The test method in question is named after the ophthalmologist who developed it, Otto Schirmer. This test determines the level of secreted tear fluid, the degree of moisture maintenance of the surface of the cornea.
Indications and contraindications
Schirmer's test is used when the presence is suspected:
- inflammation of the cornea of the conjunctiva;
- dry eye syndrome;
- Sjögren's syndrome (a chronic progressive lesion of the connective tissue that affects the glands that secrete external secretion - salivary and lacrimal);
- tear disorders due to medications.
Dry eye syndrome can develop for a number of reasons:
- Dehydration.
- Old age of the patient.
- Conjunctivitis or other eye infection.
- Hypovitaminosis A (lack of vitamin A in the body).
- White eyes.
- Postoperative or permanent complication after laser vision correction.
- The so-called secondary syndrome, which manifests itself in rheumatoid arthritis, leukemia, lymphoma.
Schirmer test is contraindicated in:
- perforation (shape change)eyeball;
- fistula;
- developing ulcer of the corneal layer;
- large-scale erosion of the stratum corneum.
Test methods
Schirmer test strips are special filtered paper of standard size: 5 mm wide and 35 mm long. Stepping back 5 mm from the marked edge of the strip, the ophthalmologist turns it at an angle of 45 degrees and lowers it behind the patient's lower eyelid, focusing on the area between the outer and middle parts. It is important not to touch the cornea during the procedure.
According to some methods, the patient should close his eyes during the procedure, according to others - look ahead and slightly up. The lighting in the office should be comfortable - not dim and not too bright.
The Schirmer test lasts approximately five minutes. During this time, the paper strips absorb the precorneal tear film and moisture from the tear lake.
Types of test techniques
Schirmer's test is carried out in two ways:
- Using local anesthesia. The anesthetic eliminates the addition of reflex tear secretion to the basal fluid in response to paper irritation. After instillation of the anesthetic, the lower fornix of the conjunctiva is drained so that excess drops of the drug do not mix with the lacrimal fluid, thereby increasing its volume.
- Without the use of an anesthetic. Such a test is considered by a number of ophthalmologists to be more accurate, since it completely eliminates the mixing of tears and the administered drug, and shows only a "clean" result. This type of test is typical fordiagnosing the symptom of "dry eye".
Also, the Schirmer test is divided into I and II. The first is carried out using test strips according to the method indicated by us. The second type helps to investigate the amount of reflex (reactions to an irritant) lacrimal secretions. It is carried out in a similar way, but at the same time, the ophthalmologist stimulates the release of lacrimal secretion by irritating the nasal passages of the examined with a cotton swab.
Schirmer's test: norm and deviations
In severe cases of dry eye syndrome, the readings on the test strip may be at the level of zero. The norm for the young contingent of patients are indicators exceeding 15 mm. If the indicators are lower, then the subject suffers from one of the types of "dry eye" syndrome:
- 14-9 mm - slight variation of inhibition of tear secretion;
- 8-4 mm - the average degree of development of the syndrome;
- less than 4 mm - severe forms of corneal dryness syndrome.
Optimal performance: 10-30 mm. If the patient is over 60 years old, then a test strip reading below 10 mm will be considered normal for him, but he should not tend to zero either.
The norm for sample II, which determines the amount of reflex tear release, is not less than 15 mm. Differences in test results for a pair of eyes by more than 27% are considered significant for both types of samples.
Follow-up diagnosis after the Schirmer test:
- slit lamp examination;
- coloured with pink bengal or fluores-dog;
- research to find the time interval of tear film rupture.
Schirmer's test is a simple and fast, effective method for the initial diagnosis of dry eye syndrome and similar manifestations, diseases that affect the release of lacrimal secretions. The test helps the ophthalmologist to quickly determine the level of secreted tear fluid (basal, reflex) and their total indicators in the examined patient.
