Quantitative Analysis of Retinal Vessel Diameter Reduction after Photocoagulation Treatment for Retinopathy of Prematurity

Purpose To evaluate the feasibility of using semiautomated analysis of digital fundus images to quantify effects of photocoagulation on retinal vessel diameter in retinopathy of prematurity (ROP). Design Case series. Methods Fourteen eyes of seven patients with threshold ROP and 12 eyes of six controls were included. Fundus images were captured before and after photocoagulation, or one to three weeks apart in controls, using an NM200D camera (Nidek, Inc, Aichi, Japan). VesselMap software (Imedos, Jena, Germany) measured vessel diameter. The t test analysis was used to assess vessel changes. Results The authors observed a significant reduction in average largest retinal vein diameter of −18% ± 16% (±1 standard deviation). The average largest artery diameter trended down by −12% ± 16%. Compared with controls, diameter reduction was significant in veins ( P = .014) and arteries ( P = .016). Conclusions The diameter of retinal vessels decreases after photocoagulation. VesselMap analysis of digital images is feasible and may be helpful in quantifying treatment effects.