Abstract
Abstract: :
Purpose: Adequate volume of tears is essential to prevent desiccation of the exposed ocular surface. Tear meniscus height (TMH) is an index of tear storage. We developed a new method to measure tear meniscus height (TMH) using a conventional fundus camera. Methods: Eighteen dry eye patients and 34 normal subjects were enrolled in the study. Each subject was instilled 2µl of 1% fluorescein-sodium solution, and then fluorescein photograph (meniscus photo) was taken with a fundus camera which installed a blue light illuminant as excitation and a fluorescence filter as emission. Images of tear meniscus were extracted from the digitalized images by using NIH image. The upper TMH and the lower TMH were calculated separately. Schirmer-I test and cotton thread test were also performed. Results: The upper TMH was 0.22±0.06 mm and the lower TMH was 0.24±0.08 mm in normal subjects. The upper TMH was 0.17±0.07 mm and the lower TMH was 0.17±0.12 mm in dry eye patients. TMH of dry eye patients was significantly lower than that of normal controls. TMH showed significant correlation with cotton thread test (r=0.54, p<0.01), but not with Schirmer-I test. The ratio (upper/lower) of TMH in dry patients (1.17±0.41) was significantly higher than in normal subjects (0.97±0.23; p<0.05, unpaired t-test). Conclusion: This method enabled us to evaluate the upper and the lower TMH simultaneously without using special instruments. This method appears to be useful in the diagnosis of dry eye and to evaluate the effect of dry eye treatment such as punctual plugs.
Keywords: 356 clinical (human) or epidemiologic studies: systems/equipment/techniques • 376 cornea: tears/tear film/dry eye • 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)