important distinguishing feature is the purely corneal involvement of Mooren ulcer; in PUK, the sclera is often involved.

Two clinical types of Mooren ulcer have been described. Unilateral Mooren ulcer typically occurs in an older patient population. Sex distribution is equal in this form, which is slowly progressive. A second type of Mooren ulcer is more common in Africa. This form is usually bilateral, rapidly progressive, and poorly responsive to medical or surgical intervention. Corneal ulceration (Fig 7-19) and perforation are frequent. Many patients with this form of Mooren ulcer also have coexisting parasitemia. It is possible that in this subgroup of West African males, Mooren ulcer may be triggered by antigen–antibody reaction to helminthic toxins or antigens deposited in the limbal cornea during the blood-borne phase of parasitic infection.

Figure 7-19 Mooren ulcer with severe superior limbal ulceration and thinning.

MANAGEMENT The multitude of therapeutic strategies used against Mooren ulcer underscores the relative lack of effective treatment. Topical corticosteroids (including difluprednate), contact lenses, acetylcysteine 10% and L-cysteine (0.2 molar), topical cyclosporine, limbal conjunctival excision, and lamellar keratoplasty have all reportedly been used with variable success. More recently, topical interferon-α2a (IFN-α2a) and topical cyclosporine 2%, as well as infliximab, have also been reported as effective alternatives. Systemic immunosuppressive agents such as oral corticosteroids, cyclophosphamide, methotrexate, and cyclosporine have also shown promise in these cases. Hepatitis C–associated cases of Mooren ulcer–type PUK have responded to interferon therapy.

Erdem U, Kerimoglu H, Gundogan FC, Dagli S. Treatment of Mooren’s ulcer with topical administration of interferon alfa 2a. Ophthalmology. 2007;114(3):446–449.

Fontana L, Parente G, Neri P, Reta M, Tassinari G. Favourable response to infliximab in a case of bilateral refractory Mooren’s ulcer. Clin Experiment Ophthalmol. 2007;35(9):871–873.

Kafkala C, Choi J, Zafirakis P, et al. Mooren ulcer: an immunopathologic study. Cornea. 2006;25(6):667–673.

Tandon R, Chawla B, Verma K, Sharma N, Titiyal JS. Outcome of treatment of Mooren ulcer with topical cyclosporine A 2%. Cornea. 2008;27(8):859–861.

Wilson SE, Lee WM, Murakami C, Weng J, Moninger GA. Mooren-type hepatitis C virus-associated corneal ulceration. Ophthalmology. 1994;101(4):736–745.

Zelefsky JR, Srinivasan M, Cunningham ET. Mooren’s ulcer. Expert Rev Ophthalmol. 2011;6(4):461–467.

Corneal Transplant Rejection

The cornea was the first successfully transplanted solid tissue. After other tissues had also been