KR just turned one when he was first seen by a pediatric ophthalmologist.

It was not a planned visit at all;  he and his mother actually came to Manila for a well-baby check-up.  The pediatrician noticed her mother’s deviated right eye.  A short review of his mother’s medical history revealed that his mother started wearing glasses as a young teen, but she claims her vision did not improve much even after wearing prescription glasses and that same eye slowly drifted out through her adult years.  To complete his well-baby check-up, the pediatrician then urged his mother to take him to the pediatric ophthalmologist next door for vision screening.

What is vision screening?  Why screen for vision problems?

In medicine, a screening test is the evaluation of an asymptomatic person in a population, to detect an unsuspected disease process not known to exist at the time of evaluation.  This detects those with a high probability of having or developing a given disease or condition.  Screening tests measure specific parameters, such as blood pressure for hypertension, and cholesterol for coronary artery disease.

Vision screening is an efficient and cost-effective method to identify children with visual impairment or eye conditions that are likely to lead to visual impairment so that a referral can be made to an appropriate eye care professional for further evaluation and treatment.

How is vision screening performed?

There are several methods that can be used to screen a child's vision. The particular method chosen is largely dependent on the age of the child being screened, as well as the experience of the examiner or vision screener.

THE OCULAR HISTORY

Children with visual impairment will not usually complain about their difficulty, particularly if they are still very young and are not yet able to verbalize.  So, the parents’ observations are valuable tools that vision screeners can use in determining the probability that vision screening will turn out positive.  The following guide questions for parents and examiners will help in identifying children who will most likely benefit from vision screening.

* Does your child seem to see well?

* Does your child hold objects close to his or her face when trying to focus?

* Do your child’s eyes appear straight or do they seem to cross or drift or seem lazy?

* Do your child’s eyes appear unusual?

* Do your child’s eyelids droop or does one eyelid tend to close?

* Have your child’s eye(s) ever been injured?

The vision screener should also explore any relevant family histories regarding eye disorders, or the use of prescription glasses in preschool or early childhood by the child’s parents or siblings.

EXTERNAL EYE EXAMINATION

This method can be used on a child of any age.

It consists of a light source-assisted evaluation of the eyelids, orbits, conjunctivae, corneas, iris, pupils, and the eye’s red reflex.

The eyelids should be normal and equal in size and shape.  The eyelashes should be directed away from the eyeball.  There should be no orbital or adnexal masses.  The sclerae should be white and the conjunctivae should be transparent.  There should be no discharge or excessive tear coming from the eyes.  The corneas should be equal in size and clarity.  The pupils should constrict (become smaller) in bright light and should dilate (become larger) in the dark.  Pupil size should be equal, round, and briskly reactive to light in both eyes.

The red reflex is a reflection from the inner lining of the eye (retina) that causes the pupil to look red in photographs. Through the use of an ophthalmoscope in a darkened room, the red reflex should be seen as equally bright in both eyes.

PHOTOSCREENING

Photoscreening is an automated way of using the eye’s red reflex in identifying many types of eye problems.  Using a calibrated camera under prescribed lighting conditions, a photoscreener produces a photograph showing the red reflex in both pupils. An advantage of this screening is that it is fast, efficient, user-friendly, and thus is compatible for use in very young children. Some community screenings in the United States use this method. The newest generation of photoscreeners provides immediate information about the eye condition. Despite its reliability, photoscreening is still not a substitute for accurate visual acuity measurement (in cooperative older children), but can provide significant information about the presence of vision-threatening conditions.

CORNEAL LIGHT REFLEX TESTING

This simple test can be performed on any cooperative child using a penlight. As a child focuses on a penlight, the position of the light reflection from the front surface (cornea) of the eye is observed. The test is accurate only if the child looks directly at the light and not to the side. Normally the corneal light reflex is in sharp focus and centered on both pupils.  The result of the test is abnormal if the corneal light reflex is not crisp and clear, or if it is "off-center."

OCULAR MOTILITY AND COVER TESTING

Ocular motility evaluation should reveal smooth and coordinated eye movements.  The different cover tests detect the presence of any eye misalignment. This test requires a cooperative child, usually 3 years or older, and an experienced examiner.

