Presbyopia: Old Man Look At My Life


Neil Young on the old.  What else is new?  What’s new is old, and now even neuroplasticity is seemingly being recycled.  Presbyopia literally means old vision.  But is the opia in the eyes or in the brain?  We’ve asked this question of other opias, most notably amblyopia.

I’ve blogged before about Gabor patches and the evolution of Neurovision into Revitalvision and the potential benefits of what is essentially contrast sensitivity and crowding training as nouveau perceptual learning paradigms.  Revitalvision has the approach of trying to improve near focus in presbyopia to lessen the dependency on reading glasses.  (Parenthetically it’s interesting to see Ophthalmology struggle with how to fit such “therapy” into its clinical model of presbyopia, particularly with regard to accommodation function after IOL implantation.)

Enter Uri Polat and Dennis Levi, the researchers responsible for the science behind Neurovision and perceptual learning.  Like good musicians jamming they have found each other again and have formed a new super group to go after presbyopia.  This began in earnest with Polat’s paper in Vision Research in 2009, proceeding to a super group presentation at ARVO last year:  Polat U, Sterkin A, Yehezkel O, Lev M, Zomet A, Schor C, Levi D.  Perceptual Training Overcomes the Optical Limits of Presbyopia.  Sterkin, Yehezkel, Lev, and Zomat are members of the Polat Lab, and as you can see, they’ve been joined by Clif Schor who, like Levi, is a prolific researcher at UC Berkeley.

Their ARVO paper has now been published in Nature, Scientific Reports (2012) under the title:  Training the brain to overcome the effect of aging on the human eye. Here are some key results:

 

(a) Near visual acuity before (abscissa) and after (ordinate) perceptual learning (PL). Solid symbols are presbyopic subjects (median age 51). Open symbols are the no PL control group. The dotted gray line is the quality line. The solid gray diagonal is a power function fit to the presbyopes data. The horizontal and vertical lines show typical newsprint size (expressed in minutes of arc). (b) Near visual acuity vs. age before (blue) and after (red) PL. The large blue and red circles show the geometric mean acuities before and after PL, plotted at the corresponding pre-training abscissa values (shown by the arrows). (c) Reading speed before (abscissa) and after (ordinate) PL for the smallest letter size that each subject could read.

So here’s the deal:  The Nature article shows promise that perceptual learning through improved contrast discrimination may improve visual acuity and reading speed in presbyopia.  Though the authors note that their results would have to be replicated in a larger scale study with better controls, it is the first report of its kind to document that these changes occurred without any measurable change in accommodation, pupil size or depth of focus.  This clearly turns the optics of classical optometry and ophthalmology on its head, for if there are changes in presbyopic focus and function occurring beyond the pupil and crystalline lens, where do these changes occur?  Ah yes, – the brain thing.  Looks like optometrists like John Streff and Harry Wachs knew what they were talking about after all.  ;)

 

3 thoughts on “Presbyopia: Old Man Look At My Life

  1. From the Rev Opt article “”The idea that neuroadaptive training is unnecessary or ineffective is absolute hogwash,” says Dr. Kershner. “You don’t have to take it on faith that training the brain, at any age, can have a substantial impact on a patient’s successful rehabilitation following surgery. Just look at what’s being done with occupational therapy and stroke patients, or cognitive therapy training and Alzheimer’s patients. The neurophysiology literature is loaded with clinical studies that demonstrate overwhelming success with these training processes. It’s disingenuous to think that ophthalmology would be any different.”

    Which is all well and good, then later…

    “”Most doctors still associate this type of program with gimmickry and eye exercises,” he notes. “We have to sit there and say, ‘We don’t do any of that.’ This isn’t prism therapy, it isn’t Bates method therapy.” Not spoken by an OMD, but it does offer insight into common thinking. IOW, visual neurorehab, presumably as espoused by optometrists, amounts to either ‘prism’ therapy (like orthoptics has nothing to do with what we do), or the Bates’ method – Bates of course was an ophthalmologist.

    Baby steps, but we’re getting closer.

  2. Precisely, Charles. If there were a “Constitution” guiding Ophthalmology, it would read: “We hold all these truths to be self-evident, except what is purported to support optometric vision therapy”. Sparkling cognitive dissonance in that Rev of Ophthalmol article. Then again, what do you expect from a “journal” that ran the infamous Koller Rubber Ducky yellow journalism piece about VT in the late ’90s? It’s time for more Ped OMDs to acknowledge publicly that Optometry is a distinct field with a body of knowledge and expertise beyond what they offer. Indeed, the notion that neuroplasticity works for OMD interventions but somehow not for OD interventions is inherently poppycock, and they know it. Good news is, the public is brighter than they give them credit for being. I say this as a blanket statement, though there are clearly individual P-OMDs who get it. As they come out of the closet over the next year or two, emboldened not to worry about what their colleagues “think of them”, they will coalesce and then we’ll pursue a tipping point.

  3. William Horatio Bates, a prominent New York Ophthalmologist in 1920 as well as other Ophthalmologists of that era, as our late friend Dr. Borish stated, attempted to put Optometry out of business. Organized Ophthalmology
    informed the public that eye glasses were not needed and Optometrists were not real doctors. Of course, Bates recommended staring at the sun to normalize vision. His argument was that a patient who had normal vision could stare at the sun indefinitely without causing damage. His book was a best seller, Perfect Sight Without Glasses.

    I do agree that vision is a brain function, not an eye function, but in presbyopia, the focus without glasses is not on the ganglion cells, so training the brain to focus on a defocused object on the retina is not going to work for me.
    That said, I do believe in Dr. James (New Testament), as proved by neurologists. Patients who have faith in the outcome of surgery and neuroplasticity, seem to do better post op, than those who look at life
    as a glass half empty. James 3:4

    So, the literature is loaded with clinical studies that demonstrate overwhelming success in neuroplasticity, but the success is based on the patient’s ability to have a good outlook.
    I do not see a person with a plus 2.50 add reading without glasses unless the font is large and the lighting is great.

    So do we want to eliminate contact lenses and eyeglasses for neuroplasticity; probably not at this time for the plus 2.50 add patient. However, I do agree that we can and we do, assist patients with
    what you do best, Vision Therapy. draugust

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s