Real-time location of surgical incisions in cataract phacoemulsification

Phacoemulsification is an important surgical treatment for cataracts. The location of the surgical incision affects the surgically induced astigmatism, and the typical surgical incision for phacoemulsification is located on the steepest meridian direction of the limbus. The real-time location of the surgical incision during the cataract phacoemulsification can reduce doctors’ workloads and the potential for human error. A real-time surgical incision location algorithm in microscopic images is proposed in this paper. It is a two-part algorithm that consists of an iris external boundary detection algorithm and a rotation angle calculation algorithm. The steps in the iris external boundary detection algorithm include image space conversion, image segmentation, filtering, and least square based circle detection. The eye rotation angle calculation algorithm utilizes the SURF algorithm. Experiments on six phacoemulsification videos show that the algorithm can locate surgical incisions in microscopic videos accurately and quickly. The distance error of the iris external boundary algorithm is 2.45 ± 0.136, and the area error is 2.69 ± 0.184. The average running time of this algorithm for one image is 65.1 ± 4.80 ms; a demonstration video, the S1 Video, is available. The algorithm proposed in this paper can determine the surgical incision location in cataract phacoemulsification in real-time based on a personal computer and can provide assistance for ophthalmology surgeons.