Systemic Inflammation in Retinal Vein Occlusion and Its Role in Clinical Outcomes of Secondary Macular Edema

Objectives: This study aims to analyze the association between systemic inflammation and clinical outcomes in patients with macular edema secondary to retinal vein occlusion (RVO). Methods: A retrospective analysis of 68 patients with acute RVO, in whom cardiovascular risk factors were assessed, was conducted. Laboratory determinations included levels of C-reactive protein (CRP) and homocysteine to explore the systemic inflammatory status. Optical coherence tomography (OCT) parameters and visual acuity (LogMAR) were collected at baseline. Follow-up visual acuity was determined after 12 months. The number of intravitreal anti-VEGF injections and the performed laser treatment were assessed after 12 and 24 months. Associations of inflammatory markers with clinical outcomes were analyzed by correlation analysis, and patients with or without evidence for inflammation were compared. Results: At baseline, the mean foveal retinal thickness (FRT) was 591 ± 277 µm, the mean average central retinal thickness (CRT) was 580 ± 227 µm, and the mean average central retinal volume (CRV) was 12 ± 3 mm³. The level of CRP at baseline was significantly associated with increased FRT, average CRT, and average CRV (p = 0.024; p = 0.027; p = 0.003). CRP levels were also associated with a lower BCVA at baseline and after 12 months (p = 0.018; p = 0.006). In patients with elevated homocysteine levels, a trend towards a higher number of required laser treatments was observed. No association between increased inflammatory parameters and the number of required intravitreal injections was detected. Conclusions: Systemic inflammation is associated with the severity of macular edema secondary to RVO. CRP concentrations could represent a prognostic marker for the course of the patient's visual acuity.