Schirmer’s Test (Dry Eye Test)
The dry eye test is a simple and effective way to detect if your pet suffers from a disease or condition that causes them to suffer from frequent sneezing, watery eyes, or other symptoms of allergies. A wet nose indicates that there are no diseases present in the body.
A wet nose means that your pet has a disease or condition which causes their body to produce mucus when they sneeze. This is often caused by a viral infection such as the common cold, chicken pox, smallpox, or even human papillomavirus (HPV). If your pet has a wet nose with no other signs of illness then it is very likely that it does not have any diseases present in its body. However, if your pet has a wet nose and sneezes frequently, it is highly probable that they do have some type of disease present in their bodies.
The dry eye test is similar to the wet nose test except that it measures how much moisture there is in the eyes. The dry eye test cannot tell whether your pet has a virus or other infectious disease but it can indicate if they have a genetic disorder that causes them to develop dry eyes all the time. If your pet has dry eyes that appear to be swollen and red then it is likely that they do have a disease or condition present in their bodies. If your pet’s eyes do not look swollen and they have no other symptoms then it is unlikely that they have any diseases or conditions present in their bodies.
You should still take them to the veterinarian just to be safe though.
The most commonly performed test for eye health problems in pets is the tear production test. There are two methods of performing this test, the Schirmer test and the tear film break up time test.
The first dry eye test that is usually performed is the Schirmer Test. During this type of test, a veterinarian will apply a measured amount of pressure to your pet’s eyelid to extend the eyelid as much as possible. Then, a wetted cotton swab or similar type of object is placed on the lower conjunctival sac of your pet’s eye. The swab is left in position for about 5 seconds before being removed.
The amount of moisture or “bleed” on the swab is measured in millimeters and compared to a standard chart to give a diagnosis.
The other dry eye test that may be performed is called the tear film break up time test. This test is slightly more complex and involved than the first one. During this test, a drop of topical anesthetic is placed on your pet’s eye to prevent any pain or reflex actions that might cause the measurements to be inaccurate. Then, a pressure cuff is positioned on your pet’s upper eyelid by the eye doctor.
This type of equipment resembles that of what a human would wear for measuring blood pressure.
The main difference is that the pet’s upper eyelid is slightly extended outwards to give the greatest area of exposure possible. The equipment then releases a consistent amount of pressure on the eyelid and records the time elapsed before it can no longer be detected. This test is then repeated three times with the lowest amount of time being recorded.
The times for this test are compared to a standard chart once again to give a diagnosis. Many eye diseases and disorders can be detected with these tests, making them very important for your pet’s vision health.
If you feel as if your pet may have some form of eye disease then it is best to take them to a veterinarian and have them perform one or both of these dry eye tests. Early detection and treatment is always best for any type of medical condition.
Sources & references used in this article:
The role of the Schirmer’s test and orbital morphology in predicting dry-eye syndrome after blepharoplasty by TD Rees, GS LaTrenta – Plastic and reconstructive surgery, 1988 – journals.lww.com
Correlation of lipid layer thickness measurements with fluorescein tear film break-up time and Schirmer’s test by MA Isreb, JV Greiner, DR Korb, T Glonek, SS Mody… – Eye, 2003 – nature.com
Prevalence of dry eye among adult Chinese in the Beijing Eye Study by Y Jie, L Xu, YY Wu, JB Jonas – Eye, 2009 – nature.com
The epidemiology of dry eye in Melbourne, Australia by CA McCarty, AK Bansal, PM Livingston… – Ophthalmology, 1998 – Elsevier
Phenol red thread test vs Schirmer’s test: a comparative study by TA Saleh, B McDermott, AK Bates, P Ewings – Eye, 2006 – nature.com
Tear osmolarity as a biomarker for dry eye disease severity by M Suzuki, ML Massingale, F Ye… – … & Visual Science, 2010 – iovs.arvojournals.org