Modified Deep Sclerectomy (D-lectomy MMC) for Primary Open-angle Glaucoma

Purpose To evaluate the outcome of modified deep sclerectomy [D-lectomy mitomycin C (MMC)] for medically refractory glaucoma patients. Methods In a retrospective comparative study, the surgical outcome in 1 eye each of 31 patients who underwent D-lectomy MMC was compared with that of 91 eyes of 91 patients who underwent trabeculectomy with adjunctive MMC. These eyes had a diagnosis of primary open-angle glaucoma or pseudoexfoliation glaucoma, a record of high intraocular pressure (IOP) exceeding 25 mm Hg, and planned for surgical intervention. In the D-lectomy MMC cases, a slit incision at the trabecular meshwork and peripheral iridectomy were created. The "lake" and trabeculo-Descemet membrane ("window") were examined by ultrasound biomicroscope, gonioscopy, and time-domain optical coherence tomography. Results Postsurgical IOP at 1, 3, 6, and 12 months after the D-lectomy MMC and trabeculectomy MMC were comparable (P=0.63-0.97). The filtering bleb was noted in 14 (45%) of the 31 D-lectomy MMC eyes at 3 months, and their survival was significantly less than trabeculectomy MMC subjects in which 81 of 91 eyes had the bleb at 3 months (P<0.0001). The lake was noted in 29 of 31 D-lectomy MMC eyes. The sealing of the once penetrated trabecular meshwork was complete at 3 months in 23 of 29 eyes by ultrasound biomicroscopic and/or gonioscopic examinations, whereas that was incomplete in 6 eyes. Conclusions Addition of a slit incision to the trabecular meshwork and peripheral iridectomy (D-lectomy MMC) improved postsurgical IOP of the deep sclerectomy to the level comparable with trabeculectomy MMC, with a less frequency of the bleb formation.