SILVER SPRING, MD — A new military study looked at how accurately a type of eye inflammation predicts later multiple sclerosis development.
“Optic neuritis (ON), an acute inflammation of the optic nerve resulting in eye pain and temporary vision loss, is one of the leading causes of vision-related hospital bed days in the U.S. Military and may be a harbinger of multiple sclerosis (MS),” wrote researchers from the Vision1 Center of Excellence at the DHA and Department of Neurology, Uniformed Services University of the Health Sciences, “We developed a case identification algorithm to estimate incidence rates of ON and the conversion rate to MS based on a retrospective assessment of medical records of service members (SMs) of the U.S. Armed Force.”
The study team screened electronic medical records (EMRs) from 2006 to 2018 in the Defense Medical Surveillance System, using the case identification algorithms for ON and MS diagnosis and calculating incidences rates of ON. Findings of the research were published in Military Medicine.1
Results indicated that the overall incidence rate of ON was 8.1 per 100,000 from 2006 to 2018. Researchers pointed out that females had a rate (16.9 per 100,000) three times higher than males and that most (68%) of the subsequent diagnoses of MS were made within one year after diagnosis of ON.
The overall five-year risk of progression to MS was 15% (11%-16% for 95% CI),” according to the study, and the risk of conversion to MS in females was notably higher than in males.
“We developed an efficient tool to explore the EMR database to estimate the burden of ON in the U.S. military and the MS conversion based on a dynamic cohort,” researchers concluded. “The estimated conversion rates to MS feeds into inform retention and fitness-for-duty policy in these SMs.”
An international study led by New York University Grossman School of Medicine looked at data from 60,933 ON patients from the MSBase registry in July 2019. Of these, 1,317 patients met inclusion criteria; they had a median age of 32.8 and 74% were female. Of those, 935 were treated at some point in disease course, while 382 were never treated.
After median follow-up time of 5.2 years (IQR 2.4-9.3), researchers determined that treatment was associated with reduced risk and delayed conversion to clinically definite MS (HR = 0.70, p < 0.001), sustained expanded disability status scale (EDSS) progression (HR = 0.46, p < 0.0001) and sustained visual function score (VFS) (HR = 0.41, p < 0.001) progression.
“In the MSBase cohort, treatment after ON was associated with better visual and neurological outcomes compared to no treatment,” the authors wrote in the Journal of Neurological Sciences. “These results support early treatment for patients presenting with ON as the first manifestation of MS.”2
- Gu W, Tagg NT, Panchal NL, Brown-Bickerstaff CA, Nyman JM, Reynolds ME. Incidence of Optic Neuritis and the Associated Risk of Multiple Sclerosis for Service Members of U.S. Armed Forces. Mil Med. 2021 Aug 21:usab352. doi: 10.1093/milmed/usab352. Epub ahead of print. PMID: 34417807.
- Kenney R, Liu M, Patil S, Alroughani R; MSBase Study Group. Long-term outcomes in patients presenting with optic neuritis: Analyses of the MSBase registry. J Neurol Sci. 2021 Nov 15;430:118067. doi: 10.1016/j.jns.2021.118067. Epub 2021 Sep 3. PMID: 34537678.
