Tamoxifen Retinopathy and Macular Telangiectasia Type 2: Case-Based Differential Diagnosis

Tamoxifen is a widely used agent for the treatment of breast cancer worldwide. Despite its significant efficacy in breast cancer, serious side effects may occur with long-term or high-dose use. One of these side effects is tamoxifen retinopathy (TR). Tamoxifen retinopathy typically presents with bilateral visual impairment, crystalline deposits, and changes in the foveal reflex during fundus examination. Although characteristic features can be observed with multimodal imaging, it may be confused with various retinal pathologies. One of the primary conditions considered in the differential diagnosis of TR is macular telangiectasia type 2 (Mac-Tel 2). In this case presentation, we aim to share the differential diagnosis process of TR and highlight the distinguishing features from Mac-Tel 2 in a female patient who presented with decreased vision, based on the patient's history, detailed fundoscopic examination findings, and multimodal imaging.