Lazy Eye (Amblyopia)
Lazy eye (medically known as amblyopia) is a unique vision disorder. Its development and progression have more to do with the brain’s ability to process visual information received from both eyes than a defect in the structure of the problem eye itself. As a result, amblyopia cannot be corrected using prescription eye glasses or contact lenses. There are, however, lazy eye treatments available, including in some cases surgery. Read on to learn more about lazy eye causes and treatments, and find out what to do if you suspect your child may be suffering from this form of vision impairment.
Lazy Eye Causes
Anything that interferes with the vision field of one of a child’s eyes during the critical development phase (from birth to age 6) can result in the development of amblyopia. The most common of lazy eye causes is constant lateral strabismus, or perpetual abnormal turning of a single eye. Although a severe case of strabismus can be easily recognized by a parent, a very slight case may not be readily visible. Having your child receive a complete eye examination from a pediatric doctor is usually the best way to determine whether strabismus is causing your child vision problems.
Anisometropia, a condition in which the two eyes require separate prescriptions, can also trigger amblyopia. If the vision in one eye is significantly more blurry than the vision in the other eye, the brain can eventually stop accepting signals from the problem eye. If not caught early enough, this condition can cause permanent vision disability. Other lazy eye causes include, but are not limited to, eye injury, an excessively drooping eyelid, and the presence of a retinal tumor.
Lazy Eye Symptoms
Lazy eye symptoms can be difficult to detect if you are not a trained ophthalmologist. The fact that amblyopia occurs almost exclusively in children creates unique problems for recognizing its warning signs. For one thing, a child may not have the language skills necessary to communicate that his or her vision is blurry. Also, a child who is born severely amblyopic will have no way of distinguishing normal vision from their impaired vision.
Scheduling your child for an eye examination every year throughout the critical development period (birth through age 6) is a good way to catch any eye conditions before they become more difficult to treat later in life. Ideally the first examination should occur before the child reaches 6 months of age. For babies and very young children, the amblyopia testing can usually be performed by a pediatrician, who will refer you to an optometrist or an ophthalmologist if there appears to be a problem. If you suspect your family practitioner may be missing something, don’t hesitate to get a second opinion from an eye care specialist.
Potential Signs of Lazy Eye
Don’t wait for your child to tell you that he or she is experiencing vision problems. Behavioral cues are usually the best way to find out if something isn’t right with your child’s vision. Below are some potential signs of lazy eye.
- If your child’s eyes don’t appear to be working in unison when he or she focuses on an object, you should make an appointment to have your child’s eyes examined immediately. This is usually a sign of amblyopia or a less serious but also potentially bothersome condition known as strabismus (crossed eyes).
- Is your child doing poorly in school? Before deciding that your child has a learning disability, be sure to have your family practitioner perform a complete eye examination. A child’s learning can be stunted by vision defects resulting from amblyopia or, more commonly, a refractive error caused by a defect in the shape of the cornea. If your doctor suspects a problem, you will be referred to a licensed ophthalmologist.
- Is your child especially clumsy in relation to one side of his or her body? Some clumsiness is normal. Children are constantly adjusting to their ever-changing and developing bodies. However, if your child is always bumping into objects on one side of his or her body and noticeably less so on the other, the reason may be amblyopia.
- If your child routinely closes one eye while reading or watching the television, the vision in that eye may be impaired. If left untreated this can lead to the development of lazy eye and the need for surgery.
- Avoidance of an entire class of activities such as athletics (which tend to require distance vision) or indoor activities such as reading or coloring (which require close vision) may be a sign of vision problems. Have your child’s eyes examined to see if this is the case.
- Photographs that show milky white spots in a child's eye, rather than the more common red spots, may indicate the early development of cataracts. Although more common in seniors, cataracts can strike children and can be hard to detect with the naked eye. The presence of a cataract in a single eye during childhood almost always triggers amblyopia. Cataracts are a harbinger of very serious vision defects and, if left untreated, can eventually cause blindness.
