Normal values of Schirmer-I test are:
**Core Concept**
The Schirmer-I test is a diagnostic tool used to assess the function of the lacrimal gland, specifically to measure the rate of tear production on the surface of the eye. It involves placing a small strip of filter paper under the lower eyelid to measure the amount of tears produced over a set period. This test helps in diagnosing conditions such as dry eye syndrome, Sjögren's syndrome, and other lacrimal gland disorders.
**Why the Correct Answer is Right**
The normal values of the Schirmer-I test typically range from 10 to 30 mm of tear secretion in 5 minutes. This range is considered normal, indicating adequate tear production. The test is usually performed in a clinical setting, and the values are measured in millimeters (mm) of tear secretion. The correct answer depends on the specific reference range used in the clinical setting, but generally, values between 10 and 30 mm are considered normal.
**Why Each Wrong Option is Incorrect**
* **Option A:** This value is too low and would indicate a potential tear production disorder.
* **Option B:** This value is too high and may not be relevant to the normal range.
* **Option C:** This value is outside the typical range and would likely indicate an abnormality in tear production.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the Schirmer-I test can be influenced by various factors, such as anxiety, environmental conditions, and the presence of nasal obstruction, which can affect tear production. Therefore, it's crucial to perform the test in a standardized manner and to consider these factors when interpreting the results.
**Correct Answer: C. 15-25 mm**