Clinical Outcomes of Two Versions of the Ahmed Glaucoma Valve FP7 in Glaucoma Patients

TL;DR

This study compared two versions of a glaucoma drainage device and found the newer model reduced eye pressure more and had fewer short-term complications.

Contribution

The study provides a direct comparison of clinical outcomes between two generations of the AGV FP7 in refractory glaucoma patients.

Findings

The newer AGV FP7 model achieved a greater intraocular pressure reduction (52.5%) compared to the older model (42.4%).

The newer model was associated with fewer short-term complications like hypotony and choroidal detachment.

Both models achieved high therapeutic success in managing refractory glaucoma over one year.

Abstract

Background: The primary goal of surgical treatment for glaucoma is the sustained reduction of intraocular pressure (IOP). The Ahmed® Glaucoma Valve (AGV) (New World Medical, Inc., Rancho Cucamonga, CA) is a surgically implanted drainage device that allows bidirectional aqueous humor outflow and IOP regulation. Although multiple generations of the AGV have been developed, comparative studies evaluating patient outcomes remain limited. This retrospective study aimed to compare clinical outcomes following implantation of two different generations of the AGV FP7 in patients with complicated, refractory glaucoma.

Materials and methods: This retrospective study analyzed preoperative and postoperative clinical data from glaucoma patients who underwent AGV FP7 implantation at the Eye Clinic of St. Johannes Hospital in Dortmund, Germany. Two cohorts were compared: group A, treated with an earlier AGV FP7 model between January 2008 and December 2012 (n = 159 eyes), and group B, treated with a newer AGV FP7 model between January 2019 and December 2020 (n = 109 eyes). The newer version features a highly polished surface designed to reduce friction and tissue reaction, whereas the earlier model has a comparatively rougher surface. Clinical outcomes were assessed over a one-year follow-up period and included IOP reduction, number of antiglaucoma medications, changes in visual acuity, postoperative complications, need for reoperation, and overall therapeutic success.

Results: One year postoperatively, IOP reduction was significantly greater in group B (52.5%) compared to group A (42.4%). Despite this difference, the therapeutic target was achieved in both groups. The number of required topical antiglaucoma medications also decreased significantly following AGV implantation by 56.8% in group A and 68.6% in group B. The most common complication at discharge was ocular hypotony, observed in 30.8% of cases in group A and 19.6% in group B. However, no cases of persistent hypotony were reported in either group at the one-year follow-up.

Conclusion: Both the earlier and newer versions of the AGV FP7 effectively provided sustained IOP reduction in patients with refractory glaucoma. Although the newer generation demonstrated a greater IOP reduction and was associated with fewer short-term complications, including hypotony, choroidal detachment, and endothelial touch, overall therapeutic success remained high in both groups.

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