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Schirmer test

Q:

I saw a patient today for the first time who is an internist has been treated for dry eye for years.  She really looked to me more like chronic inflammatory OSD due to blepharitis and possible allergy with Rosace, plugging of the glands, loss of lashes, conjunctivochalsis etc.  She had no plugs in but had a normal lacrimal lake interrupted by conjunctivochalasis and tear osmolarity was 289 OD 291 OS.  No lissamine green stain.

What was interesting was that her Schirmer strips was only about 4mm before anesthetic but 13mm or so with anesthetic in both eyes.  I know that this is not the most reliable test in the world but still…..I’m having a hard time explaining this to a physician who is a patient.  She says she has had plugs in the past and benefited from them but they fall out and that she tried Restasis and it did not help.  

Wondering if anybody can explain why that might be to me.  Usually it’s the other way around with Schirmer’s .  Perhaps I’m missing something here so I thought I’d throw it out to the group.

Steve

 

A:

regarding the validity of Schirmer’s testing:

i do some expert review/testimony work, and highly suggest that all American ophthalmologists starting out do this, as it is essentially paid training to learn how to reduce your own liability risk (by seeing how others may have screwed up, not typically only or even primarily medically, but usually also additionally or primarily non-medically, like by poor documentation, etc)
you also get to see the legal system at work, so you have a better understanding of the 3 parts that you need to convict in a medical malpractice case in the US (negligence (departure from standard of care) + causation + damages). you also surprisingly get a higher level of respect for the vast majority of lawyers, who will not take cases that they don’t think are deserving (with the obvious 1% exception who bring bs cases forward with the MO of seeing “what sticks to the wall”)
so in court, i had to defend a refractive surgeon who had a patient accusing him of causing permanent debilitating DES postop, who “did not even do the basic test for DES preop, or Schirmer’s”
in court, i made the following points about Schirmer’s testing (after conducting a literature review):
  1. highly variable results between testers and even with the same tester on repeated testing
  2. large variations in results depending on time of day or which day was tested
  3. poor correlation to other recognized measures of DES
  4. no generally accepted way to even perform the test
  5. no generally accepted values of normal or abnormal
  6. no generally accepted practice on what to do with test results in terms of therapy
  7. many top cornea/refractive specialists have therefore abandoned routine Schirmer’s testing
  8. therefore, it is NOT a “gold standard” and many top surgeons wouldn’t even call it a “bronze” standard
the jury was convinced by my logic, and the defendant was unanimously acquitted
so that is a rationale that at least legally demonstrates that Schirmer’s testing is not nearly as accurate as one would believe, given how much emphasis is given to it in residency training and on ABO testing (which often isn’t very well related to what we need to know/do in real clinical practice)
i, myself, tell my fellows to use Schirmer’s w anesthesia (wo i think has almost no value as you might as well just stick a grain of sand in their eyes and see how much reflex tearing they produce), make sure to blot the fornices very carefully beforehand, make sure their eyes are closed throughout the test so as not to activate the lacrimal pump, and only use results that are extreme (eg less than 5 is dry, more than 10 isn’t that dry, 5-10 is equivocal). i would say we only do this about 10% of time preop, and rely more on the pt’s telling us about dryness w CLs, and other findings (eg SPK, etc)
hope this helps add perspective to this debate

———————————————————————————————–
*Emil William Chynn, MD, FACS, MBA*
*Dartmouth / Columbia / Harvard / Emory / NYU-trained *
*1st eye surgeon in NYC to have LASIK himself (1999)*
*Switched to SafeSight for better safety & vision (2005)*
*Performed highest Rx (-22.00) ever lasered in USA (2010)*
*Only High-Volume Pure Non-Cutting Refractive Surgeon in USA*

 

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