Amblyopia
Amblyopia, often called lazy eye, is a vision impairment caused by the visual system not developing normally. Organic amblyopia results from a structural abnormality in one or both eyes, usually in the retina or optic nerve. It cannot be fully corrected with glasses or contacts, and the underlying condition is usually irreversible.
What Is Organic Amblyopia?
Amblyopia is a disorder involving reduced clarity of vision, usually in one eye but sometimes affecting both. It’s called lazy eye because the affected eye often won’t hold a correct alignment. It may appear to wander or focus in a different direction from the other eye.
When the disorder is due to structural abnormalities of the eye or brain, it’s called organic amblyopia. Usually, this means there is a flaw in how the eye or optic nerve was formed during pregnancy or shortly after.
Causes
Structural damage to the eye, optic nerve or brain can bring about organic amblyopia. These changes to the eye often can’t be prevented and run in families. Premature infants and those with Down syndrome are also at increased risk for organic amblyopia.
Different types of organic amblyopia might be caused by:
- Congenital cataracts
- Optic nerve damage
- Severe bleeding in or around the eye
- Eye or nerve degeneration
- Oxygen deprivation and brain damage
- Nutritional deficiencies
- Chemical and toxin exposure
Symptoms
By four months of age, most babies begin to focus on objects they see, can follow a moving object and show interest in shapes, patterns and familiar faces. You may notice the following organic amblyopia symptoms in a young child:
- Eyes that are not correctly aligned, seem to be crossed or are moving independently
- Consistently tilting their head to one side when they try to focus on an object
- Crying or fussing when you cover a specific eye
- Depth perception problems
- Trouble seeing or reaching for objects on one side of their body
- Startling when approached from a specific side or not noticing objects on that side
If you’re concerned about your child’s vision, it’s best to schedule an eye exam for a vision screening. It’s always a good idea to perform a routine exam for your child at about six months, three years, and five years of age.
Diagnosis
An optometrist can look for additional signs of a vision problem. They will also ask about any family history of vision problems and thoroughly assess the structure, condition and functionality of your child’s eyes.
Additional eye chart testing in verbal children will show a significant difference in vision between the right and left eye. This vision discrepancy won’t change with corrective lenses.
Other tests, such as CAT scans, MRIs and specific eye explorations, may also be used to help determine the cause and nature of the vision problem.
Treatment Options
Your optometrist will look for any underlying issues that can be treated to help stop or slow organic amblyopia. These may include medications, eye patches, glasses and other traditional amblyopia treatments. Surgery may sometimes be used to help correct abnormalities like cataracts.
Toxic Amblyopia
Toxic amblyopia is a loss of vision in one or both eyes related to excessive ingestion of poisonous substances like lead, tobacco, alcohol or illegal drugs. This type of amblyopia damage may also come from consuming chemicals meant for external uses, such as rubbing alcohol, antifreeze or cleaning solutions.
What Is Toxic Amblyopia?
Amblyopia is often called "lazy eye". Toxic amblyopia can also be referred to as toxic optic neuropathy. Eye or optic nerve damage may result from exposure to harmful chemicals and other substances and cause toxic amblyopia. This damage leads to blind spots and blurry and limited vision. Toxic amblyopia generally occurs in both eyes, and the eyes may appear to wander or not coordinate well with visual tracking. There are two types of toxic amblyopia, classified as a temporary condition (acute) or a long-term difficulty (chronic).
Causes
Toxic amblyopia occurs due to intentional or accidental exposure to toxic or harmful chemicals. These elements can include lead, tobacco, alcohol, street drugs, or even chemotherapy or intensive treatments used to combat other serious diseases. Other harmful chemical exposures may include ingesting or exposure to external chemical compounds like cleaning products or antifreeze.
Patients with decreased kidney or liver function may also experience toxicity from additional substances.
Symptoms
Toxic amblyopia symptoms include vision changes that are often gradual and possibly unnoticeable in the early stages. Scheduling yearly eye exams can help catch these conditions before the damage becomes severe. These changes often affect both eyes. You might notice the following symptoms:
- Blind spots
- Blurring vision
- Excessive squinting or an inability to focus on an object
- A loss of color, contrast or depth perception
- Light sensitivity
- Decreased vision at night or in dark environments
Consuming substances like antifreeze can create sudden and complete vision loss along with many other serious side effects.
Diagnosis
Your optometrist can identify toxic amblyopia based on your health history, symptoms and vision screening results. Medical providers may obtain additional information about the toxin with blood and urine diagnostic tools.
Patients may require other tests, like MRIs and specific optic nerve diagnostics.
Treatment Options
Removing the toxic substance is the top priority of toxic amblyopia treatment. When the exposure to the toxic chemical is removed, the eyes may recover some of their lost vision. The longer the exposure, the more challenging recovery becomes.
A doctor may provide medication to help your body eliminate the extra toxins. In emergency poisoning situations, a patient may require hemodialysis (a mechanical method of cleaning toxins from the blood).
Once the toxin is removed, a medical professional may treat and assist the vision loss with additional medications, glasses, magnifiers or other accommodations. An eye doctor must frequently monitor the patient during recovery and every six to twelve months after that.
Frequently Asked Questions
What Are the Different Types of Amblyopia?
How Common Is Organic Amblyopia?
Can Organic Amblyopia Be Treated?
Can You Prevent Organic Amblyopia?
Should I Take My Child to an Eye Doctor if I Suspect They Have a Lazy Eye?
What Causes Toxic Amblyopia?
How Common Is Toxic Amblyopia?
Can Toxic Amblyopia Be Treated?
Can You Prevent Toxic Amblyopia?
Protect Your Vision
Healthy vision begins with regular checkups. Be sure to schedule your annual eye exam to keep your eyes healthy and help prevent vision loss.
