Amblyopia is a medical term used when the vision in one or both eyes is less than 20/20 in the absence of any obvious structural or pathologic anomalies. Vision loss occurs because nerve pathways between the brain and the eye are not properly stimulated. This causes the affected eye to see a blurry image that cannot be corrected immediately with glasses. The brain usually learns to favor one eye due to the poor vision in the other eye. Amblyopia is often referred to as a lazy eye.
Most of the time there are no obvious signs or symptoms without having an eye exam. If there are signs/symptoms, they would include:
- An eye that wanders inward or outward
- Eyes that appear to not work well together
- Poor depth perception
- Squinting or shutting an eye
- Head tilting
- Abnormal results on vision screening tests
How Common is Amblyopia?
- Amblyopia is the most common cause of visual impairment among children
- Affects approximately 2 to 3 out of 100 children
- Unless treated successfully in early childhood, it will persist into adulthood
- Amblyopia is the most common cause of monocular (one eye) visual impairment among young and middle-aged adults
Risk Factors for Developing Amblyopia:
- Premature birth
- Small size at birth
- Family history of a lazy eye or eye turn
- Developmental disabilities
Types of Amblyopia:
- Strabismic Amblyopia – a misalignment of the two eyes; a patient has a constant eye turn inward or outward, which prevents that eye from getting a clear image
- Refractive Amblyopia – the inability of one eye to focus as well as the other due to one eye being more farsighted, nearsighted, or having more astigmatism
- Isoametropic Amblyopia – the inability of both eyes to focus well due to large amounts of farsightedness, nearsightedness or astigmatism
- A physical obstruction (ex. cataract, corneal opacity, ptosis, etc.) that prevents the formation of a clear image on the retina
Treatment for Amblyopia
- It is extremely important to start treatment for a lazy eye as soon as possible in early childhood while the connections between the eye and brain are still forming. Best results typically occur when treatment starts before age 7.
- Treatment options include:
- Corrective eyewear: glasses or contact lenses that are typically worn full time
- Eye patches: an eye patch is used over the stronger eye in order to stimulate the weaker eye. The patch is generally worn for two to six hours per day.
- Bangerter filter: this special filter is placed on the eyeglasses lens of the stronger eye, kind of like an eye patch. This also works to stimulate the weaker eye
- Eyedrops: a twice-weekly eyedrop (called Atropine) is used to make the vision in the stronger eye blurry in order to stimulate the weaker eye to work
- Surgery: this is indicated if your child has an eye turn in order to repair the eye muscles. Your child may also need surgery if he or she has droopy eyelids or cataracts that are preventing a clear image from reaching the retina
Comprehensive eye exams during childhood are extremely important in order to detect and treat any amblyopia, if present, in order to prevent any permanent vision loss. For more information on Amblyopia please feel free to talk to your optometrist at Primary Eyecare!