Effect of guided Ahmed glaucoma valve implantation on corneal endothelial cells: A 2-year comparative study

Abstract

Purpose To compare the effects of guided and non-guided Ahmed glaucoma valve (AGV) implantation on the corneal endothelium. Methods Medical records of patients who underwent AGV implantation in the anterior chamber (AC) were reviewed retrospectively. The eyes were divided into two groups depending on the use of a guidance technique with spatula and a 4–0 nylon intraluminal stent. Specular microscopy was performed to measure corneal endothelial cell density (ECD) loss after surgery, and the rate of ECD change was calculated. Tube parameters were measured using anterior segment optical coherence tomography (AS-OCT). Results The ECD loss during 2 years of follow-up was significantly lower in the guided AGV implantation (gAGV) group than in the non-guided implantation (ngAGV) group, and the rate of ECD change was -0.62 ± 1.23 and -1.42 ± 1.57%/month in the gAGV and ngAGV groups, respectively (p = 0.003). The mean tube–cornea distance (TCD) and mean tube–cornea angle (TCA) were significantly greater in the gAGV group than in the ngAGV group. The frequency of tube repositioning within 2 years after surgery was 0% in the gAGV group and 12.66% in the ngAGV group (p = 0.005). Conclusions The use of a guidance technique can reduce corneal endothelial loss during the first 2 years after AGV implantation in the AC. The tube was positioned at a more distant and wider angle from the cornea in the eyes of the gAGV group, which may have contributed to the reduced need for tube repositioning to prevent corneal decompensation.

Failed Ahmed Glaucoma Valves: Trabeculectomy versus Repeat Shunt Surgery

“…After AGV failure, conventional options include repeat shunt implantation (5,6,9), capsulectomy shunt revision (4,11,18), and cyclodestructive procedures (19). Among these, second shunt procedures have shown promising results in various short-term reports (7, 8), however, corneal decompensation has been reported frequently in adult cases following sequential tubes in long-term (11,20). Furthermore, the success rates of second shunts has been modest in childhood glaucoma with common tube-related complications (21).…”

Glaucoma Drainage Device Implantation, Outcomes, and Complications

“…Progressive corneal endothelial cell loss (ECL) is a vision-threatening complication of GDD surgery, which can require complex care and additional surgery including corneal transplantation 25 . A healthy corneal endothelium is essential to maintain good visual acuity and corneal clarity.…”