In order to determine the variability of Q C in human subjects, it is necessary to develop a non-invasive technique. Using the phosphorescence quenching of oxygen sensitive dyes, we have developed a simple method for measuring tear oxygen tension while a subject is wearing a contact lens. Figure 1 shows the rate of phosphorescence decay obtained from dye placed in the tears of a rabbit. Figure 2 shows a schematic of the phosphorescence measurement system.
High oxygen is dye solution directly exposed to the air.
Low Oxygen is dye solution underneath a PMMA contact lens. Oxygen tension is related to the decay constant of each curve and can be calculated using the Stern-Volmer equation. Schematic of the phosphorescence measurement system. The same trigger initiates both flash discharge and data collection. The flash emission is band pass filtered and focused onto a bifurcated fiber optic bundle.