Myopia may precede posterior subcapsular cataract, study suggests

A “strong association” between early spectacle wear in myopia and posterior subcapsular opacity, but not nuclear opacity, was found in a large population-based study. This suggests that myopia may precede posterior subcapsular opacity, but its relationship with nuclear opacity is less clear, the study authors said.

Margaret A. Chang, MD, MS, and colleagues at the Wilmer Eye Institute analyzed data from 2,520 participants in the Salisbury Eye Evaluation Project who were between the ages of 65 and 84 years at the time of the survey. The questionnaire elicited medical history, social habits and a detailed history of spectacle wear. Participants also underwent a complete ophthalmologic exam.

Significant associations were found between myopia and both nuclear and posterior subcapsular opacities. For nuclear opacity, the odds ratio was 2.25 for myopia of between –0.5 D and –1.99 D. The odds ratio increased to 3.65 for myopia of between –2 D and –3.99 D; to 4.54 for myopia between –4 D and –5.99 D; and it decreased to 3.61 for myopia greater than –6 D. For posterior subcapsular cataract, the odds ratio ranged from 1.59 for myopia of between –0.5 D and –1.99 D to 12.34 for myopia above –6 D.

The association between posterior subcapsular opacity and myopia was equally strong for those wearing glasses by age 21 and for those not wearing glasses. For nuclear opacity, significantly higher odds ratios were found for myopes who started wearing glasses after age 21.

The researchers noted that the study’s limitations included its cross-sectional design. “The precise temporal association between onset of myopia and the different lens opacity subtypes cannot be directly ascertained,” the authors said in the study, which is published in the August issue of Ophthalmology.

“Our results suggest that myopia may precede and predispose to posterior subcapsular lens opacity, whereas we cannot exclude nuclear opacity associated with later myopic shift,” they said.