Elevated Inflammatory Cytokines Persist in the Aqueous Humor Years After Cataract Surgery

There is currently limited information regarding inflammation and cytokine levels in the aqueous humor (AH) of adult patients with cataract who have undergone phacoemulsification cataract extraction without other ocular comorbidities.

AH samples were collected from healthy, non-surgical donors and donors with a history of cataract surgery performed 3 to 12 years prior. Sixty-three cytokines and growth factors were measured using bead-based ProcartaPlex immunoassays. Data analysis included normal distribution assessment, pairwise correlation, logistic regression, and ridge regression.

Of the 63 molecules analyzed, 34 were selected for further study. Cytokines, such as CD40L, IL-7, MIP-1α, and LIF, were found at significantly higher concentrations in AH samples from donors with a history of cataract surgery compared with non-cataract controls. In contrast, lower concentrations of IL-23, TRAIL, IL-12p70, IFNγ, MIP-3α, and SCF were observed in post-surgical samples. Pairwise correlation analysis identified clusters of significantly correlated molecules, suggesting their potential involvement in the inflammatory environment of AH post-cataract surgery. AH concentration of 34 proteins was combined into a post-cataract surgery inflammation index (PCSII) using ridge regression, which differs significantly between post-cataract surgery donors and non-cataract controls. This PCSII shows that any increase in AH levels of these molecules can stratify cataract surgery donors into low and high-risk of inflammatory groups.

This study indicates that cataract surgery may lead to a chronic inflammatory state in the AH, which can persist for extended periods post-surgery.