{Reference Type}: Journal Article
{Title}: Trastuzumab-induced optic neuritis: "blindness" side effect.
{Author}: Önder T;Karaçin C;
{Journal}: J Oncol Pharm Pract
{Volume}: 0
{Issue}: 0
{Year}: 2024 Aug 14
{Factor}: 1.416
{DOI}: 10.1177/10781552241275538
{Abstract}: <B>BACKGROUND: </B>Trastuzumab improved the prognosis of patients with human epidermal growth factor receptor 2 (HER2)+ breast cancer (BC). Here, we present a patient who developed acute vision loss due to optic atrophy in both eyes after trastuzumab.<BR><B>METHODS: </B>A 60-year-old female patient was diagnosed with locally advanced HER2+ BC in January 2021. After four cycles of neoadjuvant anthracycline-based chemotherapy followed by four cycles of docetaxel, trastuzumab, and pertuzumab combined treatment, the patient underwent a right modified radical mastectomy. Three days after the end of the second cycle of adjuvant trastuzumab, she presented with acute vision loss. The patient's visual acuity was 90% in the right eye and 60% in the left eye. The left eye had optic nerve edema and spindle hemorrhages. First, on suspicion of optic neuritis, the patient was given a 1 gram/day pulse steroid for three days. However, optic neuritis was not considered during the follow-up. Metastasis was considered at the exit of the left optic nerve. Trastuzumab was started by making a mutual decision with the patient. Six days after the sixth dose of adjuvant trastuzumab, she presented with almost complete vision loss.<BR><B>METHODS: </B>The patient was diagnosed with optic neuritis, and a pulse steroid was administered. Trastuzumab was permanently discontinued. However, the patient's visual acuity in both eyes remained at 5-10%.<BR><B>CONCLUSIONS: </B>Vision loss due to optic neuritis is a devastating side effect. Understanding that trastuzumab-induced optic neuritis may develop will help clinicians detect side effects early and manage them more effectively.