Month: January 2023

Turns out that when your mother told you to stop sitting near the TV or you might need glasses, she was onto something.

Myopia, or nearsightedness, is a growing problem worldwide. While a nearsighted child can see close objects clearly, more distant objects look blurry. Part of this growing problem, according to experts, is that children are spending too much time indoors looking at things close to them rather than going outside and looking at things that are far away.

What is nearsightedness?

Nearsightedness is very common, affecting about 5% of preschoolers, 9% of school-age children, and 30% of teens. But what worries experts is that over the last few decades its global prevalence has doubled — and during the pandemic, eye doctors have noticed an increase in myopia.

Nearsightedness happens when the eyeball is too large from front to back. Genes play a big role, but growing research shows that there are developmental factors. The stereotype of the nerd wearing glasses actually bears out; research shows that the more years one spends in school, the higher the risk of myopia. Studies also show, even more reliably, that spending time outdoors can decrease a child’s risk of developing myopia.

Why would outdoor time make a difference in nearsightedness?

While surprising, this actually makes some sense. As children grow and change, their lifestyles affect their bodies. A child who is undernourished, for example, may not grow as tall as they might have if they had better nourishment. A child who develops obesity during childhood is far more likely to have lifelong obesity. And the eyes of a child who is always looking at things close to him or her might adjust to this — and lose some ability to see far away.

Nearsightedness has real consequences. Not only can it cause problems with everyday tasks that require you to see more than a few feet away, such as school or driving, but people with myopia are at higher risk of blindness and retinal detachment. The problems can’t always be fixed with a pair of glasses.

What can parents do?

• Make sure your child spends time outdoors regularly — every day, if possible. That’s the best way to be sure that they look at things far away. It’s also a great way to get them to be more active, get enough Vitamin D, and learn some important life skills.
• Try to limit the amount of time your child spends close to a screen. These days, a lot of schoolwork is on screens, but children are also spending far too much of their playtime on devices rather than playing with toys, drawing, or other activities. Have some ground rules. The American Academy of Pediatrics recommends no more than two hours of entertainment media a day, and has a great Family Media Plan to help families make this happen.
• Have your child’s vision checked regularly. Most pediatricians do regular vision screening, but it is important to remember that basic screening can miss vision problems. It’s a good idea for your child to have a full vision examination from an ophthalmologist or an optometrist by kindergarten.
• Call your pediatrician or child’s eye doctor if you notice signs of a possible vision problem, such as
  • sitting close to the television or holding devices close to the face
  • squinting or complaining of any difficulty seeing
  • not being able to identify objects far away (when you go for walks, play I Spy and point to some far-away things!)
  • avoiding or disliking activities that involve looking close, like doing puzzles or looking at books, which can be a sign of hyperopia (farsightedness)
  • tilting their head to look at things
  • covering or rubbing an eye
  • one eye that turns inward or outward.

If you have any questions or concerns about your child’s vision, talk to your pediatrician.

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About the Author

Claire McCarthy, MD, Senior Faculty Editor, Harvard Health Publishing

Claire McCarthy, MD, is a primary care pediatrician at Boston Children’s Hospital, and an assistant professor of pediatrics at Harvard Medical School. In addition to being a senior faculty editor for Harvard Health Publishing, Dr. McCarthy … See Full Bio View all posts by Claire McCarthy, MD

Screening tests, such as Pap smears or blood pressure checks, could save your life. They can detect a disease you have no reason to suspect is there. Early detection may allow treatment while a health condition is curable and before irreversible complications arise.

Some screening tests help prevent the disease they are designed to detect. For example, colonoscopies and Pap smears can identify precancerous abnormalities that can be addressed so they cannot continue to grow and become cancerous. And missed screening tests contribute to thousands of avoidable deaths each year in the US. Yet there’s a point of diminishing returns, as a new study on Pap smears illustrates. And many of us could benefit from a better understanding of the limits of screening, and how experts decide when people should stop routine screening tests.

Know the limits of screening tests

Even the best screening test has limitations. It can miss the disease it’s intended to detect (false-negative results). Or it can return abnormal results when no disease is present (false-positive results).

Equally important, as people grow older life expectancy declines and screening benefits tend to wane. Many conditions detected by routine screenings, such as prostate cancer or cervical cancer, typically take a while to cause trouble. A person in their 80s is more likely to die from another fatal condition before cervical cancer or prostate cancer would affect their health. Additionally, certain diseases, such as cervical cancer, become less common with advancing age.

As a result, many screening tests are not recommended forever: at some point in your life, your doctor may tell you that you no longer need to repeat a screening test, even one you finally got used to having.

Know when screening tests usually end

Expert guidelines for many common screening tests include an “end age” when people can reasonably stop having the test. For example:

• Pap smear: age 65
• mammogram: age 75
• colonoscopy: age 75
• chest CT scan (recommended for people with a significant smoking history): age 80.

There are exceptions, of course. For example, if a colonoscopy found abnormalities in an otherwise healthy 72-year-old, repeat testing after age 75 may be recommended.

Many women have Pap smears after guidelines suggest stopping

Pap smears screen for cervical cancer. In 1996, new guidelines recommended that women who received Pap smears at appropriate intervals before age 65 could safely stop.

Yet many women continue to have this screening after turning 65, according to a recent study published in JAMA Internal Medicine that looked at data from 15 to 16 million women per year between 1999 and 2019. Their average age was 76, most (82%) were white, and all were enrolled in Medicare.

The study found:

• In 1999, nearly three million women over age 65 (almost 19% of the study population) had Pap smears. By 2019, the number had fallen to 1.3 million (8.5%), a reduction of more than half.
• Among women older than age 80, about 3% had Pap smears.
• In 2019, the estimated cost related to Pap smears in these older women was $83.5 million.

Possibly, some women in this study had good reasons to continue having Pap smears. Perhaps they weren’t adequately screened when they were younger. Perhaps they had previous Pap smear abnormalities. Maybe their doctors recommended they continue having Pap smears despite their advanced age. We don’t know, because this study didn’t collect that information. Still, it’s quite likely that many (or even most) of these Pap smears represent overscreening: routine testing with little chance of benefit.

Why does overscreening matter?

Overscreening may cause

• discomfort that may be tolerable when there’s an expectation of benefit, but less acceptable when the test is unnecessary
• anxiety while awaiting the results of the test
• false-positive results that lead to additional testing and unnecessary treatment
• complications of testing, such as infection or bleeding after a Pap smear, or perforation or bleeding after a colonoscopy. (Fortunately, complications are rare.)
• unnecessary costs, including medical appointments and lab fees, time wasted, and taking health providers away from more valuable care.

The bottom line

Screening tests are typically performed for people without symptoms, signs, or a high suspicion of disease. In many cases, they’re looking for a condition that is probably not there. For most screening tests, we have guidelines developed by experts and backed by data suggesting when to start — and when to stop — screening.

But guidelines are only general recommendations, and individual preferences matter. If foregoing a screening test will cause you excessive anxiety, or if having a test will provide significant peace of mind, it may be reasonable to have a test even after the recommended end age. Be sure you understand potential downsides, such as additional tests and complications.

So, never hesitate to ask your doctor when your next screening tests are due — but don’t forget to also ask if they are no longer worth having.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD