Surgical Outcomes of Mitomycin-C Augmented Trabeculectomy in Neovascular Glaucoma and Prognostic Factors for Surgical Failure in Thailand

Purpose: To evaluate the surgical outcomes and identify ocular and systemic prognostic factors of trabeculectomy with mitomycin C (MMC) in the eyes of patients with neovascular glaucoma (NVG) in Thailand. Patients and Methods: This retrospective study was conducted by reviewing records of Thai patients with NVG who underwent trabeculectomy with MMC between 2013 and 2022. Criterion failure was defined as intraocular pressure (IOP) >21 mmHg or less than a 20% reduction below baseline on two consecutive study visits after 3 months, IOP ≤5 mmHg on two consecutive study visits after 3 months, reoperation for glaucoma, and loss of light perception. Kaplan-Meier survival curves were used to examine success rates, and risk factors were analyzed using Cox's proportional hazard model. Results: The study included 106 eyes of 106 patients with a mean age of 57 years (range, 27-87 years). The cause of NVG was proliferative diabetic retinopathy (PDR) in 63 eyes (59.43%), central retinal vein occlusion (CRVO) in 39 eyes (36.79%), and ocular ischemic syndrome (OIS) in 4 eyes (3.77%). The cumulative probability of success in the first year was 73.6% with anti-glaucoma medication and 54.7% without medication. The multivariate model demonstrated that major cardiovascular events (hazard ratio [HR], 2.778 p=0.001) and preoperative systemic antiglaucoma medication use (HR, 1.837, p=0.045) were prognostic factors for surgical failure among all NVG patients. Postoperative manipulation with a subconjunctival injection of MMC occurred significantly more frequently in the failure group (HR, 3.100; p<0.001). Conclusion: Trabeculectomy with MMC effectively reduced the elevated IOP associated with NVG in Thailand. Underlying systemic diseases involving major vascular events and the use of adjunct systemic IOP-lowering medications were prognostic factors for surgical failure.