Lazy Eye Diagnosis
Lazy eye disorder often goes unnoticed in its earliest stages, when it is most treatable. The only way to reliably diagnose the condition is to receive a complete eye exam from a trained eye care specialist. To diagnose lazy eye, an eye doctor will employ a special visual acuity test, more advanced than the standard eye chart test usually employed by school nurses and pediatricians. Special eye drops may be administered to dilate the eye to allow for a more thorough examination.
Early detection of lazy eye is very important in increasing the probability that the disorder will be completely corrected with no permanent vision damage. Since lazy eye tends to be present from birth, it is very important that infants receive a complete eye examination before they turn 6 months old. A child suffering from amblyopia has the best chance of being cured if the disease is diagnosed and treated before the age of 2. The earlier lazy eye is treated, the less likely it is to contribute to the development of learning problems such as reading disabilities.
Medical precedent has established that lazy eye can be successfully treated with relative ease in patients under the age of 17. When the eyes have ceased growing, a substantial amount of vision therapy is often necessary to achieve improvement. In rare instances, lazy eye can remain undetected until adulthood. Regardless of age, if you think you may be exhibiting signs of the disorder, you should go see an eye doctor for a complete screening. After an amblyopia diagnosis is made, lazy eye treatments, including surgery, may be necessary.
Lazy Eye Treatments
Successful lazy eye treatments have to address two distinct aspects of the disorder in order to be effective. Most of the treatments described below are meant to treat the amblyopia itself, but in order to prevent the disorder from recurring and to maximize treatment effectiveness, your doctor must first determine what is responsible for you or your child’s amblyopic condition.
Amblyopia is always caused by the brain ignoring visual data from one eye in favor of the other eye. Amblyopia treatments usually consist of training the brain to accept visual input from the weaker eye. In order for this to work, the eye must first be treated for the defects that inhibit its ability to produce reliable visual data.
If the development of amblyopia was caused by a blockage of the eye’s visual field because of a facial injury, then treatment of the eye itself may not be necessary. More often, however, this phase of lazy eye treatment involves treating constant unilateral strabismus or correcting refractive errors, to restore the weaker eye’s vision. Once the weaker eye’s visual data is accurate, rehabilitation of the relationship between the brain and the eye can begin.
Patching is the most popular method for treating lazy eye in children. The treatment is designed to force the brain to acknowledge data received from the problem eye. This treatment is very successful when the cause of the problem in the neglected eye has been corrected.
The amount of time the eye patch must be worn varies by patient. In some cases, an ophthalmologist may recommend that the patch be worn for as little as two hours a day, while in other cases a longer amount of time may be recommended. Most often, patients are required to wear the patch for six hours a day. The treatment is most effective with young children who have only recently developed amblyopia, but more and more the technique is producing significant eye sight improvements in older children as well. In adults diagnosed with lazy eye, more aggressive treatments are usually required.
Eye drops are another method of blocking the vision of the stronger eye. Eye drops are often employed when a child experiences skin irritation around the eye or is simply too fussy to tolerate an eye patch.
The eye drops contain a drug called atropine. When administered to the stronger eye, atropine temporarily blurs its vision, thus encouraging the brain to favor the eye it usually ignores. The side effects of atropine are usually minimal; however, it can produce a temporary increase in light sensitivity, and overuse can produce paralysis of the ciliary muscles. In some children, the drug can cause a decrease in heart rate. No lazy eye treatments should be attempted without the counsel of a qualified optometrist, and this is especially true of eye drop treatment.
Vision therapy is a non-surgical form of lazy eye treatment and is gaining credence with many optometrists. Many ophthalmologists, however, who prefer to treat amblyopia with surgery, view this particular treatment skeptically.
A simplified description of vision therapy would be that it is a combination of one of the above treatments (patching or eye drops), eye exercises, computer software to augment the exercises, and prescription eyeglasses or contact lenses. The eye exercises are designed to create new neural pathways between the weak eye and the brain and to then strengthen the eyes' ability to work as a team. Vision therapy is basically physical therapy for the eye. It is thus a form of neurological training and rehabilitation.
