Very Early Vision Screening Important

Nothing is more disappointing than the discovery of morbidity that could have been prevented or diminished by early screening. Amblyopia, the loss of visual acuity that results when ocular pathology is not diagnosed and corrected in the early years, is a case in point. Before children reach school age, they should have had at least three visual screenings by their health care provider. (See also amblyopia School Health Alert Oct. 98, p. 4.)

The American Academy of Ophthalmology and the American Academy of Pediatrics agree on the following recommendations for vision screening:

• Newborns should have an eye examination performed by the primary care provider. Any infant who has an abnormal exam or is at increased risk for eye disease should be evaluated by an ophthalmologist.
  
• By six months of age, all children should be evaluated for visual behavior and ocular alignment by their pediatrician or ophthalmologist.
  
• By 3 1/2 years of age, screening specifically focusing on visual acuity should be performed.
  
• At age five, children should receive a repeat visual acuity screening.
  
• Further evaluations should be performed if routine school screenings indicate a problem or the child has symptoms of visual difficulty.

Amblyopia is a central nervous system phenomenon, a failure of the brain to process visual cues accurately that results when a young child is not able to form a clear visual image in one or both eyes. This decrease in acuity is beyond the level expected from the pathology that causes the blurred image, and it may persist even when the pathology has been corrected.The causes of amblyopia include:

• anisometropia (different refractive errors in right and left eye)
  
• strabismus (divergent or convergent eye alignment)
  
• any condition blocking light to the retina (ptosis of the eye lid, corneal scar, cataract)

The outlook for amblyopia depends on the age at which the underlying cause is corrected.

(Bacal D. Why early vision screening matters. Contemporary Pediatrics 1999; 16(2):155-163)

COMMENT: Clearly the school vision screening (usually at age 5) should not be a child's first, although in reality, it often is‹all the more reason that school nurses should continue to give high priority to vision screening soon after school admission.