Types of Uveitis
Uveitis can come in three varieties, determined by the affected part of the uvea.
The most common form of the condition, anterior uveitis makes up three in four cases. It causes inflammation in the iris (the coloured part of the eye) which is known as iritis, or in both the iris and the ciliary body (a ring of muscles behind the iris) which is known as iridocyclitis. It causes pain and redness in the eye. Anterior uveitis can develop suddenly and may become recurrent.
Intermediate uveitis affects the part behind the ciliary body and vitreous jelly, leading to inflamation. It can lead to blurred vision and can result in seeing floaters (spots in your vision).
Posterior uveitis is inflammation at the back of the eye, the retina, and the choroid (a tissue layer that supports the retina), and can cause sight problems.
Panuveitis uveitis is when the entire eye, front and back, becomes affected by the condition.
Signs & Symptoms
Uveitis may present with one or more of the following symptoms:
- Reddening in the eye
- Pain in the eye – the eye may feel sore or tender, with the pain ranging from mild to severe. Trying to focus your eye may also make the pain worse.
- Peripheral Vision Loss
- Irregular Pupil Shape – it may not shrink when you shine light on it.
- Floaters (spots in your vision)
The symptoms of uveitis can affect one or both eyes, and onset can be rapid or slow. Sudden onset normally results in more pain and soreness, while chronic uveitis may present with more vision-affecting symptoms, without any distinguishing marks on their eyes.
Complications of Uveitis
There are some problems that may arise as a result of uveitis, and these can be made more likely if the condition isn’t treated well.
If you are over 60 years old, or if you have chronic, intermediate, or posterior uveitis, you may also be at more risk.
Sometimes the steroids used as treatment for uveitis can lead to complications. The following are common issues related to uveitis:
If uveitis goes untreated, it can result in the iris sticking to the outer layer of the lens, which can stop the drainage of fluid through the pupil and lead to increased intraocular pressure, also known as glaucoma. As a result the optic nerve can become damaged and your vision can become affected – you may experience foggy vision or rings around lights.
Glaucoma is usually treated with eye drops, however more severe cases may be given laser treatment or surgery.
Uveitis can lead to the development of cataracts due to the inflammation irritating the eye lens. This can lead to symptoms including blurry vision, poor night vision, and glare.
Cataracts are normally treated with surgery, however the uveitis should be well controlled and given treatment before this is considered.
Cystoid Macular Oedema
If your uveitis is affecting the back of the eye, this can lead to retinal swelling known as cystoid macular oedema. Fluid can collect in the macula if the swelling is prolonged, and this can lead to your central vision being lost without any pain.
The condition can be treated with corticosteroids, either with an injection or in tablet form, and in most cases vision is restored after treatment. However in severe instances the vision isn’t restored, making cystoid macular oedema a common cause of vision loss in uveitis patients.
In rare cases, the swelling caused by uveitis causes the retina to come apart from the blood vessels at the back of your eye – this is often treated similarly to uveitis. However if the detached retina was as a result of posterior uveitis caused by a viral infection, surgery may be required.
Retinal detachment can result in you seeing flashing lights and floaters, as well as further vision loss.
Posterior synechiae occurs when the iris and the lens stick together due to the inflammation, and can be more likely if the uveitis is untreated.
What Causes Uveitis?
Uveitis is generally linked to the body’s immune system, and while the cause of some cases may be unknown – this is known as idiopathic uveitis – many experts believe this is still related to a problem with the immune system.
Autoimmune conditions happen when the body’s healthy tissues are attacked by its own immune system. Uveitis can occur as a result of the following autoimmune conditions:
- Sarcoidosis – An inflammatory disease that affects the lungs, skin, and eyes.
- Multiple Sclerosis – A condition that affects the nervous system.
- Ankylosing Spondylitis – A condition that can affect the spine.
- Reactive Arthritis – Arthritis that affects joints, eyes, and genitals.
- Behcet’s Disease – An uncommon illness that results in ulcers on the mouth and genitals.
- Bowel Inflammation – Conditions such as Crohn’s disease or ulcerative colitis that can cause inflammation in the bowels.
- Psoriasis – When the immune system causes a disruption to normal skin cell production.
Infectious diseases can also result in uveitis, such as:
- Varicella-zoster virus – The cause of chickenpox and shingles.
- Tuberculosis – A condition that can cause uveitis if you are infected.
- Herpes Simplex Virus – The cause of cold sores.
- HIV and syphilis – These conditions can cause uveitis but it is rare.
- Toxoplasmosis – When parasitic germs from raw meat and soil cause an infection.
- Cytomegalovirus – A condition that can cause uveitis in people with weakened immune systems, but shouldn’t result in noticeable symptoms for most other people.
