Punctate Inner Choroidopathy

Punctate Inner Choroidopathy (also known as ‘Punctate Inner Choroiditis’ or ‘PIC’ for short) is a rare chronic disease in which inflammation occurs in the sensitive sight-enabling structures at the back of the eye. It is a form of ‘Uveitis’, a term used to describe a number of conditions which are characterised by inflammation within the eye. Uveitis is further classified according to which part of the eye is affected: front (anterior uveitis), middle (intermediate uveitis), back (posterior uveitis) or all parts (panuveitis).  PIC is a form of sight-threatening posterior uveitis which requires specialist treatment to prevent the inflammation causing irreversible damage to the retina (the light-sensitive layer which enables you to see) and the choroid (the major blood supply and support tissue to the retina).

What do patients with PIC notice?

The first thing that most patients with PIC and other forms of Posterior Uveitis will notice will be 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 and does need consideration of treatment.

Patients with PIC report a range of symptoms. These may include:

• blurred central vision
• blind spots (Scotoma)
• a perception of flickering or flashing lights (Photopsia)
• distorted images (Metamorphopsia)

In PIC, examination of the retina and choroid by an ophthalmologist reveals areas of damage. These can be recorded by photography and by newer types of scanning instrument (eg optical coherence tomography). Areas of active inflammation appear as yellow-white spots, usually around the central part of the retina and choroid. Over time these may form scars which result in blind spots in the patient’s vision. Another complication of these PIC spots is that they sometimes lead to a ‘choroidal neovascular membrane’ (or ‘CNV’). This is where there is abnormal blood vessel growth from the damaged choroid through to the retina, which may cause distortion and further loss of vision.

What causes PIC?

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 (a condition in which the immune system incorrectly attacks healthy tissues in the body). Unlike most other forms of uveitis, there is no inflammation in other parts of the eye. Researchers - scientists, patients and doctors working together - are continuing to study these early events to try to work out what triggers PIC, and how we can treat it better.

What can I expect?

In the PIC clinic, we aim to provide a ‘one-stop’ clinic. When you arrive you will be met by a specialist nurse who will measure your vision, and ask you about any ways in which the condition (or its treatment) is affecting you. We often use questionnaires to help provide a more detailed assessment of the condition and its impact.

You will then have anaesthetic drops put in your eyes to allow us to measure the pressure and ‘dilating’ drops which enable us to see the back of the eye in more detail. A very important part of your assessment is to have specialist imaging to help assess whether the condition is still active or controlled, and to help guide your treatment. We have a range of world-class imaging devices which enable us to detect changes down to a few thousandths of a millimetre, all as easily as having a photograph taken.

How often will I come to the PIC Clinic at the Centre for Rare Diseases?

For local patients it is likely that all their clinic appointments – usually four per year - will be in the PIC Clinic at the Centre for Rare Diseases, but patients from further away are likely have their care shared between the PIC Clinic and their local eye specialist, with perhaps two review appointments per year in our PIC clinic.