Author Topic: Dr. Aller, close to telling the truth about plus-prevention.  (Read 827 times)

Offline OtisBrown

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As always, the subject of personal responsibility, to use the plus when you still can read the 20/40, is never discussed.
This is because few people have any interest in protecting their long-term distant vision, by ACTUALLY wearing a strong
plus - at all.  But that is why no OD is going to tell you anything - they make the correct judgment of you.

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By: Thomas Aller, O.D., San Bruno (Metro San Francisco), CA:

“I was taught in school that myopia is a genetic condition. There were no effective means to control myopia progression, at least none that were proven in controlled trials, and there was no point in trying as myopia was genetic. When Goss and Grosvenor published a reanalysis of their original bifocal paper showing that bifocal spectacles do, in fact, work for children with esophoria, I started using bifocal and progressive spectacles for that type of patient with much more frequency and with more confidence. I found a little under 50% reduction in myopia progression rates in these patients as compared to their rates when wearing single vision lenses. When a somewhat inexpensive bifocal soft contact lens was introduced in the early 1990’s, I started using it and started to track progression rates. It was very exciting and gratifying to find that there was a 90% reduction in progression rates, and it has been my primary method for treating myopia ever since.

    Why they work as well as they do is still subject to much speculation. The primary theories are: 1. Bifocals work for esophores, bifocal contacts work better because their bifocal power is available no matter how they are used; 2. Bifocal contact lenses expose the retina to conflicting images, i.e. an image in front of the retina (anti-myopia stimulus) and an image on the retina (myopia-neutral); or 3. Bifocal contact lenses lessen peripheral retina hyperopic defocus and lessen a primary stimulus to growth characteristic of all spectacle and contact lens corrections for myopia. Or maybe all three, or it is something else, but in any case in my mind it has been settled that they are very effective.

    As to whether there are methods for preventing myopia, prior to myopia, it’s a little more difficult to say and I have no studies to report. I do consider a gradual reduction in hyperopia in a child of age 6-8 to be the same as a progression in myopia — they are just starting on the other side of zero. So, particularly for children that exhibit eso fixation disparity at near with no hyperopic correction in place, I will prescribe reading glasses usually at the level necessary to eliminate the fixation disparity.

    I expect that these research findings will cause major changes in how myopia is treated and if implemented widely will result in much less myopia and eventually, less blinding complications of high myopia. As a result of ongoing and future research, there will be contact lens corrections and other types of corrections that will be able to reduce myopia progression, yet offer better vision quality than existing bifocal contact lenses. I hope my colleagues will adopt these new strategies and I expect that they will, once the (new) studies are widely reported.”