Tear Secretion Test by the use of Hamano Fibers

ABSTRACT

We measured the tear secretion rate in normal and dry eyes by using a cotton thread method. This new method measures basal tears by means of a yellow colored cotton thread(Hamano fiber) impregnated with phenol red. The 3mm bent end of a 70mm long thread is placed in the inferior conjunctival sac on the temporal side of the eye for 30 seconds. The length of the thread that is wet by the tears changes color soon from yellow to red as a result of the change in pH. We obtained the following results by using of Hamano thread test, as a modified Schirmer test. 1. The proper test time of this test was 30 seconds in view of the analysis of the amount of tear secretion with time. 2. Average wet lengths of normal male was 16.6mm, that of female was 15.7mm from 30 seconds test. 3. Distribution of wet lengths in 300 normal eyes were ranged from 4.0mm to 34.0mm and most of them(61%) were within 10 to 20mm. 4. Wet lengths with and without anesthesia showed no statistical significance(paired t-test, p>0.05). 5. Reproducibility of Hamano fiber test that was tested 3 times in same eye represented significance in statatics(paired t-tast, p<0.05).