Healthoughts

Healthoughts compiled by Jon Nalick and Kathleen O’neil
Illustrations by Diane Bigda

on the blink

A visually demanding video game can end in disaster in, literally, the blink of an eye, so many players adopt a simple unconscious strategy to ensure they are not taken by surprise: They do not blink.

Alfredo Sadun, M.D., Ph.D., the Flora L. Thornton Chair in Vision Research and professor of ophthalmology and neurosurgery at the Keck School of Medicine of USC, says that as a result, players—most commonly young adults and children—risk dry and irritated corneas. In rare, extreme cases, prolonged dryness can result in scarring that can only be treated with a corneal transplant.

“Nature has evolved a system of regular blinking to keep the eye moist and healthy,” he says. “But at the same time, it’s no good to have your eyes closed when you have a saber-tooth tiger jumping out at you, so nature ensures that when you are strongly focused on something visual, it relaxes the need to blink.”

The problem is that “in video games, something is always jumping out at you. And when kids play for hours on end, the cornea gets dry enough to irritate the eye,” Sadun says.

Interestingly, the problem is not limited to video games. Anything that engrosses visual attention such as a compelling novel or computer work can have the same effect on readers of any age, he adds.

Sadun notes that preventing dryness can be as simple as taking regular breaks to blink or applying eye drops to keep the cornea moist.

 

nail down infections

California lawmakers are worried that nail salon patrons may get more than just lustrous nails—many patrons are leaving with acute nail infections.

In September 2005, the State legislature approved a bill to hold nail salons to stricter sanitary standards after a spate of infections at manicure and pedicure salons.

But USC dermatologist Han Lee, M.D., assistant professor of dermatology at the Keck School of Medicine of USC, says that even under the best conditions, the manicure process itself is partially to blame for infection risk.

“Most manicure salons push back the cuticle and sometimes cut the cuticle as a matter of course, but the cuticle is a natural protection for the nails. They do it for aesthetic reasons even though it breaks the barrier and opens a portal for infections,” she says.

Lee says that staph and strep bacteria are the chief culprits in painful nail infections acquired at salons and may require antibiotics to treat.

To avoid infection, she recommends that manicure and pedicure aficionados patronize certified businesses and either bring their own instruments to the salon or ensure that the salon’s instruments are sterilized before each use.

Lee urges people with nail infections to postpone trips to the nail salon until they are cured, noting that “people worry about getting an infection, but they can pass along something too.”

 

all in vein

People heading for the skies on transcontinental or international flights have plenty of precautions to remember, from carrying prescription medications in hand luggage to drinking water to avoid dehydration. For some people, extra care also should be taken to keep blood circulating in the legs to avoid a condition known as deep vein thrombosis (DVT).

Vascular surgeon Vincent L. Rowe, M.D., assistant professor of surgery at the Keck School of Medicine of USC, says DVT occurs when a vein located deep within the leg experiences a cessation of blood flow and a clot develops. When the clot blocks the blood flow, pressure develops and causes leg pain and swelling. In some cases, the clot can break loose. If this happens, the clot can travel to the lungs and create a pulmonary embolism, or cause sudden blockage in a lung artery, which can lead to difficulty breathing or even death.

“Veins that are closer to the skin surface are smaller, while the veins deeper in the leg and closer to the bone are larger,” Rowe explains, “so there is more concern with blockages in the deeper, larger veins.”

He says that people with cancer or a traumatic injury, or those who are dehydrated run a higher risk for forming blood clots, as do people with an injury of the vein or severe varicose veins. Prior blood clots or incidence of DVT also put people at risk. Women taking birth control pills or who are pregnant and people who are obese or elderly also are more prone to DVT.

The airplane environment—where people are cramped and immobile for long periods of time and are not using their muscles to help stimulate blood flow—is a prime setting for developing DVT. To prevent the formation of blood clots and to keep blood circulating in the legs, Rowe advises performing leg exercises while seated and drinking plenty of fluids, but not the alcoholic version.

“Unfortunately, there is not much that can be done on the plane if the leg becomes swollen and painful with deep vein thrombosis,” Rowe says. “If this happens, medical attention should be sought as soon as the plane lands. The treatment of DVT usually involves taking blood thinners for about three to six months to diminish the risk of additional clots and lessen the chance of a piece of the clot traveling to the lungs.”

 

take me out of the ballgame

Many children who play organized sports after school are at an increased risk of over-use injuries.

“Children are more prone to repetitive stress injuries than adults,” says George F. Hatch III, M.D., assistant professor of orthopaedics at the Keck School of Medicine of USC, who also treats USC athletic teams.

Children are being encouraged to compete at younger ages, he says. Also, many children, especially in Southern California and other places with mild winter weather, compete year-round in sports, which often leads to an increase in sports injuries.

Because their bones are still growing, stress that would cause minimal injury in an adult can fracture the weaker growth plates at the ends of childrens’ and adolescents’ bones, he says.

“We’re seeing a lot more 8-, 9- and 10-year-olds with ‘Little League Shoulder,’ an overuse injury in pitchers,” Hatch says. “They shouldn’t be throwing that much while they are young.”