The clinical application of critical flicker fusion frequency in demyelinating optic neuritis

Abstract

Background: To investigate the application of critical flicker fusion frequency (CFF) in demyelinating optic neuritis (DON). Methods: A total of 127 eyes in 69 DON patients and 63 eyes in 33 healthy control (HC) groups were included between January 2021 and September 2021. Patients underwent best-corrected visual acuity (BCVA), visual field, optical coherence tomography (OCT), flash visual evoked potential (F-VEP), and CFF examinations. The patients were divided into different subgroups according to antibody subtypes, different degrees of visual acuity impairment, the different time intervals from onset to CFF examination, and performed subgroup analysis. The correlations between CFF and other ophthalmological examination: BCVA, visual field, flash visual evoked potential (F-VEP), in DON patients were analyzed in order. Results: The trichromatic values of red, green, and yellow in DON affected eyes were 21.83 9.03, 23.66 10.21, 24.09 10.77 Hz, respectively, which was significantly reduced compared with the HC group (t ¼ 14.82, 14.22, 14.00; P < 0.001). The subgroup analysis showed no significant difference between different antibody subtypes (P > 0.05), whereas, a significant decrease of CFF trichromatic value was found in severe visual acuity impairment (P < 0.001). There was a significant difference in CFF-red, green, and yellow values at different time points (P < 0.001), to be specific, CFF fluctuated under 20 Hz within 3 months after onset and tended to be stable around 24–28 Hz. The results of correlation analysis showed that the peak time of F-VEP (r ¼ 0.486, 0.515, 0.526; P < 0.001), BVCA (r ¼ 0.640, 0.659, 0.642; P < 0.001), and which was negatively correlated with CFF three color. MD and CFF were positively correlated (r ¼ 0.486, 0.453, 0.476; P < 0.05). Conclusions: A significant decrease of CFF value was found in DON-affected patients, and it has a good correlation with visual function and latency of F-VEP, and it can provide more valuable information about the impairment of visual function.