A compact rarebit test for macular diseases.
BACKGROUND
Rarebit testing implies probing for gaps in the neuro-retinal receptive field matrix, using bright microdots on a dark background. Previous reports have found rarebit testing useful for the detection of macular lesions. In its original implementation, the test requires darkroom facilities and a long test distance (2 m).


METHODS
A self-contained rarebit test device was realised using a modified miniature data projector driven by a laptop computer. Its performance was assessed in normal subjects and in patients with advanced age-related macular degeneration.


RESULTS
Normal subjects (N=49) produced test results very similar to those reported for the original rarebit fovea test. The patient group (N=12) performed significantly worse. The reproducibility was good, and the mean test time was 142 s.


CONCLUSIONS
The new test allows portable rarebit testing for neuro-macular damage, without the need for a darkroom. It may prove useful for screening for early age-related macular degeneration.
Winther
Christina
C
Institute of Neuroscience and Physiology, Department of Clinical Neurosciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Frisén
Lars
L
D000368:Aged; D000375:Aging / Q000502:physiology; D003196:Computer Graphics; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology; D014787:Vision Tests / Q000295:instrumentation / Q000379:methods; D014792:Visual Acuity / Q000502:physiology