Author Topic: Does the eye got "longer" in myopia?  (Read 1319 times)

Offline OtisBrown

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Does the eye got "longer" in myopia?
« on: July 08, 2014, 04:58:28 AM »
Does the eye get "longer", or is it "dynamic" and always change its refractive STATE in a negative direction.

Item: This is a scientific question - not a question for speculation.

I would expect a "yes" or "no" statement - on a  "pure scientific level".

http://frauenfeldclinic.com/axial-elongation-of-the-eyeball-facts-fiction/

I know I would prefer "bitter truth", to an "invited lie" for the convenience of existing practice, (or to justify placing a minus lens on a face).

« Last Edit: July 09, 2014, 08:06:07 AM by OtisBrown »

Offline ZC

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Re: Does the eye got "longer" in myopia?
« Reply #1 on: July 09, 2014, 03:28:13 PM »
The first link that Otis gives:

http://frauenfeldclinic.com/axial-elongation-of-the-eyeball-facts-fiction/

is fascinating. It appears to represent an evolution in the author's thinking.

In an earlier article, he distinguished four "pillars." Regarding his first pillar:

http://frauenfeldclinic.com/the-frauenfeld-method-vision-rehabilitation/

he states that near work causes ciliary spasm which leads to minus lenses which cause axial elongation. Thus, axial elongation is a concomitant of wearing minus lenses.

In the blog post he takes a different position. Minus lenses do not cause axial elongation in the vast majority of myopes. They only cause axial elongation in the minority of myopes who use -6.0D or stronger.

The blog post was odd however. The introduction and conclusion state emphatically that change in axial length is not required for rehabilitation for most people. Normal writing conventions dictate that the body of the article provide evidence supporting the thesis that is stated in the introduction and conclusion. Instead, the body of the article demonstrates that axial length reacts dynamically to stimulus changes.

If the target audience was high myopes, the thesis should have been that high myopes can change axial length. If the target audience was typical myopes, the body of the post should have demonstrated that many of his patients emmetropized without changing axial length. If the target audience was all myopes the thesis should have been that high myopes have axial elongation and other myopes do not. The body of the post should have explained that the studies that demonstrate axial change only demonstrated it in high myopes. In addition, he should have presented his own experience with moderate myopes who emmetropized while keeping axial length constant.

Let's assume that he has evidence that moderate myopes do not undergo axial change while normalizing their vision. This is an amazing bit of information. Has anyone else ever heard of this? He says that he used to test all his patients for elongation. I presume that means he has lots of data correlating axial lengths and lens prescriptions. If that is true, then what is the rehabilitative process for non-high myopes? Is it only ciliary relaxation and neuroplasticity?