# Long-term visual outcomes in spasmus nutans

## TL;DR

This study examines long-term vision outcomes in children with spasmus nutans, finding a high risk of vision problems like amblyopia and strabismus.

## Contribution

The study provides new insights into the long-term visual outcomes and comorbidities in spasmus nutans patients.

## Key findings

- A high prevalence of amblyogenic refractive error was found in spasmus nutans patients.
- Many patients developed strabismus and required amblyopia treatment.
- Ongoing ophthalmic follow-up is recommended even after nystagmus resolves.

## Abstract

The long-term visual outcomes in spasmus nutans patients is largely unknown. The purpose of this study was to characterize visual outcomes and identify comorbid ophthalmic conditions in patients with spasmus nutans.

We retrospectively reviewed the charts of consecutive patients diagnosed with spasmus nutans between 2000 and 2020. Demographic information, ophthalmic characteristics, and neuroimaging results were assessed over time.

Of the 32 patients included in the study, 13 (41%) were female. Underlying medical conditions included a diagnosis of Trisomy 21 in 6 (19%) and prematurity in 8 (25%). Twenty-one patients (66%) self-reported as a race other than Caucasian. 18 patients (56%) had non-private health insurance and 1 (3%) was uninsured. Mean age at diagnosis and resolution were 16 months (range 45 months) and 48 months (range 114 months), respectively. All 32 patients had nystagmus, 31 (97%) had head nodding and 16 (50%) had ocular torticollis. Mean follow-up was 66 months (range 185 months). On initial presentation, 6/32 (19%) had an amblyogenic refractive error and mean best-corrected visual acuity (BCVA) in the better-seeing eye was 0.78 Logarithm of the Minimum Angle of Resolution (LogMAR) (range 1.24). In a sub-analysis that included patients with > 1 exam (n = 23), 17/20 (85%) had an amblyogenic refractive error and mean BCVA in the better-seeing eye was 0.48 LogMAR (range 1.70). At the final exam, 12 patients had measurable stereopsis, eight had strabismus, and three had undergone strabismus surgery. Eight patients required treatment for amblyopia.

We found a high prevalence of amblyogenic refractive error, strabismus and amblyopia among patients with spasmus nutans. Children with spasmus nutans benefit from ongoing ophthalmic follow-up until they are past the amblyopic age range, even after resolution of nystagmus.

The online version contains supplementary material available at 10.1186/s12886-024-03494-7.