Eye Examinations: Children with Down Syndrome (Trisomy 21)
Assessment of vision and visual response can be challenging in children and teenagers with special needs. A visit to the eye doctor can present will a new set of challenges for the sensory experience for children with Down syndrome. At our practice, we are dedicated to making your child feel “at home” and to decrease his or her anxiety about having an eye exam. We use musical toys and stuffed animals to comfort but also to create a sense of fun!
What Causes Down Syndrome?
Down syndrome is caused by a duplication of all or part of Chromosome 21, making three copies of the chromosome, rather than the usual two copies of the chromosome. The most common form of Down syndrome is called Trisomy 21. In a person with Trisomy 21, there are 47 chromosomes in each cell, instead of the 46 chromosomes. The extra genetic material in children with Trisomy 21 can cause multi-system disease, including but not limited to ophthalmic, cardiac, and hematologic.
How Common Is Down Syndrome?
Trisomy 21 is the most common chromosomal anomaly in humans.
In the United States, about 6,000 babies are born with Down Syndrome every year, which is about 1 in 700 babies born.
Are Children with Down Syndrome at Increased Risk for Vision or Eye Problems?
Yes, children with Down Syndrome are at increased risk for vision disorders and ocular problems. Many of these eye problems can be treated, especially if discovered and diagnosed at an early age.
What are the Common Eye Problems in children with Down Syndrome?
(1). Refractive Errors:Children with Down Syndrome are more likely to need glasses as compared to children without special needs. The need for glasses is due to myopia (nearsightedness), hyperopia(farsightedness), and/or astigmatism (curvature of the cornea and/or lens). These refractive error may develop early in childhood or later on during the teenage years.
(2) Strabismus:Children and teenagers with Down Syndrome are more likely to have strabismus (ocular misalignment) as compared to other children without special needs. In particular, between 20% and 60% have strabismus. Regarding the type of ocular misalignment, esotropia (inward turning of the eyes) is more common than exotropia (outward turning of the eyes). Strabismusmay be treated with glasses, patching, and/or strabismus (muscle) surgery.
(3) Nasolacrimal Duct Obstruction: Children with Down Syndrome are more likely to have epiphora (increased/excessive tearing) of the eyes as compared to other children without special needs. This occurs because the nasolacrimal drainage channel/valve is partially or fully blocked. Partial nasolacrimal duct obstruction often resolves with gentle massage of the nasal bone next to the lacrimal sac to help increase the flow of tears through the drainage channel. If the epiphora remains bothersome, especially with matting of the eyelashes with a persistent increased tear lake, intervention with probing of the nasolacrimal duct may be required.
(4) Cataracts: Children with Down syndrome have an increased incidence of congenital cataracts (present at birth) as well as acquired cataracts (develop later). These cataracts may progress slowly and should be monitored regularly, with surgical treatment performed when the vision is affected.
(5) Keratoconus:Children with Down Syndrome have an increased incidence of an abnormally shaped cornea with a cone shaped distortion as compared to other children and teenagers without special needs. In particular, up to 30% have keratoconus. Keratoconus is usually diagnosed around puberty and should be monitored regularly. Signs and symptoms resulting from keratoconus include blurred vision, corneal thinning, or corneal haze. Of note, eye rubbing should be avoided and discouraged because the corneal thinning can worsen and cause decreased vision.
(6) Glaucoma:Children with Down Syndrome are at increased risk for infantile glaucoma (elevated intraocular pressure within the eye) as compared to children without special needs. The intraocular pressure and the optic nerve should be monitored regularly. Both medical and surgical treatment options are available depending on the severity of the glaucoma.
(7) Nystagmus:Children with Down Syndrome are at increased risk of nystagmus as compared to children without special needs. Nystagmus is an involuntary shaking or “back-and-forth” movement of the eyes. Regarding the eyes’ movements, they are moving horizontally with a rotary component and high frequency, low amplitude. Of note, nystagmus can affect vision and can also cause an abnormal head position (face turn or head tilt) to occur to achieve a quieting (null point or null zone) of the shaking or “back-and-forth” movement of the eyes. It is important to monitor regularly to ensure that the vision is maximized and that if there is a face turn or head tilt, it is not interfering with his or her quality of life.
When should children with Down Syndrome have an eye examination?
The American Academy of Pediatrics recommends that children with Down syndrome be examined by a pediatric ophthalmologist or an ophthalmologist who is familiar with the examination of infants with disabilities. The initial examshould be done by six months of age with follow up exams once per year or more if needed during the first decade of life.
Please call our office at 203-878-1236 or 203-226-1234 for an evaluation.
Eye Physicians and Surgeons PC. Blog submitted by Jennifer A. Galvin, MD