Mooren's Ulcer is the Painful Peripheral Corneal Ulceration
Mooren's ulcer is characteristically a painful peripheral corneal ulceration, presenting with severe pain, redness, photophobia, and tearing as its hallmark features. 1, 2, 3
Clinical Presentation
Mooren's ulcer presents with a distinctive constellation of symptoms that clearly differentiate it from painless peripheral corneal conditions:
- Pain is a defining feature, described as severe and persistent, occurring in the vast majority of patients 1, 2, 4, 3
- Redness and intense limbal inflammation are the most common presenting symptoms alongside pain 1, 5
- Photophobia and tearing accompany the pain in most cases 2, 3, 5
- Progressive peripheral corneal ulceration begins at the limbus and advances circumferentially and centrally 1, 4, 5
The average limbal involvement is approximately 6.8 clock hours at presentation, indicating substantial disease burden 1.
Key Distinguishing Features
This is critical to understand: Mooren's ulcer is an idiopathic, chronic, relentless peripheral ulcerative keratitis that can only be diagnosed after excluding all infectious and systemic autoimmune causes 4, 3, 5. The pain distinguishes it from Terrien's marginal degeneration, which is typically painless and slowly progressive 5.
Diagnostic Workup Required
Before confirming Mooren's ulcer, you must exclude:
- Infectious etiologies through corneal cultures and appropriate staining to safely initiate steroid therapy 3
- Systemic autoimmune diseases through extensive laboratory testing including rheumatologic workup 1, 3
- Hepatitis C virus association has been reported in some cases and should be tested 5
Treatment Approach
The management is challenging with historically poor responses to conventional therapy 4, 5:
Medical Management
- Topical and systemic corticosteroids are first-line therapy for all patients 1, 3
- Systemic immunosuppression with methotrexate or cyclophosphamide for severe disease or poor steroid response 1
- Oral doxycycline may be considered as adjunctive therapy 5
Surgical Interventions
- Conjunctivectomy with cryotherapy is performed in approximately 60% of patients with severe disease 1
- Scleral patch graft for cases with impending or actual perforation 1, 2
- Amniotic membrane grafting, conjunctival flap, or lateral tarsorrhaphy may be attempted but often fail to provide permanent salvage 2
- Penetrating keratoplasty is reserved for perforated corneas after other interventions fail 5
Prognosis and Outcomes
Important caveat: Despite aggressive treatment, outcomes are often suboptimal:
- Approximately 85.7% of treated eyes heal with varying degrees of corneal opacity 1
- About 76.2% of eyes maintain their presenting visual acuity, but progressive vision loss can occur 1
- Complications include descemetocele, anterior staphyloma, or corneal perforation in 14.3% of cases 1
- Complete loss of vision can occur despite multiple interventions, particularly in bilateral cases 2
The disease is more common in southern and central Africa, China, and the Indian subcontinent, but remains rare in the northern hemisphere 4. Treatment must be initiated rapidly once the diagnosis is established, as the natural history is severe with frequent devastating complications 3, 5.