Binocular vision assessment among children with hearing impairment

Abstract

Background: Hearing is the ability to perceive sound. A person is said to have hearing loss when he/she is not able to hear as well as someone with a normal hearing threshold of 25 dB or better in both ears. Binocular function plays an important role as it helps to coordinate both eyes. Methodology: A prospective study was conducted with 103 subjects. After taking permission authority and Hearing impairment school (Sheila Kotavalla Institute of Deaf), consent was taken from participants. The comprehensive evaluation included demographic data, history of hearing impairment, refraction. Then binocular vision assessment (sensory, motor, accommodative, vergence tests) was done. Results: 103 children with a mean age of 14.36±3.07years were included in the study. 54 % had a severe hearing impairment and 46 % of children had a profound hearing impairment. 9.7% refractive error among hearing-impaired children. Myopia is 4%. Hyperopia is 1% and Astigmatism is 5%. NSBVA was found around 49 % among HI children. Convergence excess 20.4%, Convergence insufficiency 3.9%, Divergence excess 1%, Divergence Insufficiency 3.9%. Accommodative insufficiency 5.8% and Accommodative excess 13.6%. Conclusion: Non-strabismus binocular vision anomalies among profound and severe hearing-impaired subjects. So, it is important to consider binocular evaluation among hearing-impaired subjects.