Macular edema as the first sign of acute lymphoblastic leukemia: A rare ophthalmic presentation

Macular edema (ME) is a rare initial manifestation of acute lymphoblastic leukemia (ALL) and may serve as a critical early diagnostic indicator of the disease. We hereby report the case of a 21-year-old male who presented with sudden onset, painless diminution of vision and was found to have ME in the left eye (LE). Optical coherence tomography confirmed ME. The systemic evaluation revealed splenomegaly, anemia, anisopoikilocytosis, and thrombocytopenia. The presence of atypical blast-like cells suggested acute leukemia. The patient was started with topical steroids and referred to the oncologist for a bone marrow biopsy confirming ALL and underwent intensive intravenous and intrathecal chemotherapy. Follow-up after 4 weeks in the ophthalmology clinic demonstrated the resolution of ME and visual improvement. In young patients presenting with unexplained ME, leukemia should be considered a differential diagnosis. This case emphasizes the importance of simple baseline investigations such as peripheral smear and blood counts, which can uncover serious underlying systemic illnesses. Unlike typical leukemic ocular presentations, this case demonstrates that ME alone may precede other retinal findings, reinforcing the importance of considering leukemia in the differential diagnosis of isolated ME. Early recognition and timely intervention in such hematologic malignancies are vital for improving the patient outcomes.