Title : The glaucoma drainage device (GDD) experience in a tertiary referral centre in Ireland over the past six and a half years
Abstract:
Background: The control of intraocular pressure (IOP) is a cornerstone of treatment for glaucoma. Glaucoma drainage devices (GDDs) are increasingly used in cases with uncontrolled IOP, despite maximum medical therapy. Recent trials demonstrated that the Baerveldt implant achieved lower IOP with fewer failures compared to the Ahmed valve, though at the cost of higher complication rate[1, 2]. The Paul Glaucoma Implant (PGI), a newer GDD, has shown a lower failure rate in recent studies[3].
To our knowledge, this is the largest presented sample of patients having received GDD surgery examined in Ireland.
Aims: To evaluate the efficacy of Baerveldt-350 and Ahmed FP-7 implants over a 6.5-year period and to analyse outcomes for the PGI, introduced in the past year.
Methods: We conducted a retrospective review of all patients who received GDD surgery with Baerveldt-350, Ahmed FP-7, or PGI implants at the Royal Victoria Eye and Ear Hospital (RVEEH) in Dublin from January 2018 to July 2024. Data included glaucoma type, ethnicity, and prior surgeries (trabeculectomy, cataract, MIGS, and cyclophotocoagulation). Failure was defined as IOP of <5mmHg or >18mmHg at most recent follow up, loss of light perception, or additional glaucoma surgery. Complete success was IOP control without medications, while qualified success permitted medication use.
Results: Among 112 patients, 41 received Baerveldt, 53 Ahmed, and 18 PGI implants. 87 with analysed due to incomplete data.
Qualified success was achieved in 53.7% (22) of the Baerveldt patients and 45% (24) of the Ahmed valve patients while complete success was seen in 7% (3) and 6% (3) respectively. The average follow-up period for Baerveldt patients was 841days and 794 days in Ahmed patients.
In terms of re-operation, 3 Baerveldt patients required revision or repositioning of tubes, none received further cyclodiode therapy. 4 Ahmed patients required cyclodiode therapy, 2 of which required repositioning reinsertion of tubes, and a further 1 patient had a tube removal. 72% of the PGI patients achieved complete success over an average follow up period of 97 days. In total, 54% of patients (66) achieved IOP reduction, and 56.5% (69) reduced medication use postoperatively.
Conclusions: All three GDDs provided sustained IOP reduction and decreased medication burden, with PGI demonstrating a promising complete success rate.
