Clinical Observation On Ahmed Valve Implantation For The Treatment Of Refractory Glaucoma

Objective: To evaluate the clinical efficacy and postoperative complications ofAhmed glaucoma valve (AGV) implantation for the treatment of refractory glaucoma.Methods: A retrospective case series of23eyes in21patients with refractoryglaucoma that received AGV implantation between August2012and August2014were studied. There were15(71.4%) male patients and6(28.6%) female patients,with a mean age of55.9years (range29-74years).10cases of neovascular glaucoma,7cases of failed filtering operation,2cases of traumatic glaucoma, and4cases ofsecondary glaucoma after vitrectomy were included. Postoperative visual acuity,intraocular pressrure (IOP), anterior chamber depth, endothelial cells, andcomplications during the follow-up were recorded.Results: The follow-up period was12months. The probability of completesuccess was69.57%(16eyes), the rate of part success was13.04%(14eyes), and totalsuccess was82.61%(19eyes). Invalid cases included2eyes of neovascular glaucoma,1eye of failed filtering operation, and1eye of secondary glaucoma after vitrectomy.Visual acuity was improved in11eyes (47.82%), was no changed in8eyes (34.78%)and was reduced in4eyes (17.39%) at1month after AGV implantation, while whichwas improved in7eyes (30.43%), was no changed in9eyes (39.13%) and wasreduced in7eyes (30.43%) at12month after surgery. The preoperative average IOPwas (33.19±10.93) mmHg. After the surgery, the average level of IOP was (11.24±3.87) mmHg at1month, with reduced IOP in22eyes (95.65%) and increased IOP in1eye (4.35%). Postoperative IOP at12months was (14.08±3.26) mmHg with reducedIOP in23eyes (100%). There was no significant difference in the anterior chamberdepth at1month or12months after the surgery compared with that before surgery.The density of corneal endothelium cells decreased after Ahmed glaucoma valve implantation in all23eyes. Compared to a preoperative value of (2051.37±90.58)cells/mm2, the corneal endothelium at1month was (1962.98±179.01) cells/mm2and at12months was (1800.94±187.75) cells/mm2(P<0.01). Postoperative complicationswere observed in8eyes of8patients (34.7%), including shallow of anterior chamberin2eyes, transient ocular hypotension in2eyes, obstruction of the inflow tube in2eyes and hyphema in1eye at early stage, and encapculated cyst formation in1eye atlate stage.Conclusion: Ahmed glaucoma valve implantation is an effective method forreducing the intraocular pressure in the treatment of refractive glaucoma, althoughthere are some complications.