KERATOPROSTHESIS WITH BIOCOLONIZABLE MICROPOROUS FLUOROCARBON HAPTIC - PRELIMINARY-RESULTS IN A 24-PATIENT STUDY

Background: Most complications of a keratoprosthesis occur at the tiss ue-to-implant interface. The ideal prosthesis would eliminate this int erface by having the tissue actually grow into the supporting material . We present a prospective clinical human study of a novel biocoloniza ble keratoprosthesis in 24 eyes of 24 patients. Design: To promote imp lant stability, the 9-mm-diameter haptic was fashioned using a custom- made microporous fluorocarbon with a 4-mm-diameter, 2.67-mm-long, cent ral optic made of medical grade polymethylmethacrylate, giving a globa l visual field of 110 degrees to 130 degrees. Only bilaterally blind p atients with untreatable corneal diseases were included in the study. The haptic was inserted into a lamellar pocket delaminated in the stro ma, and the optic was positioned through a hole trephined in the centr al cornea. Results: The average follow-up was 15.7 months (range, 4 to 28 months). The host corneal fibroblasts penetrated and proliferated into the peripheral microporous fluorocarbon and provided anchorage be tween the cornea and prosthesis. Seventeen patients (70.8%) had visual acuity improvements. Mean corrected final visual acuity was 20/100 (r ange, zone to 20/400). Five anatomic failures occurred in the first 6 months (three extrusions, one dislocation of the optic, and one endoph thalmitis). We had one case (4.1%) of treatable glaucoma. We successfu lly removed four of five retroprosthetic membranes that had occurred. No retinal detachment occurred. Conclusion: The biocompatible inert mi croporous polymer did not eliminate all mechanical complications assoc iated with a keratoprosthesis.