Retinal image acquisition system in intraocular pressure measurement

A new image-based tonometry is presented in this paper which is founded on the traditional principles of intraocular pressure (IOP) measurement. It can not only measure intraocular pressure but also observe the changes in retinal blood vessels. Based on the new tonometry, this paper designs a real-time fundus image acquisition system as a subsystem of the new tonometry, which is used to calculate the flattening area of the eyeball and record real-time changes of fundus images in the process of measurement. As the core of the subsystem, FPGA coordinates operating timing among the sensor, SDRAM and USB and uploads image data. The applications can process and display real-time images and set the image resolution and frame rate dynamically. After testing, the performance of the subsystem is up to the mustard and stable, which lays the foundation for further research of the new tonometry.