How is the severity of retinopathy of prematurity described?

• A. Stages
• B. Clock hours
• C. Zones
• D. Grades

Answer: (A)

Severity of retinopathy of prematurity is described by stages. The stages reflect how far retinal involvement has progressed, from stage I with a faint line to stage II with a ridge, stage III with extraretinal fibrovascular proliferation, stage IV a partial retinal detachment, and stage V a total retinal detachment. Zones describe where in the retina the disease is located, and clock hours describe the extent around the retina; these add detail but do not define overall severity by themselves. Plus disease can indicate a more aggressive process, but the primary measure of severity is the stage.