Outcomes of Sequential Glaucoma Drainage Implants in Refractory Glaucoma

Area of Science:

• Ophthalmology
• Glaucoma Research
• Surgical Outcomes

Background:

• Glaucoma drainage implants (GDIs) are used to manage refractory glaucoma.
• A second GDI surgery may be necessary when initial treatment fails.
• Understanding outcomes of secondary GDI surgery is crucial for treatment planning.

Purpose of the Study:

• To evaluate the efficacy and safety of a second glaucoma drainage implant (GDI) surgery.
• To assess intraocular pressure (IOP) reduction and success rates after secondary GDI implantation.
• To identify factors influencing outcomes in eyes undergoing repeat GDI surgery.

Main Methods:

• Retrospective review of 65 eyes (63 patients) undergoing a second GDI surgery between 2006 and 2013.
• Primary outcomes: IOP reduction and success rates (defined as 6 ≤ IOP ≤ 21 mm Hg with ≥20% IOP reduction and stable medication use).
• Secondary outcomes: Glaucoma medication use, visual acuity, reoperations, and complications.

Main Results:

• Mean follow-up was 22.4 months. IOP decreased from 25.8 to 17.4 mm Hg (P=0.004) and medication use decreased from 3.6 to 2.5 (P=0.01) at 3 years.
• Success rates were achieved with no significant difference based on GDI type (Ahmed FP7, Baerveldt 250) or quadrant (inferotemporal, inferonasal).
• No significant change in visual acuity; common complication was corneal edema (14%).

Conclusions:

• Secondary glaucoma drainage implant surgery provides adequate IOP control and reduces medication burden in most patients.
• The choice of GDI type or surgical quadrant does not significantly impact failure rates.
• Repeat GDI surgery is a viable option for managing advanced glaucoma, with predictable outcomes.