Menopausal hormone therapy and the risk of cataracts in postmenopausal women in South Korea.

Purpose: Postmenopausal women have a higher prevalence of cataracts than men of a similar age. This study aimed to evaluate the effects of menopausal hormone therapy (MHT) on lens opacities in postmenopausal women.

Methods: This retrospective cohort study analysed population-based health insurance data in South Korea collected from 2002 to 2019. To determine the risk factors associated with cataract, postmenopausal women (N = 2,506,271) were grouped according to post-MHT use. The treatment group was further divided into the following subgroups: tibolone, combined oestrogen plus progestin by manufacturer, oral oestrogen, combined oestrogen plus progestin by physician and topical oestrogen groups. The main outcome measure was the prevalence of cataracts.

Results: The control group comprised 463,151 postmenopausal women who had never used MHT after menopause, while the treatment group included 228,033 postmenopausal women who had used MHT continuously for at least 6 months. The treatment group had a higher incidence of cataracts than the control group based on Cox proportional hazards ratio analysis. Low socioeconomic status and high parity were identified as risk factors for cataracts, and reduced risk of cataracts was associated with living in rural areas and drinking alcohol.

Conclusions: Women undergoing post-MHT, including tibolone, had a higher incidence of cataracts. Cataract development should be a concern when examining postmenopausal patients using MHT.