Effect of immunosuppressive therapy on oxygen saturation and diameter of retinal vessels in initial onset acute uveitis associated with Vogt-Koyanagi-Harada disease

Purpose: To demonstrate changes in oxygen saturation and calibre of retinal vessels in initial-onset acute uveitis associated with Vogt–Koyanagi–Harada (VKH) disease at baseline and during immunosuppressive therapy. Methods: In this prospective study, 22 patients (44 eyes) were studied. Retinal oximetry measurements were performed using the noninvasive spectrophotometric retinal oximeter (Oxymap T1) at baseline and at 1–3 months, 4–6 months, 5–7 months and more than 9 months after treatment. Results: At baseline, mean logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) was 1.12 ± 0.78 (Snellen equivalent, 20/265). Arteriolar and venular oxygen saturations were 108 ± 7% and 70 ± 9%, respectively and calibres of arterioles and venules were 12.1 ± 1.1 pixels and 16.9 ± 1.4 pixels, respectively. At 4–6 months of follow-up, logMAR BCVA was almost maximum (0.08 ± 0.1, Snellen equivalent 20/24; p < 0.001) and thereafter remained almost unchanged. After immunosuppressive therapy, arteriolar and venular oxygen saturation values continued to decrease up to >9 months of follow-up (92 ± 7% and 56 ± 10%, respectively; p < 0.001 for both arterioles and venules). Similarly, arteriolar and venular calibres continued to decrease up to >9 months of follow-up to 11.4 ± 0.9 pixels (p = 0.006) and 15.6 ± 1.3 pixels (p = 0.001), respectively. Conclusions: Eyes with initial-onset acute uveitis associated with VKH disease have increased oxygen saturation and calibres of retinal vessels at baseline. Immunosuppressive therapy normalizes these changes and in a similar pattern improves BCVA.