Vision Screening

Policy Statement: Vision Screening for Infants and Children

Policy
The American Academy of Ophthalmology and the American Association for Pediatric Ophthalmology and Strabismus recommend timely screening for the early detection and treatment of eye and vision problems in America's children. This includes institution of rigorous vision screening during the preschool years. Early detection of treatable eye disease in infancy and childhood can have far reaching implications for vision and, in some cases, for general health.

Background
Good vision is essential for proper physical development and educational progress in growing children. The visual system in the young child is not fully mature.   Equal input from both eyes is required for proper development of the visual centers in the brain.  If a growing child's eye does not provide a clear focused image to the developing brain, then permanent irreversible loss of vision may result.  Early detection provides the best opportunity for effective, inexpensive treatment.  The American Association for Pediatric Ophthalmology and Strabismus, the American Academy of Ophthalmology, the American Academy of Pediatrics, the American Academy of Family Physicians and the American Association of Certified Orthoptists recommend early vision screening.

Vision screening programs should provide widespread, effective testing of preschool and early school-age children.

Many school systems have regular vision screening programs that are carried out by volunteer professionals, school nurses, and/or properly trained lay persons. Screening can be done quickly, accurately, and with minimum expense by one of these individuals. The screener should not have a vested interest in the screening outcome.  As with all screening programs, vision screening should be performed in a fashion that maximizes the rate of problem detection while minimizing unnecessary referrals and cost.  Beginning in the preschool years, those conditions which can be detected by vision screening using an acuity chart are: reduced vision in one or both eyes from amblyopia, uncorrected refractive errors or other eye defects and, in most cases, misalignment of the eyes (called strabismus).

Amblyopia is poor vision in an otherwise normal appearing eye, which occurs when the brain does not recognize the sight from that eye. Two common causes are strabismus (misaligned eyes) and a difference in the refractive error (need for glasses) between the two eyes. If untreated, amblyopia can cause irreversible visual loss. The best time for treatment is in the preschool years. Improvement of vision after the child is 8 or 9 years of age is rarely achieved. 

Strabismus is misalignment of the eyes in any direction. Amblyopia may develop when the eyes do not align.  If early detection of amblyopia secondary to strabismus is followed by effective treatment, then excellent vision may be restored.  The eyes can be aligned in some cases with glasses and in others with surgery.  However, restoration of good alignment does not assure elimination of amblyopia.

Refractive errors cause decreased vision, visual discomfort ("eye strain"), and/or amblyopia. The most common form, nearsightedness (poor distance vision) is usually seen in school-age children and is treated effectively, in most cases, with glasses. Farsightedness can cause problems with focusing at near and may be treated with glasses. Astigmatism (imperfect curvature of the front surfaces of the eye) also requires corrective lenses if it produces blurred vision or discomfort. Uncorrected refractive errors can cause amblyopia particularly if they are severe or are different between the two eyes.

In addition to detection of vision problems, effective screening programs should also place emphasis on a mechanism to inform parents of screening failures and attempt to ensure that proper follow-up care is received.

Recommendations
The American Academy of Ophthalmology and the American Association for Pediatric Ophthalmology and Strabismus recommend an ophthalmological examination be performed whenever questions arise about the health of the visual system of a child of any age.  They recommend that infants and children be screened for vision problems as follows and any child who does not pass these screening tests have an ophthalmological examination.

1.  A pediatrician, family physician, nurse practitioner, or physician assistant should examine a newborn's eyes for general eye health including a red reflex test in the nursery.  An ophthalmologist should be asked to examine all high risk infants, i.e., those at risk to develop retinopathy of prematurity (ROP), those with a family history of retinoblastoma, glaucoma, or cataracts in childhood, retinal dystrophy/degeneration or systemic diseases associated with eye problems, or when any opacity of the ocular media or nystagmus (purposeless rhythmic movement of the eyes) is seen. Infants with neuro-developmental delay should also be examined by an ophthalmologist.

2.  All infants by six months to one year of age should be screened for ocular health including a red reflex test by a properly trained health care provider such as an ophthalmologist, pediatrician, family physician, nurse, or physician assistant during routine well-baby follow-up visits.

3.  Vision screening should also be performed between 3 and 3 1/2 years of age. Vision and alignment should be assessed by a pediatrician, family practitioner, ophthalmologist, optometrist, orthoptist, or individual trained in vision assessment of preschool children.  Emphasis should be placed on checking visual acuity as soon as a child is cooperative enough to complete the examination.  Generally, this occurs between ages 2 1/2 to 3 1/2.  It is essential that a formal testing of visual acuity be performed by the age of 5 years.

4.  Some evidence currently exists to suggest that photoscreening may be a valuable adjunct to the traditional screening process, particularly in pre-literate children.

5.  Further screening examinations should be done at routine school checks or after the appearance of symptoms. Routine comprehensive professional eye examination of the normal asymptomatic child has no proven medical benefit.

6.  School aged children who pass standard vision screening tests but who demonstrate difficulties learning to read, should be referred to reading specialists such as educational psychologists for evaluation for language processing disorders such as dyslexia.  There is not adequate scientific evidence to suggest that  "defective eye teaming", and "accommodative disorders" are common causes of educational impairment.  Hence, routine screening for these conditions is not recommended.

Many serious ocular conditions, which can be found at screening are treatable, if identified in the preschool and early school-aged years. Many of these conditions are associated with a positive family history. Additional screening emphasis should, therefore, be directed to high risk infants and children with a low threshold for obtaining a comprehensive eye examination by an ophthalmologist.