Phacoemulsification and Viscocanalostomy With or Without Silicone Implant in Primary Open-angle Glaucoma: A Randomized Clinical Trial.

Abstract

Purpose: To compare the outcomes of combined phacoemulsification and viscocanalostomy with versus without intrascleral implantation of Ahmed glaucoma valve (AGV) tube remnants in patients with primary open-angle glaucoma (POAG) and cataract.

Methods: A randomized clinical trial involving 60 patients with cataract and POAG was carried out. The case group underwent phacoemulsification and viscocanalostomy together with intrascleral implantation of AGV tube remnants, while the control group underwent the same procedures without any implant. The two groups were compared in terms of best-corrected visual acuity (BCVA), intraocular pressure (IOP), cup-to-disc ratio, number of ocular hypotensive medications, surgical success rate, and scleral lake size.

Results: Sixty patients were enrolled and equally divided into two groups. Postoperative IOP, BCVA, and cup-to-disc ratio did not differ significantly between the groups (P = 0.196, P = 0.724, and P = 0.443, respectively). Despite comparable IOP outcomes, the case group required a significantly higher number of ocular hypotensive medications at the final follow-up (P = 0.043). Anterior segment optical coherence tomography (AS-OCT) revealed significantly larger scleral lake dimensions in the case group in terms of length, height, surface area, and perimeter (all P $\le$ 0.001).

Conclusion: Our study found no significant difference in success rates or postoperative IOP control between combined phacoemulsification and viscocanalostomy with or without silicone implants. Although the case group demonstrated larger scleral lake dimensions on AS-OCT, this anatomical difference did not translate into superior IOP outcomes and was associated with a higher requirement for postoperative ocular hypotensive medications. The clinical significance of increased scleral lake size in the presence of an implant remains uncertain, and longer-term follow-up is warranted.