I feel this type of method in evaluating the efficacy of OTC artificial tears is long overdue. When using instrumentation, such as TearLab, the eyedrop’s ability to decrease osmolarity is very easy to quantify and measure which removes ambiguous endpoints such as patient perception or examiner bias.

We have now discovered a tremendous amount of information showing Type 2 Diabetes has an inflammatory component (one can search Journal of Inflammation for numerous citations). So I feel this article showing the link between increased tear osmolarity (inflammatory dry eye) and diabetes is very useful and timely.

I hope to see more articles soon discussing tear osmolartiy and other systemic diseases such as arthritis, thyroiditis, colitis, etc.

However, I would like to add some controversy to this topic. First let me say I am NOT being critical of the article or the technique. I would like to challenge whether or not the procedure should be done?

We know clinically and from the literature (such as DEWS) that dry eye is inflammatory with increased osmolarity. My concern is that it is impossible for gland expression, in and of itself. to not be an inflammatory process. So by doing gland expression for short-term relief are we increasing the inflammatory cascade which in turn could worsen the DED disease? If this is possible, shouldn’t we presribe steroids for several days after expression? And then of course the major question, “Is the short-term benefit worth the long-term outcome?”

It may be interesting for those actively expressing glands to do TearLab measurments before and at some time point after expression.

It has been noted that contact lens wearers are more than ten times likely than emmetropes and five time more likely than patients wearing spectacles to complain of dry eye symptoms.(ref 3) Interestingly enough, not only are contact lens patients more likely to complain of dry eye, it is speculated contact lenses can even precipitate dry eye (known as CLIDE or contact lens induced dry eye).(ref 4,5)

I encourage you that the next time you deal with a contact lens patient who presents with these “vague” symptoms of their contact lens wear being uncomfortable to perform a TearLab test on them. Many times you will find elevated osmolarity which indicates the inflammatory condition of dry eye disease is already established. By obtaining this diagnosis in the early stage you can initiate dry eye treatment and many times prevent this patient from becoming another contact lens dropout.

1. Rumpakis JMB. New data on contact lens dropouts: an international perspective. Rev Optom. 2010;147(1)37-42.
2. Young G, Veys J, Pritchard N, Coleman S. A multi-centre study of lapsed contact lens wearers. Ophthalmology Physiology. 2002;22;516-527.
3. Nichols JJ, Ziegler C, Mitchell GI, Nichols KK. Self-reported dry eye disease across refractive modalities. Invest Ophthalmol Vis Sci. 2005. June;46:1911-1914.
4. Krohn, Jeffrey. How to Address CLIDE. Rev Optom. 3-19-12
5. Agarwai, Amar. Tear film environment disrupted by introduction of a contact lens. Ocular Surgery News. US Edition, July 1, 2007.

I would like to comment on the issue of which puncta should be plugged. There has been extensive research regarding the tear outflow apparatus. In 1983 Lemp and Weil published the results of a study in which they evaluated the mechanisms of tear flow, blinking, and tear drainage. They instilled 15um black balls suspend in solution into the tear film. Using high-speed motion picture photography they recorded the outflow of these particles via the upper and low canaliculi. Their final conclusions included the following:

• Tears exit via an active mechanism, i.e. negative pressure created by compression of lacrimal sac.

• Immediately upon completion of the blink multiple spheres were seen rapidly flowing into the puncta, confirming negative pressures created within the canaliculi.

• The movement of the spheres into both inferior and superior puncta was visualized, thus confirming that tears exit from the meniscus through an active process.

• If one puncta is occluded, the remaining un-occluded puncta is still able to drain the tear film including the extra liquid that would normally exit through the occluded punctum.

• Their study demonstrated the efficacy of either the superior or inferior puncta acting alone as a sufficient tear drainage mechanism. This suggests that total elimination of drainage is accomplished by occlusion of both puncta.

Other researchers have confirmed the results of study. In clinical practice we often find that while punctal occlusion of a single orifice often relieves dry eye symptoms, it may be necessary to occlude both the upper & lower puncta to significantly impact tear film volume.

Lemp MA, Weiler HH. How do tears exit? Invest Ophthalmol Vis Sci. 1983 May;24(5):619-22.