Eye color as a risk factor for acquired sensorineural hearing loss: a review

Eye color may be an indicator of inner ear melanin content and has been associated with hearing loss. There is controversy as to whether eye color has an effect on acquired causes of sensorineural hearing loss. This review was conducted to analyze the literature evaluating the relationship between eye color and causes of sensorineural hearing loss. Six databases were searched to identify eligible studies. Included articles were independently assessed for quality by two authors. Eighteen articles were eligible for review. Eye color was not found to have an effect in the non-exposed population or in presbycusis. In noise-induced sensorineural hearing loss, light-eyed patients had more significant loss following noise exposure, although the variability reported due to eye color was modest (r(2) = 0.01-0.14). Two out of three studies reported that dark eye color is associated with cisplatin ototoxicity. In one study, green-eyed patients were found to be at higher risk of radiation-induced hearing loss. Eye color does not appear to play a role in hearing loss in non-exposed individuals or presbycusis. It is possible that dark-eyed individuals, with greater inner ear melanin content, are better protected against noise-induced hearing loss. Evidence suggests that melanin can be protective against radiation-induced sensorineural hearing loss, but may predispose individuals to cisplatin ototoxicity. Future studies are required to support these conclusions.