Aqueous carbonic anhydrase-1 overexpression and its association with cytokine profiles and macular structural changes in retinal vein occlusion-associated macular edema

The purpose was to evaluate aqueous carbonic anhydrase-1(CA-1) expression and explore its correlation with macular structural changes and other cytokines in patients with macular edema (ME) secondary to retinal vein occlusion (RVO). This was a retrospective cross-sectional study in which patients with RVO (n = 109) and control subjects (n = 37) were included. The concentrations of cytokines, including CA-1, PPK/PK, ICAM, bFGF, VEGF and MCP-1, in the aqueous humor were measured before intravitreal injection of anti-VEGF drugs or DEX drugs. We collected optical coherence tomography (OCT) images before obtaining aqueous humor. CA-1 levels in the aqueous humor were greater in the RVO group than in the control group, and CA-1 levels were lower in treated RVO patients than in treatment-naïve patients. In addition, the levels of other cytokines (PPK/PK, ICAM, bFGF, VEGF and MCP-1) tended to be similar to those of CA-1. CA-1 was positively correlated with visual acuity (VA) logMAR (r = 0.215; p = 0.03), PPK/PK (r = 0.58, p < 0.001), ICAM (r = 0.70, p < 0.001), bFGF (r = 0.48, p < 0.001), VEGF (r = 0.55, p < 0.001), MCP (r = 0.67, p < 0.001) and retinal hemorrhage (r = 0.309, p = 0.003) in RVO patients. In conclusion, CA-1 was overexpressed in RVO patients, especially in treatment-naïve patients. Additionally, increased CA-1 levels are associated with other aqueous cytokines, VA logMAR values and retinal hemorrhage in RVO patients.