The prevalence of internuclear ophthalmoparesis in a population-based cohort of individuals with multiple sclerosis

• Published in: Multiple sclerosis and related disorders Vol. 63; p. 103824
• Main Authors: Hof, S.N., Loonstra, F.C., de Ruiter, L.R.J., van Rijn, L.J., Petzold, A., Uitdehaag, B.M.J., Nij Bijvank, J.A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-07-2022
• Subjects: Eye-Tracking technology; Internuclear ophthalmoparesis; Internuclear ophthalmoplegia; Multiple sclerosis; Ocular motility disorders; Oculography; Prevalence; Internuclear ophthalmoparesis; Internuclear ophthalmoplegia; Multiple sclerosis; Prevalence; Oculography; INO; Eye-Tracking technology; Ocular motility disorders
• DOI: 10.1016/j.msard.2022.103824
• EISSN: 2211-0356
• ISSN: 2211-0348

•Internuclear ophthalmoparesis (INO) is a common eye-moment disorder in MS.•INO can be reliably detected with infrared oculography eye-tracking methods.•INO is detected in 24% of individuals with multiple sclerosis.•INO is more prevalent among males with MS.•INO diagnosis is associated with worse cognition, arm function and disability in MS.
Internuclear ophthalmoparesis (INO) occurs in 15–52% of individuals with multiple sclerosis (MS) and is reliably detected by infrared oculography. Methods for diagnosing INO with infrared oculography and the association between INO and MS characteristics need confirmation. We aimed to describe INO prevalence and the clinical characteristics of individuals with MS and INO in a population-based cohort of individuals with MS born in the year 1966 (Project Y).
Previously described thresholds for the versional dysconjugacy index (VDI), assessed with standardized infrared oculography, were used to detect INO in participants of project Y. Clinical characteristics, visual functioning and complaints were compared between individuals with MS with INO and individuals with MS without INO.
Two-hundred-twenty individuals with MS and 110 healthy controls were included. VDI values exceeding the threshold for INO presented in 53 (24%) individuals with MS and 19 controls (13%). INO was associated with male sex, greater disability, worse cognition and worse arm function in individuals with MS. There was no association with disease duration, visual functioning or complaints.
INO is prevalent among individuals with MS aged fifty-three and related to clinical characteristics of MS. INO was more frequently detected in healthy controls than previous studies, implying that oculography based diagnosis of INO requires further refinement.