TCR MicroAssay™

FACT SHEET

Research Use Only

INTRODUCTION

The TOUCH TEAR CLEARANCE MICROASSAY KIT™ is a test card platform used to determine the in situ rate at which fluorescein is cleared from the tears. This test requires the use of the M9 instrument, which contains the necessary algorithms to analyze the respective color absorption, and to convert these data into a rate expressed in "% per minute." A full description is contained in the Package Insert. In research it may also be used when a topical medication is tagged with fluorescein. The turn-over rate will give data related to how fast the medication is diffused or no longer a significant part of the tear film.

BRIEF SUMMARY

Over the past 10 years, many studies have been conducted looking at tear turnover rates using techniques such as Woods Lamp, flurophotometry, and other methods to measure the disappearance (rate) of fluorescein. These studies have used this measurement to have objective scientific data to better characterize several ocular conditions.

Because many people in the ocular research community desire to measure Tear Clearance Rates (TCR), Touch Scientific has incorporated this test into the Touch Tear MicroAssay System as a research tool only. As a research tool, no clinical claim is made for this test.

Studies using the Tear Clearance Rate (TCR) have used the data as a means to study efficacy of punctal/canalicular obstruction, glaucoma versus ocular hypertension, and corneal epithelial permeability. Other studies have used TCR to determine the corneal implications of hormonal levels, contact lens implications, inflammatory cytokines, tear pH, normal aging, evaporation, preservatives, adrenalectomy, cold-induced edema, and vasoconstrictors.

PERFORMANCE CHARACTERISTICS

Precision: Using fluorescein standards diluted in human tear fluid, the precision of the Touch TCR assay is 96% (CV of 4%).
Dynamic Range: This Touch TCR assay can accurately measure fluorescein concentrations in human tears between 2% and 0.001%.
Quality Control: The System, based upon options selected for a study, will determine and display valid protocol parameters. If the M9 displays valid protocol parameters, the patient value is also acceptable. If the protocol parameters are not valid the run is unacceptable; retest the patient. The protocol parameters evaluated by the M9e algorithm are: 1) the amount of time it takes to collect the tear samples; 2) the actual time points of collection, and; 3) the amount of fluorescein in the initial sample.

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