Getting Stronger: Discussion Forum

Discussion Topics => Rehabilitation => Topic started by: Ydgrunite on March 28, 2014, 10:56:03 PM

Title: Amblyopia and myopia reduction
Post by: Ydgrunite on March 28, 2014, 10:56:03 PM
Amblyopia (lazy eye) affects only 3% of the population, so I’m not sure if this will interest many people.  But I have it and I wanted to share some thoughts about it.

I had strabismus (crossed eyes) as a child and this led to amblyopia.  Since my brain could not fuse the two images from my eyes, it permanently suppressed the image from the left eye.  I had surgery to straighten the eyes, but I was given no vision therapy to counter the suppression that was already there.  So from infancy until now (45 years old), my eyes have been aligned but I have no stereoscopic vision.  My brain uses the peripheral image from my left eye, but my central field of vision comes from my right eye alone.
I read Susan Barry (http://en.wikipedia.org/wiki/Susan_R._Barry)’s book Fixing my Gaze (http://www.amazon.com/Fixing-My-Gaze-Scientists-Dimensions/dp/0465020739), which inspired me to correct my amblyopia.  She did it at age 48 when ophthalmologists have always said that this was not possible after about age ten.  However, I also started reading about myopia reduction then.  I decided not to try to correct both at the same time.  Successful elimination of amblyopia requires both eyes to have good visual acuity (with or without corrective lenses).  The brain cannot learn to fuse images from the two eyes if one is sharp and the other is blurry.  Since I chose to reduce my myopia, I could not guarantee that the two images would always be equally sharp.  I have not given up on achieving 3D vision, but I will do it after my efforts to reduce my myopia.

Many people say that print pushing or active focus is required to reduce myopia.  I respect that opinion, but I don’t share it.  As I have been reducing my prescription, the visual acuity in my left eye has usually been a little worse than the right.  I use a prescription for close work that is lower but print is always in focus with my right eye.  However, the vision in my left eye (which I can only confirm by closing my right eye) is pretty much always in full blur.  And yet, the left eye still improves.

In the last six months, I have reduced my prescription from -9.5 D to -6.5 D for both eyes.  In that whole time, my left eye has been in blur, not at or inside the edge of blur.  I have also not been actively trying to focus my left eye because my brain completely suppresses that image.

I think that print pushing or active focus can lead to quicker improvement.  My right eye does improve a little faster than the left.  But I don’t think that it is absolutely necessary.
Title: Re: Amblyopia and myopia reduction
Post by: Tom on March 29, 2014, 09:28:50 AM
Ydgrunite. Thanks for posting. Even if amblyopia doesn't affect lots of people, interested people might eventually pick up our posts through search engine.

Strabismus is a general term for a plethera of eye alignment issues. Some people have one eye looking up and the other looking down, others are crossed-eyes (esotropia), yet others have diverging eyes. In addition, a distinction is made between the tropias, and the phorias - The former refers to permanent misalighment, while the latter refers only to a tendency of the eyes to misalign, given certain visual stimuli. There is also a distinction between near phoria and far phoria.

I came across a study from McGill talking about using Tetris to improve amblyopia last year. Maybe something to consider:
Intro - http://www.mcgill.ca/newsroom/channels/news/lazy-eye-disorder-promising-therapeutic-approach-226011
Link to the paper - http://www.sciencedirect.com/science/article/pii/S0960982213000948

This shows that to improve stereoscopic vision, it's better to perform exactly that! (i.e., no monocular vision). This kind of treatment, which is analogous to CI therapy, has deep root in neural hormesis, which is in turn based on the concept of neuroplasticity (there was a post under my topic, but no longer there anymore 8)). This is really a good example that Todd can use to illustrate the role of hormetism in treating certain ocular issues.

