Abstract
An improved continuous reading fluorophotometer with provision for controlling the blink rate has been used to measure tear turnover rates in 14 normal healthy volunteers. A significant difference between morning and afternoon tear turnover results has been found, indicating a possible circadian rhythm in tear flow. Sources of potential systematic error in the measurement method have been identified and analysed. Fluorescence measurements using a thin film cell have confirmed predictions of nonlinearity in fluorophotometer output at high tear film concentrations. The error in tear film fluorescence due to diffusion of fluorescein into the cornea has also been investigated. Simple precautions to minimise these errors are suggested, which should make the measurement method suitable for clinical application.
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Webber, W.R.S., Jones, D.P. Continuous fluorophotometric method of measuring tear turnover rate in humans and analysis of factors affecting accuracy. Med. Biol. Eng. Comput. 24, 386–392 (1986). https://doi.org/10.1007/BF02442693
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DOI: https://doi.org/10.1007/BF02442693