Incidence of photokeratitis after a salon visit: A retrospective observational study

Abstract

PURPOSE:

The purpose of this study was to report the incidence of bilateral photokeratitis in patrons of hair-cutting salons following inadvertent exposure to ultraviolet (UV) rays from germicidal sterilizing cabinets.

MATERIALS AND METHODS:

It is a retrospective observational study of 30 patients who were diagnosed with UV-associated photokeratitis after a visit to a salon.

RESULTS:

Thirty patients presented between January 2019 and November 2023, with bilateral conjunctival congestion with superficial punctate epithelial erosions typical of photokeratitis. All of them were males, aged between 27 and 64 years (mean = 35 years; median = 33 years). All of them gave a history of a visit to a salon within 24 h before the onset of symptoms. The typical onset of symptoms was seen after a few hours of exposure, ranging from 4 to 12 (mean = 7.4; median = 6.5 h). They were treated with topical lubricants and antibiotics. Six of them were reviewed after 24 h when five were asymptomatic and one patient developed a corneal epithelial defect.

CONCLUSION:

Germicidal UV lamps are used ubiquitously for disinfection in barbershops. This report highlights the risk of accidental exposure to such lamps and the need to increase awareness among the general public to prevent such accidents.

Introduction

Photokeratitis is a common ophthalmic emergency caused by exposure to ultraviolet radiation (UV-R). It is usually seen in welders or mountaineers not using proper protective eyewear.[1] Many artificial sources of UV-R are used for industrial, medical, and domestic purposes, including welding arcs, mercury-vapor lamps, and disinfection systems such as sterilization lamps and cabinets.[2,3] During the global pandemic caused by COVID-19, there was a spurt in the popularity of consumer-grade ultraviolet (UV) lamps, which prevented the transmission of the virus at individual and business levels. However, improper use of these lamps can lead to complications. There are reports in the literature about patients who presented with features of UV-associated photokeratitis following inadvertent exposure to these lamps.[3,4] We noticed a significant number of patients in our clinic presenting with typical features of photokeratitis without any apparent history of exposure to UV-R. The only common finding in all these patients was a history of visit to a barbershop or salon within the past 24 h. On further investigation, we found that UV light sterilizing machines are kept in these salons for cleaning the tools. Based on the characteristic features of UV-R-induced photokeratitis, the history of haircuts, and the presence of UV-R-emitting lamps in the salons, we generated the hypothesis that some of the patrons of the barbershops unwittingly developed photokeratitis after getting exposed to the UV light from these machines. They failed to make the connection as the symptoms start quite a few hours after the exposure. To the best of our knowledge, this novel entity has not been reported in the medical literature to date.

Materials and Methods

It is a noncomparative, retrospective, observational study approved by the Regional Research Ethics Committee and adhered to the tenets of the Declaration of Helsinki. Electronic medical records were retrospectively reviewed for all patients who were evaluated at our department of ophthalmology between January 2019 and November 2023 and diagnosed with UV-associated photokeratitis after a visit to a hair-cutting salon. Slit-lamp photographs were reviewed when available. The data collected included sex, age, nationality, time gap between exposure to symptom development, clinical features, and course following exposure to UV-R.

Inclusion criteria

Any patient presenting with signs and symptoms of photokeratitis (pain, lacrimation, photophobia, and corneal superficial punctate epithelial erosions [PEEs]) within 24–72 h of visiting a barbershop was included in the study.

Exclusion criteria

Any patients presenting with photokeratitis without a history of visit to any barbershop in the past 24 h or definite history of exposure to UV-R (welders) without adequate protective eyewear were excluded from the study.

All patients underwent a comprehensive ophthalmological examination with special emphasis on slit-lamp examination of the cornea with fluorescein staining. A diagnosis was made according to each patient’s history, including a visit to a salon within 24 h before onset; symptoms that included eye pain, photophobia, watering, conjunctival hyperemia, and corneal PEEs seen on examination with a slit lamp; and positive fluorescent staining. The diagnosis of photokeratitis was made based on the patient’s characteristic clinical picture. On showing the photograph of a sterilization cabinet, these patients recalled the presence of the same in the salons while getting their hair cut [Figure 1].

Figure 1.

The sterilization cabinet with blue light kept inside a barbershop

To promote corneal epithelial healing and prevent infection, patients were treated with lubricants and antibiotics and advised to follow up after 24 h.

