Failed Ahmed glaucoma valves: trabeculectomy versus repeat shunt surgery

Area of Science:

• Ophthalmology
• Glaucoma Surgery
• Surgical Outcomes

Background:

• Ahmed glaucoma valve (AGV) implantation is a common treatment for refractory glaucoma.
• Failure of AGV implants necessitates further surgical intervention.
• Evaluating alternative surgical strategies for AGV failure is crucial for optimizing patient care.

Purpose of the Study:

• To compare the efficacy and safety of trabeculectomy (TRAB) versus repeat Ahmed glaucoma valve (re-AGV) implantation in patients with prior AGV failure.
• To assess intraocular pressure (IOP) reduction and surgical success rates between the two surgical approaches.

Main Methods:

• A quasi-experimental study involving 48 patients with failed AGV implants.
• Patients underwent either TRAB with mitomycin C or re-AGV implantation.
• Surgical success was evaluated based on predefined IOP targets and percentage reductions from baseline.

Main Results:

• Trabeculectomy demonstrated a significantly higher cumulative probability of survival at one year compared to re-AGV, particularly with stricter success criteria.
• Both procedures significantly reduced IOP postoperatively, with TRAB achieving lower IOP levels beyond one month.
• Significantly fewer TRAB eyes (5%) required glaucoma medications at 12 months compared to re-AGV eyes (48%).

Conclusions:

• Trabeculectomy is a safe and effective alternative for managing failed AGV implants.
• TRAB leads to superior IOP control and higher success rates compared to repeat AGV implantation in selected patients.
• These findings support considering TRAB as a primary surgical option in cases of AGV failure.