Indications and outcomes of Ahmed glaucoma valve implants in Kenya

Abstract

Title: Indications and outcomes of Ahmed glaucoma valve implants in Kenya. Objective: To establish the indications, efficacy in control of intraocular pressure , complications and need for additional anti - glaucoma medication and surgery after Ahmed glaucoma valve implantation. Design: Retrospective case series Setting: The study was conducted in various institutions in Kenya where Ahmed valve implants are used as surgical therapy for control of intraocular pressure. These were: KNH , K ikuyu Eye U nit and Tenwek Mission Hospital . Subjects: All adults and children who had undergone Ahmed glaucoma valve implantation between 2006 and 2012. Outcome measures: This comprised of the mean intraocular pressure , use of additional anti - glaucoma drugs post - ope ratively, surgical complications and the need for additional surgery. Results : A total of 50 records were reviewed. The male to female ratio was 3:2.M ajority of the patients were in the 0 to 10 year age group. The age range was 2 to 83 years. The mean pre - operation IOP was 42.50 mm/ H g with a range of 21 to 63 mm/H g .Failed trabeculectomy was the most common i ndication of AGV implantation (20%).Four percent of all the patients had Ahmed valve surgery as the primary surgery. Paediatric glaucoma was the indicati on for surgery in 16% of the patients. There was a statistically significant reduction in the mean IOP after surgery throughout the follow - up period. On the firs t day after surgery the mean intraocular pressure reduced to 17.5 mm/H g from a mean IOP of 42.50 mm/H g before surgery. Sixty four percent of the patients were not on any glaucoma medication on the first post - operative day. The most common complication noted was hypotony, seen in four patients in the first day after surgery and in one patient in the fi rst year of follow - up. Conclusion : The most common indication for AGV use in Kenya was failed trabeculectomy. Other common indications were primary congenital glaucoma and neovascular glaucoma.Good IOP control was achieved with the AGV in patients who ha d uncontrolled glaucoma with the use of conventional medical therapy.There was a statistically significant reduction in the number of 10 anti - glaucoma medication used after surgery . Hypotony was the most common complication noted, whereas endophthalmitis was the most serious complication.