Influence of tamoxifen on ocular morphology and function

Tamoxifen, a commonly used selective estrogen receptor antagonist for adjuvant therapy in hormone receptor-positive breast cancer, can cause ocular side effects due to estrogen receptors in ocular structures. This prospective study explores its impact on ocular morphology and function.

This prospective, non-interventional, cross-sectional study explores the effects of tamoxifen on ocular morphology, visual acuity, and quality. Examinations included objective refractometry, visual acuity, contrast sensitivity, color vision, visual field tests, corneal topography, optical coherence tomography, autofluorescence, and slit lamp biomicroscopy. Participants completed a health questionnaire. Statistical analysis, using linear or logistic (mixed) regression, compared tamoxifen's effects to a control group.

A total of 102 patients were included: 90 in the study group and 12 controls. The duration of tamoxifen therapy showed a clinically relevant impact on the visual field, with a mean loss variance change of 0.045 dB² per week (95% CI [0.012 dB²; 0.079 dB²]). Corneal thickness decreased by -0.12 μm per week (95% CI [-0.20 μm; -0.031 μm]) with longer therapy duration. Fourteen patients received additional aromatase inhibitors, and this group showed clinically significant reductions in both visual acuity and contrast vision. No correlation was observed between tamoxifen intake and visual acuity, contrast vision, color vision, mean defect in visual fields, retinal thickness, macular morphology, or slit-lamp biomicroscopy findings.

According to this study, tamoxifen intake influences corneal thickness and perimetry, which are two parameters associated with glaucoma development. Regular ophthalmological glaucoma controls could be useful in tamoxifen patients, especially if glaucoma is already known.