title: Microdot test of foveal function. A comparison with visual acuity at high and low contrast.
abstract: OBJECTIVE
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Section of Ophthalmology and Vision, Department of Clinical Neuroscience, Karolinska Institutet, St Erik's Eye Hospital, S-112 82 Stockholm, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Malmer
authors.forename: L
authors.initials: L
authors.lastname: Martin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003196:Computer Graphics; D015350:Contrast Sensitivity; D005584:Fovea Centralis / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity; D012684:Sensory Thresholds; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests / Q000379:methods