Effect of Intravitreal Triamcinolone on Hard Exudates in Patients With Diabetic Retinopathy – A Pilot, Randomized Controlled Clinical Trial

Abstract

Abstract: : Purpose: To assess the effect of triamcinolone acetonide on hard exudates in patients presenting with bilateral diabetic macular edema and hard exudates. Methods: A large randomised controlled trial investigating the effect of intravitreal triamcinolone on diabetic macular edema is currently underway. After baseline retinal photography, treatment eyes received a single dose (4mg), intravitreal injection of triamcinolone acetonide and controlled eyes received subconjuntival saline injection. Sixteen patients who had bilateral macular edema together with hard exudates at baseline were included in this report, all with one eye randomly selected for treatment and the fellow eye for control. Patients were re–examined and retinal photographs re–taken 3 months after the injection.. Hard exudates were assessed for location (central, inner and outer circles of the Wisconsin Age–related Maculopathy grading system), total areas (measured using 4 circles from the Wisconsin ARM grading system) and proportion of area involved within 3000 µm radius from the foveola. Visual acuity was assessed following ETDRS procedure. Results: The overall total areas occupied by hard exudates were reduced more in treated than in controlled eyes (p<0.01). At baseline, one control and four treated eyes had an area of hard exudate involvement larger than the O–2 circle (660 µm diameter). At the 3–month visit, four control and no treated eyes had this amount of hard exudate.From baseline to 3–months, the mean proportional change in the area occupied by hard exudate within 3000 µm radius from the foveola was reduced by 13 ± 63 % in treated eyes but was increased by 17 ± 63 % in control eyes (p=0.2). The corresponding proportion within 1500 µm radius from the foveola was reduced by 34 ± 61% in treated eyes but was increased by 71 ± 143% in control eyes (p=0.003). The mean visual acuity was improved in the treated eyes with an additional 5 ± 4.4 letters read correctly, compared to a slight deterioration in control eyes with 1.7 ± 7.5 less letters read correctly (paired t test, p=0.01).Conclusions: Paired comparison of 16 patients with bilateral diabetic macular edema and hard exudate suggests that intravitreal triamcinolone reduces hard exudates and preserves better visual outcome than placebo treatment in the short–term.

Keywords: diabetic retinopathy • pharmacology