In the Ocular Hypertension Treatment Study (OHTS), the most important baseline risk factor predicting conversion from ocular hypertension to POAG was:

• A Cup-disc ratio greater than 0.5
• B IOP greater than 26 mmHg
• C Age greater than 65 years
• D Central corneal thickness less than 555 microns ✓

Explanation

OHTS identified central corneal thickness (CCT) less than 555 micrometers as the single strongest predictor of conversion from ocular hypertension to POAG. Thin corneas underestimate true IOP (Goldmann applanation reads falsely low in thin corneas) and may also represent intrinsic optic nerve vulnerability. Other significant predictors in OHTS included higher IOP, larger vertical cup-disc ratio, older age, and pattern standard deviation on visual field testing. The study also demonstrated that topical medication can reduce the 5-year conversion risk from ~9% to ~4.5%.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.