Observation of the efficacy of ranibizumab combined with dexamethasone intravitreal implant in the treatment of retinal vein occlusion-associated macular edema

Purpose: To observe the short-term efficacy and safety of ranibizumab combined with dexamethasone intravitreal implant (DEX) in the treatment of macular edema (ME) secondary to retinal vein occlusion (RVO) (RVO-ME), with a focus on biomechanical changes in retinal vascular and tissue dynamics. Methods: A prospective clinical case study was conducted. A total of 88 patients (88 eyes) with RVO-ME were included in the study. According to the treatment strategy, they were divided into the DEX and ranibizumab combination group (combination group), the DEX group, and the ranibizumab group, with 33 eyes, 24 eyes, and 31 eyes, respectively. Patients underwent best-corrected visual acuity (BCVA), spectral domain optical coherence tomography (SD-OCT), optical coherence tomography angiography (OCTA), contrast sensitivity (CS), and visual field testing. The combination group received DEX one week after the first ranibizumab injection, while the other groups followed standard regimens. Follow-up assessments were conducted at 1 week, 2 weeks, and monthly for 6 months. Results: All groups showed significant improvements in BCVA, the retinal thickness (CRT), superficial and deep macular vascular density (SVC-MVD) and macular vascular density of deep macular vascular complex (DVC-MVD), mean defect of light sensitivity (MD), contrast sensitivity (CS), compared to baseline (P < 0.001). The combination group demonstrated superior vascular microstructure improvement, with better SVC-MVD and DVC-MVD at multiple time points (P < 0.05). Biomechanical analysis revealed enhanced vascular compliance and hemodynamic stability in the combination group, contributing to its efficacy. The average injection frequency was lower in the combination group (4.39 ± 0.55) compared to the ranibizumab group (4.65 ± 0.92, P < 0.05). Adverse events included subconjunctival hemorrhage and transient intraocular pressure elevation, with no serious complications. Conclusion: The combined group had a more significant effect in improving vascular microstructure, good short-term efficacy, could reduce the number of injections, and had better safety. The biomechanical benefits, including improved vascular compliance and hemodynamics, highlight its potential for optimizing retinal microcirculation.