Other forms of vision therapy can be used to treat crossed eyes, double vision, convergence problems, and certain reading and learning disabilities. The course of treatment and the techniques employed for one patient are never identical to what is used for another patient with a similar disorder. This is because vision therapy is completely custom tailored to fit the patient’s specific medical profile and individual needs.
Most doctors approach vision therapy as a goal-oriented, short-term course of treatment. The goal is to improve the patient's vision in as short a time frame as possible while also ensuring long term results. Most vision therapy treatment plans last for three months to two years, depending upon the severity of the vision problem. Vision therapy tends to be the most effective treatment for older people with lazy eye, who, incidentally, may think it is too late to effectively treat their amblyopia.
Lazy Eye Surgery
Lazy eye surgery is a hotly contested topic among optometrists and ophthalmologists. Some eye doctors believe it is the only effective form of lazy eye treatment, while others are less convinced of its effectiveness. Doctors who are reluctant to recommend lazy eye surgery cite the lack of reliable statistics on the procedure's success rate and say that multiple surgeries are often needed to produce positive results. The Optometrists Network recommends that parents always obtain a second opinion when surgery is recommended for their children's amblyopia, particularly if non-surgical treatment options have not already been explored.
Lazy eye surgery is most successful in cases where the child’s amblyopia is caused by constant unilateral strabismus in a single eye. The surgery is performed to turn the eye in the proper direction, both for vision and cosmetic purposes. Although these two goals are hardly mutually exclusive, you should always ask whether the main goal of the procedure is to make the eyes look better or work together better. Making the lazy eye appear more evenly positioned will achieve only a cosmetic improvement. Only the achievement of a perfect alignment will help restore vision, and this outcome may not always be possible with a single surgery. Ask your eye surgeon about the possibility of needing follow up surgeries before you agree to the procedure.
There have been many cases where cures for lazy eye disorder or significant improvements in lazy eye symptoms have been achieved through surgery, particularly in cases where the surgery was paired with vision therapy. Be sure to do your homework and research the procedure thoroughly before deciding whether it is in your or your child's best interest. Don't be afraid to ask your eye doctor questions until you feel completely comfortable making a decision.
Lazy Eye vs. Strabismus
Children who have a lazy eye are often mistaken for having crossed eyes, but amblyopia and strabismus are not the same condition. One reason that the two eye conditions are often mistaken is that constant unilateral strabismus, a specific type of crossed eyes, is one of several lazy eye causes. It is important to remember that not everyone diagnosed with strabismus has or will develop lazy eye. Cases of lazy eye occurring in conjunction with intermittent or rotating strabismus are almost non-existent. Conversely, not everyone diagnosed with lazy eye has been diagnosed with strabismus. Amblyopia can result from eye injuries or conditions such as eyelid droop or tumors that occur during a child’s critical period of development.
One important difference between crossed eyes and lazy eye is the age range during which treatments retain their effectiveness. Although it is usually diagnosed and treated in children, strabismus can be treated at any age. Amblyopia on the other hand, can be controlled but usually not completely treated in people older than 17. That is why a misdiagnosis of strabismus when the true condition is lazy eye is a serious matter.
If you suspect your child may have amblyopia but your doctor disagrees, it is important to seek a second opinion so that lazy eye treatments can begin as soon as possible if your child does, in fact, have the condition.
Talk to a Doctor
Amblyopia is a complex condition involving both the eye and the brain. The cause of lazy eye is often the presence of another eye disorder. Remember, the condition is not one that can be treated with home remedies. If you believe that your child is exhibiting the symptoms of lazy eye, you should schedule a complete eye examination as soon as possible. If your child has already been diagnosed with lazy eye, safeguarding his or her sight requires prompt medical treatment. For more information on vision therapy, lazy eye surgery, and other lazy eye treatments, use our directory to find an ophthalmologist in your area today.