[Characteristics of visual function in children with autism complicated with mental retardation]

Objective: To explore the characteristics of visual function and eye diseases in children with autism spectrum disorder (ASD) and mental retardation. Methods: It was a cross-sectional study. Two hundred and ninety-two cases (584 eyes) of children with ASD combined with mental retardation from 7 special education schools in Chaoyang District of Beijing, including 235 males (80.48%) and 57 females (19.52%); The age ranged from 2 to 18 years old. Subjective far and near vision, near stereoacuity, objective vision, diopter, anterior segment and fundus were examined. In addition, 300 students with normal intelligence level, aged 2 to 18 years, were included as controls. LogMAR was used to record vision examination. Subjective, objective vision and diopter were examined. Mann Whitney U test or Kruskal Wallis H test was used for the data of children with different genders, different age. Results: Among 584 eyes of children with ASD and mental retardation, 272 eyes (47.22%) were ametropia, 260 eyes (45.14%) were astigmatism, 29 eyes (5.03%) were hyperopia, 10 eyes (1.74%) were myopia, and 47 eyes (8.16%) were amblyopia risk factors. Among 292 children, there were 20 cases of strabismus (6.85%), 3 cases of color weakness (1.03%), and 4 cases of external eye abnormalities (1.37%). Two hundred and eleven children completed near stereopsis examination, of which 54 (25.59%) were within 100″ and 157 (74.41%) were within 200″ to 900″. Two hundred and seventy-two eyes with ametropia, 157 eyes (57.72%) needed correction but did not. The median and quartile of subjective and objective logMAR visual acuity were 0.22(0.10, 0.35), 0.10(0.00, 0.22), respectively; There were no significant differences in far visual acuity, near visual acuity, objective visual acuity, diopter, and near stereoacuity between different genders of ASD children with mild or moderate mental retardation (all P>0.05); There was a statistically significant difference in ASD children with mild mental retardation at different age rangs (H=21.453, P<0.001). There was a statistically significant difference in subjective tests such as far visual acuity and near visual acuity, for children with moderate mental retardation (Z=-3.508, -4.503; P<0.001). There was no statistically significant difference in objective visual acuity, diopter and near stereo acuity(all P>0.05). There are 300 healthy children as the control group, with LogMar's subjective far vision is 0.10(0.00, 0.22), and the objective vision is 0.00(0.00, 0.10), diopter 0.25 (-0.25, 0.50) D. Compared with healthy children, ASD children with mental retardation had a significant difference in subjective far vision and objective vision (Z=-8.527, -10.393; P<0.001). There was no significant difference in diopter (Z=-1.274, P=0.203). Conclusions: The subjective and objective visual acuity of children with ASD combined with mental retardation was lower than that of healthy children. The prevalence and uncorrected rate of refractive errors, strabismus, amblyopia and other eye diseases were significantly higher than those of healthy children. Their refractive errors were mainly astigmatism, and the rates of correction and treatment were low.