Amblyopia

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Also referred to as: Lazy Eye

Amblyopia is the medical term for lazy eye. An amblyopic eye is anatomically normal, but the vision is poor – even with glasses. In amblyopia, the amount of vision loss can range from very slight to severe.

Amblyopia occurs when a child’s brain learns to ignore a blurred or a double image. Common causes of amblyopia include strabismus and anisometropia.

Strabismus is when the eyes are misaligned. The misaligned eye may be turned towards the nose (esotropia), turned outwards (exotropia), may drift up (hypertropia), or may drift down (hypotropia). When a patient has strabismus, the two eyes are not looking in the same direction. If the eyes do not look at the same object, the image seen by each eye is different – this results in double vision. Double vision can be very troublesome; the ability to walk, read and perform regular activities is disrupted. Therefore, children learn to ignore the double image caused by the misaligned eye. As a result of this unused eye, amblyopia develops. It is important to know that amblyopia associated with strabismus cannot be corrected by eye muscle surgery (realignment of the eyes). Therapy to reverse the amblyopia should be completed first. Strabismus surgery is performed afterward to improve eye alignment. Sometimes, children require additional amblyopia therapy following strabismus surgery.

Anisometropia is a difference in the refractive power between the two eyes. For example, one eye may be far sighted or near sighted, and the other eye may be normal. If anisometropia is the underlying cause of amblyopia, the eye with the blurry vision becomes amblyopic.

Amblyopia develops sometime between birth and 8 or 9 years of age; this is called the ‘critical period’, when the visual system develops and matures. This problem must be identified and treated prior to 8 or 9 years of age, or the vision loss becomes irreversible. Generally, early treatment results in better vision.

Patching (Occlusion therapy)

The most rapid and successful treatment of amblyopia is to patch the better eye, until vision in the amblyopic eye recovers to the better levels. Amblyopia may also be successfully treated by instilling eye drops in the better eye. The eye drops prevent focusing, thereby blurring the vision in the treated eye. These eye drops can cause some systemic side effects.

The extent of the recovery of vision depends on the age treatment is started and the underlying cause of the amblyopia. Many children also require glasses as part of their visual therapy.

Tips on patching

Some children do not tolerate patching because vision in the amblyopic eye is so poor that they continually remove the patch from the “good” eye. It is very common for children to object to wearing the patch in the beginning of treatment. It is important to make things as comfortable and easy as possible. The amblyopic eye will not be able to see things at the same distance as the good eye.

Tips:

• Wearing a patch over one eye reduces depth perception, so take care with outdoor activities like bike riding.
• Create indoor activities for your child, play fun board games, look through picture books. If your child is old enough, use books with larger print.
• Allow your child to sit close to the TV; this will not damage their eye.
• Give your child thicker markers to draw and color with.
• Allow your child to decorate their patches with thick markers.
• Have the teacher seat them in the front of the classroom.
• In the beginning, sit with your child, so they don’t feel alone in a “ blurry world“ .
• Use bribery, you know what your child likes to do, eat, or play with, so use it to their advantage! Patching usually gets easier with time. Just hang in there!

When children look over their glasses

Tips:

• If your child is prescribed glasses, it is very important for your child to wear them and look through them while they are patching. Place the patch over the eye, then have your child wear glasses over them.
• If the frames are too loose, have them adjusted by your optician.
• You can purchase a band from the optician which is placed on each temple of the frames. It will make the glasses fit more snugly, so the child has no way to look over them.

The adhesive in the patch may cause irritation

Tips:

• Try applying liquid Maalox to the skin area where the patch adheres. AVOID SKIN CLOSE TO THE EYE AND THE EYE ITSELF. Once the Maalox has dried, place the patch over the eye. The Maalox provides a barrier between the adhesive and the skin. Later, when the patch is removed, the liquid Maalox will be removed. Wipe away any remaining Maalox with a warm wash cloth.
• You can trim the patch to avoid red and irritated skin. By rotating the areas of the trimmed patch it can allow time for the skin to recover. Usually, the skin adapts to the patch, then trimming the patch is unnecessary.

Please feel free to call us at Northwest Eye Surgeons if you have any other questions.

Click here for instructions on how to make eye patches.