Microdot test of foveal function. A comparison with visual acuity at high and low contrast

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.