TABLE 1.

Classification of retinopathy of prematurity

Stage 1	Demarcation line separates avascular from vascularized retina
Stage 2	Ridge arising in region of demarcation line
Stage 3	Extraretinal fibrovascular proliferation/neovascularization
Stage 4	Partial retinal detachment
Stage 5	Total retinal detachment
Pre-plus disease	More vascular tortuosity than normal, but insufficient for diagnosis of plus disease
Plus disease	Vascular dilation and tortuosity of at least two quadrants of the eye