Visual Acuity Improves in Children and Adolescents With Idiopathic Infantile Nystagmus

Abstract

Purpose: Idiopathic infantile nystagmus is associated with reduced visual acuity. Recent work has linked extraocular muscle surgery to improvements in visual acuity through childhood but no work has reported long-term secular trends in visual acuity in infantile nystagmus. Our aim is to describe visual acuity changes for children and adolescents with idiopathic infantile nystagmus to allow comparison for future interventional studies.

Design: Retrospective chart review.

Methods: Review of patients attending our center up to the age of 18 with a diagnosis of idiopathic infantile nystagmus and visual acuity measured using Snellen visual acuity. Patients provided informed consent.

Results: We observed improvements in best corrected visual acuity in 43 children and adolescents with idiopathic infantile nystagmus. Binocular best corrected visual acuity improved at a rate of -0.16 logarithm of the minimum angle of resolution (logMAR)/log year of age (P < 0.001), an improvement of 0.05 logMAR (half a Snellen line) as the age doubles. Intraclass correlation was 0.95 and interindividual correlation between visual acuity and age was significant (r = -0.24, P < 0.001).

Conclusions: We describe a natural history of gradual improvement in binocular visual acuity in infantile nystagmus and provide a baseline against which future interventional work can be compared.

Keywords: idiopathic infantile nystagmus; visual acuity.