Retinal vein occlusion

Disease Description (Causes and Symptoms)

• Definition summary: Retinal vein occlusion (RVO) is a condition in which a retinal vein becomes blocked or compressed, causing impaired blood flow, hemorrhage, macular edema, or ischemia, which can lead to reduced vision or visual field defects. Depending on the location of the occlusion, it is classified as central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO).
• Pathophysiology: When venous occlusion causes increased venous pressure and blood stasis, retinal hemorrhage and increased vascular permeability (macular edema) occur. If ischemia is severe, substances that promote neovascularization, such as VEGF, increase and may lead to neovascularization and neovascular glaucoma.
• Common causes and risk factors: Hypertension, diabetes, hyperlipidemia, atherosclerosis, glaucoma (especially elevated intraocular pressure), older age, smoking, alcohol consumption, hormonal medications (including contraceptives), and hypercoagulable states (which need to be evaluated in younger patients).
• Main symptoms: Usually sudden (painless) decreased vision or partial visual field loss in one eye; some people have no symptoms. Floaters and glare may occur.

Treatment Methods

• Immediate measures and principles
  • Prompt evaluation by an ophthalmologist is necessary if RVO is suspected. The treatment plan is determined after diagnosis (fundus examination, OCT, fluorescein angiography, etc.).
  • Controlling systemic risk factors (blood pressure, blood glucose, and lipids) and quitting smoking are important for the prognosis.
• Drug treatment
  • Intravitreal anti-VEGF injections (first-line treatment): Standard treatment for macular edema. Examples of injectable drugs: aflibercept, ranibizumab, and bevacizumab (used off-label). Treatment is adjusted with maintenance therapy as needed after an initial series of intensive injections.
  • Intravitreal corticosteroid preparations: Dexamethasone implants (Ozurdex), etc., may be considered when the response to anti-VEGF is insufficient or when a different medication is needed. Side effects include worsening of glaucoma and cataracts.
• Laser and procedures
  • Focal (grid) laser: Previously used to treat macular edema in BRVO, but anti-VEGF is currently preferred and laser is used selectively.
  • Panretinal photocoagulation (PRP): Performed when neovascularization caused by retinal ischemia develops, including when there is a risk of neovascular glaucoma.
  • Vitrectomy: Performed when vitreous hemorrhage persists or mechanical complications, such as tractional retinal detachment, occur.
  • Glaucoma surgery/drainage device: Used when intraocular pressure cannot be controlled because of neovascular glaucoma.
• Treatment monitoring
  • Monitor the status of macular edema with visual acuity testing and OCT. Evaluation is initially performed at intervals of 4–12 weeks; for anti-VEGF treatment, the interval is adjusted after an initial intensive regimen (e.g., monthly injections).
• Lifestyle management and precautions
  • Strictly manage blood pressure, blood glucose, and lipids; quit smoking; and manage body weight.
  • Consult a doctor (internal medicine/ophthalmology) about anticoagulants and antiplatelet agents, depending on the circumstances. RVO itself is not a primary indication for anticoagulant therapy.
  • Immediate evaluation is necessary if there is sudden severe worsening, pain, or signs of new edema or hemorrhage.

Checklist Before an Outpatient Visit (Items to Prepare and Examination Records, etc.) — Including Example Questions

• Items and materials to bring
  • List of medications currently being taken (including anticoagulants, antiplatelet agents, and hormonal medications) and allergy history
  • Previous ophthalmic examination results and images, if available (fundus photographs, OCT, fluorescein angiography, etc.)
  • Recently measured blood pressure, blood glucose, and cholesterol test results, if possible
  • Record the date symptoms began and changes in symptoms (the time course and pattern of vision loss)
  • Amsler grid, if available (self-test results), or vision records
• Items to prepare and ask the doctor about during the outpatient visit
  • The time symptoms began and how they have progressed (e.g., whether they suddenly improved or worsened)
  • Current discomfort (floaters, dark spots, visual field defects, etc.)
• Example self-check questions before the outpatient visit
  • Which eye is affected, and did it occur all at once or gradually?
  • Is there pain? Is it accompanied by eye redness, tearing, or glare?
  • Do any of the medications normally taken include anticoagulants or hormonal medications?

General Example Questions to Ask the Doctor

• "Do I need anti-VEGF treatment in my case? If so, how often do I need the injections?"
• "What is the prognosis for this condition? How likely is it that my vision will recover?"
• "What are the common side effects and risks of injections (or steroid treatment)?"
• "How strictly should I manage my blood pressure, diabetes, and lipids? What target levels are recommended?"
• "What is the risk of recurrence or occurrence in the other eye in the future?"

Examples of Condition-Specific Questions (1–2)

• "What is the degree of macular edema (central macular thickness) on OCT? Could you tell me the central macular thickness measurement?"
• "Has it been determined whether this lesion is ischemic or nonischemic? If it is ischemic, what additional treatment is needed because of the risk of neovascularization and glaucoma?"

(Note: Accurate diagnosis and treatment decisions are based on clinical examinations and imaging findings by an ophthalmologist. If there are suspicious findings or vision changes rapidly, an immediate visit to an ophthalmologist is recommended.)