Purpose Patients with Vogt–Koyanagi–Harada (VKH) disease are known to have severe inflammation after cataract surgery. This study was designed to investigate the role of IL-17-producing T helper (Th17) cell-related pro-inflammatory cytokines on postoperative inflammation in VKH patients.

Methods Serum from nine VKH patients and nine controls with age-related or congenital cataract was collected before and 1, 7, 30 and 90 days after surgery, and aqueous humor (AqH) at the commencement of surgery. Protein levels of IL-23, IL-27, IL-17 and IFN-γ in serum and AqH were measured by ELISA. A laser flare-cell photometer was used to quantify intraocular inflammation.

Results Serum IL-23 levels were significantly increased in VKH compared with control patients and peaked at 1 day postoperative, decreased rapidly in the first week, then attenuated gradually. In VKH patients, serum levels of IFN-γ were elevated in the first week after surgery and IL-27 was upregulated in the first month. Importantly, serum IL-23 levels were strongly correlated with aqueous flare value (r=0.689; p=0.007) and cell counts (r=0.671; p=0.01) in VKH compared with control patients.

Conclusions The data indicate that serum IL-23 levels are significantly elevated in VKH compared with control patients and are strongly associated with postoperative intraocular inflammation.