Intermediate uveitis: floaters, blurred vision and long-term care

Uveitis is inflammation of the uvea, the middle layer of the eye. The NHS describes it as a rare condition that can lead to vision loss if not treated early. Uveitis is named by where the inflammation sits: anterior (front), intermediate (middle), posterior (back) or panuveitis (all parts).

In intermediate uveitis the inflammation is mainly in the vitreous, the gel-like structure between the lens and the retina. Moorfields explains that blurred vision can result from cells and protein leaking from inflamed retinal blood vessels into the gel (retinal vasculitis), or from deposits behind the ciliary body, which is called pars planitis. The Dudley Group leaflet uses the term cyclitis for inflammation mainly of the ciliary body.

Moorfields lists the main symptoms as floaters (dots that move across the field of vision) and blurred vision, sometimes with mild redness. RNIB describes thick floaters, black dots, shapes and wispy lines that move across vision because tiny inflamed cells float in the gel. Vision may become gradually blurrier and occasionally you may be sensitive to light.

Because intermediate uveitis is usually painless, it can be easy to ignore. The NHS notes that uveitis symptoms can develop in hours and days or gradually over weeks and months, and that sometimes there are no symptoms at all.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you have eye pain, sensitivity to light, changes in your vision such as flashing or blurring, or very red eyes. It says to go to A&E or call 999 if you cannot see (loss of vision). Moorfields advises seeking urgent attention from an ophthalmologist when signs of uveitis come with sudden or pronounced blurred vision.

New floaters and flashes can also have other causes, including a retinal tear or detachment, which needs urgent assessment in its own right. Moorfields says an optometrist may also be able to detect uveitis if it is very severe and recommend referral to a uveitis specialist.

The NHS says that in most cases the cause of uveitis is unknown. Moorfields says approximately 40 per cent of people have no cause determined after investigation. Where a cause is found, it can include inflammatory or autoimmune conditions (for example sarcoidosis, ankylosing spondylitis, Behçet disease and inflammatory bowel disease), infections such as toxoplasmosis, herpes viruses, tuberculosis, Lyme disease and syphilis, injury or, rarely, eye surgery.

Moorfields notes that juvenile idiopathic arthritis is the most common identifiable cause of uveitis in children. The Dudley Group leaflet explains that most uveitis is caused by an autoimmune reaction, where the immune system attacks healthy cells by mistake, and that it may be associated with similar inflammation in other parts of the body.

The NHS says a GP who thinks you have uveitis will refer you to an eye specialist (ophthalmologist). The Dudley Group leaflet notes that your pupils may be dilated at visits, so you should not drive yourself to appointments, and that the doctor will take a thorough history to look for associated disease, asking about joints and back, skin, chest, ear, nose and sinus, neurological, stomach and kidney problems, mouth or genital ulcers, and sexually transmitted infections.

Depending on these clues, the severity, recurrent episodes and whether both eyes are involved, doctors may arrange blood tests, X-rays, a scan of the eye and special photographs after dye is injected into the arm. If other parts of the body may be involved you may be referred to other specialists.

RNIB says that treatment for intermediate and posterior uveitis varies from person to person and depends on the cause. Apart from certain infection-related types, treatment usually focuses on reducing inflammation and controlling the immune system. Steroids are commonly used. They can be given as injections around or into the eye, as a small implant for non-infectious uveitis, or as tablets, which may also treat an underlying inflammatory condition elsewhere.

• Immunosuppressants reduce inflammation by slowing some immune activity. RNIB says they are important for people who need long-term treatment, because it is not safe to take high-dose steroids for a long time.

• Anti-TNF drugs may be used if steroids or conventional immunosuppressants have not worked or are causing health problems, and the uveitis is affecting vision, according to RNIB.

• If infection is the cause, antiviral, antibiotic, antifungal or antiparasitic medicines are used, sometimes with steroids to control excessive inflammation.

• The NHS lists laser phototherapy, cryotherapy and surgery on part of the eye as options when uveitis is very severe or keeps coming back.

RNIB lists complications of uveitis as raised eye pressure, macular oedema, cataract, floaters, new blood vessel growth and retinal detachment. It says controlling the inflammation properly gives a much better outcome for sight than under-treating it, even though the treatments can have side effects and need monitoring.

Moorfields says uveitis can lead to cataracts and glaucoma but that most cases recover well with treatment. After starting treatment you are seen again by the ophthalmologist to check how treatment is working, look for side effects and check for complications such as vision loss, according to the NHS.

RNIB acknowledges that it is natural to be upset by a uveitis diagnosis and to worry about the future. If vision is reduced, you can ask your ophthalmologist, optometrist or GP about low vision aids and a low vision assessment. Charities such as RNIB and the Uveitis Information Group provide information and peer support.