Improved retinal photography method and visualization of multiple retinal images

The current instantaneous retinal photography method has large variations in the retinal vessel diameter measurement due to retinal vessel pulsation which has been reported associated to the cardiac cycle. The previous limited studies show limitation on their methodologies. To better understand and analyze the variation in the cardiac cycle, we developed an Electrocardiogram (ECG) synchronized retinal photography method which overcomes the previous limitations. Our method is able to detect ECG signal and calculate R-R interval in real time. The retinal camera can be triggered electronically and automatically at the designated time delays based on the real-time calculated R-R interval. Our results demonstrate this method is able to provide the visualization of the retinal vessel pulsations. It will be helpful for studying the relation of ophthalmology and cardiology. It also provides a possible solution to eliminate the cardiac cycle related photography variation in the retinal images analysis.