The authors present their experience using sterile, γ-irradiated corneal tissue without viable endothelium (VisionGraft Sterile Cornea, Tissue Banks International) in lieu of fresh donor cornea in Boston type 1 keratoprosthesis (KPro) implantation in 11 patients. They used precut donut-shaped corneal lenticules measuring 8.5 mm in diameter with a 3-mm central hole made with a femtosecond laser.
Surgical procedures were uneventful. Complete corneal re-epithelization was noted within 10 days in all cases. No complications related to the donor cornea (e.g., stromal necrosis, wound leak, or device extrusion) occurred over an average follow-up of 16.5 months.
The tissues selected for γ-irradiation processing have a clear and uncompromised stroma and meet the procurement and screening standards set forth by the Medical Standards of the Eye Bank Association of America but are not suitable for penetrating keratoplasty. The harvested tissues initially are frozen, cut into various shapes and thicknesses, and then sterilized by a validated γ-irradiation process.
VisionGraft Sterile Cornea is available as a whole cornea with a scleral rim or precut for specific applications, according to surgeon's specifications, with varying diameters, shapes, and thicknesses. The tissue has a shelf-life of one year at room temperature, allowing it to be kept in stock for use in emergency procedures, such as corneal patch and tectonic graft placement, as well as for scheduled procedures for which a viable endothelium is not required, such as in KPro implantation or glaucoma tube shunt surgery.
The authors note that fees for VisionGraft Sterile Cornea for use in KPro implantation are approximately 20 percent less than typical fees for fresh donor cornea. Although use of KPro implantation outside of industrialized countries requires careful consideration, experience gained thus far offers cautious optimism. The VisionGraft Sterile Cornea’s advantages in availability, long-term storage capability, and ease of use, make it an attractive alternative.