Uveitis is the swelling of the uvea, the pigmented sheeting that lies in the middle of the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea comprises the middle layer of pigmented vascular structures of the eye and includes the iris, ciliary body, and choroid.
WHAT IS UVEITIS?
WHAT ARE THE TYPES OF UVEITIS?
Uveitis is usually classified by where it occurs in the eye. Uveitis is usually classified by where it occurs in the eye.
What is anterior uveitis?
Anterior uveitis occurs in the front of the eye. It is the most common form of uveitis, frequently occurring in young and middle-aged people. Many cases occur in healthy people and may only affect one eye but some are associated with rheumatologic, skin, gastrointestinal, lung, and infectious diseases.
What is intermediate uveitis?
Intermediate uveitis is commonly seen in young adults. The center of the inflammation often appears in the vitreous (see diagram). It has been linked to several disorders including, sarcoidosis and multiple sclerosis.
What is panuveitis?
Panuveitis is a term used when all three major parts of the eye are affected by inflammation. Behcet’s disease is one of the most well-known forms of panuveitis and it greatly damages the retina.
Intermediate, posterior, and panuveitis are the most severe and highly recurrent forms of uveitis. They often cause blindness if left untreated.
The signs, symptoms and characteristics of uveitis may include:
- Eye redness
- Eye pain
- Light sensitivity
- Blurred vision
- Dark, floating spots in your field of vision (floaters)
- Decreased vision
Symptoms may occur suddenly and get worse quickly, though in some cases, they develop gradually. They may affect one or both eyes. Occasionally, there are no symptoms, and signs of uveitis are observed on a routine eye exam.
The uvea is the middle layer of tissue in the wall of the eye. It consists of the iris, the ciliary body, and the choroid. When you look at your eye in the mirror, you will see the white part of the eye (sclera) and the colored part of the eye (iris).
The iris is located inside the front of the eye. The ciliary body is a structure behind the iris. The choroid is a layer of blood vessels between the retina and the sclera. The retina lines the inside of the back of the eye, like wallpaper. The inside of the back of the eye is filled with a gel-like liquid called vitreous.
The type of uveitis you have depends on which part or parts of the eye are inflamed:
- Anterior uveitis affects the inside of the front of your eye (between the cornea and the iris) and the ciliary body. It is also called iritis and is the most common type of uveitis.
- Intermediate uveitis affects the retina and blood vessels just behind the lens (pars plana) as well as the gel in the center of the eye (vitreous).
- Posterior uveitis affects a layer on the inside of the back of your eye, either the retina or the choroid.
- Panuveitis occurs when all layers of the uvea are inflamed, from the front to the back of your eye.
The cause of uveitis is often unknown and frequently occurs in otherwise healthy people. It can sometimes be associated with another illness such as an autoimmune disorder or an infection from a virus or bacteria.
An autoimmune disease occurs when your immune system attacks a part of your body. Autoimmune conditions that may be associated with uveitis include:
- Rheumatoid arthritis
- Ankylosing spondylitis
- Ulcerative colitis
- Kawasaki disease
- Crohn’s disease
Infections are another cause of uveitis, including:
- CMV retinitis
- West Nile virus
Infections are another cause of uveitis, including:
- Exposure to a toxin that penetrates the eye
Uveitis can affect any age from infancy onwards, however, the average age of patients presenting with this condition is 40 years. A uveitis diagnosis requires a thorough examination by an ophthalmologist, including a detailed look into your past and present health history.
The type of eye examinations used to establish a uveitis diagnosis is:
- An eye chart or visual acuity test,
- A funduscopic exam,
- An ocular pressure test,
- A slit lamp exam.
Treatment for uveitis depends on what’s causing it and which area of the eye is affected.
Medicine is the main treatment, but in rare cases, surgery may be recommended to treat particularly severe uveitis.
Most cases of uveitis can be treated with steroid medicine. Steroids work by disrupting the normal function of the immune system so it no longer releases the chemicals that cause inflammation. Steroid medicines come in different forms, and the type used will often depend on the areas of your eye affected by uveitis.
Steroid eye drops
Steroid eye drops are usually the first treatment used for uveitis that affects the front of the eye and is not caused by an infection.
Depending on your symptoms, the recommended dose can range from having to use eye drops every hour to once every 2 days.
