An injury to the eye, a viral or bacterial infection, and some underlying diseases may cause uveitis. It can cause swelling and damage in the tissues of the eye. Untreated, it can lead to vision loss. It can affect one or both eyes.
The term uveitis is not only used to refer to an inflammation of the uvea, but to any part of the inside of the eye. It is not a single disease, and it has different causes.
It is the fifth leading cause of vision loss in the United States, and so it has serious social and economic implications.
It mainly affects people aged from 20 years to 60 years.
Types of uveitis
Red eye can be a sign of uveitis.
The uvea consists collectively of the iris, the choroid of the eye, and the ciliary body. Inflammation of the iris, or iritis, is the most common type of uveitis.
The uvea is also known as the uveal layer, uveal coat, uveal tract, or vascular tunic.
The uvea consists of:
- The iris, the colored part of the eye that surrounds the pupil
- The pars plana, one of the layers of the eye
- The choroid, a thin, vascular middle layer between the white of the eye, or the sclera, and the retina, the light-sensing part at the back of the eye
- The ciliary body, a ring of muscle behind the iris; this body of tissue connects the iris with the choroid
There are different types of uveitis.
Anterior uveitis is also known as iritis, affects the colored part of the eye, the iris. Iridocyclitis is similar, but it include inflammation of the ciliary body.
Intermediate uveitis can be vitritis or pars planitis. Vitritis is an inflammation of the jelly-like part of the eye, the vitreous cavity. An inflammation of the pars plana is called pars planitis.
Posterior uveitis is an inflammation of the retina and choroid. Posterior refers to the back of the eye.
Pan-uveitis is an inflammation in all layers of the uvea.
Signs and symptoms
Signs and symptoms of uveitis may include:
- General vision problems, including blurred or cloudy vision
- Floaters, spots in the eye that look like tiny rods or chains of transparent bubbles floating around in the field of vision
- Eye pain and redness
- Photophobia, an abnormal sensitivity to light
- A small pupil
- Alteration of the color of the iris
Symptoms can appear on gradually or rapidly.
The exact cause of uveitis is often unclear, but some factors increase the chance of it happening.
- Juvenile arthritis, psoriasis and other autoimmune disorders, such as rheumatoid arthritis
- Inflammatory disorders, such as Crohn's disease, ulcerative colitis
- AIDS/HIV and other diseases that weaken the immune system
Uveitis may occur as a normal immune response to fight an infection inside the eye.
Research suggests that there may be a link between black tattoo ink and uveitis. It is thought that skin tattoeing may trigger an immune response that affects both the eyes and the skin, in some people.
Diagnosis, treatment, and complications
An ophthalmologist, or eye specialist, will ask about signs, symptoms, and general medical history.
A doctor will look at symptoms and check for underlying conditions.
It is important to know whether the uveitis is caused by an infectious process or an underlying disease.
If another condition appears to underlie the uveitis, the ophthalmologist may refer the patient to a specialist to make sure that condition receives proper treatment.
The ophthalmologist will look at the eye with a special slit lamp. When the light hits the inside of the eye, the doctor can determine whether that area is clear or foggy.
If there is inflammation in the iris, patients may feel some pain when the pupil contracts, which is when light hits it.
If uveitis is present, white blood cells and protein in the eye fluid can be seen through the microscope.
The doctor may also order blood tests and x-rays.
A patient with uveitis who receives prompt and appropriate treatment will usually recover. Without treatment, there is a risk of cataracts, glaucoma, band keratopathy, retinal edema, and permanent vision loss.
Antibiotics or antiviral medication will be used if there is an infection.
Corticosteroid medications are sometimes given as well, in the form of eye drops (prednisolone acetate), tablets, or as an injection into the eye. Steroids are effective in treating inflammation. Before giving corticosteroids, it is important rule out corneal ulcers by using a florescence dye test.
Immunosuppressants might be recommended if symptoms are very severe and there is a risk of vision loss, or if the patient has not responded well to other therapies.
Mydriatic eye drops, such as atropine or cyclopentolate, dilate the pupil and help the eye to heal. It also helps with eye pain and stops the pupil from sticking to the lens. There may be blurred vision and unusual sensitivity to light, known as photophobia.
With prompt and proper treatment and close monitoring, the chances of complications are significantly reduced.
If they do occur, they may include:
- Macular edema
- Scar tissue
- Retinal detachment, or detached retina
- Vision loss
Research is ongoing to find out who is most likely to develop uveitis, the possible causes, and new ways of treating it.