Tamoxifen related chorioretinal structural changes.

Purpose: To evaluate the vascular structure of the choroid and each retinal layer in patients with breast cancer on tamoxifen therapy and compare them with healthy subjects.

Materials and methods: 124 eyes of 62 patients with breast cancer who were on tamoxifen therapy (group 1) and 80 eyes of 40 healthy controls (group 2) were included in this prospective cohort study. The structure of the choroid was evaluated using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) and choroidal binarisation. Spectral-domain OCT (SD-OCT) was performed to analyse the peripapillary nerve fibre layer thickness (pRNFL) and each retinal layer thickness. A subgroup analysis was performed based on chemotherapy history in Group 1. All parameters were compared between Group 1 and the healthy controls and between the subgroups of Group 1.

Results: The subfoveal choroidal thickness and temporal and nasal directions were increased in Group 1 when compared with Group 2 (p < 0.05, each comparison). Choroidal vascularity index was significantly decreased in Group 1 compared with Group 2 (63.15 ± 3.11% and 65.37 ± 4.63%, p < 0.001). There were no significant differences in each retinal layer, pRNFL thickness, and choroid structural parameters between the subgroups of Group 1.

Conclusions: Increased choroidal thickness may be the initial finding of subclinical tamoxifen-induced retinopathy. Patients with breast cancer undergoing tamoxifen therapy may be screened prior to tamoxifen therapy and followed during treatment by SD-OCT.