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

OBJECTIVE: 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.

STUDY DESIGN: 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.

RESULTS: 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.

CONCLUSIONS AND RELEVANCE: 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.