Most people, have heard of cataracts, and know it pertains to the eyes. But what, exactly, does the condition entail?
Put simply, a cataract is any clouding of the eye’s natural lens. The natural lens is normally clear, and lies behind the iris and the pupil. When we think of cataracts, we typically think of older adults, but the condition can affect both infants and older children.
Approximately 3 out of 10,000 kids have a cataract in the United States. Some cataracts are present at birth (congenital cataracts) while others develop later (acquired cataracts). They can affect one eye (unilateral) or both eyes (bilateral). The cataract may also affect different parts of the lens and can range in size from a tiny dot to a dense cloud.
Causes of Pediatric Cataracts
The majority of pediatric cataracts have no identifiable cause. This is especially true if the cataract affects only one eye.
For bilateral cataracts (both eyes), the most common identifiable cause is a genetic mutation. Researchers have identified numerous genes involved in cataract formation. There are ongoing clinical studies to look at the genetic basis of congenital cataracts.
Other causes include: metabolic disorders (such as diabetes or Wilson disease), part of a syndrome (such as Down Syndrome), infections during pregnancy, inflammation, or trauma.
Symptoms of Pediatric Cataracts
Infants with mild cataracts and/or a unilateral cataract may have no discernible issues with their vision. This can lead to a delay in the diagnosis.
Some children may show a lack of reaction to light, failure to notice toys or faces, strabismus (misalignment of the eyes), or sometimes nystagmus (involuntary shaking of the eyes).
A cataract is often suspected when there is a missing or irregular red reflex. This is often detected when the child is first examined at birth, at a later well-baby exam, or noticed by parents.
How does a cataract affect vision?
Light enters the eye and is projected onto the retina (inner surface of the back of the eye) which transmits the signal to the brain. Since all light that enters the eye must pass through the lens, any clouding of the lens will affect the amount and clarity of light that can enter. In cases of very dense or large cataracts, it may stop light from reaching the retina altogether, therefore preventing the eye from seeing.
For children, whose eyes and brain are still learning to see, clear light is a must for the brain to receive a clear image. Any distortion or loss of light will limit a child’s visual development and cause amblyopia. Therefore, the younger the child, the more important it is for timely evaluation and treatment of their cataract.
How are pediatric cataracts treated?
Once a cataract is suspected, treatment begins with a full eye exam, typically administered by a pediatric ophthalmologist. Most pediatric cataracts are found at birth or at well-baby exams. Sometimes they are noticed by parents. Treatment will vary depending on the size and type of cataract and the overall eye health.
Not all cataracts will need to be removed. Cataracts that are small and/or off center in the lens may have minimal effect on vision. These children may be monitored, or medically treated with dilating eye drops, eyeglasses and/or patching therapy. Surgery may be delayed or avoided entirely.
Cataracts that interfere with vision development should be removed as soon as it is safely possible.
How is a cataract removed in children?
Unlike adults with fully grown eyes, children require specialized surgical instrumentation and techniques. Among other factors, general anesthesia is needed. Depending on the age of the child, a full exam under anesthesia and measurements of the eye may be done before the cataract is removed.
Tiny incisions are made into the eye for specialized micro-sized surgical instruments to enter. Using these instruments, a small opening is first made on the surface of the lens capsule, and the cataract is then broken up and suctioned out. Depending on the age of the child, an opening might be needed on the back surface of the lens capsule, and some of the thick gel (vitreous) that fills the eye will also be removed. This reduces the chance of scarring, which may cloud vision.
If a child is old enough and the eye is in healthy condition, a lens implant may be recommended. The implant is a man-made lens that will permanently remain in the eye. The power of the lens is a complex decision with many factors, all of which should be discussed with the treating surgeon. Whether a child receives a lens implant or not, they will need contact lenses and/or eyeglasses after surgery.
What are the risks of cataract surgery in children?
With modern technology, cataract surgery performed by an experienced surgeon is generally very safe and serious complications are rare. However, no surgical procedure is entirely without risk. Some risks are the same as adult cataract surgery and other types of eye surgery. Other risks are more specific to the pediatric population.
Risks include inflammation, infection, retinal detachment, development of capsular scar or cloudiness in the visual axis, clouding of the vitreous, and glaucoma.
The risk of glaucoma is perhaps the most serious for kids undergoing pediatric cataract surgery, especially those at a younger age. Glaucoma is high pressure in the eye. It is not caused by cataract surgery. Rather, it is due to improper development of the drainage channels in the eye. Glaucoma may develop months to years after surgery. The pressure can be controlled with medicated eye drops, but some children may require additional surgery to lower the pressure in the eye.
What to expect after cataract surgery?
Surgery will generally take about 1 to 2 hours, but it can vary depending on the complexity of the cataract. When you see your child in the recovery room, they will have a soft patch and hard shield protecting the eye. This will be secured with tape, which may be bothersome but will ensure protection of the eye and help with the mild discomfort that is normal after surgery. The patch and shield will be removed the next day at your post-operative appointment.
Overall, discomfort from cataract surgery is mild. Most children will require no pain medication, though a few may use Tylenol.
Medicated eye drops will help the eye heal and prevent infection during the first 4 to 6 weeks after surgery. A clear shield should be worn to protect the eye during the first two weeks. Your child should avoid rough play, submerging their eye in a bath, and swimming for 10 to 14 days after surgery. Most children will return to school after a few days.
How does vision improve after cataract surgery?
Cataract surgery is just the first step to improving vision. Connections between the eye and brain must be rebuilt. After removal of the cataract, children will need a combination of intraocular lenses implanted in the eye, contact lenses, or eyeglasses to train the eye(s) to focus properly.
Amblyopia treatment is also an important part of vision rehabilitation. This involves patching, or covering the stronger eye to stimulate vision in the weaker eye.
Depending on the age of the child at the time of surgery, vision rehabilitation may continue until the child is 8 to 10 years of age and vision development is complete. After this time, amblyopia is very unlikely to return.
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