Pearls from the EGS Guidelines
Publishing date: June 2020
Risk factors for conjunctival scarring include young age, African ancestry, inflammatory eye disease, long-term multiple topical medical therapy, recent intraocular surgery, previous conjunctival incisional surgery (including previous filtering surgery), and neovascular glaucoma. Anti-metabolites such as 5-fluorouracil (5-FU) and mitomycin-C (MMC) are frequently used to reduce the risk of postoperative conjunctival scarring. Research suggests that a large surface area of cytotoxic treatment, together with a large scleral flap and accurately sutured fornix-based conjunctival flap, leads to more diffuse posteriorly extended non-cystic blebs, giving a considerable reduction in bleb-related complications. Anti-metabolites should not enter the eye. 5-FU has a pH of 9.0 and one drop (0.05ml) of MMC is enough to cause irreversible corneal endothelial damage.
EGS Guidelines, 4th edition, Page 173.
1. Wells AP, Cordeiro MF, Bunce C, Khaw PT. Cystic bleb formation and related complications in limbus- versus fornix-based conjunctival flaps in pediatric and young adult trabeculectomy with mitomycin C. Ophthalmology 2003;110(11):2192-7.
2. Melo AB, Spaeth GL. A new, safer method of applying antimetabolites during glaucoma filtering surgery. Ophthalmic Surg Lasers Imaging 2010;41(3):383-5.
Pearls Manager: Andrew Tatham