Incidence Of Visual Impairment Research Articles

Early services for young children with visual impairment: From diagnosis to comprehensive services

The article addresses practical considerations in planning services for infants and young children with visual impairments. It describes prevalence and incidence of visual impairment, most common etiologies, interpretation of acuity scores, maximizing use of functional vision, and the curricular and program concerns to consider in selecting early intervention services and advising families on caregiving. Finally, the article discusses the impact of visual impairment on a young child's development and provides a list of resources for practitioners seeking further information.

The incidence of eye lesions and visual impairment in onchocerciasis in relationship to the intensity of infection

Data from follow-up surveys of onchocerciasis, conducted in the rain-forest and savanna areas of the United Cameroon Republic, are used to fit equations relating the incidence of eye lesions and visual impairment to microfilaria concentration in skin-snips. The incidence of lesions in those aged under 45 appears to be directly proportional to concentration, though the association is less clear in females over 25 in the savanna. The incidence of visual impairment appears also to be directly proportional to concentration among those under 45, but only in the savanna. Predictions of changes in incidence rates under transmission control are made, using hypothetical values for the rate of decline of infection. They are compared with reported incidence of lesions from the Onchocerciasis Control Programme: they are in good agreement for those aged under 30 years, but they understate the observed decline in older subjects.

Modifying nutrition education materials for handicapped students

Mental retardation is a major problem affecting some­ where between one to three percent of the total U.S. population. It has been suggested that if diagnostic procedures were more refined, mental retardation would likely rank as the most common handicap (1, 2, 3). Learning disabilities constitute a large category of hand­ icapped, with an estimated prevalence of three percent of the total U.S. population (3, Note 1). Hearing impair­ ment, an inclusive term for both partial and total deaf­ ness, has been estimated at approximately 0.6 percent of the population of school-age children (3,4). As many as two million U.S. citizens may suffer from visual impair­ ment, an inclusive term for both partial and total blind­ ness. Incidence for the 0-19 age group is estimated at 0.1 percent (3, 4), but incidence of visual impairment in­ creases substantially with age. Health and physical handicaps, which include epilepsy, multiple sclerosis, arthritis, anemias, cystic fibrosis, and cerebral palsy affect an estimated 330,000 school-age children in the U.S. (3, 4). It is generally agreed that one-third to one­ half of those who are handicapped by cerebral palsy are also mentally retarded (3). Multiple handicapped is a term that is applied to those persons with two or more serious handicapping conditions, e.g., individuals who are mentally retarded and blind or cerebral palsied and deaf (5). The above statistics indicate that there is a need for teaching materials that are adapted for use with the handicapped. However, in light of the generally reduced funding for development of new teaching curricula and aids, we decided to modify existing nutrition education materials to meet the needs of handicapped and multiple handicapped student populations. Consequently, in re­ sponse to a request from a vocational education for the handicapped (VEH) teacher for nutrition education materials that could be used with a group of multiple

The incidence of visual impairment in the elderly population—a progress report

The incidence of visual impairment in the elderly population—a progress report

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.