Đang chuẩn bị liên kết để tải về tài liệu:
The Guide to Clinical Preventive Services 2008 - part 9

giảm thị lực và các yếu tố nguy cơ của nó và (2) lỗi khúc xạ không liên quan đến giảm thị lực. Giảm thị lực đề cập đến giảm thị lực mà không có một tổn thương hữu cơ phát hiện của mắt và thường được kết hợp với các các yếu tố nguy cơ amblyogenic gây trở ngại cho tầm nhìn hai mắt bình thường, | Screening for Visual Impairment in Children Younger Than Age 5 Years Summary of Recommendation The U.S. Preventive Services Task Force USPSTF recommends screening to detect amblyopia strabismus and defects in visual acuity in children younger than age 5 years. Grade B Recommendation. Clinical Considerations The most common causes of visual impairment in children are 1 amblyopia and its risk factors and 2 refractive error not associated with amblyopia. Amblyopia refers to reduced visual acuity without a detectable organic lesion of the eye and is usually associated with amblyogenic risk factors that interfere with normal binocular vision such as strabismus ocular misalignment anisometropia a large difference in refractive power between the 2 eyes cataract lens opacity and ptosis eyelid drooping . Refractive error not associated with amblyopia principally includes myopia nearsightedness and hyperopia farsightedness both remain correctable regardless of the age at detection. Various tests are used widely in the United States to identify visual defects in children and the choice of tests is influenced by the child s age. During the first year of life strabismus can be assessed by the cover test and the Hirschberg light reflex test. 201 Visual Impairment in Children Younger Than Age 5 Years Screening children younger than age 3 years for visual acuity is more challenging than screening older children and typically requires testing by specially trained personnel. Newer automated techniques can be used to test these children. Photoscreening can detect amblyogenic risk factors such as strabismus significant refractive error and media opacities however photoscreening cannot detect amblyopia. Traditional vision testing requires a cooperative verbal child and cannot be performed reliably until ages 3 to 4 years. In children older than age 3 years stereopsis the ability of both eyes to function together can be assessed with the Random Dot E test or Titmus Fly Stereotest visual