Fundus-controlled examination of reading in eyes with macular pathology

The ability to read is an important parameter for the optical rehabilitation of visually handicapped patients. For the choice of the best therapy, more detailed knowledge of the physiology of reading is required. We evaluated reading velocity as well as the number of saccades in and against the dire...

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Bibliographic Details
Published inGerman journal of ophthalmology Vol. 5; no. 5; p. 300
Main Authors Rohrschneider, K, Bethke-Jaenicke, C, Becker, M, Kruse, F E, Blankenagel, A, Völcker, H E
Format Journal Article
LanguageEnglish
Published Germany 01.09.1996
Subjects
Adult
Aged
Fixation, Ocular
Fundus Oculi
Humans
Macula Lutea - pathology
Middle Aged
Ophthalmoscopy
Reading
Retinal Diseases - complications
Retinal Diseases - physiopathology
Scotoma - pathology
Scotoma - physiopathology
Vision Disorders - etiology
Vision Disorders - physiopathology
Visual Acuity
Visual Fields
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Summary:The ability to read is an important parameter for the optical rehabilitation of visually handicapped patients. For the choice of the best therapy, more detailed knowledge of the physiology of reading is required. We evaluated reading velocity as well as the number of saccades in and against the direction of reading for reading plates with different character sizes (10 steps from a letter height of 3-0.25 degrees) using the scanning laser ophthalmoscope in 20 healthy eyes and 30 eyes with central and paracentral scotomas. The number of characters read during each fixation increased with decreasing size of characters from 3.2 to 4.4 in normals. However, the reading velocity decreased from 14 to 11 digits/s when digits became very small. In patients' eyes the greatest reading velocity was reached at 6.1 digits/s for a 1 degree size, and the maximal number of digits read during one rest phase was 3.2 for a 0.75 degree size. In patients we observed a high number of saccades against the reading direction and different loci of fixation. Fundus-controlled examination allows for new insights into the physiology and pathophysiology of reading. Loss of the central visual field leads to an increase in the number of saccades because the number of digits perceived during each fixation decreases. The high number of regressions may be caused by the typical shift of the center of fixation following paracentral scotoma. Saccades directed toward the scotoma have to be corrected due to failure of exact positioning.
ISSN:0941-2921