Ahmed glaucoma valve versus Ex‐PRESS glaucoma shunt in the surgical treatment of glaucoma: 2‐year follow up

Abstract Purpose To compare the surgical outcomes of Ex‐press glaucoma shunt with Ahmed glaucoma valve in glaucoma patients. Methods This study retrospectively reviewed the records of patients who underwent Ahmed valve implantation or EX‐PRESS shunt surgery. Neovascular glaucoma patients were excluded. Primary outcome measure was surgical success, defined as an intraocular pressure between 5 and 21 mmHg and a 20 % intraocular pressure reduction from baseline (with or without glaucoma medications) without glaucoma reoperation. Preoperative and postoperative endothelial cell count was also compared. Results In total, 52 patients (56 eyes) were included (27 Ahmed valve, 29 Ex‐PRESS shunt). 2 years complete success rate (without glaucoma medication) was 84.9% for Ahmed valve, 81.3% for Ex‐PRESS shunt (p = 0.452), and qualified success rate (with/without glaucoma medication) was 95.8% for Ahmed valve, 96.6% for Ex‐PRESS shunt. (p = 0.877) The Ex‐PRESS group had significantly greater reduction of intraocular pressure than Ahmed valve group at post‐op 3, 6 months. (18.3±5.3 mmHg versus 14.2±6.2 mmHg, 15.4±3.9 mmHg versus 13.3±4.4 mmHg, p = 0.001, p = 0.033). The number of glaucoma medication was significantly lower in Ex‐PRESS group than Ahmed valve group throughout the follow up period. At post‐op 2 years, corneal endothelial cell counts were significantly higher in Ex‐PRESS group than Ahmed valve group at post‐op 2 years. (1794.5±403.5 /mm 2 versus 2212.2±399.0/mm 2 , p = 0.010). Conclusions Compared with Ahmed valve, Ex‐PRESS shunt showed similar success rate and greater intraocular lowering effect until post op 6 months. Ex‐Press shunt also seems to be a safer surgery regarding the risk of endothelial cell loss.