Abstract:AIM: To evaluate the long-term prognostic outcomes associated with different treatment regimens for PDR, including panretinal photocoagulation (PRP), anti-vascular endothelial growth factor (anti-VEGF) therapy, vitrectomy, and combination approaches. METHODS: A comprehensive literature search was conducted across PubMed, Embase, Web of Science, and the Cochrane Library from database inception through March 31, 2024, with manual supplementary screening extended to June 30, 2024. Randomized controlled trials (RCTs) and comparative observational studies that directly evaluated at least two treatment regimens with a minimum follow-up of 1y were included in the principal therapeutic synthesis; imaging, screening, epidemiologic, and disease-characterization studies were retained as contextual evidence. Owing to substantial clinical and methodological heterogeneity, findings were synthesized through structured narrative synthesis in accordance with SWiM guidance, with evidence certainty assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. RESULTS: The evidence base comprised 20 studies encompassing 8742 participants and 9521 eyes. Major comparative trials, interpreted as moderate-certainty evidence, indicated that anti-VEGF therapy (ranibizumab) and PRP achieved broadly comparable long-term visual acuity outcomes in selected trial populations receiving structured follow-up. Anti-VEGF therapy was associated with better visual field preservation and a lower cumulative incidence of vision-impairing diabetic macular edema (DME) compared with PRP [22% vs 38%; hazard ratio (HR) 0.4, 95%CI: 0.3–0.7]. Combination therapy (PRP plus ranibizumab) demonstrated favorable neovascular regression in selected small comparative studies, and perioperative anti-VEGF adjuncts improved intraoperative conditions and reduced early postoperative hemorrhage in vitrectomy-treated eyes. CONCLUSION: Anti-VEGF therapy and PRP may provide broadly comparable long-term visual acuity outcomes in selected PDR patients, though important differences exist in treatment burden, visual field preservation, and complication profiles. Treatment selection should be individualized according to DME status, vitreous hemorrhage, tractional or fibrovascular components, prior PRP, anticipated adherence, and healthcare accessibility, with long-term surveillance remaining essential given the chronic and progressive nature of PDR.
