Prevalence of Visual Abnormalities in Deaf Boy's in Tehran

To determine the prevalence of refractive error and binocular vision abnormalities in deaf individuals.
In this cross sectional study, a team of optometrists and social worker visited 158 deaf students at their schools and those who needed more detailed evaluation were referred to the Farabi Eye Hospital's strabismus clinic. These students in the selected schools underwent detailed visual acuity testing, refraction, binocular examination, color vision, and fundoscopy.
The percentage of ocular abnormalities in the deaf boys included in this study was 52.8%. The frequency of refractive errors in the present study was 39.9%. Astigmatism was the leading refractive anomaly (31%). Hypermetropia was found in 13.2% of the children and myopia was found in 12.6%. Anisometropia was detected in 30 children (19%) and amblyopia was found in 22 children (13.9%). A disturbance of ocular motility was present in 18 cases (11.3%). In 44 (28%) cases, stereopsis was reduced, and in 6 (3.8%) cases, it was absent. The majority of the students (89.9%) had congenital hearing loss and 6.3% of the children had color vision deficiency. Seventy-four deaf boys (46.8%) had a normal eye examination, while 84 (53.2%) cases had ocular problems, and 20 (12.65%) of them had more than one problem. The prevalence of refractive error, amblyopia, and strabismus was found to be significantly increased compared to the general population. In addition, the prevalence of ocular abnormalities generally increased with the severity of the hearing loss.
We recommended that screening for ocular abnormalities should be made mandatory in hearing-impaired children and parents must be aware of the high prevalence of ocular abnormalities in deaf children, as they need appropriate visual sense to compensate their poor auditory sense.