OUR EXPERTS DISCUSS THE HOT TOPICS IN OPTOMETRY
|Milton Hom, O.D., F.A.A.O.: Recently, I was having a conversation with a scientist about Schirmer tests. First, does anyone actually do this test in clinical practice?
|Ben Gaddie, O.D., F.A.A.O.: I only use the test if I am conducting a clinical trial. There are so many other valuable clinical tests such as Lissamine Green staining, meibomian gland evaluation, fluorescein break up pattern observation, tear osmolarity and patient questionnaires all seem infinitely more fruitful than Schirmer testing.
|M.H.: I do not use Schirmer for routine exams. I perform the test for separate, stand-alone dry eye work-ups and when I have to, usually as part of a study. Also, I prefer the strips that have the scale in millimeters printed right on the strip. It reduces error in measurement.
Do you perform Schirmer I, no anesthesia or Schirmer II with anesthesia? Most of my patients prefer anesthesia, but most of the studies I have seen perform the test without anesthesia. Ouch.
|B.G.: If you do Schirmer I without anesthesia, you are going to cause reflex tearing and a false positive for tear production. If you do Schirmer II, you are blocking the normal neural feedback mechanism to the lacrimal gland that will impact tear production in the opposite direction.
|M.H.: I remember years ago at the Delphi panel, we went round and round as to what the cut-off should be. The panel agreed that the cut-offs should be 5mm or less. Now, the newer studies have been using 7mm or less, adjusted to catch the mild aqueous deficient.
Does it really tell you something?
|B.G.: This test is cruel and a waste of clinical time in my experience. The test has a high specificity (if it doesn’t wet, you have dry eye) but very poor sensitivity to identify patients who actually have dry eye. Evaporative dry eye would be the logical subtype to test for with Schirmer, but often by the time the ocular surface is exposed from evaporation, the exposure triggers a compensatory reflex tearing that will cause the Schirmer to show high or normal readings.
|M.H.: I agree with you here. The basic concept is for Schirmer to diagnose aqueous deficient dry eye. In a simplistic way, dry eye is actually either evaporative or aqueous deficient. The quick and dirty: Avoid the Schirmer test by exclusion. So, you express the glands, there is no meibomian gland dysfunction present, there are symptoms present, then diagnosis by exclusion would be aqueous deficiency dry eye. Is this always accurate? No, but in most cases, it is faster than performing Schirmer. OM
DR. HOM PRACTICES IN AZUSA, CALIF. HE IS A MULTI-AWARD WINNER, MOST RECENTLY WINNING THE 2012 AOA CLCS LEGEND AWARD. E-MAIL HIM AT EYEMAGE@MMINTERNET.COM.
DR. GADDIE IS THE OWNER AND DIRECTOR OF THE GADDIE EYE CENTERS, A MULTI-LOCATION, FULL-SERVICE PRACTICE IN LOUISVILLE, KY., AND IS CURRENTLY THE CHAIR OF THE CONTINUING EDUCATION COMMITTEE FOR THE AMERICAN OPTOMETRIC ASSOCIATION. E-MAIL HIM AT IBGADDIE@ME.COM, OR SEND COMMENTS TO OPTOMETRICMANAGEMENT@GMAIL.COM.
The authors report no financial interest in the products mentioned.
Optometric Management, Volume: 48 , Issue: March 2013, page(s): 56