Metodologia computacional para auxílio no diagnóstico da paralisia do sexto nervo óptico através de vídeos digitais

Abstract

The sixth cranial nerve, also known as the abducens nerve, is responsible for controlling the movements of the lateral rectus muscle. Palsies on the sixth nerve prevent some muscles that control eye movements from proper functioning, causing headaches, migraines, blurred vision, vertigo, and double vision. Hence, such palsy should be diagnosed in the early stages so that it can be treated without leaving any sequela. The usual methods for diagnosing the sixth nerve palsy are invasive or depend on expensive equipment, and computer-based methods designed specifically to assist on the diagnose of the aforementioned palsy were not found, until the publication of this work. Therefore, a low-cost, non-invasive method can support or guide the ophthalmologist’s diagnosis. In this context, this work presents a computational methodology to aid in diagnosing the sixth nerve palsy using videos, in order to assist ophthalmologists in the diagnostic process, serving as a second opinion. The proposed method uses convolutional neural networks and image processing techniques to track both eyes’ movement trajectory during the video. With this trajectory, it is possible to calculate the average speed in which each eye moves. Since it is known that paretic eyes move slower than healthy eyes, comparing the average speed of both eyes can determine if the eye is healthy or paretic. The results obtained with the proposed method showed that paretic eyes move at least 19.65% slower than healthy ones. This threshold, along with the average speed of the movement of the eyes, can help ophthalmologists in their analysis. The proposed method reached 92.64% accuracy in the diagnosis of the sixth nerve palsy, with a Kappa index of 0.925, which highlights the reliability of the results and gives favorable perspectives for further clinical application.