Results

We saw a total of 30 patients during the period from January 2019 to November 2023. All of them presented to our outpatient department with complaints of varying degrees of ocular pain, foreign-body sensation, photophobia, watering, and blurred vision. On examination, all of them had bilateral conjunctival congestion with superficial PEEs with positive fluorescein staining [Figure 2a and b]. All of them were males, aged between 27 and 64 years, with a mean of 35 years and a median of 33 years. None of them gave any history of exposure to welder’s arc or UV lamps. However, on further questioning, all of them gave a history of a salon visit for a haircut the previous day. The typical onset of symptoms was seen after a few hours of exposure, ranging from 4 to 12 h. The mean was 7.4, and the median was 6.5 h. Majority of these patients were from India(18); four were from Pakistan and two from Bangladesh. One patient each was from Nepal, Philippines, Algeria, Palestine, Egypt, and Sri Lanka.

Figure 2.

The right (a) and left (b) eyes of a patient with punctate epithelial erosions stained with fluorescein. (c and d) Healed corneal epithelium with the clear cornea after 24 h of the same patient

None of the patients had any preexisting ocular conditions. The vision was unreliable in many because of pain, photophobia, and watering. Noncontact intraocular pressure was within normal limits. Fundus examination by indirect ophthalmoscopy was deferred because of the associated photophobia. We treated all of them with the frequent installation of lubricating eye drops with a course of topical antibiotics. Two patients complaining of severe pain were also advised oral analgesics (acetaminophen). All the patients were advised to review the next day.

However, only six of them returned to the clinic. One patient developed an epithelial defect and was closely monitored for 4 days, during which he showed clinical improvement. After 4 days, he was also lost to follow-up [Figure 3]. The rest of the patients (n = 5) were completely healed and were asymptomatic after 24 h [Figure 2c and d].

Figure 3.

Corneal epithelial desquamation leading to a large epithelial defect

Discussion

Ultraviolet rays (UV-R) can be divided into three bands: UV-A at 320 to 400nm, UV-B at 290 to 320 nm, and UV-C at 200 to 290 nm.[5] Ozone in the atmosphere effectively filters most of the harmful UV radiation of wavelengths shorter than 290 nm, which is serendipitous, as shorter UV-R wavelengths have more energy and a greater potential for ocular damage. The cornea absorbs 10%–20% of UV-A and close to 100% of UV-C.[6] Inadvertent exposure to UV-C rays, which are produced artificially, can lead to damage to the corneal epithelium. Photokeratitis is the most common consequence of acute UV-induced damage due to the susceptibility of surface epithelial cells of the cornea.[7] Many artificial sources of UV-R are used for industrial, medical, and domestic purposes, including welding arcs, mercury-vapor lamps, and disinfection systems such as sterilization lamps and cabinets. For disinfection, most ultraviolet lamps on the market produce UV-C.

UV-R sterilization cabinets are commonly used in hair-cutting salons in this country. These cabinets are used for disinfecting and sterilizing hairbrushes and other salon tools after every use, as they are extremely effective in inhibiting the growth of viruses and bacteria in both vegetative and spore forms. They are also inexpensive, quick, and reliable.[8] However, the very aspect (phototoxicity) that makes short-wavelength UV-R an effective germicidal agent is also responsible for the photokeratitis we noticed in the patrons of these salons.[9] These cabinets are placed at the eye level in front of the customers when they are undergoing the services provided at the salon.

Other associated risk factors for corneal epithelial damage are prolonged duration of exposure and proximity to the light source.[5]

Most welding workers are aware of UV-R dangers, and exposure in this population is mainly due to a lack of caution or inadequate protection, and the exposure duration is short. However, people in other circumstances are not aware of UV-R damage, and they may remain in a UV-R environment for a long time. A cluster of 284 people, attendees as well as performers, developed photokeratitis during a musical function after being exposed to broken metal-halide lamps.[10] Ting et al. reported a mass casualty of 22 young people following UV-B light exposure in a nightclub.[11] Stripp et al. reported photokeratitis in 18 restaurant employees following exposure to UV-C spectrum bulbs in insect light traps.[12] Leung and Ko reported a family of three adults with photokeratitis following exposure to UV-C germicidal lamps for domestic use during the COVID-19 pandemic in Hong Kong.[13] Similarly, Sengillo et al. reported a case series of seven patients of photokeratitis following exposure to UV-C-emitting germicidal lamps at work or home.[14] Das et al. reported 12 patients who developed photokeratitis after exposure to consumer-grade germicidal UV lamp at their places of work.[15] Typically, the clinical syndrome is characterized by a lag time between exposure and the beginning of clinical symptoms, which further prevents people from leaving the UV-R environment. The latency period is inversely proportional to the degree of radiation exposure.[9] As a haircut takes about 30 min, the patrons were exposed to the UV-R environment for a long time. All our patients typically gave a history of onset of bilateral redness, followed by pain and watering 4 to 12 h after the salon visit (median = 6.5 h).

