Eye Color as a Risk Factor for Acquired Sensorineural Hearing Loss: A Systematic Review

Abstract

Objectives: There is controversy as to whether eye color has an effect on acquired sensorineural hearing loss. The objectives of this review were to analyze the literature evaluating the association between eye color and acquired causes of sensorineural hearing loss and to propose the potential mechanisms of this association. Methods: Six databases were searched to identify clinical studies relating eye color and acquired causes of sensorineural hearing loss such as noise, cisplatin ototoxicity, radiation, and presbycusis. Included articles were independently assessed for quality by two authors using the Downs and Black rating scale. Results: Seventeen 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 (r2 = 1-14%). 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. Conclusions: 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 that it may predispose individuals to cisplatin ototoxicity. Future studies are required to support these conclusions.