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Informative Article | Ophthalmology | India | Volume 12 Issue 3, March 2023
Bilateral Ultraviolet Keratitis following Exposure to Mercury Vapour Lamp and Unshielded Metal Halide Lamp in a Primary School in South Tamilnadu
D Anandhi | Rita Hepsi Rani M
Abstract: Background: We investigated an outbreak of Ultraviolet (UV) Keratitis in attendees at a school event in a rural primary school in Ervadi, Tamilnadu, South India, the first of its kind to be reported in India. Objective: To confirm the diagnosis, describe the cluster by time, place and person and identify reasons for its occurrence Design and setting: A retrospective cohort study of persons presenting with UV Keratitis following exposure to mercury vapor and metal halide lamps at the event. Participants: 154 persons potentially exposed during the event Main outcome measure: UV keratitis of onset within 12 hours of exposure. We defined UV Keratitis as the occurrence of any of the following symptoms in an event attendee since the start of the event: redness, photophobia, tearing, foreign body sensation or swelling of eyelids Results: Out of the 154, we identified 111(72%) persons who met our case definition of UV keratitis. The age specific attack rate was 70% in the below 5 age group, 72% in 5- 13 age and 77.9% in adults. The median incubation period was 6 hours. Of the 154, 134 were seated in the first ten rows at the event. Among persons seated in the high risk area the attack rate was 80 %. Two lamps, one mercury vapor and one unshielded metal halide used 8 Ft above the dais were responsible for the UV Keratitis. Conclusion: The UV Keratitis was caused by exposure to the mercury vapor lamps and the unshielded metal halide lamp. Proximity of the participants to the lamps increased the severity of UV K. Avoiding indoor use of mercury vapor lamps, avoiding use of unshielded metal halide lamps, and enforcement of high fixture of these UV Radiation sources are recommended to prevent further occurrence of similar outbreaks.
Keywords: Ultraviolet Keratitis, Photokeratitis, Mercury vapor lamp, unshielded metal halide lamp exposure
Edition: Volume 12 Issue 3, March 2023,
Pages: 279 - 282