Purpose:
This report describes three patients who underwent successful AlphaCor (Coopervision) keratoprosthesis implantation but had limited post-operative vision. The use of different contact lens fitting strategies for the visual rehabilitation of Alpha-Cor patients, as well as the complications that can arise with contact lens use in this population are reviewed.The Alpha-Cor keratoprosthesis is a synthetic cornea consisting of a one piece disc made of PHEMA (2 hydroxyethyl methacrylate). The outer skirt has a sponge-like consistency which promotes biointegration and the optic portion is a transparent core which allows the passage of light. Indications for Alpha-Cor placement include multiple failed grafts or conditions in which the prognosis for successful keratoplasty is guarded. The irregular corneal surface imparted by the keratoprosthesis can prevent visual rehabilitation with spectacles alone. In particular, the central portion of the synthetic cornea is focally depressed at the area of the central optic and the mid peripheral cornea in the area of the skirt tends to be very steep. This topographic configuration can present challenges for contact lens fitting.
Methods:
Retrospective chart review
Results:
In this case series, soft lenses were not able to provide usable vision. The rigid lens designs that worked best were reverse geometry designs with very flat base curves and larger diameters. Hybrid lens design also worked well in two cases. Care must be exercised in the choice of solutions and frequent follow up is needed to monitor for complications.
Conclusions:
In this series, soft contact lenses were not a viable option. Reverse geometry, large diameter rigid lenses made of highly oxygen permeable materials, as well as hybrid lenses yielded the best results.
Keywords: contact lens • keratoprostheses • proliferation