Keratoprosthesis with biocolonizable microporous fluorocarbon haptic. Preliminary results in a 24-patient study
J. M. Legeais, G. Renard, J. M. Parel, M. Savoldelli and Y. Pouliquen
Department of Ophthalmology, Hotel-Dieu de Paris, France.
BACKGROUND: Most complications of a keratoprosthesis occur at the
tissue-to-implant interface. The ideal prosthesis would eliminate this
interface by having the tissue actually grow into the supporting material.
We present a prospective clinical human study of a novel biocolonizable
keratoprosthesis in 24 eyes of 24 patients. DESIGN: To promote implant
stability, the 9-mm-diameter haptic was fashioned using a custom-made
microporous fluorocarbon with a 4-mm-diameter, 2.67-mm-long, central optic
made of medical grade polymethylmethacrylate, giving a global visual field
of 110 degrees to 130 degrees. Only bilaterally blind patients with
untreatable corneal diseases were included in the study. The haptic was
inserted into a lamellar pocket delaminated in the stroma, and the optic
was positioned through a hole trephined in the central 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 between the cornea and prosthesis.
Seventeen patients (70.8%) had visual acuity improvements. Mean corrected
final visual acuity was 20/100 (range, 20/30 to 20/400). Five anatomic
failures occurred in the first 6 months (three extrusions, one dislocation
of the optic, and one endophthalmitis). We had one case (4.1%) of treatable
glaucoma. We successfully removed four of five retroprosthetic membranes
that had occurred. No retinal detachment occurred. CONCLUSION: The
biocompatible inert microporous polymer did not eliminate all mechanical
complications associated with a keratoprosthesis.
