MOOREN’S ULCER

Signs and Symptoms

Mooren’s ulcer represents an idiopathic, inflammatory, marginal or peripheral ulceration of the cornea. There are two recognized presentations, which were initially described by Wood and Kaufman in 1971.1 The first of these is the typical or benign type, which tends to be unilateral, mild to moderate with regard to symptoms, and more commonly seen in elderly Caucasian individuals. The second variety is atypical or malignant, and tends to be bilateral in 75% of patients, progressive and more severe in terms of presentation and symptomology; it is encountered more frequently in younger patients and those of African descent.2,3 Overall, the condition is slightly more common in men than in women.4

Patients with Mooren’s ulcer typically present with variable levels of discomfort, ranging from foreign body sensation to excruciating and incapacitating pain. Photophobia is also common. On presentation, the involved eye will display hyperemia, tearing and blepharospasm in more severe cases. Vision may be impacted in association with progression of the ulcer toward the visual axis, or from the development of secondary astigmatism.

Biomicroscopically, Mooren’s ulcer begins with patchy, peripheral stromal infiltrates, usually affecting the nasal or temporal cornea.5 Eventually these infiltrates will coalesce, with subsequent dehiscence of the overlying epithelium. Ultimately, the condition progresses to involve active thinning of the anterior third to half of the stroma, often inferiorly and extending to the limbus. It is not uncommon to see quiescent regions adjacent to active, inflamed areas.

A classic finding in Mooren’s ulcer is a steep, overhanging edge to the lesion, which is quite characteristic of the disease.6 Associated findings may include anterior uveitis, hypopyon, glaucoma and cataract in extreme instances.7 The greatest associated risk in Mooren’s ulcer is progression to corneal perforation, which can result from minor trauma and occurs in up to 36% of cases.7

Pathophysiology

The precise etiology of Mooren’s ulcer is unknown; however, genetic and environmental factors for the disease have been proposed.6 Suggested environmental causes include an antecedent history of trauma or surgery as well as exposure to viral and parasitic infections, including helminthiasis. Human leukocyte antigens (HLAs) may also confer susceptibility to Mooren’s ulcer.8-10

Whatever the basis, it is widely held that Mooren’s ulcer is an autoimmune disease that solely impacts the cornea, without expression in other tissues of the body.11 This is in direct contrast to the condition we know clinically as peripheral ulcerative keratitis, which is associated with systemic disease in the vast majority of cases, including such disorders as rheumatoid arthritis, granulomatosis with polyangiitis (i.e., Wegener’s granulomatosis), polyarteritis nodosa, relapsing polychondritis, systemic lupus erythematosus, hepatitis and syphilis.12

Management

Therapy for Mooren’s ulcer generally follows a stepladder approach, moving from less to more invasive based upon the severity of the condition. The goal is to arrest the inflammation and ulcerative process, thereby helping to facilitate corneal reepithelialization. In most cases, topical corticosteroids (e.g., difluprednate 0.05% Q2H-QID) are employed early, along with strong cycloplegia (e.g., scopolamine 0.25% BID-TID) and antibiotic prophylaxis (e.g., besifloxacin 0.6% TID). Additional topical therapies that have been attempted with modest success include cyclosporine 1% drops and acetylcysteine 10%.6,13 Artificial tears and bandage contact lenses may be helpful as a supportive therapy to further reduce discomfort and promote healing. In cases where topical steroids are contraindicated or ineffective after seven to 10 days, oral pulse therapy (e.g., prednisone 60mg to 100mg daily) may be attempted.

Should the condition be recalcitrant to topical and oral therapy, however—which is often the case—surgical excision of the perilimbal conjunctiva and episclera is indicated.2,6 This helps to eliminate the inflammatory impetus, which is believed to stem from the vasculature located at the corneal margin. In more severe cases or in those with impending corneal perforation, lamellar keratoplasty may be required.6 The use of amniotic membrane transplantation in patients with Mooren’s ulcer has shown mixed results.11,14,15 A variety of other systemic immunomodulatory therapies have also been documented in association with surgical therapy, including oral cyclosporine, methotrexate, interferon alpha-2b, infliximab and adalimumab.6,16-20

Clinical Pearls

Mooren’s ulcer is considered by some to be an idiopathic form of peripheral ulcerative keratitis, and in fact, the two may be clinically indistinguishable. A careful history is required in order to differentiate these conditions. In acute cases presenting without a known systemic history, medical testing is indicated to identify or rule out any associated systemic disorders.

