irritation and reßex component to the tearing; thus, a better approximation of basal tear production can be obtained.

In our experience, we Þnd it most useful to perform the test with topical anesthesia, being certain enough applications of topical anesthetic have been given to eliminate the irritation of the Þlter strip.

Care must be taken to wick away (gently, without irritation) any reservoir of tears or ßuid in the inferior cul-de-sac that will immediately wet the test strip and invalidate the results.

The eyes may be closed or kept open with normal blinking, whichever the patient prefers and causes minimal or no sensation.

A positive Schirmer’s test of less than 5 mm of wetting is always a positive indication of inadequate tear production. Between 5 and 10 mm of wetting is suspect.

A negative Schirmer’s test with copious wetting, however, indicates only that adequate innervation to the lacrimal system exists to produce reßex tearing. It does not rule out mild-to- moderate disease and diminished basal secretion, but does suggest a more favorable, more easily managed course.

It is worth noting that there is a very poor correlation between symptoms and Schirmer’s test results. One explanation for this difference is that the SchirmerÕs test is predominantly a measurement of water ßow, while the patientÕs symptoms may be correlated with mucin content and stability of the tear Þlm that allow the upper lid to glide over the ocular surface.

It is important to recognize this difference not only in the review of outside records, but also in publications describing studies that compare eye treatments, as they may use different methods (with and without topical anesthetic) in their patients in evaluating treatments.

Corneal topographyÑa non-invasive medical imaging technique for mapping the surface curvature of the cornea (the outer structure of the eye)Ñoften produces images that are highly suggestive, if not diagnostic, of dysfunctional tear conditions.

Rather than the nice regular optical contour maps seen in a normal eye, areas of irregularity and distortion, which change frequently after

blinking, can be observed. Even without such sophisticated instrumentation, this same phenomenon may be observed utilizing an ophthalmoscope focused on the surface of the eye (high plus lenses) and observing the regularity and quality of the red reßex through the pupil. Such observations may corroborate patientsÕ symptoms of ßuctuating acuity and episodically blurred or distorted vision.

Other tests exist to clarify the diagnosis of dry eye and/or ÒdysfunctionalÓ tear disorders, but they often require more expensive and elaborate equipment, represent investigational procedures and have yet to be standardized, or are simply impractical. One such test is measurements of tear film osmolarity that demonstrates

¥The hyperosmolar nature of the abnormal tear film (when not subjected to an excessively evaporative environment),

¥The decrease in the concentration of normal tear components such as lactoferrin, Þbronectin, epidermal growth factor and dinucleotide adenosine polyphosphate (AP4A)

¥The increased concentration of inflammatory by-products such as cytokines, proteases, and even white blood cells.

They have all been documented and provide

important insights into the pathophysiology of the disease. But they are not widely used in clinical practice.

12.4Overview of Dry Eye Management

12.4.1Dry Eyes Deserve Respect and Careful Monitoring

Once a diagnosis of dry eye has been entertained and supported by any of the above signs, symptoms, and tests, it must still be borne in mind that many of the other disorders considered in the general differential diagnosis of the red eye and ocular irritation may, and in fact often do, co-exist!

For the rheumatologist, it is important to look for medications with anticholinergic side effects.

Indeed, more than 50% of the 100 most commonly used prescription medications list ocular and oral dryness as a signiÞcant adverse effect.