As with your experience in myopia reduction, I can say that it's not atypical. Your case is quite similar to the monovision undercorrection study, who only use the fully corrected eye for close work. Surprisingly, it's the weaker eye, that they don't use for close work, that has myopia progression substantially reduced. As far as we are concerned, this is the strongest evidence for the merit of undercorrection, as this kind of monovision study eliminates individual variabilities, and the other studies involving two separate subject groups do not.

Title: Re: Amblyopia and myopia reduction
Post by: Arachne on March 29, 2014, 01:32:15 PM
Just to say that I had strabismus and amblyopia as a child and ended up with eyes that were nearly 3 diopters apart and one eye (the more myopic one) that was overly dominant. I eventually equalised both eyes during my 30s and 40s. Not until my late 50s did I fix my myopia and get my eyes working properly together. I've mainly done this over the past three years, using a combination of therapies. One of the most important was the "magic-eye" exercises for fusing images. I'm having fun now with the ultimeyes app. Almost ready to report on this, but have noticed a big difference on the Snellen. The 20/15 line is almost there... Watch this space.
Title: Re: Amblyopia and myopia reduction
Post by: Alex_Myopic on March 29, 2014, 01:45:20 PM
In the book "Relearning to see" there is a very good chapter about amblyopia, strabismus and stereoscopic 3D vision. I has many exercises also and states that eye surgery usually only solves the aesthetic part in strabismus and not the amplyopia.
Title: Re: Amblyopia and myopia reduction
Post by: Ydgrunite on March 30, 2014, 08:55:32 AM
Just to say that I had strabismus and amblyopia as a child and ended up with eyes that were nearly 3 diopters apart and one eye (the more myopic one) that was overly dominant. I eventually equalised both eyes during my 30s and 40s. Not until my late 50s did I fix my myopia and get my eyes working properly together. I've mainly done this over the past three years, using a combination of therapies. One of the most important was the "magic-eye" exercises for fusing images.

Thanks for sharing your situation, Arachne.

It helps to inspire me that I will be able to get my eyes working together too.

Those magic-eye images have always been a source of frustration for me.  After I had surgery to straighten my eyes as a child, I was never told that I did not regain true 3D vision (I don't even know if my ophthalmologist knew himself that he had not fixed the problem).  I had coping mechanisms like comparing the positions of objects that I know to be at different distances or use of the parallax effect, but I had no true stereopsis.  The thing is that I didn't know that other people saw the world differently than I did.  When I told people that I could not see the magic-eye image, they would insist that I just keep staring at it.  I was an adult before I realized that those exercises would never work for me.
Title: Re: Amblyopia and myopia reduction
Post by: Ydgrunite on March 30, 2014, 09:10:37 AM
I came across a study from McGill talking about using Tetris to improve amblyopia last year. Maybe something to consider:

Thanks for the info, Tom.

I actually found that study already from an internet search.  I will continue to follow it.  The contraption that they put in front of the eyes is probably the best way to do it with a separate image for each eye and a mixture of different contrasts, but I doubt that the equipment will be available to me any time soon at a reasonable cost.

I have found a tetris game (http://www.scheelzien.be/wp-content/uploads/2013/08/javascript-tetris-master.zip) that can be used with red-cyan glasses and a solitaire game (http://www.scheelzien.be/wp-content/uploads/2014/03/edspencer-extjs-solitaire-94e356e.rar) that can be used with red-green glasses.  Both free.

This tetris game works fine as far as making my eyes work together, but I wish that I could adjust the speed that the blocks fall.  I need a little more time to align the blocks since when they are aligned to fit, the image that I see actually shows them as about to collide.
Title: Re: Amblyopia and myopia reduction
Post by: Ydgrunite on March 30, 2014, 05:51:11 PM
This tetris game works fine as far as making my eyes work together, but I wish that I could adjust the speed that the blocks fall.

I should have made a little effort to adjust the speed before griping about it here.

This tetris game is written in html code and the speed is defined on this line (and easily changed):
speed   = { start: 0.6, decrement: 0.005, min: 0.1 }, // how long before piece drops by 1 row (seconds)