Adequate illumination for otoscopy. Variations due to power source, bulb, and head and speculum design
F. Barriga, R. H. Schwartz and G. F. Hayden
To determine the working condition of otoscopes used in our community to
diagnose middle-ear disease in children, we examined 221 otoscopes located
in a hospital clinic, four emergency rooms, and the private offices of 96
physicians. The light output of each unit was measured in "as is" condition
and then remeasured after a new lamp and, when possible, a new battery had
been placed in the unit. A light output of 100 foot-candles or more was
judged optimal for clinical otoscopy. Replacement of the bulb was
significantly more likely than replacement of the battery to restore
adequate light output to those units with initially poor performance (80%
vs 26%). Almost one third of physicians reported changing otoscope bulbs
less often than every two years, and several did not know how to replace
the bulb. Almost half of the 93 rechargeable nickel-cadmium batteries
inspected were outdated, but even these "expired" batteries provided
adequate power when fully charged. Office otoscopes should be maintained
properly to ensure optimal performance.
