Ocular Manifestations of Leukemia
Ocular manifestations of leukemia are common, occurring in as many as 80% of eyes from patients with the disease examined at autopsy. Clinical studies have documented ophthalmic findings in as many as 40% of patients at diagnosis of the leukemia. Patients may be asymptomatic, or they may report blurred or decreased vision.
Clinically, the retina is the most commonly affected intraocular structure. Leukemic retinopathy is characterized by intraretinal and subhyaloid hemorrhages, hard exudates, cotton-wool spots, and white-centered retinal hemorrhages, also known as pseudo–Roth spots (Fig 20-13). (Classically, white-centered hemorrhages associated with endocarditis are termed Roth spots; they may be called pseudo–Roth spots when associated with other diseases.) In leukemia, these findings are usually the result of associated anemia, hyper-viscosity, and/or thrombocytopenia. True leukemic infiltrates are less common and appear as yellow-white deposits in the retina and the subretinal space. Perivascular leukemic infiltrates produce gray-white streaks in the retina. Vitreous involvement by leukemia is rare and most often results from direct extension via retinal hemorrhage. If necessary, a diagnostic vitrectomy can be performed to establish a diagnosis.
Although the retina is the most commonly affected ocular structure clinically, histologic studies have shown that the uveal tract is more commonly affected by leukemia than is the retina. The uveal tract may serve as a “sanctuary site” for leukemic cells, making the eye more likely to be a site of recurrent disease. Choroidal infiltrates may be difficult to detect with indirect ophthalmoscopy; they may be better detected on ultrasonography as diffuse thickening of the choroid. Serous retinal detachments may overlie these infiltrates. Leukemic involvement of the iris manifests as a diffuse thickening with loss of the iris crypts, and small nodules may be seen at the margin of the pupil in some cases. Leukemic cells may invade the anterior chamber, forming a pseudohypopyon. Infiltration of the angle by these cells can give rise to secondary glaucoma.
Figure 20-13 Retinal involvement in leukemia. A, Clinical photograph of leukemic retinopathy demonstrates scattered intraretinal hemorrhages, some of which have white centers (arrows).B, White-centered hemorrhages, also known as pseudo–Roth spots.
(Part A courtesy of Robert H. Rosa Jr, MD; part B courtesy of Jacob Pe’er, MD.)
Figure 20-14 Leukemic infiltration of the optic nerve, an ophthalmic emergency.
(Courtesy of Robert H. Rosa Jr, MD.)
With leukemic infiltration of the optic nerve (Fig 20-14), the patient may present with severe vision loss and optic nerve edema. One or both eyes may be affected. This is an ophthalmic emergency that requires immediate treatment to preserve as much vision as possible. Systemic imaging, CNS assessment including lumbar puncture with cytology, and bone marrow evaluation are necessary to confirm the diagnosis. Urgent external beam radiation to the optic nerves is typically used along with combined systemic and intrathecal chemotherapy.
Leukemic infiltrates may also involve the orbital soft tissue, with resultant proptosis. These rare tumors are referred to as granulocytic sarcomas or chloromas because they are solid masses of granulocytic precursors, including myeloblasts and myelocytes from myelogenous leukemias. The tumors appear to have a greenish hue on direct visualization. The term granulocytic sarcoma is a misnomer as this tumor is not a true sarcoma. These tumors have a predilection for the lateral and medial walls of the orbit.
Involvement of the eye may be seen at initial diagnosis or relapse of leukemia; treatment typically consists of systemic chemotherapy. Depending on the response, low-dose radiation to the eye may be included; however, this should be done with caution as it may limit future use of radiation therapy. The exception is optic nerve infiltration with acute vision loss, for which radiotherapy is mandatory for treatment. The prognosis for vision depends on the particular subtype of leukemia and the extent of ocular involvement.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.