Abstract
Purpose: :
To describe the effects of pegaptanib sodium injection (pegaptanib) on retinal thickness and volume in patients with diabetic macular edema (DME) in a randomized clinical trial.
Methods: :
Individuals with best–corrected visual acuity between 20/50–20/320 and DME were assigned randomly to pegaptanib (0.3 mg, 1 mg, 3 mg) or sham injections at study entry, week 6, and week 12 with additional injections and/or focal photocoagulation as needed for another 18 weeks. Effects of pegaptanib or sham injections on retinal thickness and volume from OCT were recorded.
Results: :
Of 172 participants, baseline OCT measurements were gradable in 36 assigned to sham, 41 to 0.3 mg pegaptanib, 34 to 1 mg, and 33 to 3 mg. Week 36 measurements in 115 showed average retinal thickness least in sham (421 µm) and greatest with 0.3 mg pegaptanib (487 µm). Decrease in center point thickness was greatest in the 0.3 mg pegaptanib group (–87 µm) and least with sham (+10 µm). In the 0.3 mg group (with greater differences than 1 mg or 3 mg), the retina was more likely than sham to show thinning of >50 or >150 µm and to decrease >25% or >50%. Macular volume decreased 58% with 0.3 mg and increased 12% with sham (P=0.009). OCT center point thickness and change in thickness at week 36 had only a modest correlation with visual acuity at baseline and change in visual acuity at 36 weeks (Rsquared=0.18).
Conclusions: :
In this Phase 2 trial, the 0.3 mg pegaptanib group, with a slightly greater center point thickness at baseline, on average, demonstrated greater reductions in retinal thickness and volume than sham, with only a modest correlation between visual acuity and change in visual acuity with OCT center point thickness and change in thickness. These findings suggest an anti–permeability effect of pegaptanib on diabetic retinal vessels, although not always correlating with visual acuity changes.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • diabetic retinopathy • imaging/image analysis: clinical