Baseline central macular thickness predicts the need for retreatment with intravitreal triamcinolone plus laser photocoagulation for diabetic macular edema

Differences in the characteristics of subjects achieving complete, partial, or no resolution of macular edema in the READ-3 study

PURPOSE

To identify baseline characteristics of subjects enrolled in the READ-3 study that would predict the response of macular edema to ranibizumab (RBZ) therapy at year 1.

METHODS

In this post hoc analysis of the READ-3 randomized, multicenter phase 2 clinical trial, subjects with diabetic macular edema (DME) were randomized to receive monthly intravitreal injections of RBZ (0.5 or 2.0 mg) for 6 consecutive injections followed by as-needed treatments based on pre-defined retreatment criteria. In this sub-study, subjects were divided into three groups (persistent, rebound, and resolved) based on edema status at month 12 (M12). Multi-logistic regression was utilized to assess the probability of edema outcomes M12, based on the baseline characteristics.

RESULTS

One hundred twenty-three out of 152 subjects were analyzed for this sub-study. A significant difference was observed in the baseline (BL) central subfield thickness (CST) among the study groups (p < 0.05). BL CST was a significant predictor for edema outcome at M12 with > 80% probability of the subject having persistent edema if BL CST was > 570 μm (p < 0.05). This association persisted when controlled for the dose of RBZ (relative risk (RR), 1.007; p < 0.05). BL CST was also a significant predictor for having persistent edema at M12 in subjects without vitreomacular adhesion (VMA) (> 80% probability of edema persistence at CST > 570 μm [RR, 1.006; p < 0.05]). However, in the presence of VMA, BL CST was no longer a significant predictor of having persistent edema at month 12 (RR, 1.005; p > 0.05).

CONCLUSIONS

Subjects with high CST (> 570 μm) at baseline may not benefit from repeated intravitreal injections of anti-VEGF for resolution of edema.

[Association between visual improvement after photocoagulation and the use of angiotensin converting enzyme inhibitors in diabetic macular oedema]

BACKGROUND

Angiotensin converting enzyme inhibitors are effective in delaying the progression of diabetic retinopathy. It is unknown if their use is associated with a better visual outcome in patients with diabetic macular oedema.

MATERIAL AND METHODS

A non-experimental, comparative, longitudinal and retrospective study was performed on patients with diabetic macular oedema treated by focal photocoagulation, and with systemic arterial hypertension treated with angiotensin converting enzyme inhibitors (Group 1), and without hypertension (Group 2). The dependent variable was the proportion with visual improvement, operatively defined as the gain of one or more lines of vision three weeks after photocoagulation. The independent variable was the use of angiotensin converting enzyme inhibitors. The proportion of eyes with visual improvement after treatment was compared between groups using the Chi squared (χ(2)) test.

RESULTS

A total of 33 eyes (51.6%) were assigned to group 1, and 31 (48.2%), to group 2. The mean of visual acuity improved after three weeks, compared with baseline (p=0.002). The proportion of eyes with visual improvement did not differ between patients treated with angiotensin converting enzyme inhibitors (45.5%) and those that did not use them (51.6%, p=0.4).

CONCLUSIONS

There was no statistical difference in the proportion of eyes with visual improvement between patients treated with angiotensin converting enzyme inhibitors and in those where they were not used. There is no support for the inhibition of angiotensin II in addition to photocoagulation for improving the outcome in patients with diabetic macular oedema.