The following is a summary of “Long-Term Surgical Outcomes of Glaucoma Drainage Implants in Eyes with Preoperative Intraocular Pressure Less than 19 mmHg,” published in the January 2024 issue of Ophthalmology by Hallaj et al.
Researchers conducted a retrospective study to examine patients who underwent glaucoma drainage implant (GDI) surgery and had baseline intraocular pressure (IOP) of ≤18 mmHg, with a minimum one-year follow-up period.
They collected clinical data of 67 patients, each representing one eye, and assessed the performance of GDI over up to 7 years. GDI failure was determined by criteria including insufficient reduction in IOP of less than 20% compared to baseline at two consecutive visits three months post-surgery, loss of light perception, or the necessity for further glaucoma surgical interventions.
The results showed that the average age was 65.9 ± 13.2 years. The cases were male (52.2%), White (53.7%), and diagnosed with primary open-angle glaucoma (62.7%). 44 eyes had prior glaucoma surgery (68.6%), and 46 (68.6%) were classified as severe glaucoma. Postoperative (postop) IOP changes were insignificant; the average postop number of medications decreased from 2.4 ± 1.4 to 1.9 ± 1.2 medications two years post-surgery (P=0.0451). Postop complications (23.9%) included GDI exposure (7.5%), inflammation (4.5%), shallow anterior chamber (4.5%), and strabismus (1.5%). Hypotony was observed in 4 eyes (5.9%), with none developing hypotony maculopathy. The cumulative one-year failure rate was 56.7%, primarily attributed to the failure to reduce IOP.
Investigators concluded that GDI surgery in baseline IOP (≤18 mmHg) may reduce medication use and slow visual field loss in some; its limited IOP reduction and high complication rate necessitate cautious consideration.