Biomedical subjects

F Eperjesi

Publications and source records attributed to F Eperjesi.

6 recordsLinked to original sources

PubMed2002

The application of analysis of variance (ANOVA) to different experimental designs in optometry.

Analysis of variance (ANOVA) is the most efficient method available for the analysis of experimental data. Analysis of variance is a method of considerable complexity and subtlety, with many different variations, each of which applies in a particular experimental context. Hence, it is possible to apply the wrong type of ANOVA to data and, therefore, to draw an erroneous conclusion from an experiment. This article reviews the types of ANOVA most likely to arise in clinical experiments in optometry including the one-way ANOVA ('fixed' and 'random effect' models), two-way ANOVA in randomised blocks, three-way ANOVA, and factorial experimental designs (including the varieties known as 'split-plot' and 'repeated measures'). For each ANOVA, the appropriate experimental design is described, a statistical model is formulated, and the advantages and limitations of each type of design discussed. In addition, the problems of non-conformity to the statistical model and determination of the number of replications are considered.

Analysis of Variance↗

PubMed2000

An introduction to analysis of variance (ANOVA) with special reference to data from clinical experiments in optometry.

This article is aimed primarily at eye care practitioners who are undertaking advanced clinical research, and who wish to apply analysis of variance (ANOVA) to their data. ANOVA is a data analysis method of great utility and flexibility. This article describes why and how ANOVA was developed, the basic logic which underlies the method and the assumptions that the method makes for it to be validly applied to data from clinical experiments in optometry. The application of the method to the analysis of a simple data set is then described. In addition, the methods available for making planned comparisons between treatment means and for making post hoc tests are evaluated. The problem of determining the number of replicates or patients required in a given experimental situation is also discussed.

Analysis of Variance↗

PubMed1999

A review of the management of 323 consecutive patients seen in a specific learning difficulties clinic.

Visual correlates of specific learning difficulties (SpLD) include: binocular instability, low amplitude of accommodation, and Meares-Irlen Syndrome. Meares-Irlen Syndrome describes asthenopia and perceptual distortions which are alleviated by using individually prescribed coloured filters. Data from 323 consecutive patients seen over a 15 month period in an optometric clinic specialising in SpLD are reviewed. Visual symptoms and headaches were common. 48% of patients were given a conventional optometric intervention (spectacles, orthoptic exercises) and 50% were issued with coloured filters, usually for a trial period. 40% of those who were given orthoptic exercises were later issued with coloured overlays. 32% of those who were issued with coloured overlays were ultimately prescribed Precision Tinted lenses. Approximately half the sample were telephoned more than a year after the last clinical appointment. More than 70% of those who were prescribed Precision Tints were still wearing them daily, and results for this intervention compared favourably with data for non-tinted spectacles. The data suggest that many people with SpLD need optometric care and that the optometrist needs to be skilled in orthoptic techniques and cognisant of recent research on coloured filters.

Accommodation, Ocular↗

PubMed1995

Specific reading difficulty or decompensated heterophoria?

This case report illustrates the importance of both an educational psychology and optometric assessment in the management of reading difficulties. Only after these have been concluded can the aetiology of the reading difficulty be determined and the correct course of treatment instigated.

Child↗

PubMed1995

Is there a need for binocular vision evaluation in low vision?

The purpose of this study was to determine the need for a binocular vision evaluation in the management of low vision patients. Thirty subjects were selected with visual acuities of at least 6/60 in each eye. Twenty-three had age-related macular degeneration as the primary ocular pathology and seven had various other ocular conditions. The binocular vision evaluation comprised: detailed history and symptoms with an emphasis on the occurrence of near vision problems; modified binocular vision assessment which included cover test at near, ocular movements, convergence, Bagolini glasses, horizontal vergence reserves and prismatic measurement of any observed anomaly. History and symptoms revealed horizontal and vertical diplopia, jumbling of print, asthenopia, intermittent blurring and print being too small. Binocular vision assessment revealed exophoria at near, manifest horizontal deviations, convergence insufficiency, and vertical muscle imbalance. These anomalies occurred either singly or in combination. The results indicate that there is a need for binocular vision evaluation in low vision in order to reveal near vision disorders that may be partly attributable to binocular vision anomaly and not solely due to ocular pathology. This information should facilitate the implementation of the appropriate course of optometric management for these patients.

Aged↗

PubMed1995

Luminance and chromatic contrast effects on reading and object recognition in low vision: a review of the literature.

This paper reviews the literature on the effects of luminance and chromatic contrast on reading and object recognition in low vision. The general consensus is that whereas luminance contrast can enhance reading and object recognition for some low vision subjects, chromatic contrast does not aid low vision reading but may be useful in low vision object recognition. Although providing useful theoretical results, the experimental designs have so far been remote from the conditions that low vision patients may experience in the home and work environment. Suggestions are made for an 'ideal' experimental design and details of current research, using conditions more likely to be experienced by low vision subjects in everyday life, are given. This research makes use of a recently developed instrument, the Intuitive Colorimeter.

Cognition↗