Lazy eye common in poor, obese teens

A new study linked amblyopia – otherwise called lazy eye – to poverty, below-average cognitive scores, and yes, obesity, in teenagers.

This suggests the need for more visual screening in this population, said study author Dr Hagai Levine, an epidemiologist at the Braun School of Public Health and Community Medicine of the Hebrew University of Jerusalem in Jerusalem, Israel. “A dedicated prevention and screening programme for lower socioeconomic groups is quite urgent at this time.”

Amblyopia, if not diagnosed early, leads to irreversible visual impairment, with considerable social and financial consequences.

In the study, teenagers in the lowest socioeconomic group were more likely to have amblyopia compared with those in the highest socioeconomic group (odds ratio [OR], 1.64; 95 percent confidence interval [CI], 1.45–1.87; p< 0.001 for males, and OR, 1.61; 95 percent CI, 1.30–1.98; p<0.001 for females). Those with lower cognitive function scores were also more likely to have amblyopia vs those with average scores (OR, 1.27; 95 percent CI, 1.19–1.35; p<0.001 for males, and OR, 1.27; 95 percent CI, 1.18–1.36; p<0.001 for females). [Eur J Public Health 2021;doi.org/10.1093/eurpub/ckab111]

Downward trend

Levine and colleagues retrospectively tracked 1.2 million young  Israeli candidates (mean age 17.15 years, 56 percent male) for military service who underwent eye exams between 1993 and 2017.

The percentage of teenagers diagnosed with amblyopia was 1.59 percent in 1993 and 0.87 percent in 2017. Nearly 80 percent of those with amblyopia had it in one eye. Levine said improved prevention efforts and higher awareness of the need to treat paediatric eye conditions could have contributed to the drop in amblyopia cases in this cohort.

As for teens in the lowest socioeconomic group, he said they may be more vulnerable to unresolved amblyopia because of several barriers, which included health literacy, poor access to healthcare, and cost of healthcare.

Additionally, other factors such as consumption of alcohol and drugs and maternal smoking during pregnancy were also known to be associated with strabismus and other vision problems among children, and may result in amblyopia, Levine added.

It was not clear how cognitive function and amblyopia may be linked to each other, but he theorized that amblyopia could result in poor thinking skills and difficulty in reading.

Obesity link

Overweight and obese teens were also more likely to have the condition than those of normal weight (OR, 1.44; p<0.001 for males; OR, 1.38; p< 0.001 for females). Compared with teenagers of normal height, those with shorter than average height were also more likely to have amblyopia (OR, 1.27; p< 0.001 and OR, 1.30; p<0.001 for males and females, respectively).

Among male teenagers, amblyopia was more common in those who are tall and with low BMI.

Treat early

Commenting on the study, Dr David Hunter, ophthalmologist-in-chief and the Richard M. Robb Chair of ophthalmology at Boston Children’s Hospital in Boston, Massachusetts, US said the study highlights the importance of diligence to support early screening and treatment of amblyopia. “If we don’t catch it early, and the child reaches 6, 8, or 10 years old, it comes back. The brain is set in its ways, and it won’t adjust.”