Amblyopia Causes
Strabismus
Amblyopia often stems from strabismus, where misaligned eyes send conflicting images to the brain. In adults, this commonly causes double vision, but children's more adaptable brains may ignore the image from the misaligned eye to prevent it, which disrupts normal visual development. This can lead to social challenges, impacting self-esteem, academics, and relationships.
Refractive Amblyopia
Refractive Amblyopia, the most common type, occurs when a child needs glasses but does not wear them early in life. It often results from anisometropia, where one eye has a significantly different prescription than the other, such as more nearsightedness, farsightedness, or astigmatism. The brain favors the clearer image from the stronger eye, making it dominant, while the other eye’s vision remains blurred.
Deprivation Amblyopia (Obstructed Vision During Critical Development)
Deprivation amblyopia, the rarest and most severe type, occurs when vision is obstructed during critical developmental periods. This can result from congenital cataracts, corneal haziness, or other conditions that block visual input, preventing normal development. If not treated promptly, amblyopia may remain even after the obstruction is removed. In some cases, a drooping eyelid (ptosis) or another issue physically blocks a child’s vision, leading to rapid onset of amblyopia.
Mixed Amblyopia
Mixed amblyopia occurs when a child has more than one amblyogenic factor, such as a combination of anisometropic (refractive difference between eyes) and strabismic (misaligned eyes) amblyopia. These combined factors can more severely disrupt normal visual development as the brain must compensate for both misalignment and differing visual clarity between eyes. Mixed amblyopia often requires a multifaceted treatment approach to address each underlying cause effectively.
If your child shows any of the following signs, they may have a lazy eye:
* Frequently closing one eye or squinting * Rubbing their eyes often * Difficulty with eye-hand coordination * Weak depth perception * Challenges with fine eye movements * Slower reading speed and reduced comprehension * Trouble focusing or following objects with their eyes alone * Eyes that appear crossed * Unusual eye movements, such as frequent blinking or flickering
If you notice any of these symptoms, we recommend seeing a specialist for a thorough eye examination
Some simple tests that can be conducted at home are as follows:
Cover Test: Have your child cover one eye and read letters from a chart or identify objects across the room. Then, switch and cover the other eye to observe any differences in vision between the two eyes.
Distance Vision Test: Stand about 10 feet away from a wall or door with a vision chart or letters displayed. Ask your child to cover one eye and read the smallest line of letters they can see clearly. Repeat with the other eye.
Near Vision Test: Use a printed text, such as a book or magazine, and hold it about 14 inches away. Ask your child to read a few sentences while covering one eye at a time.
Tracking Objects: Move a small object, like a toy or a pen, back and forth in front of your child’s face. Ensure they can follow the object smoothly with their eyes without moving their head.
Pen Test: Hold a pen or a small object close to your child’s nose and slowly move it away. Observe if both eyes move together as the object gets closer or farther away.
Light Sensitivity Check: In a dimly lit room, shine a flashlight briefly in your child’s eyes to see how they react to the light. Look for any unusual responses, like excessive blinking or turning away.
These simple tests can help you identify any potential vision issues, but they are not a substitute for a comprehensive eye examination by a professional. If you have any concerns, it’s important to consult an eye specialist.
Amblyopia Treatment
Treatment approaches for lazy eye focus on correcting underlying issues and promoting the use of the affected eye. For conditions such as short-sightedness, long-sightedness, or astigmatism, wearing glasses is often beneficial. Regular checks of the prescription are important, and glasses may also help treat squints, potentially resolving the lazy eye issue without additional interventions.
Surgery: If a cataract is causing amblyopia, surgery may be necessary to remove it, allowing for proper vision development in the affected eye. Surgical intervention may also be required for certain cases of strabismus (squint) to realign the eyes. While this won’t enhance vision, it improves eye alignment and coordination.
Patching Therapy: This method involves covering the stronger eye for 2 to 6 hours a day, often for up to a year, to encourage the weaker eye to work harder. However, compliance can be low due to discomfort and the social stigma attached to wearing a patch, which can lead to bullying. Furthermore, patching does not promote the development of 3D vision and depth perception since it forces one eye to function at a time. There’s also a risk of reverse amblyopia, where the patched eye can become weaker if treatment is not managed properly.
Atropine Eye Drops: Atropine drops can blur vision in the stronger eye to encourage the brain to rely on the weaker eye. While this method can be effective, it often suffers from low compliance, and side effects can include light sensitivity, blurred vision, and difficulty focusing, especially for near tasks. Like patching, atropine does not foster the development of depth perception or 3D vision since it also limits the use of one eye at a time. Additionally, there is a potential for recurrence of amblyopia if treatment is not followed through adequately.
Bangerter Filters: These filters can be applied to eyeglass lenses to balance visual input between the two eyes. However, similar to patching and atropine, Bangerter filters do not develop depth perception or 3D vision effectively, as only one eye is being utilized at a time. Compliance can be an issue, and there’s still a risk of recurrence.
Vision Therapy with Amblyofix: In contrast to the above methods, vision therapy involves engaging both eyes in exercises designed to improve visual skills and coordination, leading to better 3D vision and depth perception. Sessions typically last 30 to 90 minutes per day and are designed to be fun and interactive, significantly improving compliance rates among children. Vision therapy not only provides quicker results but also lessens the likelihood of reverse amblyopia compared to other methods. It offers an attractive alternative for children, helping to avoid the stigma and discomfort associated with patching or atropine penalization, ultimately making it easier and more effective for kids and adults.
