Significance of isolated neovascular tufts ("popcorn") in retinopathy of prematurity.

Background: The significance of isolated neovascular tufts ("popcorn") occurring in association with stage 2 retinopathy of prematurity (ROP) has not been studied.

Methods: We retrospectively reviewed the clinical courses and outcomes of all patients with zone II, stage 2 ROP with popcorn examined over the past 3 years at one institution. Eyes with zone I disease, plus disease, or stage 3 at the initial appearance of popcorn were excluded. The study group was compared with a control group of patients of similar birth weight and gestational age with zone II, stage 2 ROP without popcorn.

Results: Popcorn first appeared at a mean age of 36.4 (+/- 2.2) weeks after conception in 26 patients. Of these, 17 patients (65%) progressed to stage 3, 10 (38%) had plus disease, 6 (23%) reached threshold, and 9 (35%) required laser treatment. Of 19 control patients, 4 (21%) progressed to stage 3, 1 (5%) had plus disease, 1 (5%) reached threshold, and 1 (5%) required laser treatment. The popcorn group had a significantly higher incidence of progression to stage 3 (p < 0.005), plus disease (p < 0.025), and laser treatment (p < 0.025). All eyes of both groups had complete regression of disease.

Conclusions: The presence of popcorn significantly increases the risk that an eye with zone II, stage 2 ROP will progress to stage 3, develop plus disease, and require laser treatment. Patients with popcorn and coexistent mild vascular dilation or tortuosity insufficient for plus disease are at particularly high risk for disease progression.