(rus) Phenol Red Thread tear test (PRT-TEST)

Phenol Red Thread tear test (PRT-TEST) is developed based on Schirmer tear test. It is a special thread treated by phenol red pH indicator, which can indicate the function of the tear secretion easily with its stable color and water-absorbing ability.




2 threads/pouch, 50 pouches/box


1. Easy to use;

2. Quickly reading (20 seconds test);

3. Much more comfortable to patients.


Remove residual tears by cotton before test. Place the thread near conjunctiva. Thread changes from yellow to red when it is moistened by neutral tear. 20 seconds after moistened by tear, measure the length of part where color changes. 10 to 24 mm is normal. This number may be considered as the threshold of dry eye.

Anesthesia isn’t required. If eye drops were used, the test should be postponed for at least 5 minutes.

Tear volume may vary. Reliable results can be achieved by multiple tests in different days.

Do not use it if the inside package is broken. Each set can only be used for one patient.

Avoid light and keep at room temperature.