Intracorneal bovine albumin: an immunologic model of corneal angiogenesis.

BACKGROUND: We characterized the neovascularization that follows the intracorneal injection of bovine albumin (BA) in rabbits as a model of corneal angiogenesis. METHODS: New Zealand white rabbits received intracorneal injections of phosphate-buffered saline with and without various amounts of BA. The rabbits were co-sensitized or pre-sensitized by intramuscular BA or were not sensitized. The corneal vascular response was quantified by ranking photographs taken periodically after the injection. RESULTS: In pre-sensitized animals, blood vessels were apparent within 4 days and reached maximum intensity 14 days after the intracorneal injection. Corneas also vascularized in non-sensitized rabbits, but a larger dose (> 0.2 mg BA) was required than in pre-sensitized animals (> 0.02 mg BA). Vascularization began later in non-sensitized animals and was less extensive than in pre-sensitized animals. CONCLUSION: The intracorneal injection of BA is a reproducible model of corneal angiogenesis in rabbits and should allow the involved immunological mechanisms to be elucidated.

The Tampa Trephine technique with cat corneal endothelium.

The Tampa Trephine (Martin Marietta Speciality Components, Largo, FL, U.S.A.) penetrating keratoplasty technique uses a 7.0-mm corneal donor button with six rectangular 1 x 2-mm tabs of Bowman's layer, 75 microns in thickness, which are inserted into the recipient stroma beneath Bowman's layer. We evaluated the safety of the Tampa Trephine tissue-trephination method on the cat corneal endothelium combining vital staining and scanning electron microscopy, comparing it with the standard Weck trephination technique. The Tampa Trephine tissue trephination produces a donor button with a 6.7-mm diameter central area of normal endothelium. Localized peripheral areas of cellular loss, endothelial and Descemet's tears, endothelial detachment, and folding along the border of the trephination were observed with the Tampa Trephine method, all located in an area of < or = 150 microns, adjacent to the edge of the button. Standard trephination induced a localized peripheral area of endothelial damage < 50 microns in extension from the donor edge. A theoretic maximal 8.4% peripheral endothelial cell loss is induced with the Tampa Trephine trephination method, compared with a 2.8% loss with the standard procedure. The peripheral location of the alterations after the Tampa Trephine does not hinder the viability of the corneal endothelium, as it has been clinically observed.