Myeloproliferative neoplasms (MPN) affect blood circulation, potentially impacting tissues and organs throughout your body — including your eyes. If you’ve been diagnosed with MPN, you may experience changes to your vision, including double vision (diplopia), blind spots, and blurred vision. Fortunately, treatments are available.

MPNs are a group of blood cancers characterized by abnormal development of stem cells in the bone marrow. Two specific types of MPNs are associated with vision changes: polycythemia vera (PV) and essential thrombocythemia (ET). In fact, studies have revealed a high prevalence of visual complications in PV and ET, with 7.5 percent to 25 percent of people reporting symptoms.

How Do MPNs Cause Vision Changes?

Nervous-system issues and side effects of treatments for PV and ET can contribute to vision changes. However, blood-related abnormalities are the most common cause.

Both PV and ET affect the way blood cells are produced, leading to high red blood cell counts (erythrocytosis), high white blood cell counts (leukocytosis), and high platelet counts (thrombocytosis). Higher numbers of cells and the extra stickiness of abnormal platelets can cause obstruction of blood vessels.

These changes can lead to issues with circulation in the vessels connected to the visual organs, resulting in vision changes. A high platelet count, in particular, can block arteries and veins, causing irreversible loss of vision.

Circulation issues can also compromise blood flow to the brain, causing vision changes like monocular blindness (blindness in one eye), blurred vision, fogging in the eyes, or dimming vision. These symptoms can be short-lasting and often disappear when blood levels are corrected through treatment.

Always ask your doctor about any potential side effects before beginning a new MPN treatment — and importantly, be sure to report any you experience.

Other Potential Causes of Vision Changes

The visual symptoms resulting from PV and ET are often misdiagnosed for other eye conditions. Thus, if you experience changes to your vision, keep in mind that MPNs may not be the cause. Other potential causes of vision changes include glaucoma, cataracts, or amblyopia, also known as “lazy eye.” Talk to your doctor to learn what’s causing your vision problems so you can treat it appropriately.

Treatments for Vision Changes From MPN

Vision changes stemming from MPNs can sometimes be treated through the same methods used to manage the MPNs themselves. After all, the blood-formation characteristics from MPNs are the cause of those vision changes.

The goal of MPN treatments is to restore normal conditions in the blood, thereby helping you manage MPN symptoms — including vision issues — while reducing additional risks, such as blood clotting and abnormal bleeding.

The particular type of treatment you receive will depend on a variety of factors, including the severity of your MPN, as well as your medical history, age, and overall health.

Phlebotomy

Also known as “venesection,” phlebotomy is a procedure through which a small amount of blood is removed from the bloodstream, similar to the process of donating blood. Phlebotomy is usually the first line of treatment against PV, because it can quickly reduce the number of red blood cells in your system. Phlebotomy can also be an effective method of managing PV in the long term by inducing a low level of iron deficiency, which puts the brakes on new red blood cell production and reduces the number of circulating red blood cells.

Chemotherapy

Chemotherapy is used for both PV and ET to control the number of platelets in the bloodstream.

The drug Hydrea (Hydroxyurea) is commonly used in chemotherapy for MPNs. Administered as an oral capsule, Hydrea is often effective in reducing the risk of blood clots by controlling platelet counts.

Aspirin

In small doses, aspirin has been shown to significantly reduce the risk of blood clots. If you have PV or ET, your platelets may clump together, forming harmful blood clots in various parts of the body, including the eyes. Aspirin can reduce the risk of these clots and prevent symptoms like vision changes from occurring. However, aspirin can shift the balance toward bleeding, causing bleeding complications.

Interferon

Interferons are proteins the body uses to signal and trigger an immune response. Interferons are prescribed as part of treatment for most MPNs to help reduce the number of blood cells in the bloodstream.

Interferons — such as Intron A (Interferon alfa-2b) — are usually administered as a subcutaneous injection (under the skin). The injection can be self-administered or performed by a loved one at home.

Agrylin (Anagrelide Hydrochloride)

Agrylin (Anagrelide hydrochloride) is used to reduce the number of platelets in the blood for people with ET. It works by suppressing megakaryocytes, the platelet-producing cells in the bone marrow. Agrylin is taken in capsule form.

Janus Kinase 2 Inhibitors

In some cases of PV and ET, Janus kinase 2 (JAK2) inhibitors are used to suppress JAK2 protein in order to treat enlarged spleens and reduce other symptoms.

If you’re experiencing vision changes, be sure to discuss them with your hematologist. Early intervention and regular eye screenings can help limit the impact of MPNs on your eyes and vision.

Finding Support With MPNs

The community at myMPNteam is a supportive group who shares their experiences of living with MPNs. Have you or a loved one experienced vision problems because of MPNs? What treatments have worked for you? Leave a comment below or go to myMPNteam and share your story with others who might be having the same experience.