A Rare Case of Breast Cancer Metastasis to the Optic Nerve Head

Purpose: To report a case of metastatic breast cancer to the optic nerve with a favorable response to an increased dose of intravitreal bevacizumab injection. Case summary: A 60-year-old female presented to our clinic with blurred vision in her left eye for 3 weeks. The patient had a history of intraductal breast cancer carcinoma, metastasized to the mediastinum lymph nodes, liver, and bone and had received palliative chemotherapy and radiotherapy for 16 months. At her first presentation, best-corrected visual acuity of the left eye was 20/50 and the intraocular pressure was 11 mmHg. A yellowish elevated mass with hemorrhage at the optic disc with peripapillary swelling was observed in the left eye. Fluid at the subperipapillary and subfoveal areas and choroidal thickening with folds were observed with optic coherence tomography. The patient was diagnosed as having breast cancer metastasis to the optic nerve head. Three monthly intravitreal bevacizumab injections (0.05 mL, 1.25 mg) were administered, but showed limited effect. Two more intravitreal bevacizumab injections having twice the concentration of the previous dose (0.1 mL, 2.50 mg) were given. Tumor infiltration of the optic nerve head decreased, and serous retinal detachment subsided. No malignant cancer cells were detected in the anterior chamber. Conclusions: We report a rare case of breast cancer metastasis to the optic nerve. Administering intravitreal bevacizumab injections with twice the dosage concentration could be an alternative treatment option, to alleviate exudative retinal detachment associated with metastatic tumor progression to the optic nerve head.