To report a case of compressive optic neuropathy due to breast cancer metastasis to the periorbital lesion 26 years after the treatment of primary cancer.

A 64-year-old female presented with headache, facial pain and visual disturbance in her left eye for four months. The patient had received chemotherapy and radiotherapy after left breast modified radical mastectomy for invasive ductal carcinoma 26 years previously, and right breast wide resection with axillary dissection nine years earlier. Best corrected visual acuity was 20/20 in the right eye and 8/20 in the left eye. The color perception test showed abnormal findings in the left eye. MRI and PET-CT revealed an enhancing mass in the left periorbital area that was compressing the optic nerve. Partial resection of the tumor and left orbital wall was performed. Adjuvant chemotherapy and radiotherapy was performed after the operation. After two months later, the best corrected visual acuity was 20/20 in the left eye, and the color perception test showed normal findings, which have been maintained for one year.

Prompt management can result in visual recovery in patients with compressive optic neuropathy caused by breast cancer metastasis.