UV lamps used for COVID-19 disinfection can damage eyes

Misuse of the germicidal lamps purchased during the novel coronavirus disease (COVID-19) pandemic may lead to damages in the ocular surface, resembling symptoms of UV-photokeratitis, according to a recent study.

“With increasing consumer sales of these devices, it is important for physicians to be aware of the potential consequences of UV exposure and educate patients,” said the researchers.

Seven patients (mean age, 40 years; 71 percent male) participated in the current case series, presenting with symptoms of ocular surface irritation, such as burning, marked pain, and photophobia. All symptoms developed after exposure to consumer-available germicidal UV lamps. [Ocul Immunol Inflamm 2020;doi:10.1080/09273948.2020.1834587]

The duration of UV exposure ranged from 10 minutes to 4 hours, and all symptoms were bilateral. Severity ranged from sensations of having a foreign body in the eye to severe photosensitivity and blurred vision. Visual acuity was 20/30 or better in all but one of the participants, and intraocular pressure was within normal limits.

None of the patients reported any prior ocular history, though one had undergone LASIK in both eyes; neither were there any reports of using systemic medications with known ocular side effects.

There was also no evidence of ocular inflammation in any of the patients, but anterior segment examinations found varying degrees of conjunctival injection, as well as diffuse punctate epithelial erosions in all participants. All fundus examinations were normal.

“Exam findings and clinical course paralleled classic descriptions of UV-photokeratitis, including evidence of corneal epithelial damage and absence of intraocular inflammation, with resolution within approximately 24–72 hours,” the researchers explained.

In terms of treatment, all patients were recommended to cease exposure to direct UV lights as well as use lubricating eye drops. Other treatments prescribed included topical erythromycin, topical prednisolone acetate, and neomycin-polymyxin-B-dexamethasone eyedrops, among others.

“In order to prevent the spread of [COVID-19], individuals and local businesses are seeking novel sanitation strategies against the virus. One such method of sterilization includes the use of consumer-grade UV lamps,” the researchers said. The present study has highlighted important consequences of this consumer trend.

At particular thresholds, UV light may induce the release of free radicals within the corneal surface, potentially triggering epithelial damage, they explained. Over time, this can lead to corneal oedema and haze. [Photochem Photobiol 2017;93:920-929]

“UV-C is known to be the most cytotoxic along the ultraviolet spectrum to conjunctival and corneal epithelium,” the researchers continued. “When exposed to corneal epithelium in vitro, UV light induces apoptosis through activation of potassium channels.” [Invest Ophthalmol Vis Sci 2003;44:5095-5101]

The authors caution all persons to avoid direct exposure to UV-C germicidal lamps and follow manufacturer recommendations closely.