Aqueous-humor biomarkers and real-world efficacy of conbercept for diabetic macular edema: a prospective study in elderly patients

Abstract

Background: To evaluate real-world efficacy of conbercept and the predictive value of aqueous-humor biomarkers in elderly diabetic macular edema (DME).

Methods: In this single-arm, prospective study, 150 patients ≥ 65 years received three monthly conbercept injections followed by pro-re-nata dosing over 6 months. Baseline vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) levels were quantified from aqueous humor; best-corrected visual acuity (BCVA) and central subfield thickness (CST) were monitored. Mixed-effects modelling and receiver-operating-characteristic (ROC) analysis explored associations between biomarkers and outcomes.

Results: Mean BCVA improved by approximately nine ETDRS letters, and CST declined by about 85 µm at Month 6. Higher baseline VEGF and IL-6 were associated with greater CST reduction and moderately increased odds of a ≥ 15-letter gain; VEGF showed fair discriminative ability (AUC=0.74). Treatment was well-tolerated, with no unexpected ocular or systemic adverse events.

Conclusion: Conbercept produced meaningful anatomical and functional benefits in an elderly DME cohort. Baseline aqueous VEGF and IL-6, while not definitive stand-alone tests, may help identify eyes likely to achieve pronounced anatomical improvement and warrant further investigation as components of a multi-marker predictive panel.

Keywords: IL-6; VEGF; aqueous humor biomarkers; conbercept; diabetic macular edema; elderly.