A Case of Childhood Acute Lymphoblastic Leukemia With Retinitis Pigmentosa-like Fundus Findings.

Ophthalmic manifestations are a common occurrence in leukaemia cases and may result from a number of factors, including direct leukemic infiltration, haematologic abnormalities, central nervous system (CNS) involvement, or treatment-related effects. This case report discusses a paediatric patient with acute lymphoblastic leukaemia (ALL) who developed recurrent ocular symptoms, including retinitis pigmentosa-like findings, which is degeneration with pigment neopigmentation in the mid- to peripheral fundus, during remission, underscoring the necessity of continuous monitoring. A four-year-old female with a history of ALL, diagnosed at two years and three months of age, presented with ophthalmic complications during remission. The leukaemia was characterised by positivity for CD20, CD19, and the mature B-cell antigen, as well as a KMT2A-AFF1 gene rearrangement. Despite the administration of an intensive chemotherapy regimen and CAR-T cell therapy, the patient experienced a relapse and subsequently underwent umbilical cord blood transplantation, resulting in the attainment of molecular remission. However, at three years and seven months of age, a notable increase in the size of the left orbital tumour was observed. At three years and 11 months of age, the patient exhibited retinal changes that were consistent with retinitis pigmentosa, as confirmed by fundus photography. Additional findings included moderate left pupil dilation, an absent light reflex, optic disc swelling, dilated retinal vessels, and a serous retinal detachment. The presence of KMT2A-AFF1 mRNA in the anterior chamber fluid served to confirm the occurrence of an ocular relapse, a finding that was also evident in the bone marrow analysis. The patient was treated with salvage chemotherapy and localised radiation therapy (24 Gy) to the left eye, resulting in partial resolution of symptoms. At the four-year and three-month follow-up, retinitis pigmentosa-like changes with proliferative alterations persisted, although the serous retinal detachment had resolved. This case demonstrates that ophthalmic manifestations can occur even during the remission phase of leukaemia, emphasising the importance of regular, multidisciplinary follow-up.