Barbados Eye Study: Refractive errors continue to develop in adults

Refractive errors, both myopic and hyperopic, frequently continue to develop in older adults, according to a study in a black population. Nuclear lens opacities, glaucoma and diabetes increase the risk of older-onset myopia, an observation that has public health relevance in this population, the study authors said.

Suh-Yuh Wu and colleagues with the Barbados Eye Study Group described the 9-year changes in refractive errors and estimated the incidence of hyperopia and myopia in 2,793 adults of African descent who were enrolled in the long-term, population-based study. Refractive errors were determined by automated refraction.

Participants were said to have a refractive error if they had a change in refraction of greater than ±0.5 D. The cutoff for moderate-high myopia or hyperopia was 3 D. The incidence rates of myopia and hyperopia were estimated by the product-limit approach and were based on eyes without such conditions at baseline, the study authors said.

Nine-year refraction changes varied by age, with participants in the 40-to-49-year age range showing median hyperopic shifts of +0.38 D and those older than 60 years showing median myopic shifts of –0.75 D, the study authors said.

The overall 9-year incidence was 12% for myopia and 29.5% for hyperopia; the incidence rate for moderate-high myopia was 3.6% and for moderate-high hyperopia 2%.

The authors noted that the risk for developing myopia increased with age, baseline nuclear lens opacity, glaucoma and hypertension. Cortical lens opacities decreased the risk, they said. The incidence of developing moderate-high myopia was also related to baseline age, nuclear lens opacity, glaucoma, male gender and diabetes history. The risk of developing hyperopia decreased in participants who were older, male and diagnosed with glaucoma.

The study is published in the November issue of Investigative Ophthalmology & Visual Science.