Development of a New Two Colors Video-Ophthalmoscope for Precise Measuerment of Cardiac Cycle Induced Reflection Changes in the Retina

Abstract: The purpose of this study is to develope components of a new two colors video ophthalmoscope to measure cardiac cycle induced reflection changes in the human retina. These changes occur due to the changing blood volume. These reflection changes can also be measured using one wavelength. However, due to eye and head movements, the light intensity changes during the measurement.

The basic principle of this work is to use two wavelength, one wavelength that is absorbed by blood and another wavelength that is not absorbed by blood and can be used to compensate for intensity changes. The development of the illumination and detection components are described. The function of this principle is shown using the changing blood volume in the finger. Recently it was shown that the waveform of the cardiac cycle induced reflection changes in the eye depends on the intraocular pressure. The main aim is to use two two-color-videoophthalmoscope to measure both eyes simultaneously. Simultaneous measurement of both eyes permits to compare both waveform of the cardiac cycle. If there is an asymmetry in the waveform of reflection signal, it can be possible that an asymmetry will be noticed in the IOP as a sign of beginning glaucoma.