Regular Eye Screening Vital for MS Patients, Study Finds
Visual disturbances are common in people with multiple sclerosis (MS), particularly among those with secondary progressive MS (SPMS), longer disease duration, and worse disability status, a new study has found.
Yet, “visual complaints may occur in people with all types of MS, anytime along the disease course, and both in people with and without [inflammation of the optic nerve],” its researchers wrote, adding that regular eye screening may be essential to prevent visual disturbances from affecting quality of life.
The study, “Recognizing visual complaints in people with multiple sclerosis: prevalence, nature and associations with key characteristics of MS,” was published in Multiple Sclerosis and Related Disorders.
MS is known mostly for its damage to white matter — the region containing myelinated nerve fibers. However, lesions also can be found in the cerebral cortex, a surrounding gray matter area that is involved in cognitive function, including the processing of visual information.
As a result, visual problems are common in people with MS, who often report complaints such as impaired color vision, reduced visual acuity, abnormal eye movements, blurred vision, and difficultly seeing in bright light.
Although commonly reported, the rates of visual impairments and the level of discomfort they cause in MS is unclear. It’s possible that a patient has an intact visual function and still reports visual disturbances. Yet, other studies have assessed visual function with the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25), which primarily evaluates difficulty with visual activities, instead of the Screening Visual Complaints questionnaire (SVCq) that assesses visual problems.
Now, a team of Dutch scientists sought to investigate the rates of visual complaints and associated discomfort in a group of patients with MS registered at MS Centrum Noord Nederland (MSCNN). Eligible participants and healthy matched controls were asked to complete the SVCq based on visual disturbances they had experienced in the previous two weeks.
The SVCq contained 19 statements about visual complaints. Participants rated the statements based on how frequently they experienced each complaint: never/hardly, sometimes, or often/always. Their responses were summed to obtain an SVCq score. Participants also rated any discomfort they experienced from visual complaints on a scale ranging from 0–10.
A total of 493 people with MS and 661 matched healthy controls were included in the analyses. The groups were mainly female (70% in the MS group and 64% in the control group), with a mean age of 50.
The most common MS subtype was relapsing-remitting MS (RRMS, 48.1%), followed by SPMS (33.5%), and primary progressive MS (PPMS; 8.7%). A total of 20.9% patients had a history of optic neuritis (inflammation of the optic nerve), and most had mild disability (41.4%) — defined as an expanded disability status scale (EDSS) score from zero to 3.
The most commonly reported visual complaints in MS patients (reported by 40–55% of patients) included unclear vision, blinded by bright light, trouble focusing, reading difficulties, needing more time, light/dark adjustments, reduced contrast, and needing more light.
Other complaints reported by up to 36% of patients included dry eyes, depth perception, painful eyes, double vision, jerky images, distorted images, seeing things that others do not, and looking for something.
While visual disturbances occurred in both patients and controls, the overall rates of visual disturbances were higher in the MS group than the controls. Moreover, the number of participants who reported having visual complaints “often/always” also was significantly higher for most complaints in the MS group than the control group.
“Our study shows that not only the prevalence of visual complaints is high, people with MS also experience a wide array of different visual complaints,” the researchers wrote.
Notably, the complaints people with MS experienced varied throughout the day and were influenced by temperature and fatigue levels.
Among people with MS, there was no difference in the overall rates of visual complaints experienced between those with a history of optic neuritis and those without. However, impaired color vision (29% vs. 7%) and complaints regarding visual field (14% vs. 4%) occurred more often in those with a history of optical neuritis. These “are complaints known to be characteristic of [optic neuritis],” the researchers wrote.
People with MS had higher total SVCq scores, but did not report more discomfort than healthy controls. Among people with MS, those with SPMS had the highest total SVCq scores and reported more complaints than those with RRMS or PPMS.
Regarding disability status, people with higher disability scores experienced more discomfort from visual complaints. People with longer disease duration also experienced more frequent complaints and discomfort than those with shorter disease duration.
“SVCq brings to light that the prevalence of visual complaints among [people with MS] is relatively high compared to people without MS and the nature of these complaints shows great variety and variability,” the researchers wrote.
“Since visual problems decrease quality of life, it may be advisable to regularly assess self-reported visual complaints in clinical practice independent of the occurrence of visual disorders such as [optic neuritis],” they concluded.
Future research should investigate the types of visual complaints people with MS experience and determine which patients could benefit from additional care to maintain their quality of life.
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