Visual function in the diagnosis of multiple sclerosis and optic neuritis

To determine the diagnostic ability of various visual functions in patients with multiple sclerosis (MS) with and without optic neuritis (ON).

In this cross-sectional study, we assessed and compared refractive error, visual acuity (VA), and contrast sensitivity (CS) between patients with MS and a matched control group of healthy individuals. The MS patients were further categorized into those with ON and those without.

A total of 133 eyes from 133 participants were assessed, including 66 individuals diagnosed with MS. The mean ages for the MS group and the healthy control group were 37.5±4.27y and 38.45±4.60y, respectively (P=0.346). Among the 66 patients with MS, 18 had ON. The presence of MS was associated with a decrease in best-corrected visual acuity (BCVA) and spherical component of refractive error (P<0.05), whereas ON did not lead to any further decline in these parameters (P>0.05). MS was linked to decreased CS at spatial frequencies of 6 and 18 cycles per degree (CPD; P<0.05), while ON in MS patients resulted in an additional decrease in CS at 3 CPD (P=0.03). The most significant sensitivity for distinguishing MS patients from healthy individuals as well as MS patients with ON from those without ON was found with cylindrical component [associated criterion (AC) >-0.75 D; 71.21%] and CS at spatial frequency of 6 CPD (AC ≤1.56; 72.22%), respectively. Conversely, the highest specificity for these diagnostic measures was associated with BCVA (AC >0 logMAR; 97.01%) and CS at a spatial frequency of 12 CPD (AC ≤0.60; 93.75%), respectively.

MS significantly affects refractive error and CS, with ON further reducing CS. Assessing these visual parameters can improve MS monitoring and management.