Monday, April 29, 2013

More evidence that patching alone is not enough for amblyopia treatment in adults

There was an excellent post on adult amblyopia at about this study: Dichoptic training enables the adult amblyopic brain to learn

The summary of the study is as follows:

....Adults with amblyopia, a common visual cortex disorder caused primarily by binocular disruption during an early critical period, do not respond to conventional therapy involving occlusion of one eye. But it is now clear that the adult human visual cortex has a significant degree of plasticity, .... One possibility is an inhibitory signal from the contralateral eye that suppresses cortical inputs from the amblyopic eye. .... Here we provide direct evidence that alleviating suppression of the amblyopic eye through dichoptic stimulus presentation induces greater levels of plasticity than forced use of the amblyopic eye alone. This indicates that suppression is a key gating mechanism that prevents the amblyopic brain from learning to see.....
The way we have been treating amblyopia at our Vancouver clinic has always been a two-eyed or binocular vision centric approach.  We have seen first hand that this approach is far better than patching alone - it results in better, faster and more permanent results with better depth perception and all the other benefits that come with developing good functioning binocular vision.

Dr. Maino's comments on the study are spot on:

The research continues to show that adults with amblyopia have a treatable condition AND that amblyopia is not just related to decreased visual acuity in one eye. Amblyopia is a two-eyed-brain problem! When are my colleagues going to realize that you should not treat amblyopia by patching alone?

We wrote a similar post recently, see "Patching alone is not enough for amblyopia treatment".