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Misuse of handheld lasers may result in ‘epidemic of ocular injuries’
Optometrists should consider adding laser damage to differential diagnoses due to the availability and strength of newer devices.
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Laser devices are pervasive in many aspects of society, but recent case reports suggest that more easily available and stronger models should put eye care professionals on alert.
“Laser devices are ubiquitous in modern medicine, industry, military and everyday life,” Alsulaiman and colleagues wrote in a case series published in Ophthalmology. “Lecturers often use handheld laser pointers at conferences. Eye injuries resulting from laser exposure are a concern because optical radiation from 380 nm to 1,400 nm penetrates into various ocular structures.”
In a U.S. Food and Drug Administration consumer health paper on the hazards of laser products, Cmdr. Dan Hewett, of the FDA’s Center for Devices and Radiological Health, discussed the agency’s 5-mW limit and a possible reason as to why laser injuries are moving into the spotlight.
“A 5-mW laser aimed directly into the eye won’t cause damage instantaneously,” he said in the report. “A person’s reflexes to look away, blink or make other involuntary movements are protective. But if you keep your eyes open and stare into a 5-mW beam, it will cause damage. A higher-powered laser gives you less time to look away before injury can occur, and as power increases, eye damage may happen in a microsecond, even when looking at a beam reflection.”
Classifying lasers and mislabeling
According to the FDA, there are several laser hazard classes, ranging from class I, which is considered non-hazardous and includes laser printers and CD players, to class IV, which is considered a skin and eye hazard as well as a possible fire hazard and includes LASIK lasers and industrial lasers.
The FDA regulates all types of lasers and is responsible for both testing and inspecting various products. The agency has the authority to take several actions against manufacturers, such as sending warning letters or implementing an import alert, but noted that when the items are ordered individually, it can be difficult to determine whether the toys meet safety standards and to enforce laws.
Turaka and colleagues noted in International Ophthalmology that most red laser pointers are in class II, which includes bar code scanners, where the “hazard increases when viewed directly for long periods of time.”
Various studies have reported damage from exposure to lasers in various hazard classes, including a class IIIa green laser and class IIIb and IV lasers.
“You can get powerful lasers for virtually nothing,” Jerome Sherman, OD, FAAO, who co-authored a case report published in Retinal Cases & Brief Reports on laser pointer-induced maculopathy, explained in an interview with Primary Care Optometry News. “They’re cheap online and most of them are coming from China or Russia. The output listed on them is apparently often mislabeled. They are much more dangerous than people think they are, especially with children.”
Jerome Sherman
Laser “toys” that are of uncertain safety classification and resemble low-power laser pointers can be purchased online from outside Europe and the U.S., Raoof and colleagues wrote in a study recently published in Eye.
“Such lasers have the potential for retinal damage,” they said. “As laser technology continues to develop, more powerful portable (handheld) lasers are being produced at lower cost.”
How lasers affect the eye
“Lasers can affect the retina through several mechanisms, including photocoagulation, photodisruption or photochemical interaction,” Alsulaiman and colleagues stated. “The wavelength, duration of exposure, spot size, power and location determine the severity of retinal damage. Blue laser light is absorbed readily by foveal xanthophyll pigment. In addition, melanin in the retinal pigment epithelium absorbs greater energy at shorter wavelengths than longer wavelengths. Animal studies have demonstrated photochemical retinal damage caused by blue light. Hence, blue lasers are more likely to cause retinal injury compared to green or red lasers.
“Based on the inspection of the handheld laser devices brought by our patients, the patients’ recognition of the sample of the laser device, or both, the laser devices that caused the injuries in the current case series all had a wavelength in the blue range, at 450 nm,” they continued. “These handheld laser devices are often marketed as toys and currently are easily available to teenagers at a relatively low cost through the Internet.”
Turaka and colleagues described some of the various dangers that lasers can pose to the eye.
“The main laser-related factors to determine the eye injuries were the pulse duration and the energy level of the laser beam which cause thermal, mechanical or photochemical damage,” they wrote. “Also, the retina location which gets exposed to the laser beam is also an important factor in determining the persistence of the functional ocular damage, which means the laser burn near to the fovea caused more functional loss than the parafoveal or peripheral laser burns.
“The morphology of retinal damage from the laser pointers may vary,” Turaka and colleagues continued. “Fundus findings described in the literature include subretinal hemorrhage, retinal edema, scars in the pigment epithelium, foveal granularity, vitreous or chorioretinal hemorrhage, perifoveal drusenoid-like deposits/pigment clumps or ring-shaped hypopigmented cularization.”
How to approach patients
Sherman noted that, in his experience, laser usage is more prevalent in boys than girls. He typically addresses the topic with teenage boys.
“As we talk about eye health and things we should and shouldn’t do, if the youngster is wearing glasses or needs glasses or is playing sports, we discuss protective lenses. This sort of thing goes into that category,” he told PCON.
Sherman said children should know that looking at a laser pointer for 10 to 15 seconds can cause permanent ocular damage.
“It should also be in clinicians’ differential diagnosis,” he continued. “Most ODs don’t even consider it; when they see a young patient with a macular problem they may think of Stargardt’s or something else.”
According to Sherman as well as several studies, there is no established treatment for laser damage.
Raoof and colleagues noted that, in some cases, oral corticosteroids have been administered. Overall, some patients were reported to improve spontaneously, but others required surgery.
Alsulaiman and colleagues reported in their consecutive case series that several patients had a full-thickness macular hole that was treated with a pars plana vitrectomy with internal limiting membrane peeling. Other patients experienced a premacular subhyaloid hemorrhage that was treated with Nd:YAG laser hyaloidotomy.
Many patients experienced permanent ocular damage.
Share the message: Lasers are not toys
“Consumers and parents need to be alerted to the potential danger so-called laser ‘toys’ pose to vision,” Raoof and colleagues stated. “We suggest that children should not be given laser pointers as toys.”
Sherman echoed their sentiments, advocating that the lasers not be treated as safe items for children to play with.
“These are not toys, but they’re treated as a toy, the way they’re advertised online,” he said. “Even if they do have a safety warning online, most youngsters, teenagers or even younger kids don’t really understand that. They think it’s just a game. They play games with them; they shine them at each other.”
“Powerful handheld laser devices represent an extreme hazard to the eyes,” Alsulaiman and colleagues warned. “Most complications largely may be reversible. However, surgical intervention seems necessary in most cases, with incomplete recovery of vision in some.
“The difference between these new high-power laser devices and the low-power pointers cannot be overemphasized,” they continued. “High-power handheld laser devices may lead to an epidemic of ocular injuries that requires attention at different levels. Government action such as banning the importation of these devices, laws for assault or malicious intent, and a general public awareness campaign may be warranted.” – by Chelsea Frajerman