The clinical evaluation of infantile nystagmus: What to do first and why

ABSTRACT

Introduction: Infantile nystagmus has many causes, some life threatening. We determined the most common diagnoses in order to develop a testing algorithm.

Methods: Retrospective chart review. Exclusion criteria were no nystagmus, acquired after 6 months, or lack of examination. Data collected: pediatric eye examination findings, ancillary testing, order of testing, referral, and final diagnoses. Final diagnosis was defined as meeting published clinical criteria and/or confirmed by diagnostic testing. Patients with a diagnosis not meeting the definition were “unknown.” Patients with incomplete testing were “incomplete.” Patients with multiple plausible etiologies were “multifactorial.” Patients with negative complete workup were “motor.”

Results: A total of 284 charts were identified; 202 met inclusion criteria. The three most common causes were Albinism (19%), Leber Congenital Amaurosis (LCA; 14%), and Non-LCA retinal dystrophy (13%). Anatomic retinal disorders comprised 10%, motor another 10%. The most common first test was MRI (74/202) with a diagnostic yield of 16%. For 28 MRI-first patients, nystagmus alone was the indication; for 46 MRI-first patients other neurologic signs were present. 0/28 nystagmus-only patients had a diagnostic MRI while 14/46 (30%) with neurologic signs did. The yield of ERG as first test was 56%, OCT 55%, and molecular genetic testing 47%. Overall, 90% of patients had an etiology identified.

Conclusion: The most common causes of infantile nystagmus were retinal disorders (56%), however the most common first test was brain MRI. For patients without other neurologic stigmata complete pediatric eye examination, ERG, OCT, and molecular genetic testing had a higher yield than MRI scan. If MRI is not diagnostic, a complete ophthalmologic workup should be pursued.

KEYWORDS:

• Electroretinogram
• magnetic resonance imaging
• nystagmus

Acknowledgments

We are grateful to Edwin M. Stone, MD, PhD, and the Carver Lab for molecular genetic testing. Thanks also to Frank Bertsch, BA, MS, for assistance with data analysis.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article. Arlene V. Drack, MD, is a co-investigator in the Phase III RPE65 gene therapy trial which is funded by a grant from Spark Therapeutics.

Funding

Support for this project came from the Carver College of Medicine, NIH T35 HL007485 (Bertsch), and The Ronald Keech Associate Professorship in Pediatric Genetic Eye Disease Research, Vision for Tomorrow Foundation, Foundation Fighting Blindness, Research to Prevent Blindness, and the Wynn Institute for Vision Research (Drack).

Additional information

Funding

Support for this project came from the Carver College of Medicine, NIH T35 HL007485 (Bertsch), and The Ronald Keech Associate Professorship in Pediatric Genetic Eye Disease Research, Vision for Tomorrow Foundation, Foundation Fighting Blindness, Research to Prevent Blindness, and the Wynn Institute for Vision Research (Drack).