Figure 2. Wide-angle fundus photographs demonstrating examples of plus disease and pre-plus disease. Note varying levels of vascular abnormality, which are assessed in the central retina within the region of zone I.

(A) Mild pre-plus disease, with more arterial tortuosity and venous dilation than normal. (B) Pre-plus disease, with notable arterial tortuosity but minimal venous dilation. (C) Pre-plus disease, with moderate arterial tortuosity and venous dilation, but considered by majority of committee members to be insufficient for plus disease. (D) Plus disease with notable venous dilation and arterial tortuosity. Note that plus disease is out of proportion to visible peripheral findings, suggestive of flat neovascularization (stage 3, white arrows). (E) Severe plus disease, with dilation and tortuosity of both arteries and veins. (F) Severe plus disease. Note presence of ill-defined posterior flat stage 3 (arrows), which combined with severe plus disease is typical of aggressive ROP (A-ROP).