The OHTS (Ocular Hypertension Treatment Study) identified several baseline predictors of conversion from ocular hypertension to glaucoma. Which parameter had the HIGHEST predictive value for development of POAG in the OHTS?

• A Baseline IOP above 24 mmHg
• B Vertical cup-to-disc ratio greater than 0.5
• C Central corneal thickness less than 555 micrometers ✓
• D Family history of glaucoma in first-degree relative

Explanation

In the OHTS, central corneal thickness (CCT) was the single strongest predictor of conversion from ocular hypertension to POAG. Patients with CCT <555 μm had a 3-fold higher risk of developing glaucoma. Thin CCT leads to overestimation of IOP by Goldmann tonometry, meaning true IOP is higher than measured — and thin corneas may also indicate intrinsically stiffer or weaker connective tissue at the optic nerve head.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.