Demographic, Clinical, and Surgical Risk Factors of Pars Plana Vitrectomy (PPV) for Neovascular Glaucoma (NVG) Development in Type 2 Diabetes Mellitus Patients

Introduction: Neovascular glaucoma (NVG) is a severe type characterized by forming new blood vessels on the iris and the anterior chamber angle, often resulting from ischemic retinal diseases. Pars plana vitrectomy (PPV) is a standard surgical procedure for treating various retinal and vitreous conditions. Understanding the risk factors associated with NVG development following PPV is crucial for improving patient outcomes. Objective: To identify and evaluate demographic, clinical, and surgical risk factors associated with developing NVG following PPV. Patients and methods: A prospective cohort study was conducted over two years, involving 60 type 2 diabetes mellitus (T2DM) patients (31 males and 29 females; mean age 60.48±9.63 years) who underwent PPV at the Eye Clinic and Department of Clinical Immunology, University Clinical Center Sarajevo, Sarajevo, Bosnia and Herzegovina. Patients were thoroughly informed about the study, and written informed consent was obtained. Comprehensive data collection included demographic information, medical history, preoperative and postoperative eye examinations, and intraoperative details. Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States). Results: Within 12 months postoperatively, 17 patients (28.3%) developed NVG. Significant preoperative risk factors for NVG included prolonged duration of T2DM (p=0.037), elevated preoperative intraocular pressure (IOP) (p=0.024), and higher levels of vascular endothelial growth factor (VEGF) (p=0.011). Intraoperative factors, such as sharp dissection (p=0.000) and operative complications (p=0.004), were also significantly associated with NVG development. Multivariate logistic regression analysis identified prolonged T2DM duration (OR 1.132, p=0.023), increased preoperative IOP (OR 1.192, p=0.029), elevated VEGF levels (OR 1.002, p=0.016), and intraoperative sharp dissection (OR 0.114, p=0.006) as independent risk factors. Conclusions: Multiple preoperative and intraoperative factors influence the development of NVG post-PPV. Prolonged T2DM duration, elevated preoperative IOP, high VEGF levels, and specific intraoperative techniques significantly increase the risk of NVG. These findings underscore the importance of careful preoperative assessment and tailored intraoperative strategies to mitigate NVG risk in PPV patients.