A compact rarebit test for macular diseases
- Institute of Neuroscience and Physiology, Department of Clinical Neurosciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Correspondence to Professor Lars Frisén, Neuro-Ophthalmology Unit, Blue St 7:5, SU/S, SE-413 45 Gothenburg, Sweden; lars.frisen{at}neuro.gu.se
- Accepted 23 August 2009
- Published Online First 12 October 2009
Abstract
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.
Conclusion 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.
Footnotes
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Funding Research Fund at Skaraborg Hospital, University of Gothenburg.
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Competing interests Author LF holds a patent on the test device.
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Ethics approval Ethics approval was provided by the Regional ethics committees of Region Västra Götaland and University of Gothenburg.
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Provenance and peer review Not commissioned; externally peer reviewed.
