Wound healing and glaucoma surgery: modulating the scarring process with conventional antimetabolites and new molecules.

Subconjunctival absorption of aqueous humor is an essential part of glaucoma filtration surgery. Mitomycin C (MMC) and 5-fluorouracil have been used to reduce postoperative episcleral fibrosis and scar formation in the filtering bleb area for more than two decades. Both antimetabolites have also been frequently injected before needling revision of failing filtering blebs. Recently, MMC was tried also in tube surgery and nonpenetrating filtering surgery, but its usefulness in these applications has not yet been determined. The main complications and side effects of antimetabolite-enhanced filtration surgery comprise development of thin-walled cystic blebs, late bleb leaks, bleb infections, endophthalmitis, chronic hypotony, hypotony maculopathy and corneal epithelial toxicity. Besides MMC and 5-fluorouracil, several other agents were proposed for decreasing episcleral healing after glaucoma filtering surgery. Only few were evaluated in randomized clinical trials, and none became generally accepted or widely used.