In the presence of optic neuritis, patients with multiple sclerosis (MS) experience a significant reduction in retinal nerve fiber layer (RNFL) thickness as the disease progresses, according to a study published in BMC Ophthalmology.
Researchers sought to compare RNFL thickness in 51 eyes of 27 patients with MS with and without optic neuritis spanning 4 years. The results were compared with 50 eyes of 25 participants in a healthy control group. The investigators used optical coherence tomography at first diagnosis and at a 4-year follow-up. They calculated differences in mean RNFL thickness.
Among patients with MS and healthy controls, the mean age was 30 and 34 years, respectively. The MS group had 7 men (25.9%) and 20 women (74.1%), while the control group had 9 men (36%) and 16 women (64%). Patients with MS were separated into 2 groups: those with optic neuritis (n=14) and those without optic neuritis (n=13).
The research team found that there was a significant reduction in mean RNFL thickness among MS patients with optic neuritis at follow-up (81.21 vs 72.14μm; P =.003). According to the team, these findings are consistent with those from previous research.
Although there was evidence of RNFL thinning in MS patients without optic neuritis, the difference lacked statistical significance, researchers note. Patients with MS showed a significant reduction in RNFL thickness compared with healthy controls (76.79 vs 93.72 μm; P= .009), irrespective of optic neuritis presence/absence.
Limitations of the study include small sample size, possibility of selective bias, and the majority of patients had bilateral optic neuritis.
According to the report, “evaluation of RNFL thickness may represent a useful biomarker for monitoring disease progression in MS and its association with ON.”
Al-Mujaini AS, Al-Mujaini MS, Sabt BI. Retinal nerve fiber layer thickness in multiple sclerosis with and without optic neuritis: a four-year follow-up study from Oman. BMC Ophthalmol. Published online November 12, 2021. doi:10.1186/s12886-021-02158-0