Leukocytes in the early events of corneal neovascularization

Purpose. To study the early events in corneal neovascularization after alka li injury and their relationship to the presence and absence of leukocytes. Methods. A standardized 5.5-mm diameter penetrating central corneal alkali wound was induced in one eye in each of ten New Zealand white rabbits (2.5 kg). Tn five of the ten rabbits, 1.5 mL 5% fucoidin was given intravenousl y every 2 hours to prevent leukocytes from leaving the blood stream. Presen ce of hyaluronan (HA) and proliferating cell nuclear antigen (PCNA) in the corneas were analyzed using immunohistochemical staining 36 hours after inj ury. Results. In the alkali wounded corneas, HA was expressed intensively i n the limbal area where a massive infiltration of leukocytes was seen. PCNA was expressed in the vascular endothelium as well as in the corneal cells. In the leukocyte-free corneas, HA staining intensity and distribution were the same as in uninjured corneas. No positive PCNA staining was seen in th e vascular endothelial cells in these corneas. Conclusions. Extravasated le ukocytes in the alkali-burned corneas caused enhanced production of HA and proliferation of vascular endothelial cells.