Visual Acuity Deficits in Children With Nystagmus and Down Syndrome

• Published in: American journal of ophthalmology 2014-02, Vol.157 (2), p.458-463
• Main Authors: Felius, Joost, Beauchamp, Cynthia L, Stager, David R
• Format: Article
• Language: English
• Subjects: Adolescent; Age; Aging; Algorithms; Child; Child, Preschool; Children & youth; Cross-Sectional Studies; Data analysis; Down syndrome; Down Syndrome - complications; Down Syndrome - physiopathology; Eye Movements - physiology; Female; Health Insurance Portability & Accountability Act 1996-US; Humans; Infant; Male; Nystagmus, Pathologic - complications; Nystagmus, Pathologic - physiopathology; Ophthalmology; Patients; Prospective Studies; Sensory perception; Vision Disorders - diagnosis; Vision Disorders - etiology; Visual Acuity
• ISSN: 0002-9394; 1879-1891
• DOI: 10.1016/j.ajo.2013.09.023

Purpose To investigate the association between visual acuity deficits and fixation instability in children with Down syndrome and nystagmus. Design Prospective cross-sectional study. Methods setting : Institutional. study population :Sixteen children (aged 10 months-14 years) with Down syndrome and nystagmus, and a control group of 93 age-similar children with unassociated infantile nystagmus. observation procedures : Binocular Teller acuity card testing and eye-movement recordings. Fixation stability was quantified using the nystagmus optimal fixation function (NOFF). An exponential model based on results from the control group with unassociated infantile nystagmus was used to relate fixation stability to age-corrected visual acuity deficits. main outcome measures : Binocular grating visual acuity and NOFF. Results Visual acuity was 0.2-0.9 logMAR (20/30-20/174 Snellen equivalent) and corresponded to a 0.4 logMAR (4 lines) mean age-corrected visual acuity deficit. Fixation stability ranged from poor to mildly affected. Although visual acuity deficit was on average 0.17 logMAR larger ( P  = .005) than predicted by the model, most children had visual acuity deficit within the 95% predictive interval. Conclusions There was a small mean difference between the measured visual acuity deficit and the prediction of the nystagmus model. Although other factors also contribute to visual acuity loss in Down syndrome, nystagmus alone could account for most of the visual acuity deficit in these children.