What Is Retinal Vascular Occlusion? Retinal vascular occlusion is a condition that occurs when one of the blood vessels carrying blood to or from the retina becomes blocked. This interruption in blood flow can lead to sudden vision loss and may result in permanent damage if not treated promptly. There are two main types: Central Retinal Artery Occlusion (CRAO): A blockage in the main artery supplying the retina Central Retinal Vein Occlusion (CRVO): A blockage in the main vein draining blood from the retina There are also branch occlusions, affecting smaller vessels: Branch Retinal Artery Occlusion (BRAO) Branch Retinal Vein Occlusion (BRVO) These are considered ocular emergencies, particularly CRAO, which is sometimes likened to a “stroke in the eye.” Causes of Retinal Blood Vessel Blockage The causes can vary depending on whether the artery or vein is affected, but most cases are related to underlying systemic vascular diseases. Common Causes Include: Atherosclerosis (hardening of arteries) Hypertension (high blood pressure) Diabetes mellitus High cholesterol levels Blood clotting disorders Heart disease and arrhythmias Inflammatory vascular conditions Smoking and sedentary lifestyle Glaucoma (increases the risk of vein occlusion) In rare cases, an embolism from the heart or carotid artery can travel and lodge in the retinal vessels. Symptoms to Watch For Symptoms can vary depending on the type and severity of occlusion: Arterial Occlusion (CRAO/BRAO) Sudden, painless, severe vision loss in one eye Vision may be reduced to light perception only Occasionally preceded by transient vision loss (amaurosis fugax) Venous Occlusion (CRVO/BRVO) Blurry or distorted vision Gradual or sudden vision changes Dark spots or floaters In some cases, eye pain due to increased eye pressure These symptoms are ocular emergencies and require urgent care to minimize permanent vision loss. Diagnosis at Bangkok Eye Hospital At Bangkok Eye Hospital, timely diagnosis and assessment are critical. Diagnostic procedures include: Dilated fundus examination to visualize blood flow and retinal health Optical Coherence Tomography (OCT) to detect retinal swelling or fluid accumulation Fluorescein angiography to assess blood circulation in the retina Ultrasound (B-scan) if there is significant hemorrhage Blood tests and cardiovascular screening to investigate underlying systemic conditions Carotid artery ultrasound and echocardiography, if embolism is suspected Early intervention improves outcomes, particularly in CRAO cases where treatment within hours is most effective. Treatment Options for Retinal Vascular Occlusion There is no single cure, but various treatment options aim to restore circulation, reduce swelling, and prevent further vision loss. For Artery Occlusion (CRAO/BRAO) Immediate ocular massage and breathing into a paper bag to increase CO₂ and dilate vessels Reducing intraocular pressure using medication or anterior chamber paracentesis Hyperbaric oxygen therapy in select cases Management of cardiovascular risk factors and antiplatelet therapy Unfortunately, recovery is limited if treatment is delayed beyond a few hours. For Vein Occlusion (CRVO/BRVO) Intravitreal injections of anti-VEGF drugs (e.g., ranibizumab, aflibercept) to reduce macular edema Intravitreal steroids for inflammation and swelling Laser photocoagulation to treat neovascularization or ischemic areas Ongoing monitoring to prevent complications such as neovascular glaucoma Treatment is usually ongoing and requires regular follow-ups. Complications of Retinal Vascular Occlusion If untreated, vascular occlusion can lead to: Permanent vision loss Macular edema Neovascularization (abnormal vessel growth) Glaucoma (due to increased pressure) Retinal hemorrhage or detachment Managing systemic conditions such as hypertension and diabetes is crucial to prevent recurrence. Prevention and Risk Management Maintain healthy blood pressure and cholesterol levels Manage blood sugar in diabetic patients Stop smoking Exercise regularly and follow a balanced diet Attend regular eye exams, especially if you have cardiovascular risk factors Take prescribed blood thinners or antiplatelet drugs under medical supervision Early detection of changes in the eye’s blood vessels can reduce the risk of future blockages. Related Services at Bangkok Eye Hospital Bangkok Eye Hospital offers a range of specialized services for vascular-related eye conditions: Retinal Disease and Macula ClinicFor diagnosis and long-term management of occlusions, edema, and ischemia Fluorescein Angiography and OCT CenterFor high-resolution imaging of retinal blood flow and structure Intravitreal Injection UnitFor anti-VEGF and steroid therapy Cardiovascular and Diabetes Eye ScreeningEarly detection for at-risk individuals Emergency Eye Care UnitFor sudden vision loss or acute vascular episodes Frequently Asked Questions (FAQs) Is retinal vascular occlusion the same as a stroke?Yes, in many ways. CRAO is often referred to as an "eye stroke" and is an emergency requiring immediate medical attention. Can vision be restored after an occlusion?Partial recovery is possible, especially in vein occlusions. Arterial occlusions have a narrow treatment window for recovery. What’s the difference between CRAO and CRVO?CRAO involves an artery supplying blood to the retina, while CRVO involves a vein draining blood away. Symptoms and treatment differ. Who is most at risk for retinal vascular occlusion?People over age 50 with high blood pressure, diabetes, high cholesterol, or heart disease are at higher risk. How can I prevent future occlusions?By managing systemic health conditions, quitting smoking, and having regular eye exams to monitor eye and vascular health.

