Reduced contrast sensitivity function and outer retina thickness in convalescent Vogt-Koyanagi-Harada disease.

Background: To evaluate contrast sensitivity function (CSF) in convalescent Vogt-Koyanagi-Harada (VKH) disease and investigate the relationship between CSF and chorioretinal thickness in VKH patients with and without sunset glow fundus (SGF).

Methods: This is a cross-sectional study. Seventy-six eyes of VKH patients and 56 eyes of normal controls were evaluated. Patients were divided into SGF and non-SGF groups. The best-corrected visual acuity (BCVA) of all the participants was ≤0.0 logMAR. Their CSF and macular chorioretinal thickness were measured with quantitative CSF (qCSF) and Optical Coherence Tomography (OCT) and compared using repeated measures analysis of variance at the group level. Relationships between CSF and macular chorioretinal thickness were evaluated using generalized estimating equations.

Results: The CSF was significantly impaired in the SGF group compared to that in the control group (p = 0.001), especially at medium and high spatial frequencies. No significant CSF difference was found between the non-SGF group and control group, nor between the SGF and non-SGF groups. Compared to the controls, outer retinal thickness (ORT) in both VKH subgroups was significantly reduced (P < 0.001 or 0.005, respectively), although their outer nuclear layer thickness (ONLT) and choroidal thickness (CT) were not significantly different (both P = 1.000, P = 0.829 or 0.112, respectively). We found no significant correlation between CSF metrics and outer retinal thickness.

Conclusions: Despite good recovery of visual acuity, reduced CSF and outer retina thickness were found in convalescent VKH patients. CSF may be an important and sensitive metric to evaluate functional vision in VKH disease.