Abstract:
To compare fornix– and limbus–based Mitomycin–C (MMC) trabeculectomies with respect to bleb morphology and complications.
Retrospective review of all patients who underwent a MMC trabeculectomy at the Gainesville VA from Aug 2003 to Aug 2004. Phacotrabeculectomies, revision trabeculectomies and eyes with conjunctival incisional procedures in the post–operative period were excluded from the study. The surgical technique was similar in all eyes, other than in fashioning of the conjunctival flaps. 9 eyes with limbus–based and 8 eyes with fornix–based conjunctival flaps (FBCF) were identified. One patient with a limbus–based conjunctival flap (LBCF) died 4 months after surgery, was unavailable for final bleb analysis and hence was excluded. Digital slit–lamp photographs of the 16 blebs (8 FBCF and 8 LBCF) at final follow–up, were graded independently in a masked fashion, by two glaucoma specialists (JWD, MFS) using the Indiana Bleb Appearance Grading Scale.
LBCF and FBCF groups were similar with respect to their age and racial profile, glaucoma diagnoses and range of preoperative IOP. At the 3 month postoperative visit mean IOP in the two groups was 8.3 (Limbus) and 9.1mmHg (Fornix). LBCF achieved a mean IOP of 8.9mmHg (95%CI, 2.6) at an average of 288 post–operative days. In comparison FBCF achieved a mean IOP of 7mmHg (95%CI, 1.6) with a mean final follow–up of 140 days. None of the eyes needed postoperative glaucoma medications other than one eye in the LBCF group. Median bleb grades as per the Indiana Bleb Grading Scale are:
4 eyes (50%) in the FBCF group had bleb leaks in the early postoperative period as compared to none in the LBCF group. One eye in each group had a shallow AC needing reformation. Short–term bleb profiles in the two groups are similar with respect to their height, extent and vascularity. Both groups demonstrate excellent IOP control. Due to change in clinical practice patterns, eyes with LBCF currently have a longer follow–up. The incidence of bleb leaks was significantly higher in the FBCF group. No eyes with blebitis or endophthalmitis were noted in this small series.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • wound healing • conjunctiva