hey rebecca...how reliable are schirmers tests

[Michael2]

over the past year my schirmer's has fluctuated from 2-5. my tbut has gone from 0-8/9 and thats where the huge difference is.

what im wondering is, how important and reliable is the schirmer's test? i felt much better yesterday than a year ago because my MGD is getting better and better, but my schirmer's was actually lower (now it's at 1 rather than 5). What does that mean? That i also have significant aqueous deficiency to take care of? thanks

[RobLIC]

Hey Michael. I know I'm not Rebecca, but I'm chiming in anyway

The Schirmer's is "notoriously" unreliable, in the words of several of my eye docs. There is no reliable way to measure the aqueous component. But often, doctors will do three separate Schirmers tests over the course of one visit - or a month - and try to get a sense of your condition from the average.

Nice news about your TBUT, by the way.

Rob

[Rebecca Petris]

Dr. Holly once wrote a very interesting article about the Schirmer test and tear secretion kinetics. Here's a link.

I wouldn't sweat Schirmer variances unless your doctor is also finding more staining, lower TBUT or other test results doing more poorly. I bet if you were Schirmered at different times of the same day you'd get different results... and almost certainly different results if administered by a different tech or doctor. That's great about your TBUT though.

In my low-tech mind, Schirmer is mostly only useful when it's unequivocal (like, 0 or 1) in the very dry. For the rest of us, who make some tears, it's just hard to know whether the numbers are meaningful given all the reasons for Schirmer to be inaccurate.