Schirmer

Schirmer test, also known as Schirmer, is an ophthalmologic diagnostic procedure used to quantify tear production and assess the lacrimal function unit. It is commonly employed in the evaluation of dry eye syndrome and to help diagnose conditions such as Sjögren's syndrome, blepharitis, and allergic conjunctivitis. There are two main variants: Schirmer I test, performed without topical anesthesia to measure reflex and basal tear production, and Schirmer II test, performed after topical anesthetic to isolate basal tear production.

Procedure: A sterile filter paper strip, about 5 mm wide and 35 mm long, is inserted into the inferior conjunctival fornix of the lower eyelid, with the strip resting at about 1-2 mm from the lid margin. The patient keeps the eyes gently closed for five minutes. The length of the strip that becomes wet is measured in millimeters. In Schirmer I, no anesthesia is used; in Schirmer II, topical anesthetic is applied before measuring. Normal values are typically considered to be greater than about 15 mm of wetting in 5 minutes; 10-15 mm is interpreted as borderline; less than 10 mm indicates reduced tear production, with less than 5 mm suggesting aqueous deficiency.

Limitations: results can be influenced by environmental conditions and patient cooperation; reflex tearing can inflate results in Schirmer I; prosthetic lenses, medications, and lid abnormalities can affect accuracy. The Schirmer test is one component of dry eye evaluation and is often complemented by tear breakup time and ocular surface staining.