Complications of AlphaCor keratoprosthesis: A clinicopathologic report

PURPOSE: To describe the clinical and histopathologic features of intractable secondary glaucoma induced by AlphaCor keratoprosthesis. METHODS: An elderly woman with pseudoexfoliation glaucoma and pseudophakic bullous keratopathy in the right eye had graft failures after penetrating keratoplasty. Her best-corrected visual acuity at presentation was counting fingers in the right eye and 20/30 in the left eye. Examination showed severe corneal neovascularization. Chirila keratoprosthesis type II was implanted in 2 stages. Ten months later, the patient developed dense retrocorneal membrane, 360° occlusion of angles, intractable glaucoma, no light perception, and nasal stromal melting associated with partial extrusion of the keratoprosthesis. RESULTS: Histopathology revealed invasion of the porous material of the keratoprosthesis by reactive fibroblasts and multinucleated foreign-body giant cells. In the area of dehiscence, we noted thinning and lysis of the collagen fibers, infiltration of lymphocytes, and plasma cells with a sheet of fibroinflammatory tissue extending into the anterior chamber. CONCLUSIONS: Corneal stromal melting and retrocorneal prosthetic membrane formation after AlphaCor keratoprosthesis implantation led to intractable glaucoma and extrusion of the implant.