Differences in the Histopathology and Matrix Metalloproteinase Expression in Tenon's Tissue of Primary Open-Angle Glaucoma and Primary Angle-Closure Glaucoma

Abstract

PurposeTo investigate the differences in the histopathology and matrix metalloproteinase (MMP) expression in the Tenon's tissue of primary open-angle glaucoma (POAG) patients, primary angle-closure glaucoma (PACG) patients, and non-glaucomatous patients.MethodsPOAG and PACG patients, who underwent a trabeculectomy and had no history of ocular disease except glaucoma, were enrolled. The number and instillation period of topical eye drops were reviewed. For the controls, which were patients without glaucoma or a history of ocular surgery, the Tenon's tissue was obtained in the course of retinal detachment surgery. For glaucoma patients, the Tenon's tissue was obtained during the trabeculectomy. H&E and Masson's trichrome staining and immunohistochemistry for MMP-1, MMP-2, and MMP-9 were performed. A total of six eyes of POAG, six eyes of PACG, and four control eyes were evaluated.ResultsThe duration of topical anti-glaucoma medication and the mean number of anti-glaucoma medications were similar in the POAG and PACG groups. The levels of MMP-1 and 2 were elevated in the POAG and PACG groups compared to the control group (p=0.03, 0.01, respectively). Compared with the control group, the MMP-2 level was higher in the POAG patients (p=0.01), whereas the MMP-1 was higher in the PACG patients (p=0.04). The levels of MMP-9 in the POAG and PACG patients were not significantly different from that of the control patients (p=0.48, 0.26). The levels of MMP-2 were significantly lower in the PACG patients than in the POAG patients (p=0.02).ConclusionsThe MMP expression was altered in the Tenon's tissue of glaucoma patients compared to the control group. The levels of MMP-2 were lower in the PACG patients than in the POAG patients. These results suggest that there may be histopathological differences in the Tenon's tissue of POAG and PACG patients.

Histopathology, matrix metalloproteinase-2 and alpha smooth muscle actin expression in Tenon's capsule of eyes with congenital glaucoma

“…We observed more cellular and denser fibrous connective tissue within Tenon's capsule of glaucomatous eyes with significant increase in the collagen fibers compared to control group. These results are in agreement with Seo et al study 24 who reported increased collagen deposition with denser connective tissue in Tenon's capsule of adult glaucomatous eyes than in control group. Seo et al explained these results to be related to the long-term use of topical antiglaucoma medications but in contrast to the current study, children did not receive any preoperative topical medications.…”

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in the aqueous humour of patients with primary angle closure glaucoma - a quantitative study

“…The level of MMP-3 was significantly lower in PACG compared to in POAG, and comparable to the non-glaucoma controls. Seo et al reported that PACG patients showed lower levels of fibrosis and MMP expression in Tenon’s tissue than POAG patients [ 17 ]. They suggested that the difference was due to involvement of distinctive pathological mechanisms.…”

Retinal nerve fiber layer defect patterns in primary angle-closure and open-angle glaucoma: A comparison using optical coherence tomography

“…However, POAG is found equally in both sexes. Biochemically, Seo et al 2 found lower levels of matrix metalloproteinase 2 in the Tenon's capsule of PACG eyes than in that of POAG eyes. In addition, both structural and functional differences between these two types of glaucoma remain uncertain.…”