[Clinical factors favoring excessive subconjunctival fibroblastic proliferation after glaucoma surgery]

To understand risk factors for failure of glaucoma filtering surgery.

A retrospective study of 67 eyes (16 nonpenetrating trabeculectomies, 51 trabeculectomies [31 with 5FU and 20 with mitomycin]) of 61 patients in whom 5FU bleb revision was needed because of increasing intraocular pressure. Postoperative incidents were analyzed to explain excessive subconjunctival fibroblastic proliferation.

In eight cases, IOP increased after 6.16 months (+/-2) and for 59 eyes, after 33.5 days after surgery (+/-11.4). Postoperative incidents were 24 (35.9%) bleb leaks, nine cases (13.4%) of hypotony with choroidal detachment, six (9.0%) iris incarcerations, seven (10.4%) cystic blebs, and 21 (31.3%) inflammatory flat blebs. After a mean follow-up of 27 months +/- 18, the success of bleb 5FU revision was 84.6% for nonpenetrating trabeculectomy (without glaucoma treatment, 69.2%; with medical treatment, 15.4%) and 73.9% for trabeculectomy (47.8% and 32.6%).

Postoperative outcomes favor an inner or outer obstacle to conjunctival filtration. Aqueous humor can no longer remain in the subconjunctival spaces, increasing the risk of glaucoma surgery failure. Early follow-up of glaucoma surgery is crucial to obtaining long-lasting filtration.