What Is Uveitis?

Many patients look up uveitis after being told their red, aching, light-hurting eye is not simple conjunctivitis. Others come in because a bright room or oncoming headlights suddenly feel painful, or because floaters and haze appeared and would not clear. The word sounds alarming, and people want to understand what part of the eye is inflamed, why it happened to them, and whether their sight is at risk.

The uvea is the pigmented, blood-vessel-rich middle layer of the eye, between the white outer wall and the light-sensing retina. Because it is so vascular, it is a common target for inflammation, whether from the immune system or an infection. When it inflames, white blood cells and protein spill into the normally clear fluid inside the eye, which is what the doctor sees at the slit lamp and what blurs and irritates your vision.

Where the inflammation sits determines what you feel. Anterior uveitis inflames the iris, causing a deep ache, redness around the cornea, and painful light sensitivity, sometimes with the pupil sticking to the lens. Intermediate and posterior uveitis inflame deeper structures and the retina, producing floaters, haze, and dimmed or distorted central vision. The complications that steal sight, including raised eye pressure, cataract, and swelling of the central retina, come from inflammation left unchecked.

Uveitis has many causes. A large share is immune-mediated: anterior uveitis is strongly associated with the HLA-B27 gene and conditions like ankylosing spondylitis and reactive arthritis, while other cases connect to sarcoidosis, juvenile idiopathic arthritis, Behcet disease, or inflammatory bowel disease. Infections can also cause it, including herpes viruses, shingles involving the eye, toxoplasmosis, syphilis, and tuberculosis. Some cases follow trauma or surgery, and many remain idiopathic despite a proper search.

The course varies by type. Anterior uveitis is often acute and can recur, sometimes in the same eye. Intermediate, posterior, and panuveitis are more likely chronic and carry a higher risk to central vision. Some patients, such as children with juvenile arthritis, can have quiet, painless uveitis that is dangerous precisely because it produces few symptoms, which is why at-risk groups are screened even when they feel fine.

Uveitis is a prompt-care condition, and some features make it more urgent. Get examined quickly, and seek same-day care, if you have:

• A red, painful eye with strong light sensitivity, especially with blurred vision.
• New floaters with dimming or distorted vision, which can mean the back of the eye is involved.
• A rapid drop in vision, severe pain, or symptoms in the second eye.

Because uveitis can quietly raise eye pressure or swell the retina, do not simply watch it, and do not treat it as ordinary conjunctivitis.

Diagnosis is made mainly at the slit lamp, where the doctor sees inflammatory cells and protein in the front of the eye and grades how active the inflammation is. Eye pressure is measured, because uveitis can raise or lower it. The pupil is dilated for a careful look at the vitreous, retina, and optic nerve to check for deeper involvement, and OCT imaging documents swelling of the central retina. When the cause is unclear or the uveitis is recurrent, bilateral, or in the back of the eye, targeted blood tests and imaging (such as HLA-B27, chest imaging for sarcoid, and tests for syphilis, tuberculosis, or toxoplasmosis) look for a systemic or infectious source.

The core of treatment is controlling inflammation while protecting the eye's structures. Anterior uveitis is usually treated with steroid eye drops on a tapering schedule, along with a dilating drop that eases painful spasm and prevents the iris from scarring to the lens. More severe, deeper, or chronic uveitis may need steroid injections around or inside the eye, oral steroids, or longer-term immune-suppressing medication managed with a rheumatologist. If an infection is the cause, that infection is treated specifically rather than steroids alone. Complications such as raised pressure, cataract, or retinal swelling are treated in their own right, and the underlying disease is addressed to reduce future flares.

• Do not treat a painful, light-sensitive red eye as ordinary pink eye or wait it out.
• Do not use leftover steroid drops on your own; steroids can be harmful if the cause is a herpes infection and can raise eye pressure without monitoring.
• Do not stop prescribed drops abruptly once you feel better, because stopping too soon commonly triggers a rebound flare.
• Do not skip follow-up visits or the recommended tests to find an underlying cause, especially with recurrent or two-eye disease.

Call promptly if you have a red, aching, light-sensitive eye, new floaters, or blurred vision that does not clear, since these can mean inflammation inside the eye. Sudden pain with vision loss deserves same-day care. May Eye Care Center, serving the Hanover, Pennsylvania area, can examine the eye at the slit lamp, start treatment, and, when needed, look for the systemic cause behind recurrent inflammation.

Uveitis is inflammation inside the eye that is often tied to autoimmune or infectious disease and can threaten sight, so a painful, light-sensitive, or blurry eye should be examined promptly rather than treated like pink eye.