Other possible causes of uveitis include:
- Eye Surgery
- Eye Trauma
- Some Forms of Cancer
In some cases no cause may be found – this is known as idiopathic uveitis. While uveitis is not a genetic disease, therefore it can’t be inherited, your genes may make it more likely that you will develop it.
How is Uveitis Diagnosed?
Uveitis can be diagnosed by your GP or they might refer you to an ophthalmologist. The ophthalmologist normally uses a slit lamp (a microscope and light), but they may also take scans of your eyes as well as blood tests and X-rays.
Knowing what causes the symptoms can help eye specialists and GPs suggest a method of treatment.
How do you treat Uveitis?
Most cases of uveitis are treated by medication, however severe uveitis may require surgery. The treatment normally depends on the type of uveitis and the underlying cause.
Many cases of uveitis are treated by corticosteroids, normally using a medicine called prednisolone. They work by preventing the immune system from functioning properly so the chemicals that cause swelling aren’t released.
The type of corticosteroids you use depend on where the uveitis has affected your eye.
Anterior uveitis that isn’t caused by an infection is normally first treated using corticosteroid eye drops, with the dosage varying from hourly to every two days depending on the severity of the condition and normally reducing after a few weeks.
Corticosteroid eye drops can cause blurred vision, which means you shouldn’t operate machinery or drive after using them, and in some people the eye drops can also raise intra-ocular pressure. If this occurs your ophthalmologist will advise you on what to do.
You should continue using the eye drops even if your symptoms disappear as stopping the course prematurely may allow the symptoms to redevelop – only stop the treatment when your GP or eye care specialist tells you to.
Intermediate and posterior uveitis, or uveitis that doesn’t respond to the eye drops, may then be treated by corticosteroid injections. These can be given as subconjunctival (in the side of the eye) or periocular (around the eye area) injections, and local anaesthetic eye drops are normally given to ease soreness.
You may only need one injection, even while your symptoms are at their most severe. There are rarely any side effects associated with corticosteroid injections, however they may cause an increase in intraocular pressure – if this is the case, your ophthalmologist will give you advice on what to do.
The strongest form of corticosteroids are tablets or capsules, and they are normally used for posterior uveitis, or if other forms of corticosteroids aren’t effective. However, oral corticosteroids can have a number of side effects and are only usually recommended if your vision may be permanently damaged.
The dosage you will be given depends on your response to the treatment as well as any other underlying conditions that affect your immune system – some courses can last weeks while others can last years.
Oral corticosteroids can cause weight gain, increased appetite, mood swings, and insomnia in the short term, while in the long term they may result in fragile bones, thinning of the skin and a higher risk of infection. As there are many side effects, you will normally be given the smallest possible effective dosage.
Your GP or ophthalmologist should gradually reduce your dosage when they want to end your treatment, rather than stopping the course suddenly.
Mydriatic Eye Drops
As well as steroid medication, anterior uveitis can also be treated using mydriatic eye drops. They work by dilating your pupils and relaxing your eye muscles, relieving pain. They can also lower the risk of developing glaucoma by reducing the chance of the iris and lens sticking together.
Mydriatic eye drops can also cause blurred vision and trouble with focusing your eyes.
Treating the Infection
If the uveitis occurred as a result of an infection, treating the infection may also be required. The medication is normally taken alongside the steroids and drops – viral and fungal infections may need antiviral or antifungal medication, while bacterial infections normally require antibiotics.
If corticosteroids, eye drops, and treating the infection don’t work, you may be prescribed immunosuppressants. Immunosuppressants control the immune system and prevent it from causing inflammation.
They can be used to reduce the required dosage of steroids, however they can also present with the following side effects:
- High blood pressure
- Nausea and vomiting
- Body parts tingling or becoming numb
- Reducing your appetite
- A rash on your skin
- Your hair starting to fall out
Immunosuppressants can also make you more susceptible to infections, therefore you should avoid close contact with people who have an infection.
If your uveitis is severe or occurs frequently, or happens as a result of certain infections, you may require surgery. This involves a procedure called a vitrectomy, where the vitreous humour in your eye is gently sucked out and replaced temporarily by liquid or a bubble of air or gas, before the eye naturally replaces the vitreous humour with a slightly different fluid called the aqueous humour.
Vitrectomies, like all other surgeries, carry a risk of complications such as needing further surgery and a higher risk of cataract development.
You can also take steps to relieve your symptoms, such as:
- Taking painkillers like ibuprofen to reduce the pain.
- Wearing glasses to reduce the effects of photophobia.
- Using a warm flannel to soothe the inflammation.
- eye health