Likewise, Mooren’s ulcer must be differentiated from other forms of progressive, peripheral corneal thinning, such as Terrien’s marginal degeneration or pellucid marginal degeneration. Aside from having different courses and etiologies, the primary distinction between these entities and Mooren’s ulcer is that the degenerations are characteristically painless and bilateral, whereas Mooren’s is typically painful and often unilateral.

Before initiating any topical therapy for presumed Mooren’s ulcer, first be sure to rule out perforation. Should a Seidel test reveal leakage of aqueous from the wound indicating perforation, immediate referral to a board-certified cornea specialist is in order. Some might even argue that, since surgical intervention is virtually inevitable, all cases of suspected Mooren’s ulcer should be referred to a corneal surgeon.

1. Wood TO, Kaufman HE: Mooren’s ulcer. Am J Ophthalmol 1971;71(1 Pt 2):417-22.

2. Cellini M, Fresina M, Strobbe E, et al. Corneoscleral graft in Mooren’s ulcer: a case report. Cases J. 2009;2:180.

3. Chow CY, Foster CS. Mooren’s ulcer. Int Ophthalmol Clin. 1996;36(1):1-13.

4. Tuft S. Mooren’s Ulcer. In: Johnson GJ, Minassian DC, Weale RA, West SK, eds. Epidemiology of Eye Disease, 2nd edition. London:Arnold, 2003. 209-11.

5. Kanski JJ. Clinical Ophthalmology: A Systematic Approach, 5th Edition. Philadelphia:Butterworth-Heinemann, 2003. 117-9.

6. Alhassan MB, Rabiu M, Agbabiaka IO. Interventions for Mooren’s ulcer. Cochrane Database Syst Rev. 2014;(1):CD006131.

7. Sangwan VS, Zafirakis P, Foster CS. Mooren’s ulcer: current concepts in management. Indian J Ophthalmol. 1997;45(1):7-17.

8. Zhao JC, Jin XY. Immunological analysis and treatment of Mooren’s ulcer with cyclosporin A applied topically. Cornea 1993;12(6):481-8.

9. Taylor CJ, Smith SI, Morgan CH, et al. HLA and Mooren’s ulceration. Br J Ophthalmol. 2000;84(1):72-5.

10. Zelefsky JR, Taylor CJ, Srinivasan M, et al. HLA-DR17 and Mooren’s ulcer in South India. Br J Ophthalmol. 2008;92(2):179-81.

11. Schallenberg M, Westekemper H, Steuhl KP, Meller D. Amniotic membrane transplantation ineffective as additional therapy in patients with aggressive Mooren’s ulcer. BMC Ophthalmol. 2013;13:81.

12. Galor A, Thorne JE. Scleritis and peripheral ulcerative keratitis. Rheum Dis Clin North Am. 2007;33(4):835-54, vii.

13. Zhao JC, Jin XY. Immunological analysis and treatment of Mooren’s ulcer with cyclosporin A applied topically. Cornea. 1993;12(6):481-8.

14. Ngan ND, Chau HT. Amniotic membrane transplantation for Mooren’s ulcer. Clin Experiment Ophthalmol. 2011;39(5):386-92.

15. Chen KH, Hsu WM, Liang CK. Relapsing Mooren’s ulcer after amniotic membrane transplantation combined with conjunctival autografting. Ophthalmology. 2004;111(4):792-5.

16. Stammen J, Althaus C, Sundmacher R. Mooren ulcer. 4 severe bilateral disease courses with systemic cyclosporin A therapy. Klin Monbl Augenheilkd. 1997;211(5):306-11.

17. Wilson SE, Lee WM, Murakami C, et al. Mooren-type hepatitis C virus-associated corneal ulceration. Ophthalmology. 1994;101(4):736-45.

18. Fontana L, Parente G, Neri P, et al. Favourable response to infliximab in a case of bilateral refractory Mooren’s ulcer. Clin Experiment Ophthalmol. 2007;35(9):871-3.

19. Saw VP, Cornelius N, Salama AD, et al. Infliximab therapy for aggressive mooren ulceration. Arch Ophthalmol. 2008;126(5):734.

20. Ashar JN, Mathur A, Sangwan VS. Immuno­suppression for Mooren’s ulcer: evaluation of the stepladder approach—topical, oral and intravenous immunosuppressive agents. Br J Ophthalmol. 2013 Nov;97(11):1391-4.