Retinopathy of prematurity (ROP) — Plus disease is defined by:

• A Stage 2 ROP with ridge formation in zone 2
• B Presence of extraretinal fibrovascular proliferation (ridge with popcorn)
• C Iris vascular engorgement alone
• D Vascular dilatation and tortuosity in at least 2 quadrants of the posterior retinal vessels ✓

Explanation

Plus disease in ROP is defined as vascular dilatation and tortuosity of the posterior pole retinal vessels in at least 2 quadrants, indicating a worsening prognosis and active disease. It is a modifier applied to stages 2–5 and triggers consideration for treatment (along with zone and stage). Extraretinal fibrovascular proliferation defines stage 3. Iris vascular engorgement can be a sign of plus disease in advanced cases but alone is insufficient. Plus disease is the single most important adverse feature in ROP.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.