Increased levels of inflammatory immune mediators in vitreous from pseudophakic eyes

To determine if pseudophakic eyes have an increased and sustained level of inflammatory immune mediators in the vitreous compared to phakic eyes.

Vitreous fluid samples were obtained from 73 patients undergoing elective pars plana vitrectomy (PPV) as a result of a macular hole, epiretinal membrane, vitreous macular traction, or vitreous floaters. Forty eyes were pseudophakic and had previously undergone uncomplicated cataract surgery, ranging from a few months to several years prior to PPV. The vitreous samples were analyzed for 29 different inflammatory immune mediators using multiplex bead immunoassays.

A total of 14 cytokines (eotaxin, interferon-γ-induced protein-10 [IP-10], monocyte chemotactic protein-1 [MCP-1], macrophage derived chemokine [MDC], macrophage inflammatory protein [MIP]-1α, MIP-1β, thymus activation regulated chemokine [TARC], IL-12p40, IL-15, IL-16, IL-7, VEGF, IL-6, and IL-8) were detected in the vitreous of both study groups. Using multiple linear regression analysis, pseudophakia was significantly correlated with higher levels of vitreous immune mediators compared to phakia. Elevated vitreous levels were estimated to decrease over time for IL-6, IL-8, IL-15, IL-16, and VEGF, though they remained elevated for many months and even years compared to the levels detected in phakic eyes.

This is the first study to demonstrate that cataract surgery and pseudophakia can induce increased vitreous levels of a substantial range of inflammatory immune mediators. The elevated levels seem to be maintained for a long period of time. These increased levels of cytokines may be involved in inflammatory processes leading to several complications to cataract surgery, both early and late.