Abstract PO2-12-11: Ocular Toxicity of Tamoxifen in Patients with Breast Cancer

Background: The latest recommendations in breast cancer treatment protocols with tamoxifen indicate that it should be used from five to 10 years. It depends mainly on the cumulative dose of the drug in the body. Despite its multiplicity, the various studies conducted on this subject did not reach conclusive results. Objectives: This research aims to study retinopathy associated with hormonal treatment of breast cancer using tamoxifen. Methods: A cross-sectional study was conducted at Al-Mouwasat University Hospital on a sample of 130 eyes according to (G-Power) with a statistical power of 95%. The participants were briefed on the research and consented on the ethical considerations. Then, the patients who entered the study were interrogated, clinically examined, and were asked about their medical history, the time of breast cancer diagnosis along with the details about the treatment protocols they underwent or currently undergoing. The refractive errors were measured with an automatic refractive device, then they were examined on the slit lamp to investigate the refractory media, then the corrected and uncorrected visual acuity were taken. Finally, after ensuring that the inclusion criteria were met and excluding those who fulfil one or more of the exclusion criteria, optical coherence tomography was performed using SD-OCT technique to measure and review the retinal thickness map in circles of 1-3-6 mm, respectively, to notice possible changes on it. Results: We found that the use of tamoxifen irrespective to cumulative dose leads to increase in the macula thickness values in the upper and lower sectors within the 3 mm circle, and to significant decrease in the macula thickness values in the upper and lower sectors within the 6 mm circle, in addition to decrease in nasal sector thickness within the circles of 3 and 6 mm. Conclusion: We conclude that the difference between people treated with tamoxifen and those not treated with it is not limited to the occurrence of crystals deposition in the macular area or the presence of a cavity in the central macula (with or without typical cystic macular edema), but rather to existence of macula thickness differences unrelated to the cumulative dose of the drug, whether by increase or decrease in thickness of the upper, lower and nasal segments. Citation Format: Husain Alhouz, Arwa Azmeh, Maher Saifo. Ocular Toxicity of Tamoxifen in Patients with Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-12-11.