Abstract
Abstract: :
Purpose: To establish the feasibility of objectively measuring intraocular pressure using a dual tonometer through the eyelids, utilising electronically driven sensor tonometers. Methods: A dual tonometer which allowed both head mounting as well as direct application to the eyelid was constructed, with low voltage power supply to the electronic components allowed two sensor tonometers to measure the force applied to the eyelid with cross talk software capability. The measure of force was then calibrated against Goldmann applanation tonometry and the data compared. The device when head mounted allows for measures of IOP during sleep, as well as in office measurements for both diurnal [ day phasing] as well as single measurement. Results: The results show repeat reliability with stable eye positions. During sleep the sensors were not disruptive to sleep, but were affected by REM phase sleep. The device was subjectively perceived to be very gentle even relaxing as the forces applied are very low, being additive for end point measure. Correlations against Goldmann were calibrated on an individual basis. Conclusions: A dual through the eyelid tonometer, in development, allows for repeatable measures of intraocular pressure and can be worn during sleep.
Keywords: intraocular pressure • circadian rhythms • outflow: trabecular meshwork