Head mirror versus headlight: illumination, visual identification and visual acuity for otolaryngological examination

Objective: To investigate and compare the performance of head mirrors and headlights during otolaryngological examination. Methods: The illuminance and illumination field of each device were measured and compared. Visual identification and visual acuity were also measured, in 13 medical students and 10 otolaryngology specialists. Results: The illuminance (mean +/- standard deviation) of the LumiView, Kimscope 1 W and Kimscope 3 W headlights and a standard head mirror were 352.3 +/- 9, 92.3 +/- 4.5, 438 +/- 15.7 and 68.3 +/- 1.2 lux, respectively. The illumination field of the head mirror (mean +/- standard deviation) was 348 +/- 29.8 grids, significantly greater than that of the Kimscope 3 W headlight (183 +/- 9.2 grids) (p = 0.0017). The student group showed no statistically significant difference between visual identification with the best headlight and the head mirror (score means +/- standard deviations: 56.2 +/- 9 and 53.3 +/- 14.1, respectively; p = 0.3). The expert group scored significantly higher for visual identification with head mirrors versus headlights (59.7 +/- 3.3 vs 55.2 +/- 5.8, respectively; p = 0.0035), but showed no difference for visual acuity. Conclusion: Despite the advantages of headlight illumination, head mirrors provided better, shadow-free illumination. Despite no differences amongst students, head mirrors performed better than headlights in experienced hands.