Endostatin directly inhibits corneal neovascularization, histology shows

SALVADOR-BAHIA, Brazil — A collagen/endostatin pattern observed around blood vessels in the corneal limbus has a direct inhibiting effect on corneal neovascularization, according to a poster presented here. The poster won the research award here at the Brazilian Congress of Ophthalmology.

Bruno Cançado Trindade, MD, and colleagues at Brazil’s Federal University of Minas Gerais, collected four normal corneas from three patients after they were rejected for transplant surgery. Five sclerocorneal rings were also collected after central button trephination. The tissues were fixed in 80% methanol and 20% DMSO at –20º C and embedded in paraffin. The researchers used an indirect immunofluorescence technique to localize collagen 18/endostatin in the tissue sections, which were analyzed using confocal microscopy.

The researchers reported that the limbus was highly vascular while the cornea was avascular in these tissues. The researchers found in their study that “a diffuse pattern of collagen 18/endostatin was detected around limbic blood vessels. Collagen 18 was found in epithelial basement membrane and in the basement membrane of the limbic blood vessels.”

The researchers went on to say, “the location of this protein and the antiangiogenic properties of endostatin may play an important role as a controlling mechanism against corneal neovascularization.”

More research is needed to determine the exact mechanism of corneal neovascularization and aid in its prevention, the researchers noted.