumab (RBZ) required to achieve resolution of diabetic macular edema (DME) on spectral-domain optical coherence tomography (SD-OCT), and the time interval for DME to recur

Methods : The READ-3 Study assessed efficacy of two doses (0.5mg and 2.0mg) of intravitreal RBZ for DME. Study eyes were randomized to one of two doses to receive monthly injections starting at baseline, until month 5. Thereafter, patients were followed monthly and retreated if central retinal thickness was ≥250µm (time-domain OCT) and/or fluid was detected on SD-OCT within 20⁰x20⁰ macular scan centered on fovea, until month 24. Two masked graders determined presence or absence of edema on OCT. Fisher’s exact test was used to calculate difference between two arms

Results : 152 eyes (152 patients) were randomized in READ-3 study. 107 (70%) eyes (0.5mg=50, 2.0mg=57) had resolution of DME during the course of the study. 45 (30%) eyes had persistent DME that did not resolve at any visit during the course of study or until exit visit. Of the 107 eyes, 58 eyes (0.5mg=23, 2.0mg=35; p=0.123) received 5-7 injections, 14 eyes (0.5mg=8, 2.0mg=6) received 8-10 injections, 22 eyes (0.5mg = 13, 2.0mg = 9) received 10-15 injections; 13 eyes (0.5mg=6, 2.0mg=7) received 16-23 injections to achieve resolution of edema. Mean number of injections required to achieve resolution of DME was 9.21 and 10.26 injections in 2.0 and 0.5mg groups, respectively (p=0.21). DME did not recur in 8 eyes (0.5mg=4, 2.0mg=4) throughout the study after initial resolution. Among the remaining eyes which were followed monthly, 62 (0.5mg=32, 2.0mg=30) had recurrence of edema after treatment was deferred beyond one month, 20 eyes (0.5mg=10, 2.0mg=10) after treatment was deferred beyond two months while another 10 eyes (0.5mg=1, 2.0mg=9) had recurrence of edema after treatment was deferred beyond three months. Mean duration to retreatment was 69 days for both groups (0.5mg=69 days, 2.0mg=68 days; p>0.05). There was no difference in number of patients requiring more than 6 injections in two treatment arms (p=0.42)

Conclusions : Eyes with DME require continuous treatment with RBZ despite initial resolution of fluid on OCT. Higher dosage of RBZ did not exhibit greater efficacy in reducing rate of recurrence of DME

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