A 70-year-old man presents with a painful peripheral corneal ulcer that starts in the periphery, undermines the epithelium centrally with an overhanging edge, and progresses circumferentially. Systemic workup including rheumatoid factor, ANCA, and syphilis serology is negative, and there is no scleral inflammation. The most likely diagnosis is:
- A Peripheral ulcerative keratitis of rheumatoid arthritis
- B Terrien marginal degeneration
- C Mooren ulcer ✓
- D Pellucid marginal degeneration
Correct answer: C. Mooren ulcer
Explanation
Mooren ulcer is an idiopathic, painful, progressive peripheral ulcerative keratitis diagnosed only after excluding all systemic associations. Its defining separation from rheumatoid peripheral ulcerative keratitis is the absence of scleritis and negative systemic workup. Terrien degeneration is painless thinning with lipid deposition and intact epithelium, and pellucid marginal degeneration is a painless ectatic disorder with protrusion above the thinned inferior band.
Reference: American Academy of Ophthalmology Basic and Clinical Science Course, External Disease and Cornea, BCSC Section 8 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.