The tear (lacrimal) meniscus height in human eyes: a useful clinical measure or an unusable variable sign?

Purpose: To review notes and reports in the literature on assessments of human tear meniscus height (TMH) with the view to defining what the current state of knowledge is, and allow comparisons with data obtained on elderly individuals. Methods: TMH data was obtained from 97 elderly individuals without significant eye disease. Photo-slit-lamp views, perpendicular to the lower marginal tear strip, were used to obtain close-up images by videography over approximately 30 s. Repeated measures at the same location separated by a few seconds (time-dependent TMH measures, tTMH), or repeated measures along the length of the middle portion of the lower eyelid (position-dependent TMH measures, pTMH) were made. The results were compared to those from published reports of TMH. Results: For elderly individuals, tTMH averaged 0.185±0.088 mm, while pTMH averaged 0.189±0.093 mm. The distribution of TMH measures however included a number of data sets with a much higher average, and which could be separated from the main group of data using cluster analyses approach (> 0.23 mm, P