ABSTRACT
Retinal microcirculation can vary with associated retinopathies. One of the most widely used techniques for analyzing these variations is uorescein angiography. Scanning laser ophthalmoscope (SLO) sequences are obtained from a patient who was injected with a uorescent dye. These SLO techniques are useful for measuring biomedical metrics such as the arteriovenous (AV) passage time. As the acquisition of the whole sequence takes a lot of time, the patient’s eye will move during the process; hence an alignment procedure must take place afterward. This work discusses an automatic methodology for the alignment of large SLO sequences for AV passage time measurement. This methodology is a combination of two different approaches for registration: mutual information (MI) and landmark. The rst one will be used for registration in dark frames where the dye is not yet present in the vessels. This is so because of its ability to work without any prior processing or structure segmentation. The second one will use the vessels as landmarks for registration. Although the methodology considers rigid transforms only, it has been proven to work well in the presence of alterations in the perspective of the eye. The results obtained in the experiments were validated by expert ophthalmologists.
