One is an unwieldy, medieval torture device. The other is a magnifying glass attached to a purple flashlight. In a busy Emergency Department, adapting to space requirements and patient flow needs, which one are you going to reach for?
Unfortunately – and rather obviously – the easy option is not equally effective. This small study pulled a convenience sample of anterior chamber-type eye complaints presenting to an eye urgent clinic, and evaluated them first with the Wood’s lamp, and then the slit lamp. Of the 73 patients included in the study, the overall sensitivity of the Wood’s lamp was 52% – missing, as the sensitivity might imply, about half of corneal abrasions, half of corneal ulcers, half of corneal foreign bodies, and most all of the keratitis or rust rings. Most of the provisional diagnoses given with the Wood’s lamp examination were different enough from the final diagnoses that the misses were clinically important.
Take a few minutes to re-familiarize yourself with the dials and widgets on your slit lamp – and use it. These data are hardly conclusive the slit lamp is, in fact, a “gold standard”, or that the Wood’s lamp is non-inferior in a general ED setting when used by emergency physicians. However, I’d rather put the onus on the evidence to demonstrate the effectiveness of the less-intensive diagnostic method, rather than base my practice on the assumption.
“Prospective study of the sensitivity of the Wood’s lamp for common eye abnormalities”
https://www.ncbi.nlm.nih.gov/pubmed/30630841
Bonus link: “What Really Glows” with the Wood’s lamp.