Intraluminal stenting versus external ligation of Ahmed glaucoma valve in prevention of postoperative hypotony

AIM:To compare intraluminal stenting and external ligation of Ahmed glaucoma valves(AGV)for refractory glaucoma management and postoperative hypotony prevention.METHODS:This randomized prospective blind study included 30 eyes of 25 patients(age range:44-56y)with refractory glaucoma.This study was conducted from September 2018 to January 2020.The study included two groups,AGV with intraluminal stenting group(n=15 eyes)and AGV with external ligation group(n=15 eyes).Follow-up period was one year postoperatively.The primary outcome was intraocular pressure(IOP)and its association with the number of postoperative glaucoma medications.IOP≤21 mm Hg without medications indicated complete success while IOP≤21 mm Hg with medications indicated qualified success;and IOP<6 mm Hg was defined as hypotony.RESULTS:After a year of follow-up,IOP was significantly reduced in the intraluminal stenting group than in the external ligation group(11.67±0.89 vs 14.2±4.0 mm Hg,respectively,P=0.024).Postoperative hypotony was more common in the external ligation group(2 cases,13.33%)than in the intraluminal stenting group(1 case,6.67%).CONCLUSION:Application of intraluminal stenting or external ligation during AGV surgery usually prevents postoperative hypotony(transient and persistent)that occurs in conventional AGV surgery.

An Ex-Press implant versus trabeculectomy in a fibrotic bleb with late failure after previous trabeculectomy

AIM: To compare the outcome of an Ex-Press implant and subscleral trabeculectomy(SST) in the management of glaucoma after previous trabeculectomy on a fibrotic bleb.METHODS: This randomized prospective study included 28 eyes from 28 patients(age range: 42-55 y) with primary open angle glaucoma(POAG) presented with elevated intraocular pressure(IOP) with fibrotic bleb despite previous SST for more than 4 mo. The eyes enrolled in the study were divided into two groups: group I(subjected to Ex-Press implant surgery) and group II [subjected to SST with mitomycin C(MMC)]. The follow-up continued one year after surgery to evaluate IOP, visual acuity(VA), visual field(VF), and postoperative complications. RESULTS: A significant decrease in IOP was found in both groups with a higher reduction in Ex-Press implant surgery with the mean IOP of 14.50 mm Hg(P=0.001), while the SST group recorded the mean IOP of 16.50 mm Hg(P=0.001) after one year. However, the difference between the two groups in terms of the decrease in IOP was insignificant. Fewer postoperative complications were recorded in the Ex-Press implant surgery and more cases requiring further anti-glaucomatous medications were seen in the SST group. Both groups showed stability in terms of VA and VF.CONCLUSION: Ex-Press implant surgery and SST with MMC are two surgical alternatives for controlling IOP in late failure that occurs more than 4 mo after previous SST with a fibrotic bleb. However, Ex-Press shunt is a safer surgery with fewer complications.