Early-stage corneal toxicity secondary to high-dose systemic cytarabine: a case report

BACKGROUND: High-dose systemic cytarabine chemotherapy may cause fine corneal opacities and refractile microcysts, which are densely distributed in the center of the cornea. Most previous case reports on microcysts have been those following complaints of subjective symptoms, and the findings at the initial stage of development and time-course changes are still unknown. This report aims to clarify the time-course changes of microcysts using slit-lamp photomicrographs. CASE PRESENTATION: A 35-year-old woman who was treated with high-dose systemic cytarabine therapy (3 courses of 2 g/m(2) every 12 h for 5 days) for acute myeloid leukemia and presented with subjective symptoms, such as bilateral conjunctival injection, photophobia, and blurred vision, on the 7(th) day of treatment in both the first two courses. Anterior segment findings by slit-lamp microscopy revealed microcysts densely distributed in the central region of the corneal epithelium. In both courses, microcysts disappeared within 2–3 weeks upon prophylactic steroid instillation. In the 3(rd) course, daily ophthalmic examinations were conducted from the start of the treatment, and on the 5(th) day without subjective symptoms, the microcysts in the corneal epithelium appeared evenly and sparsely distributed throughout the cornea except for the corneal limbus. Thereafter, the microcysts accumulated towards the center of the cornea and disappeared gradually. The change from low-dose to full-strength steroid instillation immediately following the occurrence of microcysts in the 3(rd) course resulted in the peak finding being the mildest compared to that in the past two courses. CONCLUSIONS: Our case report revealed that microcysts appeared scattered throughout the cornea before the appearance of subjective symptoms and then accumulated in the center and disappeared. A detailed examination is necessary to detect early changes in microcyst development resulting in prompt and appropriate treatment.