Visual Outcomes in Children with Infantile Nystagmus (IN)
Zahir B. Mirza, BSc, MBChB, FRCOphth; Jason Gan, MBBS, BSC, IBSC; Maria Theodorou, FRCOphth, PhD
Moorfields Eye Hospital
Introduction: There is limited research on visual development in children with IN. Our study looked at the natural history of vision development, aswell as the prevalence of refractive errors, strabismus, and current management.
Methods: We identified all children (<16 years old) with IN seen at Moorfields Eye Hospital (London) between 2001 and 014 (excluding children with congenital cataracts). Retrospective notes review was performed on a random selection of 68 (to date).
Results: Mean age of presentation was 37 months. Mean duration of follow-up was 133 months (range 23-254). Diagnoses included: idiopathic(47), albinism(10), optic nerve dysfunction(5), and retinal dysfunction(6). Mean best-corrected binocular LogMAR Visual Acuity (VA) at presentation was 0.69 (range 0-2.2), and 0.39 (range 0.02-1.6) at the end of available follow-up. VA improved in 61/68 children over time with refractive correction +/- occlusion therapy. All patients had significant ametropia corrected with spectacles.
Discussion: Almost all patients demonstrated subnormal VA at presentation. In most, VA improved over time with correction of refractive error and treatment of strabismus/amblyopia. Contributing factors include:age of refractive correction, compliance, amblyogenic effect of constant oscillatory movements. 7/15 had worsening VA over time. These patients included those with co-existing pathology, for example optic nerve dysfunction.
Conclusion: Our results demonstrate the development of (delayed) visual maturation in children with IN over time, and will allow further evidence based information to be given to parents. This may change with emerging treatments. As expected, co-existing visual afferent abnormalities adversely affect visual outcome.
References: Weiss AH, Kelly JP. Acuity development in infantile nystagmus. Invest Ophthal Vis Sci 2007;48:4093-9.