Which test is used to measure the amount of tear production?

The Schirmer test is used to measure the amount of tear production and is a significant diagnostic tool in assessing dry eye conditions. This test involves placing a small strip of filter paper under the lower eyelid and measuring the amount of moisture collected on the strip over a specified period, typically five minutes. A low reading indicates reduced tear production, which can contribute to dry eyes and other ocular surface diseases.

The test is valuable for clinicians to evaluate the function of the lacrimal glands and can help in formulating appropriate treatment plans for patients experiencing dry eye symptoms. The results of the Schirmer test can guide further investigations or interventions to improve tear production or relieve discomfort.

In contrast, other options like fluorescein staining assess the health of the corneal surface, the basic secretion test involves more comprehensive examination techniques for tear film but is not a direct measure of tear production, and the exophthalmometer is designed to measure the extent of eye protrusion and does not provide information about tear production. Thus, the Schirmer test stands out as the primary method for directly quantifying tear output.