Reading Abilities and Visual Evoked Potentials in Hearing-Impaired Children: A Comparative Study of Cochlear Implant and Hearing Aid Users.

BACKGROUND: This study aimed to evaluate reading comprehension skills, visual evoked potentials (VEP), and saccadic eye movements in hearing aid (HA) users, cochlear implant (CI) users, and individuals with normal hearing (NH), to investigate the relationship between sensory processing and reading ability. METHODS: The study included 45 participants, 15 HA users, 15 CI users and 15 NH. VEP, a saccadic test, and a reading comprehension test were performed. VEP recordings were conducted with and without the hearing device for HA and CI users. RESULTS: Reading comprehension scores in the CI group were significantly lower than those in the NH and HA groups (p < .001). Rightward saccade velocity was consistently lower than leftward velocity across all groups. Notably, VEP amplitudes in HA users (N1-P1: p = .048) and CI users (N1-P1: p = .005, .019, .001; P1-N2: p = .010, .008, .022) were significantly larger in the unaided condition (without device) compared to the aided condition. Correlation analyses did not reveal a consistent pattern of association between reading comprehension scores and VEP parameters. CONCLUSION: While reading skills were found to be weaker in the CI group, the absence of a direct correlation between VEP/saccadic parameters and reading scores suggests that lower-level sensory processing and higher-order reading comprehension may operate through distinct mechanisms. The increased VEP amplitudes observed without hearing devices suggest a cross-modal neuroplastic compensation in the visual cortex during auditory deprivation.