Hearing Problems Linked To Vision Problems In KIds

By Margarita Nahapetyan

About 20 per cent of all the kids with sensorineural hearing loss also have eye disorders, a new study has reported in the February issue of Archives of Otolaryngology - Head and Neck Surgery, one of the JAMA/Archives journals.

Sensorineural hearing loss is a hearing loss that is caused by damage to the inner ear or to the nerves that link the ear to the brain. According to the background information in the study, the condition affects up to 3 of every 1,000 children. Fifty per cent of all its cases occur due to genetics, and one gene, called GJB2 accounts for a large proportion of sensorineural hearing loss cases among white people.

The experts wrote in their statement that particularly at an early age, sensorineural hearing loss is more associated with delays in language and speech, as well as with the development of cognitive and social abilities. According to them, if children who already have hearing impairment, in addition will develop ophthalmologic problems that usually limit visual activity, it could lead to irreparable effects in their development.

For the study, Dr. Arun Sharma, of the University of Washington, Seattle, and his colleagues analyzed data on 226 children with sensorineural hearing loss. All young patients were seen at a children's hospital between 2000 and 2007. Of all kids, 49 (21.7 per cent) had eye disorders, including 23 (10.2 per cent) with refractive errors that included nearsightedness, farsightedness and astigmatism, and 29 (12.8 per cent) had non-refractive errors.

The scientists also discovered that the cause of sensorineural hearing loss was syndromic, meaning that it had others symptoms associated, in 11 kids (4.9 per cent), and five patients (2.2 per cent) had syndromes with similar problems related to the eyes.

Genetic testing for mutations in the GJB2 gene was offered to all the study participants. Out of the 226 children, 144 chose to undergo the gene screening procedure. The results showed that 27 kids (18.8 per cent) had 2 mutated copies of the GJB2 gene, and one of the 27 patients (3.7 per cent) had an eye problem. No eye disorders were found in the 11 kids with a single copy of the mutated gene, compared to eye disorders that were discovered in 22 (20.8 per cent) out of the 106 young patients with no mutations.

The researchers wrote that all this coincides with the impression that GJB2 mutations lead to sensorineural hearing loss only, and by no means to an additional conditions, disorders, anomalies or syndromes. They concluded that testing of both hearing and vision loss in kids should be highly encouraged and added that more and more research is still needed do be done. According to them, a multidisciplinary approach is required in order to test and treat young patients with sensorineural hearing loss, and to make sure that medical, educational and social needs of children are met.

The scientists suggested that ophthalmologists could greatly help otolaryngologists in establishing the cause of sensorineural hearing loss by ophthalmologic diagnose and evaluation of the co-existing problematic conditions that affect vision.