Schirmer’s test

The Schirmer’s test is used to determine whether your tear glands produce enough tears to keep your eyes adequately moist. Calibrated strips of a non-toxic filter paper are used. One free end is placed within your lower eyelid. Both eyes are tested at the same time. Before the test, you may be given numbing eye drops to prevent your eyes from tearing due to irritation from the paper. You will be asked to keep your eyes gently closed for 5 minutes. At the conclusion of the test, the paper strips are removed from each lower eyelid and the amount of wetting of the paper strips is measured.  

PATIENT UNDERGOING SCHIRMER'S TEST

CAUSES OF INCREASED TEAR SECRETION AND DECREASED TEAR SECRETION

Potential causes of dry eyes include:-

• ageing
• a bacterial infection
• climate change (or seasonal changes)
• eyelid or facial surgery
• laser eye surgery
• leukaemia
• lymphoma
• rheumatoid arthritis
• Sjogren syndrome (an autoimmune disorder)
• vitamin A deficiency

Potential causes of excess tears include:

• a strong emotional response (crying)
• climate (including cold and/or windy weather)
• allergies
• infections
• blocked tear ducts
• complications from dry eyes
• irritation of the eye (from stray eyelashes or other debris)
• ingrown eyelashes
• relaxation of eye muscles (limits the eye’s ability to drain)
• the common cold
• pink eye (conjunctivitis)
• reactions to certain medications (antihistamines, eye drops, diuretics, sleeping pills, etc.)

Procedure

Your optometrist will recommend Schirmer’s test if you are exhibiting signs of dry eyes, or in some cases, watery eyes.

If you wear corrective contact lenses, you will need to remove them before the test. It is best to bring your glasses because you should keep your contact lenses out for at least two hours after the test.

Before the test is administered, your optometrist will put numbing drops into your eyes. These will prevent your eyes from watering in reaction to the test strips. The numbing drops may cause irritation or stinging, but the sensation is temporary.

Next, the optometrist will ask you to look upward. He or she will pull out your bottom eyelid and gently place a special strip of paper underneath the lid. Both eyes may be tested at the same time. You will gently close your eyes and keep them shut for about five minutes with the paper strip in place. Closing your eyes too tightly or touching your eyes during the five-minute test process could alter the results.

After five-minutes, the ophthalmologist will take out the paper strips. The doctor will ask you to look upward as he or she pulls out your bottom eyelid and carefully removes the strips. The doctor will then measure the amount of moisture on each paper strip.

There are no known risks associated with Schirmer’s test.

As an alternative to Schirmer’s test, your doctor can also test tear production with Fluorescein eye drops or a red thread test. A red thread test is similar to Schirmer’s test, but uses thread instead of paper. Another option is a tear osmolarity test which measures how concentrated your tears are. A higher concentration signals dry eyes. 

Results 

      1. Normal which is ≥15 mm wetting of the paper after 5           minutes.

2. Mild which is 14-9 mm wetting of the paper after 5 minutes.

3. Moderate which is 8-4 mm wetting of the paper after 5 minutes.

4. Severe which is <4 mm wetting of the paper after 5 minutes.

IMPORTANT POINT FROM CLINICAL POINT OF VIEW

It reveals a reduced flow of tears on the side of a facial nerve palsy affecting the greater palatine nerve.