Fuch's endothelial corneal dystrophy is caused by dysfunction of which corneal layer, and at what level of endothelial cell count does bullous keratopathy typically develop?

• A Bowman's layer; <1000 cells/mm²
• B Corneal endothelium; below 500 cells/mm²
• C Corneal stroma (keratocytes); below 300 cells/mm²
• D Corneal endothelium; below 400–500 cells/mm² ✓

Explanation

Fuchs' endothelial corneal dystrophy is characterised by progressive degeneration of corneal endothelial cells, with accumulation of collagen in Descemet's membrane forming guttae. The normal endothelial cell density is approximately 2,500–3,000 cells/mm². The endothelium cannot regenerate; when cell density falls below approximately 400–500 cells/mm², the endothelial pump fails, leading to stromal oedema and bullous keratopathy. Treatment is Descemet's membrane endothelial keratoplasty (DMEK) or DSAEK.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.