COMANAGEMENT Q&A

Laser-Pointer Retinopathy on the Upswing

Edited by Paul C. Ajamian, O.D.

Question: What injuries can result from the misuse of laser pointers?

Answer:  Thanks to the increased popularity of laser pointers, you might see more laser-induced retinal burns that occur when someone stares into the beam. Even though there have been few reported instances of these injuries and they pose little threat to permanent vision, there have been cases of children deliberately staring into them.

Laser retinopathy occurs when the retina is damaged following prolonged exposure to the beam, generally defined as 10 seconds or longer. Children are at greater risk because of their more effective light transmission through the cornea and lens, explains Martin Mainster, M.D., Ph.D., retinal specialist at the University of Kansas Medical Center and an expert on laser-related injuries.

On occasion, clinicians have received serious injury when they were accidentally exposed to high-energy class IV lasers without ocular protection, such as the Nd:YAG laser. However, injuries caused by the commercially marketed laser pointers, which the FDA ranks as class IIIa, are generally less serious. In fact, Dr. Mainster points out that most unintentional injury will be prevented by the eye's blink reflex.

Momentary exposure to a class IIIa laser beam can cause temporary discomfort and impairment, such as glare, flashblindness and afterimages, according to an AOA advisory issued last December. The severity of these effects de-pends on the power of the beam, the wavelength of light and the length of exposure.

The FDA requires all lasers designated as a class IIIa or higher to carry "danger" label warnings. Class II pointers, carrying a "caution" as opposed to a "danger" label, are preferable for the general public, the AOA advises.

Dr. Mainster cautions that some laser pointers manufactured overseas and available over the Inter-net can project beams brighter than class IIIa lasers and can cause more intense damage.

Question: What are the symptoms of a laser injury, and how do you treat them?

Answer: Scotoma, photophobia, metamorphopsia, chromatopsia or decreased visual acuity can occur several hours after exposure.

It's always best to conduct a complete ocular exam, including a funduscopy of both eyes and an anterior segment exam to make sure there has been no corneal trauma. Ask to see the laser pointer so that you can check its FDA classification, and attempt to determine the length of exposure.

The retina will look similar to one damaged by solar retinopathy: a small yellow lesion with gray outline in the foveal or parafoveal area. In mild cases, a lesion might not be visible. Fluo-roscein angiography might reveal transmission defects due to retinal pigment epithelial irregularities.

There is no specific therapy for a retinal laser injury; the lesions generally heal on their own. Cor-ticosteroids have occasionally been used, but there is little conclusive evidence to indicate they hasten recovery.

In the weeks following the injury, the yellow lesion will be replaced by a permanent focal depression with epithelial molting or a lamellar hole. Vision usually improves to normal within six months, although the scotoma might persist.

In one recent case, an 11-year old girl experienced decreased visual acuity after staring into a laser pointer for a prolonged period.

Her acuity gradually improved over the following months, and her retinal lesion faded away, without medical intervention, Dr. Mainster says. He adds, however: "The verdict is still out on whe-ther the injury will put her at greater risk for age-related macular disease than she would otherwise be."

Have a question you'd like Dr. Ajamian to answer in a future column? Please e-mail it to reviewofoptometry@jobson.com.