|Title||A STUDY OF THE RELATIONSHIP BETWEEN TEAR BREAK-UP AND THE DRY AREA GROWHT RATE|
|Author, Co-Author||Salih Al-oliky, Graeme Wilson, Gerald Lowther, Carolyn Begley|
|Abstract|| PURPOSE. To investigate the relationship between tear break-up time and area of drying, and to determine the rate of dry area growth in different subjects.
METHOD. Fluorescein from sterile fluorescein strips was instilled onto one eye of 40 subjects. The subjects were positioned in a biomicroscope and asked to blink a few times and then told to voluntarily hold the eye open as long as possible; the other eye was held shut. During the time the eye was open the appearance of the corneal surface was recorded with a VCR. Analysis of the videotape allowed us to measure the time for development of each dry spot (TBUT), and to determine the dry area growth rate (DAGR). The procedure was repeated three times.
RESULTS. Subjects were divided into two groups on the basis of the traditional diagnostic cut-off for dry eye of 10 s. Group A (TBUT 10s) contained 14 subjects. The TBUT (MEAN/MEDIAN/RANGE) for Group A was 5.7/5.6/2.7 to 9.3 s, for Group B it was 25.7/15.2/10 to 110 s. The DAGR (MEAN/MEDIAN/RANGE) for Group A was 12.50/8.2/0.8 to 50.0 mm2/s, for Group B it was 3.9/1.9/0.1 to 24.2 mm2/s.
CONCLUSION. The data show that shorter TBUTs are associated with high DAGRs, and longer TBUTs are associated with low DAGRs. The new measurement may allow separation of those eyes with low BUTs that have a relatively normal tear film. The technique could prove useful in assessing the factors that cause dry eye.
|Affiliation of Co-Authors||Indiana University School of Optometry, Indiana University School of Optometry, Indiana University School of Optometry|