Uveitis vs Conjunctivitis: Understanding the Difference Between These Eye Conditions
Inflammation of the eyes is commonly seen in two conditions - uveitis and conjunctivitis. While both cause red, irritated eyes, uveitis and conjunctivitis have different underlying causes and require different treatments.
What is Uveitis?
Uveitis refers to inflammation of the middle layer of the eye called the uvea, which contains blood vessels and nerves. It can affect one or both eyes. Uveitis is broadly categorized into anterior, intermediate, posterior, and panuveitis types based on the part of the uvea affected.
Anterior Uveitis
Anterior uveitis, also known as iritis, involves inflammation of the iris and adjacent tissues in the front of the eye. It accounts for 50-90% of uveitis cases.
Intermediate Uveitis
Inflammation of the ciliary body and vitreous humor in the middle part of the eye is termed intermediate uveitis.
Posterior Uveitis
Posterior uveitis affects the back of the eye including the choroid, retina, and optic nerve.
Panuveitis
Panuveitis refers to inflammation of the entire uvea spanning the iris, ciliary body, and choroid.
Underlying Causes of Uveitis
Various conditions can trigger uveitis, including:
- Autoimmune disorders like ankylosing spondylitis, sarcoidosis, and inflammatory bowel disease
- Infections such as herpes, toxoplasmosis, tuberculosis, and Lyme disease
- Eye injuries that damage the uvea
- Complications from surgery
- Cancer that spreads to the eye
However, the exact cause is unknown in over half of uveitis cases. These are termed idiopathic uveitis.
Uveitis Symptoms
Common symptoms of uveitis include:
- Redness, pain, and light sensitivity in the affected eye(s)
- Blurred vision
- Small pupil size
- Floaters or dark spots in vision
- Headache
- Eye discharge or excessive tearing
Symptoms can develop rapidly and often affect only one eye initially. Without treatment, uveitis may lead to complications like glaucoma, cataracts, and permanent vision loss.
Uveitis Diagnosis and Treatment
Diagnosing uveitis involves a comprehensive eye exam and medical history. Tests may include:
- Visual acuity assessment
- Eye pressure measurement
- Slit lamp exam
- Imaging tests like X-ray, CT, or MRI
- Blood tests
Mild acute anterior uveitis may resolve with steroid eye drops to reduce inflammation. Other medications like cycloplegic or mydriatic eye drops and oral pain relievers may also be prescribed. For chronic or severe uveitis, steroid injections into or around the eye along with immunosuppressive medications are required. Prompt treatment helps prevent permanent eye damage and vision loss.
What is Conjunctivitis?
Conjunctivitis refers to inflammation of the conjunctiva, the thin transparent membrane covering the outer surface of the eye and inner eyelid. It is commonly called pinkeye or red eye.
Infectious Conjunctivitis
Infections are the most common cause of conjunctivitis. Viruses like adenovirus are the primary source, while bacteria (Staphylococcus, Streptococcus, etc.) and fungi also trigger infectious conjunctivitis. It spreads easily through contact with discharge from the infected eye.
Allergic Conjunctivitis
Allergies to pollen, pet dander, perfumes, smoke, and other irritants provoke allergic conjunctivitis. It may occur alone or with other allergy symptoms.
Chemical Conjunctivitis
Irritating chemicals like cleaning products, cosmetics, chlorinated pools, and air pollution can cause chemical conjunctivitis by damaging the conjunctiva.
Conjunctivitis Symptoms
Common conjunctivitis symptoms include:
- Redness in one or both eyes
- Itchy, burning, or gritty eyes
- Excess tear production and discharge
- Crusting of eyelids or lashes
- Sensitivity to light
- Mild eye pain or foreign body sensation
Viral and bacterial conjunctivitis also cause swollen eyelids and a sticky, pus-like discharge. Symptoms typically start in one eye then spread to the other. Vision is generally unaffected.
Conjunctivitis Diagnosis and Treatment
A physician can diagnose conjunctivitis by examining the eyes and asking about symptoms. Specific tests are rarely needed. Mild symptoms can be managed with cool compresses, ocular decongestants, and antihistamine eye drops. Antibiotic eyedrops or ointments are prescribed for bacterial conjunctivitis. Viral and allergic conjunctivitis are self-limiting but may be relieved with lubricating drops. Avoid wearing contact lenses until the infection clears.
Key Differences Between Uveitis and Conjunctivitis
Although redness is seen in both conditions, uveitis and conjunctivitis have distinct differences summarized below:
Parts of the Eye Affected
- Uveitis involves the uvea in the middle of the eye.
- Conjunctivitis affects the conjunctiva outer layer.
Underlying Cause
- Uveitis often arises from autoimmune disorders, infections, cancer, etc.
- Conjunctivitis is caused by viruses, bacteria, allergens, or irritants.
Onset and Duration
- Uveitis develops rapidly and lasts longer without treatment.
- Conjunctivitis comes on more gradually and is often self-limiting.
Symptoms
- Uveitis causes eye pain, blurry vision, light sensitivity, and headaches.
- Conjunctivitis leads to itching, burning, tearing, and discharge.
Complications
- Uveitis can severely impair vision and damage the eye if left untreated.
- Conjunctivitis does not affect vision and resolves on its own.
Treatment
- Uveitis requires prescription steroidal and immunosuppressive medications.
- Mild conjunctivitis can be managed with OTC eyedrops and compresses.
When to Seek Emergency Care
Seek prompt medical attention if you experience:
- Sudden loss of vision
- Intense eye pain
- Nausea/vomiting
- Sensation of curtain falling over the eye
- Significant light sensitivity or blurry vision
- Redness with pus-like discharge
These symptoms may indicate a serious eye condition like acute glaucoma or globe rupture and require emergency care to prevent permanent damage.
The Takeaway
While uveitis and conjunctivitis both cause red, irritated eyes, uveitis involves inflammation of the middle layer of the eye that can permanently impair vision if not treated quickly. Conjunctivitis stems from an external eye infection or allergen causing milder symptoms. See an ophthalmologist urgently for eye redness with vision changes or severe pain, which may be signs of uveitis requiring prompt treatment. Be aware of the key differences between these conditions to ensure proper diagnosis and management.
FAQs
Is uveitis contagious?
In most cases, uveitis itself is not contagious. However, some underlying infections that cause uveitis like herpes are contagious. Bacterial forms of conjunctivitis are very contagious through eye discharge contact.
Can conjunctivitis cause blindness?
Conjunctivitis does not cause blindness or long-term vision loss. However, untreated uveitis can lead to permanent blindness if eye damage is severe.
What's the fastest way to get rid of conjunctivitis?
Viral conjunctivitis goes away on its own in 1-2 weeks. Bacterial conjunctivitis is treated with antibiotic eyedrops to speed recovery. Strict hygiene helps prevent spreading conjunctivitis.
Can contacts cause uveitis?
No, contact lenses do not directly cause uveitis. But those with uveitis should avoid contacts until the condition resolves as they may worsen inflammation and eye irritation.
When to see a doctor for red eyes?
See a doctor immediately if red eyes are accompanied by impaired vision, eye pain, sensitivity to light, or headache. These may indicate uveitis requiring prompt treatment.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.
Add Comment