Medical Care
The treatment of leukemia is in constant flux, evolving and changing rapidly over the past few years. Most treatment protocols use systemic chemotherapy with or without radiotherapy. The basic strategy is to eliminate all detectable disease by using cytotoxic agents. To attain this goal, three phases are typically used, as follows: remission induction phase, consolidation phase, and maintenance therapy phase.
Chemotherapeutic agents are chosen that interfere with cell division. Tumor cells usually divide more rapidly than host cells, making them more vulnerable to the effects of chemotherapy. Primary treatment will be under the direction of a medical oncologist, radiation oncologist, and primary care physician. Although a general treatment plan will be outlined, the ophthalmologist does not prescribe or manage such treatment.
The initial treatment of ALL uses various combinations of vincristine, prednisone, and L-asparaginase until a complete remission is obtained.
Maintenance therapy with mercaptopurine is continued for 2 years to 3 years after remission.
Use of intrathecal methotrexate with or without cranial irradiation to cover the CNS varies from facility to facility.
Daunorubicin, cytarabine, and thioguanine currently are used to obtain induction and remission of AML.
Maintenance therapy for 8 months may lengthen remission. Once relapse has occurred, AML generally is curable only by bone marrow transplantation.
CML is characterized by a leukocytosis greater than 100,000 cells. Emergent treatment with leukopheresis sometimes is necessary when leukostastic complications are present. Otherwise, busulfan or hydroxyurea may control WBC counts. During the chronic phase, treatment is palliative.
When CML converts to the blastic phase, approximately one third of cases behave as ALL and respond to treatment with vincristine and prednisone. The remaining two thirds resemble AML but respond poorly to AML therapy.
Allogeneic bone marrow transplant is the only curative therapy for CML. However, it carries a high early mortality rate.
Leukemic retinopathy usually is not treated directly. As the hematological parameters normalize with systemic treatment, many of the ophthalmic signs resolve. There are reports that leukopheresis for hyperviscosity also may alleviate intraocular manifestations and improve visual acuity. [32]
When definite intraocular leukemic infiltrates fail to respond to systemic chemotherapy, direct radiation therapy is recommended.
Relapse, manifested by anterior segment involvement, should be treated by radiation. In certain cases, subconjunctival chemotherapeutic agents have been injected.
Optic nerve head infiltration in patients with ALL is an emergency and requires prompt radiation therapy to try to salvage some vision.
Consultations
A multidisciplinary approach is required in the treatment of a patient with leukemia. Routine ophthalmic evaluation should be considered at the time of diagnosis because ocular lesions can be asymptomatic.
Surgical Care
Patients with increased intracranial pressure leading to papilledema may benefit from optic nerve fenestration. [33]
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A 4-year-old boy presented with sudden proptosis of his left eye.
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Same patient as in the image above. A CBC revealed anemia (Hb 8.6 mg/dL), thrombocytopenia (64,000), and leukocytosis (12,900). The peripheral smear revealed the presence of blasts 28%, lymphocytes 44%, segmented 14%, monocytes 6%, bands 2%, metamyelocytes 1%, and myelocytes 1%. The boy was diagnosed with AML type M4-M5 chloroma of the left orbit.
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CT scan reveals infiltration in the left orbit. Notice that the bone is uninvolved. A lumbar puncture revealed that the cerebral spinal fluid was clean of leukemic cells.
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Systemic chemotherapy was instituted, and the proptosis resolved. Unfortunately, 4.5 months later, the boy passed away secondary to multiorgan failure.
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An impending bilateral central retinal vein obstruction was discovered during a routine examination of a 76-year-old man. Further workup revealed a WBC count of 709,000, a hemoglobin count of 12 mg/dL, and a platelet count of 104,000. The man was eventually diagnosed with CML. This image is a red-free photograph of the right fundus. Notice the intraretinal hemorrhages.
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Same patient as in the image above. This image is a red-free photograph of the left eye showing intraretinal hemorrhages.
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A 14-year-old boy with a past medical history of ALL complained of a sudden loss of vision OD. Visual acuities were counting fingers OD and 20/20 OS. Notice the macular hemorrhage responsible for the loss of vision. Courtesy of Dr Rafael Jiménez.
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Same patient as in the previous image. The hematological workup revealed a hemoglobin count of 5.6, a WBC count of 1800, and a platelet count of 3000. Courtesy of Dr Rafael Jiménez.
