The relationship between word length and threshold character size in patients with central scotoma and eccentric fixation
| Autor: | A. Déruaz, Christophe Mermoud, M. Goldschmidt, A.R. Whatham, Avinoam B. Safran |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Adult
medicine.medical_specialty media_common.quotation_subject Visual Acuity Vision Low Adaptation (eye) Fixation Ocular Stimulus (physiology) Audiology Macular Degeneration Cellular and Molecular Neuroscience Optics Reading (process) medicine Humans Scotoma Central scotoma Aged Retrospective Studies media_common Mathematics Aged 80 and over business.industry Vision Tests Middle Aged Crowding Degree (music) Sensory Systems Ophthalmology Character (mathematics) Reading Sensory Thresholds business Word (group theory) |
| Popis: | Background: Understanding limitations on text reading with eccentric fixation is of major concern in low vision research. Our objective was to determine, in patients with a central scotoma, whether threshold character size is similar for different word lengths and paragraphed texts. Methods: In 19 patients, we retrospectively analyzed the relationship between minimum readable character size for isolated words and text. Isolated letters, two, five, and ten-letter words and a paragraphed text were presented randomly through a scanning laser ophthalmoscope in eight different character sizes. Results: Threshold character size varied according to the text stimulus (p0.99), as were those for five-letter words, ten-letter words, and paragraphed text (p>0.99). Threshold character size for single letters and two-letter words was significantly lower than that measured with other text stimuli. Discussion: Reading performance is influenced by a variety of factors such as crowding, contextual effects, visual span, degree of oculomotor adaptation needed, and frequency of a defined word. Globally, when reading with a central scotoma, it appears that within word characteristics have more impact than inter-word parameters on threshold character size |
| Databáze: | OpenAIRE |
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