You may have temporary blurred vision after using the drops. Do not drive or operate machinery until your vision returns to normal.
In some people, steroid eye drops can increase pressure in the eye. The eye specialist (ophthalmologist) will check for this and advise you if this happens.
Do not stop using your eyedrops until a GP or ophthalmologist tells you it’s safe to stop, even if your symptoms disappear. Stopping treatment too soon could lead to your symptoms returning. The frequency of drops will usually be slowly reduced over a number of weeks.
If the middle or back of your eye is affected or steroid eye drops have not worked, you may need steroid injections.
Local anesthetic eye drops are used to numb your eye so you will not feel any pain or discomfort.
You’ll usually only require 1 injection while your symptoms are at their worst.
Steroid injections rarely cause significant side effects, but in some people, they can make the pressure in the eye increase. The ophthalmologist will check for this and advise you if this happens.
Steroids tablets or capsules
Steroids tablets or capsules are the strongest forms of steroids. They’re usually used if steroid eye drops and injections have not worked or are unsuitable, or for uveitis affecting the back of the eye.
Steroids tablets can cause a wide range of side effects, so will only be recommended if it’s thought there’s a risk of permanent damage to your vision.
How long you’ll have to take steroid tablets depends on how well you respond to treatment and whether you have an underlying autoimmune condition.
Some people only need to take them for 3 to 6 weeks, while others need to take them for months or possibly years.
Short-term side effects of steroids tablets or capsules can include weight gain, increased appetite, insomnia, and mood changes such as feeling irritable or anxious.
In the long term, they can cause osteoporosis, thinning of the skin, and an increased risk of infection.
To minimize any side effects, you’ll be prescribed the lowest possible dose to control your symptoms.
Do not stop taking steroids until a doctor says it’s safe to do so. Suddenly stopping your medicine can cause unpleasant withdrawal effects.
When a GP or ophthalmologist thinks you can stop the treatment, they’ll advise you about how to gradually reduce the number of steroids you’re taking.
Mydriatic eye drops
If you have uveitis that affects the front of your eye (anterior uveitis), you may be given mydriatic eye drops as well as steroid medicine.
These eye drops enlarge (dilate) your pupils and relieve pain by relaxing the muscles in your eye. They can also reduce your risk of developing glaucoma, which affects vision.
However, mydriatic eye drops can cause some temporary blurring of your vision and problems focusing on your eyes.
If an underlying infection is causing uveitis, the infection may also need to be treated.
Viruses can be treated with antiviral medicine. Bacterial infections can be treated with antibiotics. Fungal infections can be treated with antifungal medicine.
Immunosuppressants may be recommended if you’re among the few people who do not respond to the treatments described above.
Immunosuppressants work by controlling the immune system and disrupting the process of inflammation.
If steroid treatment is causing significant side effects, immunosuppressants can also be used to allow your dose of steroids to be reduced.
Possible side effects of immunosuppressants include:
- Skin rash
- Numbness or tingling in different parts of your body
- Loss of appetite
- Nausea and vomiting
- High blood pressure
- Hair loss
Taking immunosuppressants will make you more vulnerable to infection, so you should try to avoid close contact with anyone who has a known infection.
Report any symptoms of a potential infection, such as a high temperature, cough, or inflammation in other parts of your body, to a GP. You should also have the annual flu vaccine.
Immunosuppressants can also affect the functioning of some of your organs and systems in your body, such as your lungs, liver, kidneys and bone marrow. Regular blood tests are needed to check these systems remain healthy.
A small number of people with uveitis can benefit from treatment with immunosuppressants known as biologics.
Rarely, an operation called a vitrectomy may be needed to treat uveitis. It’s usually only recommended if you have repeated or severe uveitis, or if the situation is caused by infections.
A vitrectomy involves gently sucking out the jelly-like substance that fills the inside of the eye (vitreous humor). It can be done using either a general anesthetic or a local anesthetic.
During the operation, the fluid inside your eye will be temporarily replaced with either a bubble of air or gas (or a mixture of the 2) or a liquid substitute. Eventually, the vitreous humor will naturally replace itself.
Like all operations, a vitrectomy carries a risk of complications. These include needing further surgery and an increased risk of developing cataracts.