Staring at eclipse may cause solar retinopathy

Sunir Garg

Remember when you were a kid and you used a magnifying glass to concentrate the sun’s energy to burn paper? Solar retinopathy is like that except it is the fovea that is getting burned, according to one expert.

“Solar retinopathy occurs when a person looks at the sun for a prolonged period of time, with the light rays focused on the macula,” Sunir J. Garg, MD, told Healio.com/OSN of the effects of sun gazing. “That causes light-related damage to the photoreceptors and retinal pigment epithelium.”

Most people know not to look directly at the sun, Garg said, “if only because it hurts enough that you stop doing it.” However, there is a common-sense element to sun gazing that is often abandoned during an eclipse, and on Aug. 21, there will be a total eclipse of the sun that passes from west to east, traversing the U.S. from coast to coast.

“During an eclipse, because the sun is partially occluded, viewing it doesn’t hurt as much. That can lead to significant time exposure, which can then cause damage. Also, because of the rarity of eclipse events, people are motivated to go outside and look up for extended periods of time,” said Garg, who is professor of ophthalmology on the Retina Service at Wills Eye Hospital in Philadelphia and a partner with Mid Atlantic Retina.

Solar retinopathy — which may also be called photic retinopathy, foveomacular retinitis, solar retinitis or eclipse retinopathy — is defined as a photochemical toxicity that causes injury to tissue in the retina and may be accompanied by central or paracentral scotoma. This condition frequently occurs in the fovea.

The condition has been reported in certain groups of individuals, from people who believe they could draw power from the sun to military personnel charged with scanning the sky for enemy aircraft, but the condition may not be symptomatic immediately, according to Garg.

“Later in the evening or the following day, patients will complain of focal loss, discoloration of vision or a fuzzy spot,” he said. “As time wears on, the spot becomes grayer, and usually there is a characteristic appearance on OCT. Hypolucency at the level of the ellipsoid zone and retinal pigment epithelium also occurs.”

Few fundus abnormalities may be observed in mild cases, while more severe cases can involve significant fundus changes, according to the American Academy of Ophthalmology, which has issued a release on how to safely view a solar eclipse.

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Regarding the event later this month, the AAO said that there will be a path of totality roughly 70 miles wide that will pass from Oregon to South Carolina. People in Idaho, Wyoming, Nebraska, Kansas, Missouri, Illinois, Kentucky, Tennessee, Georgia, North Carolina and South Carolina will be able to view the full eclipse, while those outside of that swath will see a partial eclipse.

In terms of treatment, Garg stressed protection. “There is no treatment for solar retinopathy,” he said. “Prevention really is the key.”

While do-it-yourself indirect viewing devices such as pinhole projectors and solar cones are safe, for direct viewing the AAO and American Astronomical Society suggest a number of products, mainly glasses from companies such as Rainbow Symphony and American Paper Optics.

“These products that are listed on the websites of the American Academy of Ophthalmology and other such professional societies are reputable and high quality and meet the international ISO 12312-2 safety standard,” Garg said. “When you are buying an item like this you have to be careful because some sites are selling nothing more than glorified sunglasses.”

Garg also recommended viewing the event at a local science center or observatory. – by Rob Volansky

Reference:

How to experience the great American solar eclipse without damaging your vision. https://www.aao.org/newsroom/news-releases/detail/how-to-view-great-american-solar-eclipse-safely. Published July 12, 2017.

Disclosure: Garg reports no relevant financial disclosures.