Search PubMed⌕ Search

Biomedical subjects

D H Goode

Publications and source records attributed to D H Goode.

4 recordsLinked to original sources
PubMed2000

Pattern VEP for glare sensitivity testing.

Conditions such as optic neuritis and cataract cause a patient to be unduely affected by glare and this occurs even though they may have normal visual acuity. A new test incorporating visual evoked potential (VEP) and glare sensitivity has been developed in Christchurch which shows promise for the objective assessment of such conditions. This report describes the methodology of the new technique and its application to the glare sensitivity testing of fifteen normal volunteers and ten patients with post optic neuritis. The effect of glare was expressed in terms of the glare disability score (GDS). This was defined as the percentage reduction in the amplitude of the P2 peak in the VEP waveform after glare was introduced. In these preliminary results, in spite of relatively good visual acuity, nine out of ten patients with a past history of optic neuritis showed elevated GDS values indicating that they were more sensitive to glare than the normal volunteers. In addition we report a dramatic reduction in the GDS of one patient with a lens opacity following extracapsular cataract extraction and the implantation of an intraocular lens.

Adult↗
PubMed1992

A flexible automated data acquisition system for ophthalmic electrophysiology.

An automated system for performing VER, ERG and EOG measurements has been developed and is now in clinical use. Considerable effort has been made to retain the flexibility of non-automated systems while providing an easily followed procedure for standard tests which can be undertaken by staff with minimal training. Clinical experience has shown that the standard parameters for data acquisition which are optimal for normal subjects are not always suitable for patients who are uncooperative or have poor vision. These parameters are under software control and can be amended interactively if necessary. The five main functions of the software, namely data acquisition, data selection and commentary, report generation, patient database operation and waveform archiving are written as separate modules and called as required. During data acquisition the software rejects gross artefacts and in the case of EOG's warns of patient non-cooperation. After an ERG or VER has been acquired the operator identifies features in the waveforms and the computer measures them whereas for EOG's the measurement process has been automated. When the waveforms are subsequently reviewed by the operator they are presented in a logical sequence, a sequence which does not depend on the order in which they were acquired, and this sequence is maintained when they are printed out later in the completely automated report phase.

Adult↗