Comparison of conjunctival vascularity changes using optical coherence tomography angiography after trabeculectomy and phacotrabeculectomy.

PURPOSE: To compare bleb vascularity changes using optical coherence tomography angiography (OCT-A) between mitomycin-C (MMC)-augmented trabeculectomy and phacotrabeculectomy and to determine whether bleb vascularity measurements during preoperative and early postoperative periods could act as surrogate parameters to predict surgical outcomes. METHODS: We retrospectively reviewed data for 72 eyes from 72 glaucoma patients who underwent MMC-augmented trabeculectomy with/without cataract surgery. Bleb area scans were obtained using OCT-A during the preoperative period; 1, 2, 4, and 6 weeks postoperatively; and 2, 4, and 6 months postoperatively. For conjunctival vascularity analysis, a semi-automated program was used to calculate color and brightness densities of the selected area. RESULTS: Color and brightness densities were decreased in the trabeculectomy group during all periods but not in the phacotrabeculectomy group at 4 and 6 weeks, as well as 2, 4, and 6 months postoperatively. Color and brightness densities were significantly higher in the phacotrabeculectomy group than in the trabeculectomy group after 6 weeks and 2, 4, and 6 months postoperatively. A Kaplan-Meier survival graph indicated that intraocular pressure differed according to glaucoma type but not surgery type. Logistic regression analysis revealed that brightness density 1 week postoperatively was correlated with reoperation. CONCLUSIONS: Changes in conjunctival vascularity density measured by OCT-A differed according to the surgical method. Following trabeculectomy with MMC, brightness density 1 week postoperatively may be a predictive index for surgical outcomes.