Abstract
Purpose: :
To report 2-year results of the Ahmed versus Baerveldt (AVB) Study, a multicenter randomized clinical trial comparing the Ahmed-FP7 valve to the Baerveldt-350 implant for treating refractory glaucoma.
Methods: :
Patients were recruited from 7 clinical sites and treated by 10 surgeons between October 2005 and January 2009. Inclusion criteria required that patients be at least 18 years old and have uncontrolled glaucoma refractory to medical, laser and surgical therapy. Patients were randomized to receive either an Ahmed-FP7 valve or a Baerveldt-350 implant using standardized surgical technique. Outcome measures included intraocular pressure (IOP), visual acuity (VA), glaucoma medication use, complications and required treatments. Failure was defined as IOP>18mmHg on two consecutive visits after 3 months, additional glaucoma surgery, devastating complications, or progression to no light perception.
Results: :
250 patients were enrolled in the study, 129 of whom received the Ahmed-FP7 valve and 121 the Baerveldt-350 implant. There were no significant differences in baseline demographic and ocular characteristics, including age, ethnicity, glaucoma diagnoses, lens status, rates of rubeosis iridis, IOP, VA, mean number of glaucoma medications, mean number of previous surgeries, or mean number of previous laser therapies. At 2-years, mean IOP was 14.4±6.7 mmHg in the Ahmed group and 13.7±4.9 mmHg in the Baerveldt group (p=0.58). Mean number of glaucoma medications was 1.43±1.49 in the Ahmed group and 0.77±1.06 in the Baerveldt group (p=0.012). The cumulative probability of failure was 48.4% in the Ahmed group and 44.2% in the Baerveldt group (p=0.78). 22 (17.1%) patients in the Ahmed group had complications which required intervention compared to 31 (25.6%) patients in the Baerveldt group (p=0.098). LogMAR Snellen VA was 1.21±1.11 for the Ahmed group and 1.35±1.13 for the Baerveldt group (p=0.53).
Conclusions: :
At 2-years, the Ahmed-FP7 group and the Baerveldt-350 group had similar success rates, IOPs and visual acuities. They also required a similar number of interventions to treat complications of surgery and achieve these results. However, the Ahmed group required a greater mean number of glaucoma medications than the Baerveldt group.
Clinical Trial: :
www.clinicaltrials.gov NCT00940823
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • anterior chamber • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials