Amblyopia, lazy eye also known as lazy eye, is a vision development disorder in which an eye fails to achieve normal visual acuity, even with prescription eyeglasses or contact lenses.
Amblyopia begins during infancy and early childhood. In most cases, only one eye is affected. But in some cases, reduced visual acuity can occur in both eyes.
Particularly if lazy eye is detected early in life and promptly treated, reduced vision can be avoided. But if left untreated, lazy eye can cause severe visual disability in the affected eye, including legal blindness.
It's estimated that about 2 to 3 percent of the U.S. population has some degree of amblyopia.
AMBLYOPIA SIGNS AND SYMPTOMS
Because amblyopia typically is a problem of infant vision development, symptoms of the condition can be difficult to discern.
However, a common cause of amblyopia is strabismus. So if you notice your baby or young child has crossed eyes or some other apparent eye misalignment, schedule an appointment for a children's eye exam immediately — preferably with an optometrist or ophthalmologist who specializes in children's vision.
Children wearing Eye-Doodle eye patch stickers.
You can help your child accept patching by making it fun. Shown here are eye patch stickers by Eye-Doodle.
Another clue that your child may have amblyopia is if he or she cries or fusses when you cover one eye.
If your child is not bothered when one eye is covered, but objects when the other eye is, this may suggest that the eye you have covered is the "good" eye, and that the uncovered eye is amblyopic, causing blurred vision.
But a simple screening test is no substitute for a comprehensive eye exam.
Have your child's eyes examined as recommended to make sure he or she has normal vision in both eyes and that the eyes function together properly as a team.
Strabismic amblyopia. Strabismus is the most common cause of amblyopia. To avoid double vision caused by poorly aligned eyes, the brain ignores the visual input from the misaligned eye, leading to amblyopia in that eye (the "lazy eye"). This type of amblyopia is called strabismic amblyopia.
Refractive amplyopia. Sometimes, amblyopia is caused by unequal refractive errors in the two eyes, despite perfect eye alignment. For example, one eye may have significant uncorrected nearsightedness or farsightedness, while the other eye does not. Or one eye may have significant astigmatism and the other eye does not.
In such cases, the brain relies on the eye that has less uncorrected refractive error and "tunes out" the blurred vision from the other eye, causing amblyopia in that eye from disuse. This type of amblyopia is called refractive amblyopia (or anisometropic amblyopia)
Deprivation amblyopia..This is lazy eye caused by something that obstructs light from entering and being focused in a baby's eye, such as a congenital cataract. Prompt treatment of congenital cataracts is necessary to allow normal visual development to occur.
AMBLYOPIA TREATMENT
In some cases of refractive amblyopia, normal vision can be achieved simply by fully correcting the refractive errors in both eyes with glasses or contact lenses. Usually, however, at least some patching of the "good" eye is needed to force the brain to pay attention to the visual input from the amblyopic eye and enable normal vision development to occur in that eye.
Treatment of strabismic amblyopia often involves strabismus surgery to straighten the eyes, followed by eye patching and often some form of vision therapy (also called orthoptics) to help both eyes work together equally as a team.
Patching may be required for several hours each day or even all day long and may continue for weeks or months.
If you have a lot of trouble with your child taking the patch off, you might consider a specially designed prosthetic contact lens that prevents light from entering the good eye but does not affect your child's appearance.
Though prosthetic contact lenses are more costly than a simple eye patch and require a contact lens exam and fitting, they can work wonders in difficult cases of amblyopia treatment when compliance with eye patching is poor.
In some children, atropine eye drops have been used to treat amblyopia instead of an eye patch. One drop is placed in your child's good eye each day (your eye doctor will instruct you). Atropine blurs vision in the good eye, which forces your child to use the eye with amblyopia more, to strengthen it. One advantage of using atropine eye drops is that it doesn't require your constant vigilance to make sure your child wears the patch.
However, atropine does have side effects that should be considered: light sensitivity (because the eye is constantly dilated), flushing and possible paralysis of the ciliary muscle after long-term atropine use, which could affect the eye's accommodation, or ability to change focus.
EARLY DETECTION AND TREATMENT ARE IMPORTANT
Though modern amblyopia treatments might improve vision in older children and adults, most experts agree that early detection and treatment of lazy eye is preferred for normal visual development and the best visual outcomes from amblyopia treatment.
The American Optometric Association recommends that all children have their first eye exam at 6 months of age, another exam at age 3 and a third exam prior to entering school to ensure vision is developing normally in both eyes and there is no risk of amblyopia.
Amblyopia will not go away on its own, and untreated lazy eye can lead to permanent visual problems. If later in life your child's stronger eye develops disease or is injured, he or she will depend on the poor vision of the amblyopic eye, so it is best to treat amblyopia early on.
Op.Dr.Ahmet UMAY
Bristol University / Ophtalmology Section
United Kingdom
Resource :
Brıstol University Ophtalmology Section
