Eye Refraction Anomalies in Down Syndrome Families

The extra chromosomal material in Down syndrome patients causes a generalised disruption in the genetic balance. From this viewpoint, the non-specific developmental instability following aneuploidy might be also responsible for ocular anomalies in patients with Down syndrome. The aim of this study was to identify the eye refraction anomalies in families having individuals with Down syndrome. A total of 199 Down syndrome patients (average age 17.0 years), 85 their siblings (17.0 years) and 229 their parents (average age 48.9 years) underwent eye refraction examination. In Down syndrome patients ocular refractive findings as spherical equivalent were: emetropia 4.2±1.0%, hypermetropia 70.0±2.3%, and myopia 25.8±2.2%. Astigmatism was diagnosed in 42.8±1.5% of patients. Refraction could not be identified in 3.8±1.0% of patients. In the control group of siblings refractive findings as spherical equivalent were: emmetropia 51.2±3.8%, hypermetropia 39.4±3.7%, and myopia 9.4±2.2%. Astigmatism was diagnosed in 7.6±2.0% of siblings. In parents refractive findings as spherical equivalent were: emmetropia 42.8±2.3%, hypermetropia 40.2±2.3%, and myopia 17±1.8%. Astigmatism was diagnosed in 7.9±1.3% of parents. Refraction could not be identified in 1.1±0.5% of parents. Astigmatism, which is phylogenetically more recent, was found in Down syndrome patients 5.6 times more often than control siblings and 5.4 times more than in the parents group.