Thanks to our colleague, Dr. Curt Baxtrom, for pointing out an interesting abstract from this year’s ARVO meeting. It’s co-authored by our colleague from Canada, Professor Robert Hess. First take a look at the abstract here. You’ll note the stated purpose as follows:
Patching therapy has been commonly used clinically to improve visual functions in the amblyopic eye by occluding the fellow eye under the assumption that amblyopia is a purely monocular deficit. However, there is emerging evidence that amblyopia is the result of binocular sensory imbalance resulting in suppression. Here we show that the binocular imbalance that characterizes amblyopia can be reduced by occluding the amblyopic eye, the opposite to what has been done for the last 200 years.
1) Regarding emerging evidence that amblyopia is the result of binocular sensory imbalance resulting in suppression, we’re pleased to see research catching up with the clinical approach that is a mainstay of optometric vision therapy. As you’ll note in my textbook (original edition in 1997, OEP edition 2008), p. 83: “Abnormal binocular integration is a common feature of amblyopia. Competition between the two eyes, and inhibition exerted through the nonamblyopic eye, play a strong role in the development of amblyopia and the recovery of function during treatment.” You can also see this approach on p. 22 of the AOA’s Clinical Practice Guideline on Care of the Patient With Amblyopia, originally authored in 1994.
2) Regarding patching the amblyopic eye instead of the fellow eye, this is known as inverse or nonconventional occlusion. As you can see here, the idea has been tried before. We applaud Professor Hess for revisiting it and look forward to vision science research shedding more light on why what we do in optometric vision therapy works as well as it does when the patient is guided by the optometrist through supervised MFBF, bi-ocular and binocular activities.