The clinical manifestation of photokeratitis ranges from mild superficial PEEs to severe cases with total epithelial loss. Individuals with preexisting ocular conditions, such as dry eye syndrome, keratoconus, or postoperative refractive surgery, may be prone to develop severe forms of UV keratitis. None of the patients in our series had any of these conditions. While mild forms may only present with a red eye and increased foreign-body sensation, severe cases usually have significant ocular pain, lacrimation, congestion, chemosis, blepharospasm, and decreased visual acuity. Pain experienced by patients is due to the sloughing of epithelial cells and exposure of the subepithelial nerve plexus.[16] The absence of ocular pain for about 6–12 h is characteristic of UV photokeratitis. This phenomenon has been attributed to the loss and return of corneal sensitivity in an experimental study.[17] Fortunately, damaged superficial cells are normally sloughed off and reepithelialized within 24–72 h, leading to rapid resolution of the clinical symptoms.

Permanent damage is extremely rare. In the present study, all patients experienced symptoms hours after exposure to UV light from the sterilization cabinets. The symptoms ranged from mild foreign-body sensation to severe pain and photophobia at presentation. Examination findings and clinical course paralleled classic descriptions of UV-photokeratitis, including evidence of corneal epithelial damage and absence of intraocular inflammation. We presume that most of the patients did not return for review as their symptoms resolved within the next 24–72 h. An additional hospital visit would have resulted in the loss of yet another workday, a cost that our predominantly expatriate clientele can hardly afford. There is currently no consensus among ophthalmologists regarding best practices for the treatment of photokeratitis. Treatments are usually supportive. The frequent use of topical lubrication is recommended. The treatment strategies vary due to differing practice patterns among treatment providers and the patients’ insurance coverage. Topical anesthetics should not be used as they delay and prevent corneal reepithelialization.[18] A bandage contact lens may be used for comfort and relief of pain. In addition, a topical antibiotic should be used in moderate and severe cases to prevent infection. In severe cases, additional nonsteroidal anti-inflammatory eye drops and oral acetaminophen can be prescribed to alleviate the patients’ discomfort. The usage of cycloplegics/mydriatics is not effective in corneal abrasions and is generally not recommended.[19] Moreover, the resultant mydriasis may add to the patient’s misery, blurring near vision and increasing glare. Patching the eye, though still a popular intervention with many a clinician, has not been shown to be effective in the treatment of corneal abrasions, and can delay corneal healing, and is thus not recommended.[20]

Some limitations of our study should be noted. This was a retrospective study with a small sample size restricted to our clinic. A large sample over multiple centers in the country is needed to verify the hypothesis of our study. Some objective clinical information, such as visual acuity and retinal examination, could not be performed in many of the patients. The corneal fluorescein staining scores were not evaluated. The exact duration of exposure or the time lag between the exposure and the onset of symptoms is lacking. Most of the patients did not review with us for follow-up; hence, the outcome could not be documented. Most importantly, we hypothesize that the cause of photokeratitis was the exposure to UV sterilization cabinets present in the hair-cutting salons they visited previously. This is more of a deductive hypothesis, and we have no actual proof to authenticate this claim. The sterilizer is commonly kept on the table facing the customers. Sometimes, the door of the cabinet remains inadvertently open after the barber takes the tools out from it. The patrons who were directly exposed to the UV-R from an open cabinet are getting affected and not all of them. We are also at a loss to explain why all our patients are men. We also can only presume that even if UV sterilization cabinets are present in the salons frequented by women, none of them contracted photokeratitis as these salons are usually spacious, and the cabinets are not placed at eye level in these parlors.

Despite the shortcomings of the study, we believe that creating awareness of this entity among fellow clinicians is important for prompt recognition, diagnosis, and treatment of this condition.

Conclusion

This case series serves to emphasize the potential consequences of phototoxicity from the improper use of UV germicidal lamps for disinfection in public places. Photokeratitis is a preventable condition. Dissemination of information and public knowledge increased awareness among the general public about the ocular hazards of UV-R lamps is extremely important to achieve this.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.