In the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) study, which clinical finding at baseline most strongly predicted progression to corneal transplantation?

• A Corneal curvature (steep K) greater than 52 diopters
• B Patient age less than 30 years
• C Corneal scarring ✓
• D Manifest refraction spherical equivalent worse than -8D

Explanation

The CLEK study (prospective multicenter natural history study of keratoconus) found that baseline corneal scarring was the single strongest predictor of eventual penetrating keratoplasty (PKP). Steep keratometry (>52D) and poor visual acuity were secondary predictors. Young age at diagnosis allows more time for progression. The CLEK study also demonstrated that rigid gas-permeable (RGP) contact lenses do not worsen keratoconus progression. With the advent of CXL, the natural history has been favorably altered, reducing the rate requiring PKP to approximately 15-20% over 20 years in treated patients.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.