Tamoxifen is a selective estrogen receptor modulator that is mainly used as an adjuvant treatment for patients with hormone receptor–positive breast cancer.

Tamoxifen retinopathy is characterized by crystalline deposits and pseudocystic foveal cavitations.

The prevalence of tamoxifen retinopathy has been reported to be variable, ranging from 1.5%3 to 11.8%.

Because most previous studies were based only on the fundus examinations without OCT, it is assumed that the prevalence was underestimated.

In this study, we aimed to estimate the prevalence of tamoxifen retinopathy using both fundus photography and OCT, as well as to uncover the associated risk factors.

This study was approved by the Asan Medical Center Institutional Review Board (2017-1426) and conducted in adherence to the tenets of the Declaration of Helsinki. All participants provided informed consent.