Retinal vascular changes in eyes with diabetic macular edema treated with different doses of ranibizumab

Abstract

 

Purpose

 

The aim of this study is to assess the changes in vessel diameter in patients with diabetic macular edema (DME) treated with 2 different doses of ranibizumab (RBZ).

 

Methods

 

Fundus photos from 55 patients (55 eyes) enrolled in the READ-3 study (comparison of 0.5mg VS 2.0mg of RBZ for DME) were analyzed. Photos were divided into two groups according to the treatment arm (Group A=0.5mg; Group B=2.0mg). All eyes received 6 monthly injections starting at baseline visit. Central retinal arterial equivalent (CRAE) and central retinal venular equivalent (CRVE) were measured using Interactive Vessel Analysis (IVAN) software, ½ disc diameter to 1 disc diameter from the margin of the optic disc, in 6 largest venules and arterioles. Parametric tests (paired t-test, independent t-test) were performed to compare the CRVE and CRAE between the two groups.

 

Results

 

26 patients were included in group A; 29 in group B. The mean age was 63 and 65 in group A and B, respectively. 14 patients were males in group A; 17 males in group B. There was reduction in both CRAE and CRVE at month 6 compared to baseline for both doses of RBZ (table). The changes were statistically significant in CRVE and demonstrated a trend towards significance in CRAE. However, inter-comparison did not demonstrate any statistically significant differences between the two dose groups.

 

Conclusions

 

Treatment of DME with RBZ appears to induce similar reduction in CRVE and CRAE regardless of the dose. Such findings imply that low and high dose of RBZ may have similar effects on retinal vasculature in eyes with DME.

 

 

Keywords: 436 blood supply • 505 edema • 499 diabetic retinopathy