Purpose: To evaluate the ocular findings and refractive errors in children with intellectual disability and in controls of average intellectual development of similar socioeconomic backgrounds.
Methods: The study was conducted at Diskapi Children's Hospital in Ankara, Turkey: 724 subjects with intellectual disability and 151 control subjects were evaluated. The subjects with intellectual disability were subdivided into mild (IQ 50-69, n = 490), moderate (IQ 35-49, n = 164), and severe (IQ <34, n = 70) groups, and syndromic (n = 138) versus nonsyndromic (n = 586) disability. All children underwent cycloplegic autorefraction or retinoscopy, slit-lamp biomicroscopy, and dilated fundus examination. Ocular alignment was assessed by Hirschberg, Krimsky, or prism cover test. The main outcome measure was the prevalence of refractive errors and ocular findings.
Results: Seventy-seven percent of subjects with intellectual disability, and 42.4% of controls, had ocular findings. The children with intellectual disability had significantly more nystagmus, strabismus, astigmatism, and hypermetropia than controls. Children with syndromic intellectual disability had significantly more nystagmus, strabismus, astigmatism, and hypermetropia than subjects with nonsyndromic intellectual disability. Increasing severity of intellectual disability was related to higher prevalence of nystagmus, strabismus, astigmatism, hypermetropia, and anisometropia.
Conclusions: From a public health perspective, evaluation and treatment of ocular and refractive findings in children with moderate, severe, and syndromic intellectual disability categories is urgently needed and likely to be highly effective in alleviating future health and social care costs, as well as improving the productive lives of individuals with intellectual disability.