The aim of the study is to report a case of corneal epithelial changes in a patient with refractory multiple myeloma (MM) who was treated with belantamab mafodotin (BM). A 55‐year‐old man diagnosed with refractory MM was referred to our hospital for treatment with BM, an antibody‐drug conjugate targeting B‐cell maturation antigen. After 33 days of treatment, the patient experienced a bilateral reduction in visual acuity (VA), along with dry eye symptoms such as itchy eyes and a sensation of having a foreign body. Slit‐lamp examination revealed the presence of diffuse microcystic epithelial changes throughout the cornea. BM treatment was discontinued by the oncologist. Sixty days after stopping belantamab, VA gradually improved and the microcystic epithelial alterations progressively diminished. Ninety days after discontinuation of therapy, only a few microcystic epithelial alterations remained, and the patient had 20/20 VA in both eyes. While BM is an effective therapy for refractory MM, corneal epithelial changes are among the most common side effects of this treatment. Close collaboration between ophthalmologists and oncologists is crucial for assessing ocular adverse effects and tailoring treatment accordingly.
