Abstract
M.Phil. (Optometry)
Many advances have been made in ocular diagnosing instruments and software programs that better equip ophthalmologists and optometrists in making decisions concerning treatment for certain ocular diseases. Although these advances have greatly assisted professionals within the ophthalmic and ocular fields, the majority of the machinery and software are expensive and procedures can be time consuming for both the examiner and the patient. The primary aim of this dissertation is to investigate the reliability and reproducibility of new vision psychophysical software (developed by Professor Alan Rubin) in the hope that should it prove to be repeatable and reliable, it could be used clinically in assessing and detecting certain ocular diseases within a shorter time frame and with more comfort for the patient than alternate instrumentation currently available. This new vision psychophysical software (based on MATLAB®) uses a fairly new concept known as oscillatory sensitivity (OS) which is the sensitivity a patient has for an oscillating target within the visual field. A map of oscillatory sensitivities similar to a threshold map for a visual field is produced. Although many studies have been conducted with regards to motion discrimination, little seems to have been done concerning an oscillating target. Oscillation is defined as a regular fluctuation to-and-fro or periodic motion while sensitivity is the ability to appreciate or be responsive to changes in the environment. Therefore oscillatory sensitivity involves the ability of a patient to sense a small vibrating target as produced on a screen or monitor. In brief, the vision psychophysical software used herein measures OS by producing a computer-generated target (a point, circle or grating) that moves to-and-fro (oscillation can be in ascending or descending intervals) in a single direction (horizontal, vertical or obliquely).
A total of thirty-nine participants voluntarily participated in this study. Two participants were analysed as part of the pilot study and the remaining thirty-seven participants constituted the broader sample for the study. Due to unforeseen complications (explained later in the abstract and elsewhere), 26 of the 37 participants formed the eventual study sample used for detailed analysis. All participants (N=39) completed consent forms along with a short biographical...