Outcomes of Fornix-based Versus Limbus-based Conjunctival Incisions for Glaucoma Drainage Device Implant

Purpose: To determine the effect of conjunctival incision location on the long-term efficacy of nonvalved glaucoma drainage devices. Materials and Methods: We conducted a retrospective review of patients >= 18 years of age with uncontrolled glaucoma [intraocular pressure (IOP) >= 18mm Hg] who underwent glaucoma drainage device implantation. A comparison was made of a limbal-based (LB-BGI) versus fornix-based (FB-BGI) conjunctival flap during placement of a 350-mm(2) Baerveldt glaucoma implant (AMO, Santa Ana, CA) in subjects with at least 1 year of follow-up data. The primary outcome measure was IOP; secondary outcome measures were medication burden, visual acuity, and surgical complications. Results: One hundred sixty eyes of 147 glaucoma patients were included. Two years after surgery, the IOP in the LB-BGI group was 14.3 +/- 5.3mm Hg and in the FB-BGI group 13.1 +/- 4.7mm Hg (P = 0.47). Overall success of IOP control was achieved at the final visit (range 1 to 5 y) in 90% of the LB-BGI group and 87% of the FB-BGI group (P = 0.63). The medication burden of the 2 groups at 1 and 2 years after surgery was not statistically significantly different. Worsening of visual acuity by more than 2 lines was not statistically different between the groups 2 years after the surgery and at the final visit (P = 0.47, P = 0.60, respectively). A greater number of eyes developed endophthalmitis and were more likely to undergo subsequent tube revision in the FB-BGI group, but the differences were not significant. Conclusions: Both incision techniques were equally effective in controlling IOP. Each surgical approach has its advantages and this study suggests that either technique may be used safely and effectively.