Condition and Frequency Distribution of Causes of Visual Impairment in People Aged Under 14 Supported by Welfare Organisation in Isfahan Province

Children with visual impairment and blind are one of the groups of children with special needs, and visual impairment widely recognised as one of the most common disabilities. Visual impairments and blindness play an important role in individual life. Of the particular education categories, we perhaps feel particularly uncomfortable interacting with persons with visual impairment. Visual impairment seems to evoke more awkwardness than most other disabilities. So, we are uncomfortably aware of blindness. Perhaps for the thing, blindness is visible. Blindness is primarily an adult disability. Most estimates indicate that blindness is approximately one-tenth as prevalent in school-age children as in adults. Approximately about 0.04 percent of the population age ranging from 6 to 21 years old as visually impaired and includes those who are blind or who have low vision. This classification is probably an underestimate because many blind children also have other disabilities, and school systems are instructed to report only the primary condition. When considering both children and adults, the most common visual problems are the result of errors of refraction. Refraction refers to the bending of the light rays as they pass through the various structures of the eye. Myopia (near-sightedness), hyperopia (farsightedness), and astigmatism (blurred vision) are examples of refraction errors that affect central visual acuity. Although each can be serious enough to cause significant impairment, wearing glasses or contact lenses usually can bring vision within normal limits. Myopia and hyperopia are the most common impairments or low vision people. The three most common causes of blindness in children are cortical visual impairment (CVI), retinopathy of prematurity (ROP), and optic nerve hypoplasia (ONH). Concerning locus of causation, as a general rule, CVI occurs in the brain, ROP occurs in the eye, and ONH occurs in the nerve cells between the eye and the brain. Many studies have recognised effective factors and cause visual impairments and blindness. The study aimed to investigate the condition and frequency distribution of causes of the visual impairment in people aged under 14 supported by welfare organisation in Isfahan province. The present research was a descriptive- analytic type study and by the cross-sectional method. The statistical population of this research consisted of people with a visual impairment aged under 14 supported by welfare organization in Isfahan province in 2017-2018 Academic years. The sample of the present research consist of 527 people with visual impairment participated that selected by all counting sampling method from supported centers of welfare organization in Isfahan province. To data collection was used visual impairment causes comprehensive questionnaire (Ashori, Noruzi, Ghalamzan, Kalantari & Galil-Abkenar, 2018). The obtained data analyzed by using frequency distribution, percent and t-test with the 24th version of SPSS (p<0.05). The results showed that participant of this research was from under middle socio-economical class. The scores mean and standard deviation of the age of the male participants were (8/96±1/73), and female participants was (9/27±1/84), and results of t-test showed that two groups had no significant difference in age (p=0.11). The most causes of visual impairment were from genetically (38%) and congenital (30%) causes, respectively. Based on impairment location, causes of visual impairment were from muscular disorders (40%), retina disorders (24%), visual nerve disorders (8%), lens disorders (6%), refractive error (6%) and aqueous humor disorders (5%), respectively. Based on name of impairment, causes of visual impairment were from strabismus (23%), nystagmus (10%), optic nerve atrophy and hypoplasia (8%), amblyopia (7%), cataract (6%), astigmatism (6%), glaucoma (5%), retinitis pigments (4%), retinopathy of prematurity (3%), retinal detachment (3%), retinal laceration (3%) and albinism (3%), respectively. Based on the finding of this research, the most important causes of visual impairment were from genetically and congenital causes, respectively. Based on impairment location, the prevalence of visual impairment was from muscular disorders, retina disorders, visual nerve disorders, lens disorders, refractive error and aqueous humor disorders, respectively. Therefore, pay attention to the effective causes of visual impairments have a crucial role in prevention, early intervention and design of vision 2020 program in Iran.