Designing a Pattern Stabilization Method Using Scleral Blood Vessels for Laser Eye Surgery

In laser eye surgery, the accuracy of operation depends on coherent eye tracking and registration techniques. Main approach used in image processing based eye trackers is extraction and tracking of pupil and limbus regions. In eye registration step, iris region features extracted from infrared images are used generally. Registration step determines the angular shift of eye origin by comparing the eye position on operation table with the eye topology obtained before the operation. Registration is only applied at the beginning but patient´s movements don not stop during operation. Hence we presented a method for pattern stabilization which can be repeated during operation at regular intervals. We use scleral blood vessels as features due to texturedness and resistance to errors caused by pupil center shift and ablation of cornea region.