Title

The effect of vestibular exercise on dynamic visual acuity and reading acuity in children with sensorineural hearing impairment and vestibular hypofunction

Date of Award

2004

Availability

Article

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Physical Therapy

First Committee Member

Rose Marie Rine, Committee Chair

Abstract

Children with sensorineural hearing impairment (SNHI) have difficulty reading, attributed solely to poor language acquisition. Many of these children also have vestibular hypofunction (VH) and a deficit in dynamic visual acuity (DVA---visual acuity during head movement), which has never been linked to the reading impairment. Because head movement occurs during most activities, including reading, VH may cause enough gaze instability to hinder reading ability. Despite reports of difficulty reading and a DVA deficit in adults that improves with rehabilitation, no investigation has examined if the reading deficit reported in children with hearing loss and vestibular hypofunction is related to impairments in DVA and reading acuity. The purpose of this research was to examine the relationship of DVA and reading acuity in children with VH, as well as the effect of exercise intervention on these measures in this group.Study #1. The clinical DVA test had good reliability (ICC (3,1) = 0.82 for SVA and 0.75 for DVA. Regardless of age, no group of subjects in the normative sample had a mean DVA score greater than 2.5 lines (the 25%ile). This was used as the cut-off score to indicate failure. Sensitivity was 100% and specificity was 91%.Study #2. The reading acuity test had good reliability (ICC (3,1) = 0.86 for CPS and 0.88 for RA). All age groups were similar on CPS but the youngest group had a RA score that was higher (larger optotypes) than older groups. The CPS and RA scores of subjects with VH were significantly worse than scores of subjects without VH, and all subjects with VH failed the test using the twenty-fifth percentile as the cut-off score for CPS (0.050 logMAR) and RA (-0.148 logMAR). A positive correlation was seen between DVA, CPS and RA indicating that DVA deficits affect reading acuity.Study #3. CPS improved significantly following intervention (t = 5.196, p = 0.014). Clinically appreciable improvement of DVA was seen in one subject with BVH. DVA with limited neck movement was worse than DVA with neck movement in two of the subjects, but better in one of the subjects, indicating differences in the use of substitution mechanisms for the deficient vestibulo-ocular reflex.Vestibular hypofunction in children with SNHI leads to a DVA deficit, which contributes to lower reading acuity scores. Results suggest that DVA and critical print size can be improved with vestibular exercises. (Abstract shortened by UMI.)

Keywords

Health Sciences, Rehabilitation and Therapy; Health Sciences, Recreation

Link to Full Text

http://access.library.miami.edu/login?url=http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3141874