Comparison of Trabectome Ab Interno Trabeculectomy to Baerveldt and Ahmed Glaucoma Implants

Abstract

Purpose: To compare reduction of intraocular pressure (IOP) and number of medications after trabecular meshwork ablation with the trabectome (T) to Baerveldt (BGI) or Ahmed (AGI) glaucoma implants which bypass the conventional drainage system.

Methods: Retrospective study of outcomes of T (n=125), BGI (n=162) and AGI (n=44) up to 1 year. Procedures were performed by the same group of surgeons on comparable patient populations for primary and secondary open angle and primary angle closure glaucomas. Neovascular glaucoma led to exclusion. IOP and number of medications were compared with a non-paired Student’s t-test and considered significant for p<0.05. Postoperative vision reduction, even if temporary, elevated pressure of more than 20% or events requiring procedures were formally counted as a complication.

Results: T had a preoperative IOP of 22.0±7.7 mmHg that decreased to 14.7±3.4 mmHg at 6 months and 14.9±3.9 mmHg at 12 months. The number of medications dropped from 1.8 to 0.7. BGI had a preoperative IOP of 26.5±8.5 mmHg that decreased to 14.4±4.6 mmHg at 6 months and 14.5±4.9 mmHg at 12 months. The number of medications dropped from 3.0 to 2.1. AGI had a preoperative IOP of 31.2±8.9 mmHg that decreased to 17.2±5.1 mmHg at 6 months and 16.7± 6.2 mmHg at 12 months. The number of medications dropped from 2.7 to 2.2. IOPs at 6 and 12 months were not significantly different between T and BGI (p>0.05) or T and AGI (p>0.05). Drops were reduced in T by 0.9, in BGI by 0.9 and in AGI by 0.5. In T, transient cystoid macular edema (CME) occurred in 0.8% and 4.8% required further surgery. In BGI, there was hypotony in 6%, wound leaks in 4%, and cystoid macular edema in 4% while 5% required further surgery. In AGI, there were choroidal effusions in 7% and 7% required further surgery.

Conclusions: In this retrospective study, T, BGI and AGI had similar final IOPs and reduction of glaucoma medications at 6 and 12 months. In contrast to BGI and AGI, patients who underwent T had no serious complications.

Keywords: 568 intraocular pressure • 462 clinical (human) or epidemiologic studies: outcomes/complications • 633 outflow: trabecular meshwork