OPHTHALMOSCOPY

Ophthalmoscopy may be possible in very cooperative 3-to 4-year-olds who are willing to fixate on a toy while the ophthalmoscope is used to evaluate the optic nerve and retinal vasculature in the posterior pole of the eye.  This requires an experienced examiner.

VISUAL ACUITY ASSESSMENT

Visual acuity assessment is considered the most sensitive of all screening methods for detecting eye abnormalities in children.  The formal method requires reading an eye chart, so successful testing is highest with children age 3 or older.  Since it is the only screening method that directly measures visual acuity, it is the preferred exam for older children. It is important to test each eye separately and to verify that the child is not "peeking" with the other eye.

In the event that the child is unable to cooperate for visual acuity testing, a second attempt should be made 4 to 6 months later. For children 4 years and older, the second attempt should be made in a month.

For children younger than 3 years old, visual acuity assessment is accomplished by evaluating the child’s ability to fixate and follow objects into various gaze positions.  Failure to do so indicates significant visual impairment.  The assessment should be done with both eyes open, then with one eye at a time.  It is important to ensure that the child is awake and alert, because disinterest or poor cooperation can mimic a poor vision response.

What eye problems can be detected on a vision screening?

The main goal of vision screening is to identify children who have or are at high risk to develop amblyopia (lazy eye), which can lead to permanent visual impairment (unless treated in early childhood). Other problems that can be detected by vision screening include strabismus, refractive errors such as myopia ("nearsightedness"), hyperopia ("farsightedness") and astigmatism, ptosis, cataracts, glaucoma, nasolacrimal duct obstruction, and other more serious conditions such as tumors or neurological diseases.

At what age should a child have his or her vision screened?

Vision screening is most effective when performed periodically throughout childhood, beginning in the newborn period. The earlier a problem is detected, the better the chance to obtain maximal vision through appropriate treatment.

The first vision screening should take place in the nursery when the pediatrician inspects the newborn's eye, pupil and red reflex. The pediatrician continues to perform age appropriate vision screenings through infancy and childhood in addition to vision screening that is offered at day care, school or church.

In some parts of the United States and the United Kingdom a documented vision screening or comprehensive eye examination is required before beginning primary school.

Infants and young children at high risk of having or developing eye problems should be referred for specialized eye examination by an ophthalmologist experienced in treating children (pediatric ophthalmologist). This includes children who are born premature; those with family histories of congenital cataracts, retinoblastoma, and metabolic or genetic diseases; those who have significant developmental delay or neurologic abnormalities; and those with systemic conditions associated with eye abnormalities.

Because children do not complain of visual difficulties, formal visual acuity measurement is an important part of complete pediatric eye care and should begin at 3 years of age. To achieve the most accurate result possible, an age-appropriate eye chart should be used.

What is the difference between vision screening and a comprehensive eye examination, and which is more appropriate for most children?

Vision screening is more efficient and more cost effective than a complete examination on every child. Only a small percentage of children screened have an eye problem that requires treatment, so it is not practical to perform a comprehensive eye examination on every child. In addition, some problems are missed on a one-time comprehensive eye examination, so it is preferable to have several screenings performed over time.

Nevertheless, if a child has known risk factors for eye disease, if there is a family history of pediatric eye disease, or if a child has signs or symptoms suspicious for a vision problem, it is reasonable and appropriate for a child to have a comprehensive eye examination, regardless of age.

What particular method should be done per age?

Vision screening at birth up to 3 years of age should include:  ocular history and family ocular history, birth and maternal history, external eye examination, pupil examination, ocular motility testing, and red reflex examination.  For children older than 3, al of the above plus age-appropriate visual acuity measurement and ophthalmoscopy, should be included.

Who performs vision screening?

Pediatric ophthalmologists, general ophthalmologists, pediatricians, primary care doctor (family practitioners), and trained nurses, can perform vision screening.  In addition, there are vision screening programs for children are sponsored by the school, church, and health department.

Why is a pediatric ophthalmologist an excellent choice for children’s eye care?

