Active form of gelatinases in tear fluidin patients with corneal ulcer or ocular burn.

PURPOSE To investigate the expression of the active form of gelatinases (gelatinase A: matrix metalloproteinase-2 [MMP-2] and gelatinase B: matrix metalloproteinase-9 [MMP-9]) in ocular surface disorders, we determined the presence of the active form of these gelatinases in the tear fluid of patients with corneal ulcer or ocular burn. METHODS The subjects consisted of the ulcer group comprising 13 eyes, the burn group comprising 6 eyes, and the normal group comprising 10 eyes. Tear samples were taken by the method of the Schirmer test I. The tears were eluted using extraction buffer containing 0.01 M phosphate buffer solution (pH 7.2), 1% Tween 20 and 1 M NaCl, and analyzed by gelatin zymography. RESULTS Only the proforms of MMP-2, and MMP-9 were detected in the normal group and in uncomplicated herpetic keratitis or herpetic keratitis cases complicated by mixed infection in the ulcer group. Active MMP-9 was detected in mild corneal ulcer cases and mild ocular burn cases. Both active MMP-2 and active MMP-9 were detected in endogenous corneal ulcer cases and severe burn cases, including perforation cases. CONCLUSIONS Both active gelatinases were detected in tears of severe corneal ulcer or severe ocular burn cases. The active form of gelatinase expression may be related to the severity of ulceration.