Multiple Sclerosis Associated With Significant Reduction in Retinal Layer Thickness

Retinal scan testing for glaucoma. Woman with her head resting in a machine (left) being used by an ophthalmologist (right) to scan the retinas of her eyes and examine them for signs of glaucoma. The retina is the light-sensitive layer at the back of the eye responsible for vision. Glaucoma is a build-up of pressure inside the eye causing blurring and blindness. The technique in use here is optical coherence tomography (OCT) using a confocal scanning laser ophthalmoscope (SLO) device. This machine is from the Optovue company. The results of the scan are shown on the screens and in image C028/1548.
Retinal thickness may be a useful biomarker for monitoring MS progression in some patients, researchers speculate.

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.”

Reference

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