Ans. D: Dry eye Schirmer test producing wetting of less than 6 mm suppo the diagnosis of dry eye Schirmer's test It determines whether the eye produces enough tears to keep it moist. This test is used when a person experiences very dry eyes or excessive watering of the eyes. It poses no risk to the subject. A negative (more than 10 mm of moisture on the filter paper in 5 minutes) test result is normal. Both eyes normally secrete the same amount of tears. It is named for Otto Schirmer Schirmer's test uses paper strips inseed into the eye for several minutes to measure the production of tears. Both eyes are tested at the same time. Most often, this test consists of placing a small strip of filter paper inside the lower eyelid (conjunctival sac). The eyes are closed for 5 minutes. The paper is then removed and the amount of moisture is measured. Sometimes a topical anesthetic is placed into the eye before the filter paper to prevent tearing due to the irritation from the paper. The use of the anesthetic ensures that only basal tear secretion is being measured. This technique measures basic tear function. A young person normally moistens 15 mm of each paper strip. Because hypolacrimation occurs with aging, 33% of normal elderly persons may wet only 10 mm in 5 minutes. Persons with SjOgren's syndrome moisten less than 5 mm in 5 minutes. Newer and better tests of tear production and function are One test measures an iron-binding molecule called lactoferrin. The amount of this molecule appears to be closely related to tear production. Patients with low tear production and dry eyes have low levels of this molecule. This test may be especially valuable for patients with dry eyes since it can point to specific treatment strategies for dry eye. The tears may also be examined for their content of lysozyme, an enzyme normally found in tears. Another test involves fluorescein eye drops, which contain a dye that is placed in the eye. The dye should drain with the tears through the lacrimal duct into the nose within 2 minutes. If patients do not have enough tears to flush the dye into the nose, this time will be longer. Dry eyes can occur from conditions such as: Aging Dehydration Corneal ulcers and infections Eye infections (for example conjunctivitis) Vitamin A deficiency SjOgren's syndrome Secondary tearing deficiency (associated with disorders such as - lymphoma, leukemia, GVHD (graft vs. host disease, after a transplant), and rheumatoid ahritis) As a temporary or permanent side effect of LASER vision correction surgery such as LASIK or PRK