Increased mast cell numbers in the conjunctiva of glaucoma patients: a possible indicator of preoperative glaucoma surgery inflammation.

PURPOSE: Inflammation is a risk factor for scarring after trabeculectomy surgery. Mast cells are important mediators of inflammation and scarring in allergic eye disease. This exploratory project investigated the presence of mast cells in the conjunctiva of glaucoma patients having trabeculectomy surgery.
METHODS: Conjunctival biopsies from glaucoma patients belonging to specific groups: medically treated glaucoma (M, n=6), repeat glaucoma surgery (S, n=8), and uveitic glaucoma (U, n=7). The control group (C, n=8) was retinal detachment patients undergoing repair surgery for the first time. Immunohistochemistry techniques stained for the presence of the intracellular mast cell enzyme tryptase.
RESULTS: The median mast cell tryptase-positive counts for all glaucoma groups (M, S, and U) ranged from 0.102-0.113 cells/mm2 compared to 0.064 cells/mm2 for group C. This was statistically significant comparing group S to group C (P=0.0063), but not when comparing groups U or M to group C. The mast cell tryptase-positive counts did not significantly differ among the groups.
CONCLUSIONS: Mast cell numbers were significantly increased in glaucoma patients who have previously undergone surgery (group S). Mast cell activity may contribute to the scarring process and the increased risk of excessive conjunctival scarring after trabeculectomy surgery. Further investigation needs to be performed to evaluate this potential role.