Photodynamic therapy (PDT) is a treatment that uses a combination of a “cold” laser and a special light-sensitive dye (Verteporfin). This is injected into the blood stream to target abnormal leaking blood vessels in the retina (nerve tissue lining at the back of the eye which detects light and allows us to see) or the layer below the retina (choroid). PDT is used in the treatment of some specific forms of wet macular degeneration and a disease called ‘Central Serous Retinopathy’ (CSR).
The central part of the retina (at the back of the eye) is called the macula and it has an important function as it controls the quality and sharpness of the central part of our vision.
Macular degeneration is a condition that affects the macula resulting in distortion or sometimes loss of central vision (not the peripheral vision) and this can cause problems, when it comes to everyday tasks such as reading and driving. Read More
Central serous retinopathy (CSR) is a condition that affects the retina- the light sensitive tissue that lines the back of the eye.
Central serous chorio-retinopathy (CSCR), refers to a collection of fluid under the retina. This is caused by a disturbance in the pumping action of special cells called RPE cells (retinal pigment epithelial cells) and/or abnormalities in the vascular (blood vessel) layer, known as choroid. RPE cell layer and blood vessel layer (choroid) line the outer surface of retina and both layers function to keep the retina healthy. This dysfunction results in fluid leakage under the retina in a bubble-like swelling called central serous chorio-retinopathy (CSCR).
The combination of laser light and light-sensitive dye helps to seal off the leaking area which then reduces leakage in the retina which will either stabilise the vision (stop it getting worse) or may even improve the vision. For patients with chronic (lasting more than 4 months) Central Serous Retinopathy (CSR) there are no other proven alternative treatments apart from PDT in cases where the disease does not settle by itself within the first few months. Without this treatment there would be a risk of the leak in the retina worsening causing further damage to the eyesight. For patients with wet macular degeneration this treatment is now reserved for patients who are unable to have the recommended first line treatment of injections of drugs into the eyeball (e.g. allergy to the drug or medical reason making it difficult for patients to attend for injection treatment) or cases where there is a specific type of wet macular degeneration where combination treatment is recommended (injections into the eyeball plus PDT treatment).