Glaucoma is the world's leading progressive and irreversible cause of blindness.Lowering intraocular pressure is the main method for treating glaucoma.Refractory glaucoma is a special type of glaucoma where intraocular pressure can't be effectively controlled by medication, laser or conventional surgery.Ahmed glaucoma drainage valve (AGV) implantation is one of the main treatment methods for refractory glaucoma.Its unique valve structure effectively inhibited early postoperative low intraocular pressure and related complications.However, the long-term success rate is not ideal.The most common cause of surgical failure is excessive fibrous tissue formation around glaucoma drainage devices, resulting in the increase of outflow resistance in the filtering area, and elevating intraocular pressure.Therefore, inhibiting the formation of fibrous tissues around glaucoma drainage devices is the key to improving the success rate.At present, the most common clinical anti-scarring method is the application of anti-metabolic drugs during and after operation, but the long-term effect is not ideal.In recent years, with the continuous improvement of the structural design, manufacturing materials and manufacturing technology of aqueous humor drainage device, the success rate of AGV implantation in the treatment of refractory glaucoma is also gradually improving.In this review, we discuss the inhibition of scarring after glaucoma drainage valve implantation by adding coating, constructing porous structure and depicting surface micropatterns.These improvements in surface structure may provide a new approach for the treatment of filtration area scarring after AGV implantation.

Glaucoma is the world's leading progressive and irreversible cause of blindness.Lowering intraocular pressure is the main method for treating glaucoma.Refractory glaucoma is a special type of glaucoma where intraocular pressure can't be effectively controlled by medication, laser or conventional surgery.Ahmed glaucoma drainage valve (AGV) implantation is one of the main treatment methods for refractory glaucoma.Its unique valve structure effectively inhibited early postoperative low intraocular pressure and related complications.However, the long-term success rate is not ideal.The most common cause of surgical failure is excessive fibrous tissue formation around glaucoma drainage devices, resulting in the increase of outflow resistance in the filtering area, and elevating intraocular pressure.Therefore, inhibiting the formation of fibrous tissues around glaucoma drainage devices is the key to improving the success rate.At present, the most common clinical anti-scarring method is the application of anti-metabolic drugs during and after operation, but the long-term effect is not ideal.In recent years, with the continuous improvement of the structural design, manufacturing materials and manufacturing technology of aqueous humor drainage device, the success rate of AGV implantation in the treatment of refractory glaucoma is also gradually improving.In this review, we discuss the inhibition of scarring after glaucoma drainage valve implantation by adding coating, constructing porous structure and depicting surface micropatterns.These improvements in surface structure may provide a new approach for the treatment of filtration area scarring after AGV implantation.

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.