Prospective study of the sensitivity of the Wood's lamp for common eye abnormalities

The Wood's lamp, a handheld instrument that uses long-wave ultraviolet (UV) light with magnification of 2-3 times, is commonly used by non-ophthalmologists for examining patients with eye complaints. The goal of current research was to determine the sensitivity and specificity of the Wood's lamp for common eye abnormalities.

We examined a convenience sample of patients, 18 years of age and older, who presented for eye complaints to an urgent clinic of a large ophthalmology practice. This prospective observational trial was performed from December 2016 until July 2017. An ophthalmologist examined the patient's eyes with a Wood's lamp, followed by examination of the eyes using a slit lamp. The Wood's lamp was compared with the slit lamp, which served as the gold standard.

There were 73 patients recruited. The mean age of study subjects (29 female and 44 male) was 49 years. The overall sensitivity of the Wood's lamp was 52% (38/73; 95% CI 40% to 64%). Based on the principal final diagnosis made with the slit lamp, the Wood's lamp only detected 9 of 16 corneal abrasions, 5 of 10 corneal ulcers, 5 of 9 corneal foreign bodies, 0 of 4 cases of non-herpetic keratitis, 1 of 2 cases of herpes keratitis, 1 of 5 rust rings and 18 of 28 other diagnoses.

Examination using the Wood's lamp fails to detect many common eye abnormalities. Our findings support the need for a slit lamp examination of patients with eye complaints whenever possible.