AUTOMATED SYSTEM OF HESS SCREEN FOR THE DIAGNOSIS OF PARALYTIC STRABISMUS USING COMPUTER AIDED DIAGNOSIS

Abstract

In Ophthalmology, Hess screen is an imperative instrument which is primarily employed for the measurement of paralytic strabismus. Strabismus is the state of eye in which eyes are not properly aligned with each other and patient complaint for double vision (diplopia). In this thesis we propose a model for the automation of traditional Hess Screen instrument for the diagnosis of strabismus. Presently Hess Screen Instrument is totally manual which consume lot of time of patient as well as ophthalmologist. We present a three stage system consisting of image acquisition, point extraction, plotting of Hess chart and computer aided diagnosis algorithm. First stage is composed of a digital camera which will take images of the HESS board and transfer it to a computer. In second stage image processing techniques are used to extract points from images to draw HESS plot, and in third stage an algorithm based on fuzzy logic is designed which will automatically diagnose the paralytic strabismus using statistics of the Hess graphs. This system is convenient, fast and has an ability to manage medical record with refinement. The evaluation of proposed system is performed by using dataset provided by well known local hospital.