The ophthalmic findings described in PV and related myeloproliferative neoplasms span microvascular “flow” symptoms to less common, vision-threatening vascular occlusions. [1]

More common / microvascular-type symptoms (can be intermittent)

• Blurred or dim vision
• Transient monocular vision loss (amaurosis fugax)—brief, temporary loss of vision in one eye [1,8]
• Visual phenomena such as scotomas (spots) in the setting of microcirculatory disturbance
• Red or “bloodshot” eyes [1,3]

Less common but higher-stakes events (need urgent evaluation)

• Retinal artery or vein occlusion (sudden visual loss can occur when retinal blood flow is blocked; PV has been reported as an underlying cause in case reports/series) [1,3,8]
• Optic nerve involvement (including papilledema in rare contexts)—papilledema can occur with raised intracranial pressure, including from cerebral venous sinus thrombosis, which has been reported in PV case reports. [1,4]

Two broad mechanisms are typically discussed:

1. Microvascular disturbance / hyperviscosity: abnormal blood composition (especially elevated hematocrit) can slow flow in small vessels, contributing to transient visual symptoms that may improve when counts are controlled. [1,5]
2. Thrombosis risk: PV is associated with increased thrombotic risk, and retinal/optic pathway ischemic events can occur when blood flow is blocked. [1,2]

When PV is already known (or suspected), clinicians commonly coordinate ophthalmology + hematology:

• • Eye exam (including dilated retinal exam; OCT or fluorescein angiography when indicated) to look for retinal ischemia/occlusion or optic nerve swelling [1,8]
  • Bloodwork and PV assessment (CBC; JAK2 testing and other workup per hematology standards; bone marrow exam may be used in diagnosis pathways) [2,7]

PV care is individualized and generally aims to lower the risk of thrombosis and improve blood flow by keeping blood counts in a safer range and addressing patient-specific risk factors.

Management is guided by clinician assessment of overall risk and symptoms, and may combine blood-count control, antithrombotic risk-reduction strategies when appropriate, and ongoing monitoring. Any sudden vision loss or suspected ocular vascular event should be treated as urgent and evaluated promptly, because timely assessment can be vision-saving. [5,6]

1. Can polycythemia vera cause permanent vision loss?

It can, particularly if a retinal or optic-nerve vascular occlusion occurs; these events may cause irreversible injury. [1,3]

2. Why do eyes sometimes look red in PV?

Thicker blood slows flow in small eye vessels, leading to visible redness or “bloodshot” eyes. This often improves once hematocrit and blood counts are controlled. [1,3]

3. Are headaches and visual symptoms related in PV?

They can be, because microcirculatory disturbance and thrombotic risk can affect cerebral/ocular perfusion; however, many common conditions can also cause both symptoms. [1,2]

4. Can eye symptoms be the first sign of PV?

Yes, ocular presentations have been reported (e.g., transient monocular vision loss or retinal vascular occlusion leading to PV workup), but this is not the most typical presentation and evidence includes case reports. [1,3]

5. How often should PV patients see an doctor?

There isn’t one universal interval supported for all patients; frequency is usually individualized based on symptoms, prior ocular findings, and overall risk profile, coordinated with the care team. [1,2]

• PV — Polycythemia vera
• JAK2 — Janus kinase 2
• OCT — Optical coherence tomography
• CBC — Complete blood count
• FAQs — Frequently asked questions

1. Liisborg, C., Hasselbalch, H. C., & Sørensen, T. L. (2020). Ocular manifestations in patients with Philadelphia-negative myeloproliferative neoplasms. Cancers (Basel), 12(3), 573. https://doi.org/10.3390/cancers12030573
2. Marchioli, R., Finazzi, G., Specchia, G., Cacciola, R., Cavazzina, R., Cilloni, D., … Barbui, T. (2013). Cardiovascular events and intensity of treatment in polycythemia vera. The New England Journal of Medicine, 368(1), 22–33.
3. Landolfi, R., Marchioli, R., Kutti, J., Gisslinger, H., Tognoni, G., Patrono, C., & Barbui, T. (2004). Efficacy and safety of low-dose aspirin in polycythemia vera. The New England Journal of Medicine, 350(2), 114–124. https://doi.org/10.1056/NEJMoa035572
4. McMullin, M. F., Harrison, C. N., Ali, S., Cargo, C., Chen, F., Ewing, J., … Mead, A. J. (2019). A guideline for the diagnosis and management of polycythaemia vera: A British Society for Haematology Guideline. British Journal of Haematology, 184(2), 176–191. https://doi.org/10.1111/bjh.15648
5. McMullin, M. F. F., Mead, A. J., Ali, S., Cargo, C., Chen, F., Ewing, J., … Harrison, C. N. (2019). A guideline for the management of specific situations in polycythaemia vera and secondary erythrocytosis: A British Society for Haematology Guideline. British Journal of Haematology, 184(2), 161–175. https://doi.org/10.1111/bjh.15647
6. Tefferi, A., & Barbui, T. (2023). Polycythemia vera: 2024 update on diagnosis, risk-stratification, and management. American Journal of Hematology, 98(9), 1465–1487. https://doi.org/10.1002/ajh.27002
7. Regensburger, J., Rauchegger, T., Loacker, L., Falkner, F., Feistritzer, C., & Teuchner, B. (2022). Intermittent retinal artery occlusions as the first clinical manifestation of polycythemia vera: A case report. BMC Ophthalmology, 22, 221. https://doi.org/10.1186/s12886-022-02423-w
8. Ganesan, S., Babu, N., Raman, R., & Vaitheeswaran, K. (2017). Polycythemia causing posterior segment vascular occlusions. Indian Journal of Ophthalmology.
9. Parija, S., Mohapatra, M. M., & Patnaik, B. K. (2008). Polycythemia vera presenting with bilateral papilledema: A rare case report. Indian Journal of Ophthalmology.