Survey of low vision among students attending schools for the blind in Nigeria: A descriptive and interventional study

Abstract

Purpose:The aim of this study is to determine the prevalence of low vision among students attending all the schools for the blind in Oyo State, Nigeria. The study set out to determine the proportion of students with low vision/severe visual impairment after best correction, to determine the causes of the low vision, to document the associated pathologies, to determine the types of treatment and visual aid devices required, and to provide the visual aids needed to the students in the schools. Materials and Methods:All schools students for the blind in Oyo State were evaluated between August 2007 and January 2008. All the students underwent a thorough ophthalmic examination that included measurement of visual acuity, retinoscopy and subjective refraction, tests for visual aids where indicated, and a structured questionnaire was administered. Results:A total of 86 students were included in the study and the mean age was 19.4 ± 8.19 years. Twenty six (30%) were under 16 years of age. The most common cause of blindness was bilateral measles keratopathy/vitamin A deficiency (VAD) in 25 students (29.1%). The most common site affected was the cornea in 25 students (29.1%), the lens in 23 (26.7%), and the retina/optic nerve in 16 (18.6%). Preventable blindness was mainly from measles keratopathy/VAD (29.1%). Eleven students benefited from refraction and correction with visual aids; two having severe visual impairment (SVI), and nine having visual impairment (VI) after correction. Conclusion:The prevalence of low vision in the schools for the blind in Oyo State is 2.3%, while the prevalence of visual impairment is 10.5%. These results suggest that preventable and treatable ocular conditions are the source of significant childhood blindness in Oyo State.

Ocular Health Status and Causes of Enrolment into Special Schools in Osun State, Nigeria

“…The most common cause of blindness in our study was corneal scarring; majority of which was due to post measles keratopathy. Similarly, measles keratopathy were seen as the commonest cause of blindness among schools for the blind in Oyo State of Nigeria [12]. Others were buphthalmic corneal opacities and corneal dystrophy.…”

Causes and emerging trends of childhood blindness: findings from schools for the blind in Southeast Nigeria

“…In school for the blind studies, the most common causes of blindness were: in the southwest zone (2008) cornea 29.1% and cataract 26.7%,8 in the northwest zone (2005) cornea 35.5%,9 and in the southeast zone (2003) cataract 30.4% and cornea 21.7% 10…”

Visual profile of students in integrated schools in Malawi

“…A Nigeria-based study observed that students in low-vision schools were not using any visual aids prior to the investigator's visit, which improved the visual status significantly after proper correction. 14 In a study carried out in South Malawi among elderly patients, Kalua and colleagues 15 observed that refractive errors were a significant cause of visual impairment and suggested that a refractive error correction is the key to prevent blindness in that area. So, these findings suggest that access to appropriate refractive/optical correction is a main challenge in African continents in preventing blindness.…”