Uveitis: Understanding Eye Inflammation, Causes, and Steroid Treatment

Uveitis isn’t just a red eye. It’s inflammation deep inside your eye - in the uvea, the middle layer that feeds the retina and iris. Left untreated, it can silently damage your vision, sometimes leading to permanent blindness. It’s the third leading cause of vision loss worldwide, yet most people don’t know the signs until it’s too late. If you’re experiencing sudden eye redness, pain when reading, light sensitivity, or floaters that won’t go away, this isn’t just tired eyes. It could be uveitis.

What Exactly Is the Uvea?

The uvea is made up of three parts: the iris (the colored part of your eye), the ciliary body (which helps focus your lens), and the choroid (a layer full of blood vessels that nourishes the retina). When inflammation hits any of these, it’s called uveitis. This isn’t surface-level irritation. It’s internal swelling that can crush the delicate structures inside your eye.

Think of it like a leaky pipe inside your home. You might not see the water at first, but over time, it rots the walls, warps the floors, and ruins the foundation. Uveitis works the same way - damage builds quietly until your vision starts to blur or fade.

Four Types of Uveitis - And Why It Matters

Not all uveitis is the same. Where the inflammation happens determines your symptoms, treatment, and risk level.

• Anterior uveitis (iritis) affects the front - the iris and ciliary body. This is the most common type, making up 75% to 90% of cases. Symptoms hit fast: intense redness, sharp pain, sensitivity to light, and blurry vision. It often affects just one eye and responds well to treatment if caught early.
• Intermediate uveitis (pars planitis) targets the vitreous - the jelly-like fluid in the middle of your eye. You won’t feel much pain, but you’ll notice floaters - dark spots or squiggles floating across your vision - and blurred sight. This type loves to stick around, turning chronic and flaring up for months or even years.
• Posterior uveitis hits the back of the eye: the retina and choroid. It’s the most dangerous. Vision loss can creep in slowly, often without pain. Many people don’t realize they have it until a routine eye exam reveals damage. It usually affects both eyes and carries the highest risk of permanent vision loss.
• Panuveitis means inflammation across all layers. It’s the most severe form. Symptoms combine everything: redness, pain, floaters, blurred vision, and rapid vision decline. It’s often linked to serious autoimmune or infectious diseases.

What Causes Uveitis? The Real Story

Doctors can find a clear cause in only about two-thirds of cases. The rest? Idiopathic - meaning no obvious trigger shows up on tests. That doesn’t mean it’s random. It means your immune system is attacking your eye for reasons we don’t fully understand yet.

When there is a cause, it usually falls into three buckets:

• Autoimmune diseases: Conditions like ankylosing spondylitis, multiple sclerosis, sarcoidosis, or rheumatoid arthritis can turn your immune system against your own eye tissue.
• Infections: Viruses like herpes simplex, herpes zoster (shingles), or cytomegalovirus (CMV) can trigger inflammation. Bacterial infections like syphilis or toxoplasmosis (from undercooked meat or cat litter) are also culprits.
• Trauma or surgery: A blow to the eye, a scratch, or even eye surgery can spark inflammation as your body tries to heal.

Here’s the catch: even if you have an autoimmune disease, uveitis doesn’t always happen. And if you have uveitis, you might never develop the full-blown disease. It’s not a guarantee - just a warning sign your body’s defenses are misfiring.

Why Steroids Are the First Line of Defense

Corticosteroids - powerful anti-inflammatory drugs - are the go-to treatment for almost every type of uveitis. They work fast. They reduce swelling. They stop tissue damage before it becomes permanent.

But how you get them depends on where the inflammation lives:

• Anterior uveitis: Steroid eye drops - like prednisolone acetate 1% - are the standard. You’ll start with drops every hour or two, then taper down over weeks as the swelling fades. Most people recover fully with this approach.
• Intermediate uveitis: Eye drops don’t reach deep enough. You’ll likely need a steroid injection around the eye (periocular) or an implant that slowly releases medication inside the eye (intravitreal).
• Posterior uveitis and panuveitis: Oral steroids like prednisone are often needed. Sometimes, you’ll get a combination of injections and pills. The goal is to get enough drug into the back of the eye to calm the inflammation.

Timing is everything. The sooner you start steroids, the less likely you are to develop complications like macular edema (swelling in the central vision zone), synechiae (iris sticking to the lens), or glaucoma from increased eye pressure.

The Hidden Risk: Steroid Side Effects

Steroids save your vision - but they can hurt it too, if used too long.

Long-term steroid use raises your risk of:

• Cataracts: Clouding of the eye’s natural lens. Up to 40% of people on long-term steroids develop them.
• Steroid-induced glaucoma: Pressure builds inside the eye, damaging the optic nerve. This can happen even without symptoms.
• Increased infection risk: Steroids suppress your immune system. A simple eye scratch can turn serious.

That’s why doctors don’t just prescribe steroids and walk away. They monitor you closely - checking eye pressure, scanning for cataracts, and adjusting doses. For chronic cases, they often switch to steroid-sparing drugs like methotrexate or mycophenolate. These slow your immune system down without the same side effects.

When to See a Doctor - Right Now

Uveitis doesn’t wait. It doesn’t care if it’s Monday or you’re busy. If you notice any of these, get to an eye specialist within 24 hours:

• Redness that doesn’t go away after a day or two
• Pain that gets worse when you read or focus
• Sudden floaters or flashes of light
• Blurry vision that doesn’t clear up with glasses
• Extreme sensitivity to light - even indoor lighting hurts

Don’t wait for it to get worse. Don’t assume it’s allergies or dry eyes. If your eye feels off, especially with pain or vision changes, treat it like an emergency. Early treatment can mean the difference between seeing clearly and losing sight.

What Happens If You Ignore It?

Uveitis can scar your iris, stick your pupil to your lens, swell your retina, or destroy your optic nerve. Once that damage is done, it’s often permanent. You might not go completely blind - but you could lose your central vision, your color perception, or your ability to read or drive.

Chronic cases - especially intermediate and posterior uveitis - can flare again and again. Each flare adds more damage. That’s why long-term management isn’t optional. It’s survival.

Living With Uveitis: Beyond Steroids

Once the inflammation is under control, you’re not done. You need follow-ups - every few weeks at first, then every few months. Your doctor will check your eye pressure, take images of your retina, and watch for signs of recurrence.

If you have an underlying autoimmune disease, you’ll likely work with a rheumatologist. Controlling your whole-body inflammation helps keep your eyes safe.

Wear sunglasses outdoors. Bright light can irritate inflamed eyes. Avoid smoking - it worsens inflammation. And never skip your eye drops, even if your eye looks fine. Stopping too soon can trigger a flare.

Uveitis isn’t something you cure and forget. It’s a condition you manage. But with the right care, most people keep their vision for life.