[Cycling with a visual handicap].
OBJECTIVE
To examine bicycling habits of visually handicapped people in order to learn about the visual requirements.


METHODS
Survey of patients (age range: 14-60 years) suffering from macular or tapetoretinal degeneration with no additional relevant handicap using a questionnaire.


RESULTS
A total of 232 questionnaires were returned (62% of the questionnaires received by the participants). The results showed that if visual acuity dropped below 0.1, only 15% of the patients were able to ride a bicycle without accidents or near-accidents. This percentage increased for higher acuities between 33% (<0.2 > or = 0.1) and 67% (> or = 0.2 < or = 0.4). For visual field diameters <60 degrees and > or = 20 degrees approximately 18% were able to ride a bicycle safely and only 8% if the visual field diameter was below 20 degrees. For visual fields larger than 60 degrees diameter approximately 40% were able to ride a bicycle without problems. With a central scotoma of more than 10 degrees diameter only 21% of the patients could cycle safely, whereas with a central scotoma of 10 degrees and less this percentage increased to 47%.


CONCLUSIONS
A visual acuity of less than 0.1 is not sufficient to ride a bicycle, and a visual acuity of less than 0.2 leads to a higher accident rate. A visual field diameter of less than 60 degrees or a central scotoma of more than 10 degrees diameter for the vast majority of patients does not allow safe cycling
Abt. für Pathophysiologie des Sehens und Neuroophthalmologie, Universitäts-Augenklinik, Tübingen. wilhelm@uni-tuebingen.de
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Endres
D000063:Accidents, Traffic / Q000517:prevention & control / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000706:statistics & numerical data*; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D005901:Glaucoma / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013647:Task Performance and Analysis; D014786:Vision Disorders / Q000175:diagnosis / Q000453:epidemiology*; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*