Clinical Information - Pediatric Cataract

Children's Hospital pediatric ophthalmologists answer frequently asked questions

What is a cataract? How does it grow?
A cataract isn't really something that grows. It's just a cloudiness of the lens of the eye, which is supposed to be crystal clear. Imagine if the clear lens of your camera just turned white. That's basically a cataract. Even if it just developed a white dot in the middle, that would still be a cataract.

Don't only old people get cataracts? How could this happen to my baby?
It's very rare for a baby to get a cataract, but it does happen. The difference is that in kids, the lens clouds over because it didn't form properly. In adults, a normal lens just gets old and hard and yellow and finally clouds over. If you think about it, and especially if you learn how the eye develops before birth, it's amazing that anyone ever ends up with a crystal clear lens in each eye. The process of lens formation is an intricate and miraculous ballet of cells that takes place early in the third to fourth month of pregnancy.

Why must my baby's cataract be treated right away?
Babies with a cataract should be referred to our Pediatric Cataract Service as soon as the cataract is discovered. In adults, timing of cataract surgery won't affect vision over the long-term, but in babies delaying surgery can mean permanent vision loss. That's because when a cataract forms, the lens isn't focusing light for the brain and the brain, in turn, gets no visual experience. The brain is deprived of images during the critical time when it is supposed to be learning how to see. If the brain continues to get no input from the affected eye, it may completely ignore the eye and never learn to pay attention to it.
In our practice, we have encountered too many cases when we discovered a cataract, did the surgery, and appeared to have a perfect result, with the light focused by the crystal clear lens implant onto a normal-looking retina. Yet, we would soon discover that the child couldn't see any better because the brain never learned how to see -- the problem had been discovered too late.

How do we know if a cataract is there? Can I see it?
Occasionally, parents notice a white pupil in a baby's eye or a white dot in the pupil and bring the patient in. Usually, though, the primary care doctor sees it. Checking for cataracts is an important part of the examination that pediatricians perform on newborn babies in the nursery.

Do all cataracts have to be removed?
There are some cases where the cataract may be just a dot in the middle of the lens that doesn't have to be removed because there is room for the light to get around it. Other times it's a borderline case and doctors may disagree about surgery. In these cases, experience plays an ever greater role in the decision making process, so it is important that your child be evaluated by a pediatric ophthalmologist who sees many babies with cataracts and is qualified to make critical decisions such as whether to operate or not.

In borderline cases, are there alternatives to surgery?
Every case is different, and our pediatric ophthalmologists come up with creative solutions to fit each child. Sometimes, if the cataract represents a tiny dot on the lens, your child's doctor might recommend placing a patch over the unaffected or strong eye, to help strengthen vision is the affected eye, maybe with glasses if the focus is off. In other cases we use eye drops or contact lenses to dilate the pupil enough to get more light in but still keep the eye in focus. Either way, your child will be routinely monitored, to be sure that vision isn't slipping.

What does the surgical procedure involve?
After anesthesia is administered, the patient is positioned under an operating microscope. The eyelids are gently opened and an instrument that is as narrow as a pencil point is used to make a tiny incision in the clear window of the eye, known as the cornea. Then an equally tiny instrument opens up the front layer eye's lens (the lens capsule). The cloudy lens is then aspirated (removed). To bring the focusing power back to the eye, the lens must be replaced.
For some children, the faulty lens is replaced with a plastic intraocular lens at the time the cataract is removed. The new lens is surgically injected through the same tiny incision and unfolded to its full size, sort of like assembling a ship in a bottle. In cases where lens implantation is not recommended, children are fitted with specialty contact lenses a few days after surgery. See Contact Lens Service.

What is a lens implant and will my child have one?
In adults, surgically inserted intraocular lenses are used routinely in cataract surgery. In children, these lenses aren't always an option for several reasons. A child's growing and developing eye is much more aggressive about rejecting foreign invaders than an adult eye. So lens implantation in young children is more likely to cause complications such as inflammation. The other difficulty is determining what lens power to use in a young child's eye that will be useful now and 20 years from now in adulthood.
At Children's Hospital Boston, intraocular lenses have been successfully implanted in babies as young as 6 months old. Our pediatric ophthalmologists are on the forefront of latest surgical techniques that have improved tremendously in recent years. The incisions are smaller, so there is less trauma and disruption to the eye during surgery. In addition, the customized computer software we use enables us to model the growth of the eye, and predict the lens specifications not only for a child's eye today but also for a child's eye in adulthood. However, because of the potential complications mentioned above and the difficulty in predicting lens power in young babies, not every child is a candidate for a lens implant.

Your child's pediatric ophthalmologist will discuss the pros and cons of lens implantation with you and will determine whether or not a lens implant is appropriate for your child at this point in time. In some cases, the doctor will recommend waiting until your child is older and using contact lenses in the meantime.

Can the implant be seen?
Not normally. Usually the implant stays behind the iris, the colored part of the eye, in the middle of the pupil. Some parents say that the eye with the implant seems to have a "sparkle" or "glint" if light catches it just right, but that certainly doesn't cause any problems for the patient.

What if my child must wear contact lenses?
Some babies and children will have to wear contact lenses after cataract surgery to bring the focusing power back to the eye that had the cataract. In some cases, this is a temporary solution until your child's doctor decides lens implantation is appropriate for your child, but in other cases, the contact lenses work great and there is no need to have more surgery.

How can I possibly learn to put contact lenses in my baby's eyes? I don't even wear glasses.
If you're like most parents, you may be daunted by the idea of putting a contact lens in your baby's eye. And it's not always so easy in the beginning. However, most parents find, as the process becomes part of the daily routine, that their babies or young children become accustomed to changing lenses and it becomes second nature. We have had young patients who, by age 5, could insert and remove their own contact lenses. Our staff spends a lot of time with families to make sure they are comfortable with the contact lenses.

Will glasses be needed?
Usually glasses are needed to perfect the focus. We often have to leave the eye a little farsighted at first to allow for the eye to grow. Also the formulas, while quite exact, can never predict the final power of the eye perfectly. So a lens is added to promote the best possible vision development. One other thing - natural lenses adjust to shift focus from distance to near, but plastic intraocular lenses are going to focus at one place. They cannot shift focus, so once children are able to sit up, we tend to put them in bifocals. These glasses will help your child focus up close and far away.

What other care is required?
Children who have had cataract surgery will also require routine follow-up exams. After the surgery, we have to help the eye "catch up," so we end up patching the other eye (or using atropine to blur the eye.) This patching can go on for years to help the eye catch up. Poor vision means that the eye is more likely to wander, too. When that happens we do eye muscle surgery or sometimes we use botox injections. See Pediatric and Adult Strabismus Program.
Unfortunately an eye that has a cataract may not have formed normally in other ways. Patients with cataract have a higher risk of developing high pressure (glaucoma), sometimes years later. Between all of the visits shortly after surgery and the lifetime of follow up, many of our patients end up visiting their eye doctor more often than they see their own grandparents!