Abstract
Purpose :
Several surgical options are available after a glaucoma drainage device (GDD) fails to provide sufficient IOP reduction. Although not widely considered to be a viable option we evaluate the success rate of trabeculectomy after GDD failure.
Methods :
In this retrospective study, all patients from the Stein Eye and Doheny Eye Institutes who had trabeculectmy with MMC after a GDD were included. Demographic data, diagnosis, systemic conditions, surgery information, IOP, vision and number of medication in each visit are recorded. Criteria used to define success are defined in the Table.
Results :
Twenty eyes of 20 patients were included. Diagnoses were: primary open-angle glaucoma (10), uveitic glaucoma (4), chronic angle closure glaucoma (2) and iridocorneal endothelial syndrome (1). Median follow up was 3.7 years (range 1.1 to 10.2 years). Median time between GDD surgery and trabeculectomy surgery was 22.1 months (range 2 weeks to 6 years). Mean MMC usage was 6.2 ± 5.4 mg.min/ml. One serious complication was recorded as hypotony maculopathy in one patient.
Mean IOP (±SD) was reduced from 19.3 ± 4.2 to 9.8 ± 2.2, 8.8 ± 3.2 and 8.4 ± 1.5 at one, three and five years respectively (p<0.001 for all). Mean number of medication (±SD) before surgery was 2.9 ± 0.5 and was reduced to 0.4 ± 0.2, 0.8 ± 0.3 and 1.1 ± 0.4 at one, three and five years (p<0.001 for all).
Kaplan-Meier survival curves for each success criterion at five years of follow up are shown in the Figure.
Conclusions :
Widely used options for glaucoma treatment after prior GDD surgery include additional GDD surgery and endoscopic cyclophotocoagulation (ECP) . The results of trabeculectomy with MMC after GDD are at least comparable to these surgical options. Results for trabeculectomy after GDD surgery appear superior to those of repeat trabeculectomy surgery, perhaps due to less scarring of the limbal conjunctiva. Trabeculectomy is a reasonable option for surgical treatment of glaucoma in selected patients who have had one glaucoma drainage device implanted.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.