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P. Ji, M. Woodhouse, F. Ennis, S.A. Naroo, P.O. Watts; Ocular Biometry of Children With Down Syndrome Measured With the Pentacam and IOL Master . Invest. Ophthalmol. Vis. Sci. 2006;47(13):716.
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© ARVO (1962-2015); The Authors (2016-present)
Previous studies have reported a thinner cornea and higher corneal curvature in people with Down syndrome (DS) (Haugen et al, 2001). Haugen also calculated lens power to be lower in DS. Here we present quantitative information on central corneal thickness (CCT), minimum corneal thickness (MCT), corneal curvature (CC), anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) and the maximum lens density (MLD) and central lens density (CLD) measured in children with DS and in control children.
The children with DS, aged 6–15 years (N=21), are members of a longitudinal study group. Control children, aged 4–15 years (N=30) were recruited from patients attending the University Clinic, and through staff of the University. Corneal measurements were taken with the Oculus Pentacam, and axial length was measured with the IOL Master. Children matched by refractive error were chosen from above groups and analysis was repeated. In addition, the contribution of the lens was calculated by subtracting corneal power from the calculated total refractive power.
Data for right eyes only are presented. Reduced CCT and MCT were found in children with DS (476.9±34.8µm , 458.6±50.1µm), compared to the control children (548.1±3.43µm, 535.7±45.6µm) (p<0.001).The mean CCC of the DS group differed from that of the control group (7.40±0.39mm vs. 7.93±0.30mm) (p<0.001). There were significant differences in the CLD (7.10±1.6 vs. 7.58±2.1) (p<0.001) but no difference in MLD, ACD, ACV and ACA between DS and controls. In the refractive error matched groups, all differences between eyes in DS and controls remained, and the lens contribution was significantly lower in children with DS (12.68 D ±0.96 vs 14.41 D ±1.10, p<0.001).
We confirm the different morphology (steeper, thinner corneas, with lower lens density) of the eye in children with DS even when refractive errors are matched. The steeper (and therefore more powerful) cornea appears to be compensated for by a weaker lens. The precise properties of the lens in DS are yet to be established.
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