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Higher Order Aberrations in Children with Down Syndrome

McCullough, Sara, Little, Julie-Anne and Saunders, Kathryn (2013) Higher Order Aberrations in Children with Down Syndrome. Investigative Ophthalmology & Visual Science, 54 (2). pp. 1527-1535. [Journal article]

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DOI: 10.1167/iovs.12-10597

Abstract

Purpose: Down syndrome (DS) is associated with ocular abnormalities and reduced visual function. Studies report atypical optical structures in the DS eye such as thinner, steeper corneae and thinner crystalline lenses and, functionally, a degrading influence of the optics on resolution acuity. The present study further investigates optical quality in DS by comparing higher order ocular aberrations (HOA) in DS and control eyes.Methods: Participants were 44 children with DS (6-16 years) and 209 age-matched controls. All participants were free from corneal or lenticular pathology. HOA were measured following cycloplegia using Shack-Hartmann aberrometry. HOA were analysed over a 3mm and 5mm pupil using Zernike polynomials from 3rd to 6th order. Optical quality was explored using Visual Strehl ratios (VSX) and equivalent defocus values. Results: HOA were measured successfully from 68% of the DS group and 95% of controls. Root mean square of total combined HOA, third and sixth orders and coma were significantly greater in the DS group (p<0.005). Significant differences were found between groups for Zernike coefficients Z(3,-3), Z(3,3) and Z(0,4) (p<0.013). VSX and equivalent defocus values showed significantly poorer optical quality in the DS eye (p<0.02). Conclusions: Children with DS have significantly greater HOA and reduced central optical quality compared with typically developing children. Whilst the differences in HOA between the DS and control groups reached statistical significance they were not of pathological proportions and the DS eye maintains relatively good optical quality considering the degree of ametropia and atypical optical structures often found amongst these children. The subtle reduction in optical quality may however compound the visuo-cortical deficits previously reported in DS.

Item Type:Journal article
Faculties and Schools:Faculty of Life and Health Sciences > School of Biomedical Sciences
Faculty of Life and Health Sciences
Research Institutes and Groups:Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Optometry and Vision Science
ID Code:24924
Deposited By: Dr Julie-Anne Little
Deposited On:12 Feb 2013 09:43
Last Modified:22 Mar 2013 15:50

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