Leukemia in childhood is acute in 95% of cases and is more often lymphocytic than myelocytic. Acute lymphoblastic leukemia is the most common malignant disease of childhood and is responsible for 30% of all cancer cases; there are 4000 new cases per year in the United States. Although the most common ocular manifestation of leukemia is leukemic retinopathy, all ocular structures can be affected. Ocular involvement is highly correlated with CNS involvement.
Leukemic infiltrates in the anterior segment may lead to heterochromia iridis, a change in the architecture of the iris, frank iris infiltrates, spontaneous hyphemas, leukemic cells in the anterior chamber, and pseudohypopyon. Keratic precipitates may be seen, and glaucoma develops in some affected eyes from tumor cells clogging the trabecular meshwork. Anterior chamber paracentesis for cytologic studies may be diagnostic in cases involving the anterior segment. Systemic chemotherapy, local radiation therapy, and topical steroids may be effective for anterior segment complications. Leukemic involvement of the iris may be confused with juvenile xanthogranuloma.
The most common ocular findings are retinal hemorrhages, especially flame-shaped lesions in the nerve fiber layer. They involve the posterior fundus and correlate with other aspects of the disease, such as anemia, thrombocytopenia, and coagulation abnormalities. The hemorrhages may have white centers. Retinal hemorrhages in leukemia can resemble those associated with abusive head trauma (see Chapter 27), and they have been reported as the first manifestation of leukemia. Other forms of retinal involvement include localized perivascular infiltrations, microinfarction, and discrete tumor infiltrations. Histologically, the choroid is the most frequently affected ocular tissue, but choroidal involvement is usually not apparent clinically.
Optic nerve involvement occurs if the disc has been infiltrated by leukemic cells (Fig 28-28), which may cause loss of central vision. Translucent swelling of the disc obscures the normal landmarks; with florid involvement, only a white mass is visible in the region of the disc. The presence of disc edema and loss of central vision in a child with leukemia should be considered a medical emergency because permanent loss of central vision is imminent. Such patients should undergo radiation therapy as soon as possible.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.