There is insufficient information about the progress and variability of multiple sclerosis (MS). Afferent visual pathways are an appropriate MS clinical model. Optical coherence tomography (OCT) allows to perform precise measurements of axonal tissue in the retinal nerve fibre layer (RNFL). Visual evoked potentials (VEP) provide information about the functional status of visual pathways. The aim of our study was to use OCT and VEP to evaluate MS patients with and without optic neuritis (ON) history and to determine relationships between functional and structural changes. The cross-sectional study included 76 relapsing-remitting MS patients and 28 healthy controls. The lowest mean VEP N75/P100 amplitude was found in ON affected eyes (8.16 mkV, SD = 4.60). However, it was observed that the mean amplitude in patients without ON (M = 9.86; SD = 4.63) was by 4.64 mkV lower than in controls (p < 0.001). Similarly, the mean P 100 latency in ON eyes was 9.26 ms longer than in eyes of patients without ON history (p < 0.01). RNFL in the temporal segment (RNFLT) was the thinnest in ON eyes, and even in patient eyes without ON, it was thinner than in controls. We found a significant positive correlation between RNFLT and mean N75/P100 amplitude in patients without ON (r s = 0.43; p < 0.001), and after ON (r s = 0.45; p < 0.001). Both in patients without p < 0.001) (Di Maggio et al. 2014). Afferent visual pathways represent an acute demyelination episode through acute ON, while in the case of chronic, subclinical retinopathy and optic neuropathy -diffuse, chronic central nervous system damage. For better understanding of MS, recently a new biological marker was proposed -optical coherence tomography (OCT), which allows to perform precise measurements of retinal axonal tissue in the retinal nerve fiber layer (RNFL). Visually evoked potentials (VEP) provide information about functional status of visual pathways.The aim of our study was to use VEP and OCT to evaluate MS patients with and without ON history and to determine relationships between functional and structural changes.
MATERIALS AND METHODSThe cross-sectional study included 76 relapsing-remitting MS patients who were divided into two groups:-MS patients without ON symptoms in history; -MS patients with ON history.In the MS patient group with ON history, ON-affected eyes (ON+) and contralateral, ON-unaffected eyes (ON-) were analysed separately The control group included 28 age-matched and sexmatched healthy individuals. -refraction disorders exceeding ± 6 diopters;-other neurological and ophthalmic diseases, which could affect the afferent visual system; -inability to participate in visual system examinations.A history of ON was determined on the basis of symptoms and clinical signs (Voss et al., 2011). Neurological examination of patients with disability was assessed using the Kurzke Expanded Disability Status Scale (EDSS). In clinical assessment of the ophthalmological condition, the following functional and structural visual system tests were made separatel...