Intraocular cytokines and macular OCT used for prediction of
Aqueous humour (AH) cytokine levels before and after anti-vascular endothelial growth factor (VEGF) treatment were evaluated and linked with optical coherence tomography structural characteristics in eyes with diabetic macular oedema (DME).

This prospective study included 56 control patients with cataracts and 83 patients with DME manifesting as diffuse retinal thickening (DRT), cystoid macular oedema and serous retinal detachment (SRD). AH samples were obtained before intravitreal injection of anti-VEGF or cataract surgery. VEGF, interleukin (IL)-6, IL-8, IL-10, interferon-inducible protein 10 (IP-10) and monocyte chemotactic protein 1 (MCP-1) levels were measured by multiplex bead assay.

AH cytokine levels, central macular thickness (CMT), number of hyper-reflective foci (HF), continuity of external limiting membrane and ellipsoid zone (EZ) and best-corrected visual acuity were evaluated.

--In SRD, IL-6 and MCP-1 levels and HF were increased compared to DRT.

--At baseline, the number of HF was correlated with VEGF, IL-6, IL-8, IP-10 and MCP-1.

--Eyes sensitive to anti-VEGF treatment had high baseline levels of VEGF, MCP-1, HF and many EZ disruptions.

--DME patients with normal VEGF levels but with high levels of IL-8, IP-10 and MCP-1 had little change in CMT after anti-VEGF treatment.

AH concentrations of several inflammatory cytokines in DME were found to be variable between the three DME forms. The levels of VEGF and other inflammatory cytokines were linked to HF. Multiple HF at baseline indicated a considerable reduction in CMT, and eyes with normal VEGF but high inflammatory cytokines may be resistant to anti-VEGF therapy.