For this article, NDSS interviewed Danielle Ledoux, M.D., who specializes in Ophthalmology at Children's Hospital Boston.
Down syndrome has effects on the developing eye, which could influence the proper development of vision. Eye disease is reported in over half of patients with Down syndrome, from less severe problems, such as tear-duct abnormalities, to vision-threatening diagnoses, such as early-age cataracts. Caregivers and doctors should give particular attention to vision in people with Down syndrome.
What is different about the eyes in Down syndrome?
A person with Down syndrome has characteristic features about the eyes. This includes upward slanting of the eyelids, prominent folds of skin between the eye and the nose, and small white spots present on the iris (the colored part of the eye), called Brushfield's spots. These spots are harmless, and people without Down syndrome have them as well.
Do most children with Down syndrome need glasses?
Refractive error (the need for glasses) is much more common in children with Down syndrome than it is in the general population. This refractive error can be hyperopia (farsightedness), astigmatism, or myopia (nearsightedness). Another problem is weak accommodation (difficulty changing the focusing power of the eye from distance to near). We can test this easily in the office, and if it's detected, we will prescribe glasses that have bifocals. Some of my patients have difficulty adjusting to glasses, but once they get accustomed to having the glasses on their face, their vision is significantly better and often their eye alignment improves as well.
What are common, but less serious, eye abnormalities affecting patients with Down syndrome?
In addition to refractive errors that require eyeglasses, many children with Down syndrome have tear-duct abnormalities. Family members will notice this as frequent discharge and tearing from the eyes, worsened by colds. We generally recommend firm massage over the space between the eye and the nose (tear sac region) two to three times a day, to attempt to open the tear duct. If this continues beyond a year of age, a surgical procedure may be necessary to open the tear ducts. Strabismus (eye misalignment) is also more common in people with Down syndrome. Family members may notice that the eyes do not line up well with each other, but often the strabismus can be subtle, even to the pediatrician. The folds of skin I mentioned between the eyes and the nose can also cover up the underlying strabismus or make the eyes appear as if they are crossing, even if they are not. It is important to diagnose strabismus when the patient is a child, as crossed eyes can result in amblyopia (loss of vision also known as lazy eye) and loss of stereopsis (the use of the two eyes together, or depth perception).
What is the treatment for strabismus?
Simply glasses alone are sometimes enough to straighten eyes with strabismus. If glasses are needed, we always start there. If the eyes continue to have strabismus despite the correct pair of eyeglasses, then we recommend strabismus surgery (eye-muscle surgery). This is a one- to two-hour procedure, often done as an outpatient procedure unless there are other reasons to admit the patient, such as a serious heart condition. Unfortunately, our patients with Down syndrome are more likely to require more than one surgery to align their eyes, because they don't always respond as predictably to strabismus surgery as the general population with strabismus does.