Meta-analysis Of The Ahmed Glaucoma Valve Implantation For Refractory Glaucoma

Refractory glaucoma refers to the glaucoma that the intraocular pressures difficult to control in the normal range even the conventional filtration surgery or with adjunctive antimetabolites, as well as auxiliary and maximum tolerance of anti-glaucoma drugs are used. It includes the neovasvular glaucoma (NVG) caused by various reasons; secondary glaucoma caused by aphakic or pseudophakic, uveitis, keratoplasty, pars plana vitrectomy, etc; primary glaucoma and pediatric glaucoma after several failed filtration surgery; traumatic glaucoma and iridocirneal endothelial syndrome, and so on. As difficult to establish an effective filtering channel owing to the fibrotic effect around bleb, the success rate is only 11%-52%; especially the neovasvular glaucoma which prognosis is the worst, the success rate is only 11%-33%.At present, the treatment of refractory glaucoma consists of trabeculectomy with adjunctive antimetabolites, cyclodestruction surgery (such as cryotherapy on ciliary, laser cyclophotoc-oagulation or ultrasound treatment) and glaucoma drainage device implantation. Trabeculectomy with adjunctive antimetabolites sometimes still has difficulty in forming a functional filtering bleb. Cyclodestruction surgery is mainly applied to refractory glaucoma of operation, the strong inflammatory effects after surgery, the serious complications, the patient suffer from a great pain, moreover, because of the potential possibility of hypotony and phthisis bubli resulted from excessive destruction of the ciliary body, it should be carefully used on patients with good visual acuity or monocular visual acuity.Because the success rate of trabeculectomy with adjunctive antimetabolites, many postoperative complication of cyclophotocoagulation surgery induce bad visual acuity, and the development of the material of glaucoma drainage device, the glaucoma drainage devices (GDDS) are widely used in the clinical treatment of refractory glaucoma. In order to objective estimate the effect of Ahmed glaucoma drainage device in the treatment of refractory glaucoma, this text system evaluated the related literature to guide future clinical treatment. Objective:to system evaluate the effectiveness of Ahmed glaucoma valve implant for the treatment of refractory glaucoma.Methods:After collecting the control text clinical literatures published from 2000 to2010 on Ahmed glaucoma valve implant versus cyclophotocoagulation or trabeculectomy for the treatment of refractory glaucoma. The language of literatures is Chinese and English. The clinical evaluate index are the total success rate of the last follow-up time, the maintain of the postoperative visual acuity and the number of medications used in postoperation. Meta-analysis was carried out using Review manager 4.2. Fixed effort model or random effort model were applied for data processing to calculate the pooled odds ratio (OR) and its corresponding 95% confidence interval (95%CI) based on heterogeneity test.Results:(1) in accordance with the literature inclusion and exclusion criteria were selected to include Meta analysis of the literature 6, which AGV implant with cyclophotocoagulation for refractory glaucoma controlled trials of three documents, including a total number of cases 169 cases; AGV implant and trabeculectomy for refractory glaucoma controlled trials of three documents, a total of 109 cases, including the number of cases; (2) the literatures were described their quality score from three indicators which trabant, crypto-allocation and blinding, the results of six literatures were all B-class. Meta analysis showed that:AGV implant can be effective in maintaining visual acuity[OR 2.91,95%CI (1.31,6.44)], while the two surgical success rate of surgery was no significant difference;AGV implant can improve the success rate [OR 2.88,95% CI (1.06,7.80)] and reduce postoperative anti-glaucoma drug consumption [WMD-0.35,95%CI (-0.64,-0.06)] to compared with trabeculectomy.Conclusion:The present study showed that compared with cyclophotocoagulation, Ahmed glaucoma valve implant for refractory glaucoma surgery can improve visual acuity; compared with trabeculectomy, Ahmed glaucoma valve implantation can improve the follow-up censored time success rate. But the six literature about complications of different statistical methods, so this Meta-analysis of exposure factors was not analysis. Because of this systematic review included fewer cases, there is selection bias into the study and measurement bias of the high probability bound on the strength of evidence in this study, have a certain impact. These conclusions need more designed, large scale randomized controlled trials are needed.