Sudden reversible vitritis after keratoprosthesis: an immune phenomenon?

PURPOSE To report our experience with late vitritis associated with keratoprosthesis (KPro). METHODS Between 1990 and 2003, 218 patients underwent an all-polymethylmethacrylate, collar button-shaped KPro surgery. Eight patients developed a total of 12 episodes of sudden, massive vitritis. Five of these patients had an Ahmed shunt implant, 3 had anterior vitrectomy during surgery, and 4 had a soft contact lens in place. Preoperative diagnoses were multiple graft failures, chemical burn, Stevens-Johnson syndrome, or ocular cicatricial pemphigoid. All patients were maintained on prophylactic topical ofloxacin 0.3% or polymyxin-B/trimethoprim, as well as prednisolone acetate 1% (in 2 cases, medroxyprogesterone 1%), at least twice daily. Vancomycin (14 mg/mL) was also given twice daily in 2 patients. RESULTS Vitritis occurred in 8 patients (12 episodes), 2 to 23 months postoperatively. All patients presented with sudden, very marked decrease in vision, with little or no pain, tenderness, conjunctival redness, or discharge. Eight of the 12 events were subjected to vitreous tap and injection of antibiotics and steroids on the day of presentation. Cultures grew Staphylococcus epidermidis, only in liquid (broth) media, in 3 cases; the other 5 showed no growth. The vitritis episodes resolved after 2 to 9 weeks. Full recovery to pre-episode status of a quiet eye with clear vitreous was seen in all patients. Visual acuity recovered almost completely or completely (mental debilitation in one patient made accurate assessment uncertain). CONCLUSIONS This phenomenon of sudden vitritis after KPro, with few other symptoms and with complete recovery, would be uncharacteristic of a bacterial endophthalmitis. It may represent a uveitic immune phenomenon.