I believe that REM sleep causes retinal tears and then subsequent retinal detachments, that is, I think most of the damage occurs while you are sleeping. While this would be hard to ever prove, there are some compelling arguments for my hypothesis.
Rapid Eye Movement (REM) is a stage of sleep that occurs every night. During this stage of sleep, the eyes beat back and forth, moving to and fro with great force and speed (hence “rapid”). It is a normal physiologic stage of sleeping. As the eyes beat back and forth, forces are created inside the eye with this rapid, repeated movement (similar to shaking a bottle soda to get it to “explode”). These forces can not be reproduced voluntarily when awake, that is, these forces are the strongest when sleeping.
Most retinal detachments start with a tear, or hole, in the retina. The tear allows fluid to get underneath the retina, causing a retinal detachment.
A common cause of a retinal tear is the development of a posterior vitreous detachment (PVD). A posterior vitreous detachment occurs normally in everyone, especially as we get older. The vitreous, the gel like material that fills the eye, normally separates from the surface of the retina.
Frequently, patients complain of new floaters or a “cob-web” developing in their vision when a PVD develops. During the first six weeks of occurrence, patients are at highest risk for developing a retinal tear.
The gel, now separated from surface of the retina, can now “slosh” back and forth inside the eye. Portions of the vitreous; however, remain adherent to the retina. While this gel moves back and forth, pulling on the retina, a retinal tear can form.
A patient with a PVD undergoing REM sleep experiences tremendous new forces inside the eye as the gel is sloshing around AND the eyes are beating back and forth at a rapid rate. Again, the forces generated inside the eye during these rapid motions can not be reproduced while awake (i.e. you can not reproduce these forces while awake).
It may be at this time that retinal tears develop and cause a retinal detachment.
What Does This Mean? Again, this is my suspicion. It may be hard to prove. There is; however, a very practical side to this theory.
This means that nothing can be done to prevent a retinal tear from happening after a posterior vitreous detachment (PVD). This means that a patient does not have to refrain from any “normal” activities when a PVD occurs.
In my view, a retinal tear is beyond the control of the patient. A patient can not alter his or her behavior to prevent a tear from forming…unless you refrain from sleep.