Children are not just small adults.  They cannot always say what is bothering them.  They cannot always answer medical questions, and are not always able to be patient and cooperative during a medical examination.

Pediatric ophthalmologists know how to examine and treat children in a way that makes them relaxed and cooperative.  In addition, pediatric ophthalmologists use equipment specially designed for children.  Most pediatric ophthalmologists’ offices are arranged and decorated with children in mind.  This includes the examination rooms and waiting rooms, which may have toys, videos, and reading materials for children.  This helps create a comfortable and non-threatening environment for the child.

All ophthalmologists have some training in children’s eye problems, but the pediatric ophthalmologist has had additional training and practice in examining children and caring for their eye problems.  If your primary care doctor suggests that your child have his or her eyes checked, a pediatric ophthalmologist will have the greatest knowledge of the possible conditions and the greatest experience in examining children effectively.

What kinds of treatments do pediatric ophthalmologists provide?

Pediatric ophthalmologists are medical and surgical doctors trained in the management of eye problems in children.

They can manage amblyopia (“lazy eye” or undeveloped vision) by using glasses, patching, dilating drops or any combination. They are the best to do refraction in children and can give accurate prescription glasses for refractive errors like farsightedness (hyperopia), nearsightedness (myopia), or astigmatism.  They can treat infections such as those affecting the conjunctivae, or the tissue around the eye, or the internal part of the eye.  They can co-manage cases of intraocular inflammation (iritis, uveitis) and high intraocular pressure (glaucoma) with the appropriate subspecialists.

They can do surgery for eye misalignment (strabismus), blocked tear ducts (nasolacrimal duct obstruction), cataracts, as well as eye injuries repair.  Some do laser surgery in premature babies, glaucoma surgery, or droopy eyelid (ptosis) surgery.  This varies with the interest, training, and experience of the pediatric ophthalmologist.

What if a child fails his or her vision screening or cannot cooperate for vision screening?

If a child fails a vision screening at any age, the child should be referred to a pediatric ophthalmologist for a comprehensive eye examination. By age 3 or 4 years, most children are able to cooperate for subjective visual acuity testing using an eye chart. If a child is unable to cooperate for visual acuity testing at age 3, a second attempt should be made within 6 months, if the child is age 4, a second attempt should be made within one month. If retesting is impossible or inconclusive, then the child should be referred for a comprehensive eye examination.

Summary and Recommendations

The screening test done on KR revealed that he had amblyopia (lazy eye) on the right.  The comprehensive exam that followed showed that he has a very high refractive error in both eyes, the one on the right being significant much higher than that on the left.  He was then given a pair of prescription glasses to be worn full time.  His mother was also asked to follow a regular patching regimen of the better (left) eye to further help the development of vision on his lazy right eye.  He is almost 4 years old now, and his vision is equal in both eyes and is doing very well in school.

Vision screening is vital for the detection of conditions that result in visual impairment, lead to problems with school performance, imply serious systemic disease, or worst, threaten the child’s life.

It should be performed by the family pediatrician starting in the newborn period, and repeated at all well-child visits.  All children who are found to have an ocular abnormality or who fail vision screening should be referred to a pediatric ophthalmologist or an eye care specialist appropriately trained to treat pediatric patients, for further evaluation and appropriate management.

Visual acuity measurement, the most sensitive of all vision screening methods, should be performed at the earliest possible age that is practical, usually at approximately 3 years of age.  Children diagnosed with specific vision-threatening eye disorders should be seen regularly by a pediatric ophthalmologist.

Early detection and prompt treatment of ocular disorders in children is important to avoid lifelong permanent visual impairment.

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References:

1.  American Academy of Ophthalmology Policy Statement on Vision Screening for Infants & Children, March 2007.

2.  Red Reflex Examination in Neonates, Infants and Children, A Joint Policy Statement by the American Academy of Pediatrics Section on Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus, American Academy of Ophthalmology, and the American Association of Certified Orthoptists, in Pediatrics Vol 122 No. 6 December 2008 pp. 1401-1404.

3.  Vision Screening in Children, EYE REPUBLIC Patient Information Brochure