Retinal Vascular Caliber Changes After Topical Nepafenac Treatment for Diabetic Macular Edema

Purpose: To assess changes in retinal vascular caliber in response to short-term use of nepafenac eye drops in patients with mild diabetic macular edema. Materials and methods: Thirty-four patients with previously untreated bilateral mild diabetic macular edema were included in this prospective study. For each participant, one eye was randomly assigned to nepafenac treatment (0.1%, three times/day) and the other eye was left untreated throughout the study. Using digital fundus photographs, retinal vascular calibers were calculated and compared in treated and untreated eyes at the baseline, week 1, and week 6. Results: Baseline vessel diameters did not differ in treated and fellow eyes (p > 0.05). Over the 6 weeks of the study, significant vasoconstriction of the retinal arteriolar caliber was observed at weeks 1 (p < 0.05) and 6 (p < 0.05), while an unchanged retinal venular caliber was noted between the treated and untreated eyes (p > 0.44). Significant macular thickness difference was only observed at week 6 (p = 0.002). Conclusions: Topical nepafenac has a significant narrowing effect on the retinal arteriolar diameter and a significant reductive effect on central macular thickness in eyes with mild diabetic retinopathy.