Comparison of Baerveldt 101-350 Glaucoma Implant (BGI) versus Trabeculectomy with ExPress™ Shunt for the Treatment of Primary Open Angle Glaucoma

Importance: Trabeculectomy is very effective in lowering intraocular pressure for the treatment of glaucoma, but it carries with it possible complications and failure. The ExPress shunt (Alcon Laboratories, Fort Worth, TX, USA) is an adjunctive device that can be used at the time of trabeculectomy to create an external fistuliztion. An alternative established and highly efficacious technique is the implantation of a glaucoma drainage device for sustained intraocular pressure (IOP) lowering. Specifically, evidence has established the Baerveldt 101-350 glaucoma implant (BGI) to have the best sustained IOP lowering in long-term follow-up amongst the many options for glaucoma drainage devices. Objective: To compare outcomes in eyes that underwent Baerveldt 101-350 glaucoma implant (BGI) and trabeculectomy with ExPress shunt (Trab) in primary open angle glaucoma without any prior incisional glaucoma surgery. Design, Setting, and Participants: This was a retrospective study of outcomes in patients identified by CPT codes as having undergone glaucoma implantation or trabeculectomy (with ExPress shunt) for the treatment of Primary Open Angle Glaucoma between 2012 and 2015 at a single institution by 2 fellowship trained glaucoma surgeons. A total of 57 eyes that underwent Baerveldt 101-350 glaucoma implant and 38 eyes that underwent trabeculectomy cases with ExPress™ shunt were included in the study. All patients were diagnosed with primary open angle glaucoma. Cases were included into the study if the patient underwent BGI or trabeculectomy with ExPress shunt without any prior incisional glaucoma surgery. Main Outcomes and Measures: Main outcomes included IOP, medications, visual acuity (VA), and secondary glaucoma surgery, if any. Results: Survival rate at 12 months was 85% in the BGI group and 80% in trabeculectomy with ExPress Shunt. A statistically significant difference was not found in the survival distributions between surgery groups using the log–rank test. A total of 12 trabeculectomy and 9 BGI cases failed by our definition of success. These cases were included in the analysis of IOP, number of glaucoma medications, and VA. The mean IOP was reduced from 20.6 ± 5.6 mmHg to 12.4 ± 3.2 mmHg and from 20.7 ± 5.5 mmHg to 11.3 ± 4.8 mmHg at one year post-operation in the BGI group and the trabeculectomy with ExPress shunt group, respectively. On average, the BGI group showed an IOP reduction of 7.7 ± 6.1 mmHg, while trabeculectomy with ExPress shunt experienced a decrease of 7.9 ± 5.2 mmHg at one year post-operation. Medications were reduced from 3.5 ± 0.8 to 2.6 ± 1.3 at one year in the BGI group and from 3.7 ± 0.5 to 0.6 ± 1.8 in the trabeculectomy with ExPress shunt group. At one year post-operation, the BGI group had an average of 0.9 ± 1.1 medication reduction, while trabeculectomy with ExPress shunt cases had a reduction of 3.2 ± 1.3 medications. VA was compared in logMar. At baseline, the average for BGI logMar was 0.5 ± 0.7 and the average for trabeculectomy was 0.2 ± 0.3. At one year post-operation, the BGI group’s VA was 0.4 ± 0.4 while the trabeculectomy with ExPress shunt group’s VA was 0.1 ± 0.1. Conclusions and Relevance: The Baerveldt 101-350 glaucoma implant and trabeculectomy (with ExPress™ shunt) may have similar rates of success in the surgical treatment of primary open angle glaucoma in eyes that are naïve to prior incisional glaucoma surgery, with a higher dependence on topical medications post-operation in patients undergoing Baerveldt glaucoma implantation.