Correlations between tear fluid and aqueous humor cytokine levels in bullous keratopathy

Abstract Purpose To evaluate the correlation between tear fluid and aqueous humor (AqH) cytokine levels in eyes with bullous keratopathy (BK) and with normal endothelium. Methods This prospective consecutive case-series study included 71 eyes of 71 patients: 31 eyes with BK, 18 eyes with non-BK corneal diseases, and 22 eyes with uncomplicated cataract (healthy controls). Total protein and cytokine (interleukin [IL]-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, MIP-1α, MIP-1β, monocyte chemotactic protein [MCP]-1, E-selectin, P-selectin, soluble intercellular adhesion molecule [sICAM]-1, and IP-10) levels in the tear fluid and AqH were measured using multiplex beads immunoassay. The correlations between tear and AqH cytokine levels were assessed. Results The AqH protein level was significantly higher in BK eyes (1.09 ± 0.08 mg/mL) than in non-BK (0.63 ± 0.11, P = 0.0004) and healthy control (0.62 ± 0.06, P = 0.0002) eyes. The tear total protein and IL-4 levels were significantly higher in the BK group compared to healthy controls (P = 0.0374 and 0.0032, respectively). The AqH IL-8 and sICAM-1 levels were significantly higher in the BK group compared to controls (P = 0.0001 and 0.0083, respectively). In BK eyes, the tear IL-4 level was significantly correlated with the MCP-1(r = 0.563, P = 0.001) and total protein (r = 0.589, P = 0.001) AqH levels. The tear IL-8 level was significantly correlated with the MCP-1(r = 0.598, p = 0.001) and IL-4 (r = 0.781, p  Conclusions The tear cytokine levels are correlated with those of AqH only in BK, but not in non-BK and healthy controls.