Robust Visual Tracking for Retinal Mapping in Computer-Assisted Slit-Lamp Imaging

Abstract

The slit lamp device is a very popular equipment for inspecting the human retina due to its magnification, stereoscopy and easy control. In this context, computer assistance can provide information overlay to surgeons, improving navigation, accuracy and safety in procedures where the slit-lamp is used. Toward this goal, we describe a robust method for tracking and mapping the human retina using slit-lamp images. Inspired in [1], the proposed method is essentially a direct visual tracking method using local illumination compensation, as well as an efficient pixel selection scheme for achieving fast tracking speeds. In this paper, we describe a novel forward-backward strategy for achieving superior tracking resilience. Experiments conducted on several human patients confirm the practical value of the system.

A comparative study of transformation models for the sequential mosaicing of long retinal sequences of slit-lamp images obtained in a closed-loop motion

“…It creates viewpoint dependent artifacts, glare and specular reflections. The results recently presented in [18] demonstrate the use of the rigid transformation model. Despite the variety of works which report on different transformation models for retinal image registration, only a few address their comparison and evaluation.…”

“…The transformation models applied in these works include translation, rigid (translation and rotation), similarity, affine and quadratic. On the other hand, slit-lamp images were covered only in [2,18]. This type of data is degraded by an uneven illumination which comes from outside the eye, especially from the contact lens.…”

“…Computer-assisted retina mosaicing for view expansion using a slit-lamp device has been recently proposed [17,18] and integrated in the slit-lamp system of QuantelMedical, France (Fig. 1a).…”