Long-term Outcomes of Trabeculectomy Versus Ahmed Glaucoma Valve Implantation in Vitrectomized Eyes

OBJECTIVES: This study compares the long-term outcomes and success rates of trabeculectomy and Ahmed glaucoma valve (AGV) implantation in vitrectomized eyes.
METHODS: This study included 58 eyes of 58 patients who had undergone pars plana vitrectomy and subsequently received either trabeculectomy (25 eyes) or AGV implantation (33 eyes) at our hospital between March 01, 2017 and April 01, 2023 and had at least 1-year follow-up. Complete success was defined as maintaining an intraocular pressure (IOP) between 5 and 21 mmHg without medication, whereas overall success was defined as achieving the same IOP range with or without medication. Failure was defined as an IOP exceeding 21 mmHg or falling below 5 mmHg, visual deterioration to light perception due to glaucoma progression or complications from glaucoma surgery, or the need for further glaucoma surgery.
RESULTS: The complete success was higher in the trabeculectomy group. Whereas both groups’ overall success rates were similar at the last follow-up (p=0.04). Both groups demonstrated a comparable failure rate (p=0.44). The probability of success in the trabeculectomy group was 92.0% at 12 months, 88.0% at 24 months, and 84.0% at 36 months, whereas in the AGV group, it was 87.8% at 12 months, 81.8% at 24 months, and 75.7% at 36 months. There was no difference in terms of post-operative complication rate in both groups. (p=0.36).
DISCUSSION AND CONCLUSION: Both AGV implantation and trabeculectomy yield comparable outcomes in vitrectomized eyes. However, trabeculectomy reduced the requirement for antiglaucoma medications postoperatively. Consequently, trabeculectomy may be a viable option in carefully selected vitrectomized eyes.

Keywords: Ahmed glaucoma valve, Trabeculectomy, Vitrectomized eyes