Using The Keratometer Mire As A Clinical Tool For Tear Film Evaluation In Contact Lens Wearers.

The evaluation of tear film quality is an essential portion in the examination of the contact lens patient. The mucin, aqueous, and lipid layers that make up the tears work together to maintain the health of the cornea, not only forming the most important refractive surface of the eye, but providing it's main source of nutrition, waste removal and antibacterial action. Deficiencies in the tear film can cause problems for the contact lens patient ranging from mild discomfort to significant lens intolerance which can ultimately compromise the health of the eye. Different techniques have been used clinically to assess the tear film quality. Methods such as the instillation of fluorescein to measure tear break up time (TBUT) have been criticized due to the invasive nature of the test which in itself may alter the tear film properties (2). Also, non-invasive techniques such as the Hirji -Callander grid (3) and the slit lamp bowl grid appaarus (4) have been suggested to measure TBUT without disrupting the tear film. The idea of using the standard keratometer mire to asses the sufficiency of the tear layer has been proposed (5) but not tested on contact lens wearing patients. This paper
suggests that relevant, practical knowledge can be gathered using the standard keratometer mire as a clinical tool to quickly evaluate and quantify tear film quality in contact lens wearers.