What Does It Mean When Your Eyes Are Yellow? Yellowing of the eyes — whether in the sclera (white of the eye) or as yellow discharge (eye mucus) — is not a condition in itself but a visible symptom that can signal a range of underlying health issues, from minor eye infections to serious systemic diseases like liver dysfunction or biliary disorders. Understanding what causes yellowing in or around the eyes is essential to determining when to seek medical attention and what treatment is needed. Yellowing of the Sclera (Yellow Eye Whites) When the whites of your eyes turn yellow, this is medically referred to as scleral icterus. It usually indicates a buildup of bilirubin, a yellow pigment produced during the normal breakdown of red blood cells. Common Causes: Liver diseaseSuch as hepatitis, cirrhosis, or fatty liver disease Gallbladder or bile duct obstructionIncluding gallstones or tumors blocking bile flow Hemolytic anemiaRapid breakdown of red blood cells leading to bilirubin overload Pancreatic diseaseConditions that interfere with bile drainage Alcohol-related liver damage Newborn jaundiceTemporary condition in infants due to immature liver function This yellowing of the eyes often appears alongside jaundice in the skin and may be accompanied by other symptoms such as fatigue, dark urine, or abdominal pain. Yellow Eye Discharge (Yellow Mucus in Eyes) Unlike scleral yellowing, yellow discharge from the eyes is typically a sign of an ocular infection or inflammation. It may appear as crust around the eyes in the morning or sticky mucus during the day. Common Causes: Bacterial conjunctivitis (pink eye)Characterized by thick yellow or green discharge, redness, and irritation BlepharitisChronic eyelid inflammation leading to yellowish crusting Blocked tear duct (especially in infants)Causes fluid and mucus to accumulate KeratitisInfection of the cornea, may include pain, blurred vision, or light sensitivity Eye injuriesResulting in secondary infection or discharge Allergic conjunctivitisUsually produces clear discharge, but can mix with mucus and bacteria If yellow discharge is persistent or associated with pain, swelling, or blurred vision, it should be assessed by an eye doctor. When to Worry About Yellow Eyes You should seek urgent medical evaluation if: Both eyes show sudden yellowing Yellowing is accompanied by jaundice or dark urine Yellow discharge is thick and persistent You experience eye pain, light sensitivity, or vision changes You have a history of liver disease or substance use Early detection of systemic or ocular conditions can prevent serious complications, including vision loss or organ damage. Diagnosis at Bangkok Eye Hospital At Bangkok Eye Hospital, we provide a comprehensive evaluation to determine the cause of yellow eyes or discharge. Diagnosis may include: Slit-lamp eye examination to assess the cornea, conjunctiva, and discharge Tear duct assessment in infants or adults with chronic discharge Liver function blood tests (AST, ALT, bilirubin) if scleral icterus is present Ultrasound or imaging of the liver and biliary tract if indicated Conjunctival swab or culture for infection detection We also work closely with internal medicine or hepatology specialists when liver disease is suspected. Treatment Options Treatment depends on the underlying cause: For Yellow Sclera (Systemic Cause): Liver disease management: Includes antiviral therapy, alcohol cessation, or liver support Gallstones or biliary obstruction: May require surgical removal or stenting Dietary changes: For fatty liver or metabolic conditions Medical management: For autoimmune liver conditions or genetic disorders For Yellow Eye Discharge (Ocular Cause): Antibiotic eye drops or ointments: For bacterial conjunctivitis or keratitis Warm compresses and lid hygiene: For blepharitis or mild discharge Tear duct massage or minor surgery: For blocked tear ducts Steroid drops (under supervision): For severe inflammation Lubricating drops: For dry eyes or irritation-related discharge How to Prevent Eye Discoloration or Discharge Maintain good hand and facial hygiene Avoid sharing towels, cosmetics, or eye drops Treat systemic conditions such as diabetes or liver disease promptly Wear protective eyewear in dusty or hazardous environments Use contact lenses properly and cleanly Regular eye exams can also detect early signs of systemic illness and protect your vision. Related Services at Bangkok Eye Hospital To ensure complete and individualized care, Bangkok Eye Hospital offers: Ocular Surface and Red Eye ClinicFor discharge, infection, and conjunctivitis Corneal and Anterior Segment ClinicFor keratitis, foreign bodies, and trauma Comprehensive Eye ExaminationsScreening for early signs of systemic or ocular disease Pediatric Eye CareFor blocked tear ducts and neonatal eye conditions Multidisciplinary Referral SystemFor cases involving liver or systemic disease requiring internal medicine collaboration Frequently Asked Questions (FAQs) Is yellow sclera always a sign of liver disease?Often, yes. Yellow sclera usually indicates elevated bilirubin levels, commonly from liver or bile duct issues. Can an eye infection cause yellow discharge without redness?Usually, yellow discharge is associated with some degree of redness or irritation, but mild cases may not be obvious. Can I treat yellow eye discharge at home?Mild cases may improve with warm compresses and eyelid cleaning, but antibiotics may be necessary for bacterial infections. Is yellow eye discharge contagious?If caused by bacterial or viral conjunctivitis, yes — it can be contagious through contact with secretions.   Can newborns have yellow eyes or discharge?Yes. Newborn jaundice is common and usually temporary. Yellow discharge can result from a blocked tear duct, which often resolves over time but may require treatment.