Corneal collagen cross-linking (CXL) with riboflavin and UV-A light in keratoconus acts by:
- A Flattening the cone through photoablation of irregular stromal tissue
- B Stimulating keratocyte proliferation to regenerate structural integrity
- C Inducing new covalent bonds between collagen fibrils, increasing stromal stiffness and halting progression ✓
- D Rehydrating stromal collagen to restore normal corneal curvature
Correct answer: C. Inducing new covalent bonds between collagen fibrils, increasing stromal stiffness and halting progression
Explanation
Corneal collagen cross-linking (Dresden protocol: 0.1% riboflavin drops + 3 mW/cm² UV-A for 30 min) halts keratoconus progression by generating reactive oxygen species that form new inter- and intra-fibrillar covalent bonds between collagen molecules. This increases the biomechanical rigidity of the stroma. CXL does not directly flatten the cone (topography may show slight flattening after treatment, but the primary intent is stabilization). It does not photoablate tissue or stimulate keratocyte proliferation.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.