Punctate inner choroidopathy (PIC): symptoms, monitoring and treatment

The choroid is the layer of blood vessels that supplies and supports the retina, the light-sensitive layer at the back of the eye. University Hospitals Birmingham (UHB) describes PIC as a rare chronic disease in which inflammation occurs in these structures. It is a form of uveitis, a term used for a number of conditions characterised by inflammation within the eye. Uveitis is classified according to which part of the eye is affected: front (anterior), middle (intermediate), back (posterior) or all parts (panuveitis), and PIC is a form of posterior uveitis.

The NHS explains uveitis in general as a rare condition that causes inflammation inside part of the eye, saying it is important to get it treated early to avoid long-term complications such as vision loss and blindness. It also says that in most cases the cause of uveitis is unknown, although some are linked to autoimmune conditions, infections or injury.

UHB says the first thing most patients with PIC and other posterior uveitis notice is blurred vision or partial blind spots, caused by changes in the retina and choroid. It is not painful, but can cause serious loss of vision. Patients report a range of symptoms, which may include blurred central vision, blind spots (scotoma), a perception of flickering or flashing lights (photopsia) and distorted images (metamorphopsia).

This is different from many other forms of uveitis. The NHS lists eye pain that may feel worse when reading, red or watery eyes, reduced or blurred vision, sensitivity to light and flashes or floaters as symptoms of uveitis generally, and says it usually affects one eye but can affect both. The NHS adds that sometimes uveitis does not cause any symptoms at all, which is why regular follow-up matters.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you have pain in your eyes, 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).

Any new blurring, blind spot or distortion in someone with a known diagnosis of PIC should be reported promptly to the eye clinic that looks after them, because it may signal active inflammation or a complication.

UHB says the cause of PIC is not known. It tends to occur in young short-sighted women, and it is suggested that it is an autoimmune disease, one in which the immune system incorrectly attacks healthy tissues. Researchers are continuing to study the early events to work out what triggers PIC and how to treat it better.

UHB describes that in PIC, examination of the retina and choroid by an ophthalmologist reveals areas of damage. These can be recorded by photography and newer types of scanning instrument such as optical coherence tomography. Areas of active inflammation appear as yellow-white spots, usually around the central part of the retina and choroid, and over time these may form scars that result in blind spots in vision.

The UHB clinic describes a one-stop assessment: a specialist nurse measures vision and asks how the condition or its treatment is affecting you, anaesthetic drops are put in the eyes to measure the pressure, and dilating drops are used to see the back of the eye in more detail. Specialist imaging is an important part of assessing whether the condition is still active or controlled and of guiding treatment.

UHB says that PIC spots sometimes lead to a choroidal neovascular membrane (CNV), in which abnormal blood vessels grow from the damaged choroid into the retina, which may cause distortion and further loss of vision. Scarring from earlier inflammation may also produce permanent blind spots.

For uveitis in general the NHS says treatment depends on the cause and severity and may include medicines to reduce inflammation, medicines to reduce the activity of the immune system (immunosuppressants and TNF inhibitors) if it is very severe or keeps coming back, and sometimes laser or surgery. The sources used here do not set out a specific treatment schedule for PIC, which is decided by the treating ophthalmologist.

UHB says that for local patients clinic appointments are usually about four a year, while patients living further away often have care shared between a specialist clinic and a local eye specialist, with perhaps two review appointments a year at the specialist clinic. Regular review and imaging are how activity and complications are caught early.

Because PIC is chronic, it helps to keep a note of any change in vision, to attend scheduled imaging and to be aware of which symptoms need a same-day call to the eye clinic.