Topics Discussed: amblyopia; anophthalmos; coloboma; congenital cataract; corneal opacity; eye diseases; genetics and dysmorphology; glaucoma, congenital; microphthalmos; nasolacrimal duct obstructed; ophthalmology; retinopathy of prematurity.
Excerpt:"I. Definition. Amblyopia, or "lazy eye," is a reduction in vision when there is a difference in the quality of the images recorded by each eye and sent to the brain. The eyes and the brain must work in conjunction for vision to develop correctly. If the pathways to the visual cortex are not properly stimulated, the visual cortex cannot mature appropriately. Thus, when the brain selectively disregards the eye with the poor visual image, the visual system for that eye develops more slowly than for the eye that sent the good image. Vision loss ranges from mild (worse than 20/25) to severe (legal blindness, 20/200 or worse).
II. Incidence. Amblyopia is a major public health problem with the estimated prevalence of 1–4% in the United States. The condition affects approximately 2 to 3 out of every 100 children. Amblyopia was shown in the Visual Acuity Impairment Survey sponsored by the National Eye Institute (2004) to be the leading cause of monocular vision loss in adults 20–70 years of age.
III. Pathophysiology. Amblyopia may be caused by any condition that affects normal visual development or use of the eyes. Animal studies and clinical studies in infants and young children support the concept of a critical period during infancy and childhood for developing amblyopia. The developing brain is sensitive, and amblyopia may occur as early as the first few weeks of life. There are three general etiologies for amblyopia in the neonate.
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