Research progress on inhibition of filtration area scarring after implantation of Ahmed glaucoma valve

Ahmed glaucoma drainage valve (AGV) implantation is one of the main methods for the treatment of refractory glaucoma with a higher success rate than conventional filtration surgery.However, as a foreign body, the AGV often causes hyperplasia of scar tissue in the filtration area, wrapping around the drainage plate, thereby inhibiting aqueous fluid outflow and causing the intraocular pressure to rise again, leading to surgical failure.Although multiple injections of anti-metabolic drugs during and after AGV implantation can inhibit postoperative scarring, multiple postoperative subconjunctival injections will not only cause discomfort to patients, but also lead to complications.Therefore, it is necessary to improve the AGV to avoid repeated injection of the drug, achieve slow local release of the drug, and reduce the foreign body reaction of AGV at the same time.Recently, the development of new materials, such as Ologen collagen, poly (2-hydroxyethyl methacrylate), poly lactic-co-glycolic acid and opal shale and new techniques provides new methods to inhibit the scarring of filtration area after AGV implantation.This article reviews the methods and progress of inhibition of scar formation in filtration area from the aspects of development of AGV drainage plate materials, construction of drug delivery system of AGV combined with new materials, and improvement of AGV drainage plate structure.

Glaucoma; Glaucoma drainage implants; Drug delivery systems; Filtration area; Scar formation; Material improvement; Structural development