Choroidal thickness alterations in idiopathic acute retinal vasculitis.

Background: To evaluate changes in sub-foveal choroidal thickness in patients with acute idiopathic retinal vasculitis compared with age-matched healthy subjects and unaffected fellow eyes.

Methods: This prospective observational study included 36 eyes of 23 acute idiopathic retinal vasculitis patients (group V) which included a sub-group of 10 eyes of 10 patients with unilateral vasculitis (group UV), and 50 eyes of 25 healthy subjects (group N). The assessment involved demographics, systemic examination, comprehensive ocular examination, fundus photography with/without fundus fluorescein angiography, and spectral domain-optical coherence tomography with enhanced depth imaging.

Results: There was significant difference between the mean sub-foveal choroidal thickness in groups V and N (V: 338.86 ± 28.72 um; N: 296.72 ± 19.45 μm; 0.001). The eyes of patients with unilateral vasculitis compared with unaffected fellow eyes had no significant difference in best corrected visual acuity (group UV: median = 0.2; range = (0.0-0.3) and group N: median = 0.2; range = (0.0-0.3);  = 0.35) but the sub-foveal choroidal thickness was significantly increased in the involved eye (group UV: 333.5 ± 16.68 um; group N: 284.4 ± 15.68 um; 0.001). The BCVA was significantly lower in the eyes with anterior chamber inflammation (median = 0.2; range = (0.0-0.3) and; median = 0.1; range (0.0-0.3);  = 0.002), but there was no statistically significant difference in sub-foveal choroidal thickness measurement between the two groups of vasculitis patients with and without anterior chamber inflammation (334.3 ± 18.85 um and 336 ± 31.56 um;  = 0.22).

Conclusion: The sub-foveal choroidal thickness increases during active inflammation in eyes with idiopathic retinal vasculitis compared with unaffected fellow eyes and healthy control eyes. Thus, measurement of the sub-foveal choroidal thickness on optical coherence tomography with enhanced depth imaging can serve as a non-invasive modality in the diagnosis and monitoring of acute idiopathic retinal vasculitis.