Causes of dry eye

[brd888]

Hi.
I posted a question on the medhelp.org site about dry eye which was answered by an eye MD-

"Bruce, nothing has to "cause" dry eyes. It can just exist de novo without a cause. Blepharitis doesn't cause dry eyes but often accompanies it. Some diseases cause dry eyes like rheumatoid arthritis but it may have no cause. Physicians call that idiopathic, patient's call it bad luck."

This is confusing - I said I had dry eye which I thought was caused by blepharitis. I've not been diagnosed with Blepharitis but all my reading has pointed to this as the cause of my dry eye. So maybe I'm wrong? Surely finding out the cause of dry eye is the first step to the correct treatment? How can dry eye have no root cause?? Any thoughts, ideas?

Thanks

[Rebecca Petris]

Causes... and causes...

"Bruce, nothing has to "cause" dry eyes. It can just exist de novo without a cause....Some diseases cause dry eyes like rheumatoid arthritis but it may have no cause. Physicians call that idiopathic, patient's call it bad luck."

Doctors will of course vary in their opinions about this. Some specialists like Dr. Latkany will say there is no such thing as "idiopathic" dry eye.

"Blepharitis doesn't cause dry eyes but often accompanies it...." This is confusing - I said I had dry eye which I thought was caused by blepharitis.

Easy to miscommunicate on something like this. Possibly to the Dr., "Dry eye" = aqueous deficient dry eye so maybe what he's saying is "blepharitis does not cause aqueous deficiency!" while on the other hand what you mean is "I think blepharitis has caused my dry eye SYMPTOMS" which is quite a fair statement.

Surely finding out the cause of dry eye is the first step to the correct treatment?

Yes - and no - again, have to be really careful here about what we mean by "cause"! Sometimes we use it to refer to the "what" and sometimes to the "why".

For example, I consider it very important to establish WHAT is wrong in terms of how much is aqueous deficiency, meibomian gland problems, other surface problems... But with the exception of obvious preventable or treatable causes, trying to pin down the EXACT root cause of those individual conditions may not even be possible. (I've mentioned before a few unusual cases where it would take some serious detective work to figure it out... and where ultimately, it actually made no difference whatsoever to the treatment course.)