Associations between functional and structural measurements in non-acute Vogt-Koyanagi-Harada disease

Abstract

Purpose: To evaluate associations between functional and structural measurements in patients with non-acute VKHD.

Methods: In this cross-sectional study, 16 non-acute VKHD patients (32 eyes; 14 female) were evaluated with multifocal electroretinogram (mfERG), standardized automated perimetry (SAP) and optical coherence tomography (OCT)examinations. All included patients had a minimum 12 months of follow-up from acute onset and were participants of an ongoing prospective study since acute phase with systematic clinical imaging evaluations and electroretinogram examinations within a predefined treatment. Age- and gender-matched controls were included. Main outcomes were functional and structural abnormalities and their correlation; secondary outcome was correlation of these findings with clinical characteristics, including fundus abnormalities.

Results: SAP and mfERG parameters were significantly worse in patients than in controls. Fourteen eyes (43.7%) had disrupted ellipsoid zone (EZ); visual acuity (VA) was similar between eyes with intact or disrupted EZ. Eyes with intact and disrupted EZ differed significantly concerning N1 and P1 amplitudes and N1 peak time values on mfERG and mean sensitivity (MS), central sensitivity (CS), foveal threshold, visual field index, mean deviation (MD) and pattern standard deviation values on SAP. The area under the curve on receiver operating curves for P1 amplitude was 0.81 (cut-off value = 34.7 nV/deg² ) and for MD value was 0.84 (cut-off value = -5.2 dB). Central retinal thickness (CRT) significantly correlated with N1 and P1 amplitudes and P1 peak time values on mfERG (r = 0.354, r = 0.442 and r = -0.405, respectively) and MD, MS, CS and fovea threshold (log values) on SAP (r = 0.372, r = 0.406, r = 0.431 and r = 0.414, respectively). Statistically significant associations were found with the presence of peripapillary atrophy and recurrent anterior uveitis with a worse MD value (p = 0.004 and p < 0.001, respectively).

Conclusion: In non-acute VKHD, disrupted EZ and reduced CRT were correlated with impaired mfERG and SAP parameters, even in patients with good VA.

Keywords: electrophysiology; inflammation; optical coherence tomography; uveitis; uveomeningoencephalitic syndrome; visual fields.