Multiple myeloma is a cancer originating in plasma cells, a type of white blood cell found in the bone marrow. These abnormal plasma cells can accumulate in various parts of the body, potentially affecting organs and tissues. While less common than other systemic manifestations, multiple myeloma can involve the eyes, and recognizing these ocular changes is important for patient care.
Specific Ocular Manifestations
Patients with multiple myeloma may experience various eye symptoms, including blurred vision, double vision (diplopia), decreased visual acuity, or vision loss. These can develop gradually or suddenly.
External signs include redness, pain, discomfort, or irritation. Proptosis, or bulging of one or both eyes, may also be observed. Hyperviscosity retinopathy is a retinal complication characterized by dilated and tortuous retinal veins, retinal hemorrhages, and microaneurysms, resulting from thickened blood.
Other manifestations include optic neuropathy, which damages the optic nerve and can lead to vision loss, visual field defects, and abnormal color vision. Orbital plasmacytomas, localized tumors of myeloma cells, can develop in or around the eye, causing pain and vision problems. Amyloid deposition, an accumulation of abnormal proteins, can also occur in ocular tissues, contributing to visual disturbances.
Underlying Causes of Eye Involvement
Direct infiltration of myeloma cells into ocular structures is a primary cause. Malignant plasma cells can invade the orbit or optic nerve, leading to localized mass lesions. This infiltration can compress surrounding tissues, causing symptoms like proptosis, pain, and reduced eye movement.
Hyperviscosity syndrome is another significant cause, resulting from the overproduction of monoclonal proteins (M-proteins) by abnormal plasma cells. These proteins thicken the blood, impeding blood flow in retinal vessels and potentially leading to blurred vision, difficulty focusing, and retinal hemorrhages. Amyloidosis, the deposition of abnormal protein fibrils, can also occur in ocular tissues, contributing to eye problems.
Paraneoplastic syndromes, rare disorders triggered by the immune system’s response to cancer, can indirectly affect the eyes. Systemic treatments for multiple myeloma, such as certain chemotherapy drugs or high-dose steroids, can cause ocular side effects including blurred vision, dry eyes, and cataracts. General systemic complications, such as anemia or thrombocytopenia, can also indirectly impact eye health by affecting blood supply or increasing the risk of bleeding within the eye.
Diagnosis and Management Approaches
Diagnosing eye involvement typically begins with a comprehensive eye examination. An ophthalmologist performs a fundoscopy to examine the retina and optic nerve, and a slit-lamp examination to assess the front structures of the eye. Imaging techniques, such as MRI or CT scans of the orbit, are often used to identify tumors, infiltrations, or structural changes around the eye.
Collaboration between ophthalmologists and hematologists is important for accurate diagnosis and coordinated care. Blood tests, including M-protein levels and blood viscosity, help determine systemic disease activity and hyperviscosity syndrome. A biopsy of affected ocular tissue may be necessary to confirm myeloma cells.
Management of ocular manifestations primarily focuses on treating the underlying multiple myeloma. This often involves systemic therapies such as chemotherapy, targeted therapies, or stem cell transplantation, aiming to reduce the burden of cancerous plasma cells.
For specific ocular issues, treatments may include plasmapheresis to reduce blood viscosity in hyperviscosity syndrome. Radiation therapy may be used for localized orbital plasmacytomas. Symptomatic treatments, such as eye drops for dryness or anti-inflammatory medications for discomfort, can also provide relief. Early detection and an integrated approach to care are important for preserving vision and improving the quality of life for individuals with multiple myeloma.