Objective: To study the presence and possible quantitative differences of matrix metalloproteinase-2 (MMP2) and its endogenous inhibitor, tissue inhibitor metalloproteinase-2 (TIMP2) and connective tissue growth factor (CTGF) in aqueous humor of patients with pseudoexfoliative glaucoma (PEXG), primary open angle glaucoma (POAG) and cataract patients (serving as controls) and to determine the potential role of these elements in the pathogenesis of glaucomas.
Patients and Methods: Aqueous humor samples were collected from 75 patients (25 patients with PEXG, 25 with POAG and 25 with senile cataract, who served as controls). Glaucoma and cataract subjects underwent routine glaucoma trabeculectomy and cataract extraction surgeries respectively. MMP2, TIMP2 and CTGF levels were measured using specific enzyme immunoassay (ELISA).
Results: Total MMP2 was detected in significantly higher concentration in aqueous samples from PEXG eyes and POAG eyes compared to control eyes. The ratio of MMP2 to its principle inhibitor TIMP2 was balanced in cataract samples as well as in samples from PEXG glaucoma patients but increased in POAG samples. The CTGF concentration in PEXG group was significantly higher compared to POAG and cataract groups.
Conclusion: Complex changes in MMP2-TIMP2 balance in aqueous humor may promote the abnormal matrix accumulation (in PEXG)
and matrix degeneration (in POAG) which may be causally involved in the pathogenesis of both glucomas. The increased CTGF concentration supports the proposed fibrotic pathology of glaucoma. Regulation of MMP2/ TIMP2 expression and anti-CTGF therapy may offer potential therapeutic avenues for controlling glaucoma. (Rawal Med J 2008;33:179-183).
Aqueous humor, matrix metalloproteinase-2, tissue inhibitor of matrix metalloproteinase-2, connective tissue growth factor, primary open angle glaucoma, pseudoexfoliative glaucoma, senile cataract.