Evidence Based Medicine and Vision Therapy

Occasionally a paper is released claiming that optometry and vision therapy is ineffective and unfounded scientifically.  They often make a cursory examination of the evidence and make bold statements which are erroneous.

Double blind, multi-center studies are the holy grail of determining if a procedure or treatment works.  They are the ultimate in evidence based medicine.  The problem is they are expensive and take a long time to complete.  In the world of vision therapy there is really only one study which used this technique.  Focusing on convergence insufficiency it determined that vision therapy with an eye doctor was the best treatment.  It was very narrow in defining the problem but had many subjects, providing for the best evidence on the issue.  However there have been no other studies of similar magnitude using the same techniques on the multitude of other eye alignment and focusing disorders.

For difficulties such as convergence excess, accommodative insufficiency and accommodative infacility there are many studies which are smaller in scale or which follow different designs that provide a mountain of evidence that vision therapy works.  None of these studies individually are as scientifically sound as a double blind study however these smaller studies taken in aggregate provide a solid basis for treatment.  This is why you will occasionally hear of claims that vision therapy does not work, and there is no science behind it.  These individuals are aware of the lack of double blind study for these other disorders and are often ignorant of the ever growing body of evidence and have not fully researched its breadth.

If you click here you will find a tongue-in-cheek response to those who believe a double blind study is the only acceptable form of science.  In it the author states we do not have a double blind study on parachutes and their effectiveness at saving lives.  Yet common sense tells you, we don’t need a double blind study on parachutes and gravity to know they save lives.   How many volunteers could you find if they knew half of the parachutes would be fakes?

Double blind studies are important tools for determining treatment, however they by no means the only scientific evidence for any treatment and ignoring other studies is a disservice to patients’ health.

“Dodge”