Retinal functional changes measured by microperimetry after immunosuppressive therapy in patients with Vogt-Koyanagi-Harada disease

PURPOSE. To evaluate the effect of immunosuppressive therapy on best-corrected visual acuity (BCVA), fixation stability, and central retinal sensitivity in patients with Vogt-Koyanagi-Harada (VKH) disease in the acute uveitic phase. METHODS. In this prospective study, 14 patients (28 eyes) were evaluated. Best-corrected visual acuity and MP-1 microperimetric evaluation of retinal sensitivity in the central 12 degrees and fixation stability were assessed at baseline and at 1, 3, 6, 9, and 12 months after treatment. RESULTS. At baseline, logarithm of the minimum angle of resolution (logMAR) BCVA, fixation stability, and mean retinal sensitivity levels were 0.685 +/- 0.6 (Snellen equivalent, 20/100), 61.2%+/- 29.0%, and 2.75 +/- 3.8 dB, respectively. At 3 months, logMAR BCVA (0.11 +/- 0.2, Snellen equivalent 20/25) and fixation stability (86.4%+/- 13.4%) were almost maximum (p<0.001 for both comparisons), and thereafter remained almost unchanged. Mean retinal sensitivity continued to improve up to 12 months (12.0 +/- 2.3 dB, p<0.001); however, it was still significantly decreased. There were significant correlations between logMAR BCVA and mean retinal sensitivity at all time points. The percentages of BCVA improvement were significantly higher than the percentages of mean retinal sensitivity improvement at all time points (p<0.001 for all comparisons). CONCLUSIONS. Compared with microperimetry, BCVA significantly underestimates macular dysfunction in VKH disease.