THE NEW INTRAOCULAR AUTOMATIC PRESSURE SENSOR

K. Hille1, J. Draeger2, T. Eggers3, P. Stegmayer4, J. Binder3 and K. W. Ruprecht1

1. Dept. of Ophthalmology, University of Saarland, Homburg/Saar (Germany) 2. Dept. of Ophthalmology, Medical University Hamburg (Germany) 3. IMSAS, University of Bremen (Germany) 4. ETH Zürich (Swiss)

Purpose: Conventional intraocular pressure will be measured punctually by an indirect method like impression or applanation of the cornea. Continuous monitoring especially over night in sleeping patients was not available until now.

Methods: An implantable system consisting of a minimised sensor and telemetric unit integrated in an intraocular lens is used for intraocular pressure measurement. The intraocular pressure is determined by the sensor, modulated and transduced by the telemetric system. The signal is demodulated by an extracorporal receiver. The electric supply of the intraocular system is done via external electromagnetic induction.

Results: Testing the system shows a linear correlation between the intraocular pressure, measured by manometer and applanation, and the values of the telemetric system. Up to 3 measurements with an accuracy of +- 1 mmHg can be achieved.

Conclusions: After cataract extraction and implantation of an IOL with the integrated sensor-system a continuous observation of the intraocular pressure is possible in glaucomatous patients.