Identification and Follow-Up of Visual Impairments in Hearing-Impaired Populations

This publication provides an overview of a project on identification of visual problems and follow-up conducted by the National Technical Institute for the Deaf (NTID) at Rochester Institute of Technology (RIT).1 This project had three main objectives: (a) to determine the most appropriate means for identifying NTID students with visual impairments and make recommendations for medical and personal/social follow-up (Objective 1); (b) to determine the types and incidence of visual impairments among these students (Objective 2); and (c) to conduct research that would assist in the provision of appropriate counseling relative to academic and career opportunities/experiences for persons with both auditory and visual impairments (Objective 3).

Several approaches were investigated as possible means for assessing the visual functioning of NTID students (Objective 1). Subsequently, some of these approaches were used to determine the types and incidence of visual impairments within this population (Objective 2). The approaches investigated were: (a) a vision questionnaire (personal/family ocular history) for students; (b) an off-campus general health physical examination; (c) an off-campus opthalmological examination; (d) an on-campus ophthalmological examination (standard to which all other assessment results were compared); and (e) an on-campus visual screening program. This screening program included the use of Bausch and Lomb Orthorater Vision Testers (a vision screening instrument used in assessing visual acuity, color vision, and binocular vision), the Ishihara Color Vision Test (a test designed to evaluate the ability to discriminate colors), and Titmus Stereopsis Tests (a series of tests designed to assess the ability to perceive objects in three dimensions using both eyes). Visual parameters assessed included near and far (distance) acuity (the ability of the eyes to resolve or differentiate detail), color vision (the ability to discriminate colors), and binocular vision (muscle balance and depth perception). In addition, three psychophysical screening tests for the presence of retinitis pigmentosa (RP) (a progressive loss of vision due to retinal degeneration) were investigated; one approach involved a test for assessment of dark-adapted visual sensitivity (the ability to see in darkness or dim illumination), and the other approach involved two tests for temporal processing of visual stimuli.

The methodology designed to investigate appropriate counseling relative to academic and career opportunities/experiences for persons with auditory and visual impairments (Objective 3) was as follows: (a) literature review; (b) interviews with content/technical experts at NTID to identify both visual skills believed to be important for students to succeed in various technical areas, and academic and career recommendations relative to students having both hearing and visual impairments; and (c) in-class and on-the-job follow-up for NTID students and graduates having visual impairments (e.g., observations and interviews).

Based on the data collected using the above methodologies, recommendations have been made for identification and follow-up of NTID students with visual impairments. These recommendations address: (a) the rationale and methodology for a recommended visual screening program; (b) the pass-fail criteria for referral for an in-depth examination by an ophthalmologist; and (c) recommended follow-up procedures, including medical treatment and correction, personal/social follow-up, and counseling relative to academic/career experiences. The implications and application of this project to all persons with hearing impairments, including younger age groups, are also discussed.

Given the importance of vision to persons with hearing losses, it is recommended that: (a) an in-depth ophthalmological examination be done routinely upon discovery of a hearing loss; (b) reassessment of visual functioning, as well as auditory functioning, be done periodically for all persons with severe to profound hearing losses; (c) interpreters be used as appropriate to help ensure adequate communication during both visual assessment/examination procedures and any necessary follow-up; and (d) information be provided for hearing-impaired persons, parents, and professionals concerning the importance of visual assessment and visual hygiene for persons with hearing loss. The need for further research relative both to the status of the visual system and how to best facilitate the use of the visual modality for learning among hearing-impaired persons is emphasized. Also, the need for further investigation of academic and career experiences appropriate for persons having both auditory and visual impairments, and the need for training of instructional staff to work with these persons, are stressed.