Trastuzumab-Induced Early Corneal Melt in HER2-Positive Breast Cancer: A Case Report and Review.

BACKGROUND Trastuzumab (Herceptin) is a recombinant DNA-derived humanized monoclonal antibody that the US Food and Drug Administration (FDA) approved in 1998 for metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer therapy. It selectively binds to the extracellular domain of HER2 and mediates an antibody-dependent cellular toxicity in various tissues. Trastuzumab use alone does not typically cause aggressive ocular complications. However, herein is a case report of a patient presenting with corneal ulceration in both eyes and perforation in the left eye after 2 months of trastuzumab therapy. CASE REPORT A 59-year-old woman with a history of metastatic breast cancer receiving chemotherapy was consulted for ophthalmic evaluation. She denied any history of ocular conditions and complained of eyelid crusting and sandy sensation in both eyes for 2 weeks. She had been using antibiotic eyedrops for presumed eye infection before her vision deteriorated 3-4 days prior to presentation. A thorough workup for autoimmune and infectious diseases was unyielding. Ophthalmologic examination revealed multiple epithelial defects with ulceration in the right eye and a corneal ulcer with perforation in the left eye. Corneal cultures were negative. Orbital imaging revealed metastases with optic nerve compression. In conjunction with the oncology team, further trastuzumab treatment was deferred. Therapeutic keratoplasty along with ocular surface therapy eventually stabilized both eyes. CONCLUSIONS Ocular adverse effects such as corneal epithelial changes and melts have been reported with trastuzumab. We recommend ophthalmology consultation for any ocular symptoms in patients on trastuzumab treatment.