Children with behavioural problems run a risk from laser pointers

Children with behavioural problems may hurt themselves with laser pointers, and eye-care professionals should be alert to the risk, researchers say.

The devices are widely available, and their labels do not adequately convey the danger, according to E. Linton at Bolton Hospitals NHS Foundation Trust, Bolton, UK, and colleagues.

“Regulatory authorities and manufacturers of handheld lasers need to be aware of the risk to children,” they wrote in their article for Eye.

Having encountered both children and adults with ocular injuries from laser pointers, the authors queried the literature and surveyed 990 consultant ophthalmologists in the UK by email to gauge the extent of the problem.

The literature review turned up 84 cases of handheld laser burns in children age 18 years or younger. Among them, the researchers found a child with attention deficit hyperactivity disorder, a child with known learning difficulties, a child undergoing psychological treatment, and a young person referred for psychological treatment following a road accident. The visual acuity, where reported, ranged from 6/18 to 6/60 Snellen in 24% and was worse than 6/60 Snellen in 5%.

The survey had a response rate of 15.5% and identified 159 cases of macular injury. Fifty-four percent of the injuries occurred within the year preceding the survey, 80% of the patients were under 20 years of age and 85% were male.

Thirty-five percent of the injuries were self-inflicted while 36% were caused by someone other than the injured person. But none of the cases were classified as assault. The power of the devices exceeded 50 mW in 33% of cases. The reported visual acuity ranged from 6/18 to 6/60 Snellen in 36% and worse than 6/60 Snellen in 28%.

To illustrate the problem, the researchers described some of the children they treated for self-inflicted retinal damage from laser pointers.
In the first case, an 11-year-old boy presented with a 2-day history of black spot in the central vision of his right eye. His optometrist reported that best-corrected visual acuity (BCVA) in that eye, which had been normal in a prior visit, was now 6/10 Snellen.

The boy’s mother reported purchasing a laser from a well-known online retailer in the UK to give to the boy, who was diagnosed with pathological demand avoidance and migraine. He said he had used in a construction made of plastic building blocks.

In the second case, a 13-year-old boy presented to the Emergency Medicine Department with a BCVA of 6/60 Snellen in the right eye and 6/12 Snellen in the left eye. Spectral domain optical coherence tomography (SD-OCT) images showed full-thickness hyper-reflective damage involving both foveae.

The boy had attention deficit disorder, and reported staring into a friend’s toy laser for a few hours earlier that day.

In the third case, a 15-year old girl presented with visual acuity of 6/7.5 Snellen in both eyes. She had no previous medical or psychological history, and did not experience any symptoms. But she was referred after a routine sight test where new discrete pigmentary changes in the right fovea were observed.

Examination revealed 2 full-thickness centre-involving round scars at the right fovea.  SD-OCT showed defects in the ellipsoid zone in the outer retina in these lesions. She admitted to competing with other children 2 years previously to see who could stand to stare into a green laser beam for the longest time. She recalled shining the laser into her right eye for about 2 10-second bouts.

An analysis of the laser showed that it had a wavelength of 532 nm and an average power of 47 mW. This would make it a Class 3B laser, but it was labelled Class II. Class II lasers have a maximum output of 1mW.

Public Health England in 2014 advised “the sale of laser products to the general public for use as laser pointers should be restrict to Class 1 or 2 devices,” and that toy lasers should be limited to Class 1 or should be of such low output that hey do not need to be classified.