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Microdot test of foveal function. A comparison with visual acuity at high and low contrast
Author(s) -
Malmer L.,
Martin L.
Publication year - 2005
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1111/j.1475-1313.2004.00244.x
Subject(s) - foveal , contrast (vision) , ophthalmology , visual acuity , fundus (uterus) , medicine , fovea centralis , audiology , optometry , retinal , optics , physics
Purpose: To define normal values across age from novel computerized tests of foveal vision and to compare the findings with visual acuity (VA) at high and low contrast. Subjects and methods: Sixty‐one healthy volunteers, aged 22–87, with subjectively normal vision participated in the study. The right eye from each subject was tested with Snellen letter VA at high contrast, at 10% contrast using the Tri‐VA test and with the Rarebit Microdot Fovea Test (RMFT), in addition to biomicroscopy and fundus examination. Results: The median letter VA was 0.77 minimum angle of resolution (MAR; range 0.63–1.54) with a significant decline in letter VA with increasing age ( r = 0.7, p < 0.001). The median Tri‐VA resolution threshold at 10% contrast was 1.8 MAR (range 0.9–4.1) and a significant age effect ( r = 0.7) was observed, most pronounced above 65 years. The median RMFT hit rate was 100% (range 97–100) in the age group below 65 years and 87.5% (range 34–98) in subjects older than 65 years. Conclusion: The study shows a decline in foveal function with age with all three methods, reflecting the loss of neural detectors with increasing age. The hit rate to microdot stimuli appears to be a sensitive measure, which can be used for fine‐graded evaluation of foveal function.