Bcl-xl and Bak protein expression in human optic nerve axons in eyeballs post-trauma and in the eyes with absolute glaucoma

The aim of our study was an evaluation of Bcl-xl and Bak protein expressions in optic nerve axons in eyeballs after severe injury and absolute glaucoma. We examined a series of 41 eyeballs, which were enucleated, following extensive injury and a series of 19 eyeballs from patients with absolute glaucoma. The immunohistochemical reaction was performed, using antibodies against human Bcl-xl and Bak protein with LSAB and DAB. In the injured eyeballs in Group I, Bcl-xl protein expression was observed in 53.8%, Bak in 38.5%, in Group II, Bcl-xl in 40%, Bak 55%; in Group III, Bcl-xl in 62.5%, Bak in 62.5%. Nine (9), out of 19 (47.4%) cases showed Bcl-xl protein positivity, Bak 15, out of 19 (78.9%). The percentage of cases with Bak protein positivity was statistically higher than that for Bcl-xl (Bak/Bcl-xl p=0.0356). The results showed that there may be a dominance expression of proapoptotic proteins in optic nerve axons in glaucoma.