[Alphacor keratoprosthesis: device, surgical technique and clinical outcomes]

Abstract

Purpose: Clinical evaluation of Alphacor keratoprosthesis in patients at high risk of corneal allograft rejection.

Design: Retrospective case series.

Patients and methods: Alphacor implantation was performed via a two-step procedure with intrastromal insertion followed by secondary exposure of the optic after 6 months. Visual acuity and occurrence of postoperative complications were evaluated.

Results: Fourteen eyes of 14 patients underwent Alphacor keratoprosthesis implantation. Mean follow-up was 15.6 ± 5.6 months (from 2 to 24 months). Postoperative mean visual acuity gain was 2.5 ± 3.1 lines (from 0 to +11 lines). Visual acuity was superior or equal to 20/200 in 21% of cases. Seven cases of stromal melt (50%) occurred, of which one case (7.1%) experienced spontaneous extrusion of the implant, three cases (21.4%) required tectonic penetrating keratoplasty, and three patients underwent lamellar keratoplasty on top of the implant. Three cases (21.4%) of retroprosthetic membrane were observed and successfully managed. One patient (7.1%) developed late endophthalmitis.

Conclusion: Alphacor is an alternative to corneal allograft in cases of corneal blindness at high risk of allograft failure. Throughout the preoperative evaluation, it is imperative to take into account the limitations of this keratoprosthesis in terms of indications, and additional studies are necessary in order to determine and refine the optimal surgical technique for implantation as well as the efficacy of postoperative treatments.