Prognostic significance of vascular dilation and tortuosity insufficient for plus disease in retinopathy of prematurity

Background: Plus disease, one of the most important prognostic indicators i n retinopathy of prematurity (ROP), is designated as present or absent. A g rading system based on comparison with standard, high-quality color photogr aphs may be useful to more accurately describe the spectrum of vascular dil ation and tortuosity preceding plus disease, but it is of practical value o nly if it has prognostic significance. We hypothesized that grading of "pre -plus" vascular changes can identify eyes at risk for progression to vision -threatening ROP. Methods: Video clips of posterior pole images captured at the examination closest to 33 weeks' postconceptional age of 32 infants sc reened during an 18-month period were randomized. Two masked examiners view ed and graded the images in comparison with standard photographs representa tive of 5 distinct grades of retinal vascular dilation and tortuosity. A ca se-control design was used to compare the incidence of progression to stage 3 ROP, development of plus disease, and requirement of laser treatment bet ween infants with normal posterior poles and those judged to have early dil ation and tortuosity insufficient for plus disease. Results: Of the 8 patie nts with mild vascular dilation and tortuosity insufficient for plus diseas e, 5 (63%) eventually required laser treatment, 4 (50%) later developed sta ge 3 ROP, and 5 (63%) progressed to plus disease. Of the 24 patients with normal posterior poles, none required laser treatment, 2 (8%) developed sta ge 3 ROP, and none progressed to plus disease. The group with mild vascular dilation and tortuosity had a significantly higher incidence of progressio n to laser treatment(P = .0003), stage 3 ROP (P = .027), and plus disease ( P = .0003). Conclusions: Early vascular dilation and tortuosity judged insu fficient for plus disease have prognostic significance in the early course of ROP. A grading system that uses standard, high-quality color photographs representing the spectrum of "pre-plus" vascular changes has potential uti lity in both the clinical and research settings.