One-Year Ocular Safety Observation of Workers and Estimations of Microorganism Inactivation Efficacy in the Room Irradiated with 222-Nm far Ultraviolet-C Lamps

Two krypton-chloride germicidal excimer lamp units (Care222 TRT-104C11-UI-U3, USHIO Inc.) were installed in the examination room of an ophthalmology department. The irradiation dose was set not to exceed the former (i.e., before 2022) threshold limit value (TLV) (22 mJ/cm² /8 hours) recommended by the ACGIH. Section 1: The eyes and lids of the 6 ophthalmologists (5 wore glasses for myopic correction) who worked in the room for a mean stay of 6.7 hours/week were prospectively observed for 12 months. Slitlamp examinations revealed neither acute adverse events such as corneal erosion, conjunctival hyperemia, lid skin erythema nor chronic adverse events such as pterygium, cataract, or lid tumor. The visual acuity, refractive error, corneal endothelial cell density remained unchanged during the study. Section 2: The irradiation of samples placed on the table or floor using the same fixtures in the room (5-7.5 mJ/cm² ) was associated with >99% inhibition of φX174 phage and >90% inhibition of S. aureus. In conclusion, no acute or chronic health effects in human participants was observed in a clinical setting of full-room ultraviolet germicidal irradiation by 222-nm lamp units and high efficacy in deactivation of microorganisms was determined in the same setting.

UV-Photokeratitis Associated with Germicidal Lamps Purchased during the COVID-19 Pandemic

PURPOSE

To report photokeratitis caused by the improper use of germicidal lamps purchased during the COVID-19 pandemic.

METHODS

Case series.

RESULTS

Seven patients presented with acute ocular surface pain after exposure to UV-emitting germicidal lamps. Visual acuity was 20/30 or better in 13 of 14 eyes (93%). Anterior segment examination revealed varying degrees of conjunctival injection and diffusely distributed punctate epithelial erosions (PEEs) in every patient. No intraocular inflammation was identified across the cohort and all fundus examinations were normal. Treatment varied by provider and included artificial tears alone or in combination with antibiotic ointments and/or topical steroids. Five patients were followed via telehealth, one patient returned for an in-office visit, and one patient was lost to follow-up. Five of six patients endorsed complete resolution of symptoms within 2-3 days.

CONCLUSIONS

Patients should follow manufacturer recommendations when using UV-emitting germicidal lamps and avoid direct exposure to the ocular surface.

[Keratoconjunctivitis photoelectrica (arc eye)]

Photokeratitis is a painful keratitis caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays. We talk about "arc eye" when photokeratitis is caused by UV rays emitted by electric arc during electric arc welding process. We here report the case of a 35-year old rider, with no previous medical-surgical history, who had looked at an electric arc for a few minutes while the doors of his building were welded. He had bilateral burning in his eyes associated with lacrimation, photophobia and blepharospasm. Clinical examination showed corrected visual acuity of 8/10 and 9/10, conjunctival hyperemia with punctate erosive keratitis limited to palpebral fissure after the use of fluorescein. Given patient's clinical picture, keratoconjunctivitis photoelectrica (arc eye) was diagnosed. Treatment was based on topical antibiotics, wetting agents as well as agents with healing properties. Outcome was marked by total disappearance of the signs with restoration of bilateral visual acuity (10/10). This study highlights the role of prevention using appropriate protection equipment.

Photokeratitis among restaurant workers: A case series

This case report highlights the challenges associated with the diagnosis and workplace evaluation of occupationally acquired ultraviolet (UV) radiation-induced photokeratitis and associated skin burns in a group of restaurant workers. UV-C spectrum bulbs were inadvertently shipped and installed in insect light traps. Ocular and dermal symptoms were reported in 18 of 85 restaurant employees to varying degrees of severity over a 2-day period. One patient was formally diagnosed with a chemical burn/irritation of the cornea. More severe symptoms were reported by individuals working in close proximity to the lights. This clinical picture can resemble mass chemical or irritant exposure when multiple individuals are affected, and a multidisciplinary approach was required for rapid identification of the source to limit morbidity. Prevention strategies for similar events should be considered which can include limiting hardware compatibility and improving warning labels.