Elsevier

American Journal of Ophthalmology

Volume 208, December 2019, Pages 342-346
American Journal of Ophthalmology

Original Article
Management of Strabismus Associated With Infantile Nystagmus Syndrome: A Novel Classification to Assist in Surgical Planning

https://doi.org/10.1016/j.ajo.2019.08.016Get rights and content

Purpose

There is no consensus on the surgical management of head position associated with infantile nystagmus syndrome (INS) when strabismus coexists, and few outcome data have been published. We propose classifying strabismus into concordant or discordant based on the relationship between head positioning and strabismus and then modifying surgery accordingly. Our objective is to describe this system and to review surgical outcomes.

Design

Retrospective observational case series.

Methods

Twenty-eight patients with INS and coexisting horizontal strabismus underwent surgery for horizontal head positioning and had ≥2 months of follow-up from 1995-2018 at the Vanderbilt Eye Institute. Outcome variables included head positioning (minimal, ≤10°; mild, 11-30°; moderate 31-44°; and severe ≥45°), strabismus (range 0-70 prism diopters [PDs]; minimal ≤10 PD), and reoperation rates. Nonparametric Wilcoxon signed rank, Fisher exact, and Mann-Whitney U tests were used for statistical analysis.

Results

Twenty-one cases were concordant and 7 were discordant; the mean follow-up was 4.1 years. Ninety-six percent of patients had moderate to severe head positioning at baseline. Correction rates (to minimal) were 100% at 2-5 months postoperatively and 86% at last follow-up (P < .0001 at both time points compared with preoperatively). The magnitude of strabismus decreased compared with preoperative strabismus (30.8 ± 10.8 PDs; n = 28), strabismus at 2-5 months (9.1 ± 11.9 PDs; P = .0001; n = 26), and last follow-up (12.0 ± 14.1 PDs; P = .0003; n = 28). The overall reoperation rate was 32%.

Conclusions

Our classification system in patients with INS allows a systematic way to surgically improve head positioning and strabismus in cases of moderate to severe baseline head positioning.

Section snippets

Methods

This was a retrospective chart review of 147 patients who underwent surgery to correct head positioning associated with INS from 1995 to 2018 at the Vanderbilt Eye Institute. Twenty-eight cases of coexisting horizontal AHP and horizontal strabismus with >2 months of follow-up were reviewed. This study was deemed exempt from review board approval by the Vanderbilt Institutional Review Board, and all data collection was in conformity with county, federal, or state laws and was in adherence to the

General Characteristics

Of 147 patients who underwent surgery for INS, 37 had coexisting strabismus and 32 had ≥2 months of follow-up. Three cases with strabismus were excluded because the head positioning was in the pitch plane (chin up and down) plane, and 1 case was excluded because of a coexisting vertical strabismus. A total of 28 patients with horizontal AHP, horizontal strabismus, and ≥2 months of follow-up were identified and reviewed. The mean age at surgery was 6.8 years, and 15 patients were female. The

Discussion

Surgery to simultaneously correct strabismus coexisting with AHP in patients with infantile nystagmus syndrome can be challenging and is not well described in the literature. In cases of large (≥45°) head position when 60% augmentation is performed on the horizontal rectus muscles to correct AHP, dosages of surgery typically cannot be increased to accommodate for the strabismus because of size limitations of the globe and the concern for limiting motility. This poses a challenge to surgeons who

References (9)

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Cited by (4)

  • Long-term Outcomes Following Surgery for Infantile Nystagmus Syndrome With Abnormal Head Positioning

    2020, American Journal of Ophthalmology
    Citation Excerpt :

    Unlike in horizontal cases, surgical planning for vertical cases represented maximal doses of recession-resection of vertical recti or weakening of both agonist muscles depending on the procedure. When strabismus coexisted with abnormal head posturing, surgery was performed on the fixating eye based on the head position, but decreased in magnitude if the proposed surgery would worsen the strabismus.9 Wilcoxon signed rank tests were used to evaluate for changes in visual acuity over time.

  • Nystagmus in Children - A Survey

    2023, Klinische Monatsblatter fur Augenheilkunde
  • Congenital Nystagmus and Its Congeners

    2020, Journal of Binocular Vision and Ocular Motility

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