Amblyopia (lazy-eye) is the leading cause of vision loss affecting one eye. It develops in early childhood when the brain receives different visual images from the two eyes: one clearer, one blurrier. The brain accepts the clearer image and disregards input from the fellow eye.
Here’s why many children develop lazy eye:
- The refractive error between the two eyes may be significantly different
- The eyes may be crooked
- Something is blocking focused light rays from reaching the retina (like a juvenile cataract)
Click here to read a more detailed post about amblyopia.
True to its name, lazy eye appears to be, well, lazy! So long as the child is being treated (whether with patching or atropine eyedrops) vision recovery is steady and predictable. The problems come when the treatment stops. New research about lazy eye shows that most 10 year-olds previously treated for their amblyopia still have a residual vision deficit.
This national study followed 176 children with moderate amblyopia from the time of diagnosis until age 10. The average age at enrollment was 5 (even though their lazy eye had likely been present for years). As predicted, children whose treatment was initiated before age 5 fared much better than latecomers who enrolled after their fifth birthday. Young brains are more ‘plastic’, more responsive to amblyopia treatment. The earlier the lazy eye is treated the greater the effect of treatment and the more time is available to reverse the problem. Sometime around age 7 years the brain ‘hardens’ and becomes less responsive to lazy eye treatment.
Here’s what they found when they analyzed the entire group at age 10:
- Most of the vision improvement from earlier amblyopia treatment was maintained
- Some residual lazy eye persists in most treated children
- Patching and atropine eyedrops achieve similar benefits
- Earlier treatment results in better the long-term visual outcome
- Most children received no treatment beyond age 9
Most of these children continued to wear prescribed eyeglasses. Remember, parents, every case is different and all children respond differently to lazy eye treatment. The key take home message is that early diagnosis and treatment of amblyopia offer the best opportunity to recover lost eyesight. If treatment fails go back and try again because time is on your side.
REFERENCE: Archives of Ophthalmology, August 2008, pages 1039-1044.