Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Comparison of two different methods of stereoscopic viewing and the effect of teaching on the assessment of the cup to disc ratio for glaucoma detection

Johns, Stephen 2012. Comparison of two different methods of stereoscopic viewing and the effect of teaching on the assessment of the cup to disc ratio for glaucoma detection. MPhil Thesis, Cardiff University.
Item availability restricted.

[thumbnail of johnss.pdf] PDF - Supplemental Material
Restricted to Repository staff only

Download (1MB)
[thumbnail of Johns - Stephen Thesis  MPhil (1) dec page removed.pdf]
Preview
PDF - Accepted Post-Print Version
Download (2MB) | Preview

Abstract

This study examines the effect of teaching on a group of naive observers asked to determine the cup-to-disc ratio of a series of stereo photographs presented by two different methods using custom software StereoDxT developed at Cardiff University. One method of presentation made use of Nvidia 3D software and compatible hardware, while the other was a ‘low tech’ approach using red-cyan anaglyphs. In order to further inform the results of this study, the members of the glaucoma team at North Devon District Hospital (NDDH), consisting of ophthalmologists, optometrists and other staff, undertook a similar study. An experiment to examine the magnification factor of several different binocular indirect lenses routinely used in the glaucoma clinics was also undertaken. The study showed observers, following a training session with the more expensive presentation system, improved their performance relative to an expert observer, while those using anaglyph images returned equivocal results. Control observers’ performance remained the same throughout the study. When compared against qualified staff at NDDH it was found that generally naive observers could improve their ability to determine cup-to-disc ratios to a similar level of experienced practitioners. It is believed that the anaglyph approach could be a viable alternative to higher cost training ‘set ups’ provided images are carefully selected and produced in a controlled manner. Measurements of a simulated optic disc taken with the binocular indirect lenses at differing simulated ametropias and working distances were found to be inconsistent with all the lenses tested. This raises concerns that a single manufacturers’ magnification factor may not be ideal where accurate measurements of fundal structures such as the optic disc is concerned.

Item Type: Thesis (MPhil)
Status: Unpublished
Schools: Optometry and Vision Sciences
Subjects: R Medicine > RE Ophthalmology
Uncontrolled Keywords: cup-to-disc ratio, stereo photographs, anaglyphs, glaucoma, magnification factor, binocular indirect lenses
Date of First Compliant Deposit: 30 March 2016
Last Modified: 07 Sep 2023 13:34
URI: https://orca.cardiff.ac.uk/id/eprint/43386

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics