Photodynamic therapy is a procedure that uses a photosensitive agent in conjunction with light of a specific wavelength and tissue oxygen to kill targeted cells through apoptosis. It is used in the treatment of a wide range of medical conditions such as severe acne, psoriasis, esophageal cancer and wet macular degeneration.
Special drugs known as photosensitive agents that are activated in the presence of light are used in photodynamic therapy. The photosensitive agent is applied on the targeted tissue and, after a waiting period of a couple of minutes during which the agent is absorbed by the tissue, the area is exposed to light. In the presence of light, the agent reacts with the oxygen present in the tissue to form a chemical that's toxic to the targeted cells. In addition, this therapy alerts the immune system to the foreign nature of cancer cells, causing the immune system to attack the cells.
Potential Risks and Complications of Photodynamic Therapy
Patients who have undergone photodynamic therapy have an increased sensitivity to light and this can result in sunburn if they are exposed to any form of light, not only sunlight. Other complications include redness of the skin, a burning sensation, discoloration of the skin and blisters on the skin. Some of the tiny blood vessels might become prominent. The patient might have a prolonged period of hypersensitivity to light. Sunscreens, sunshades and clothes that cover the entire body are essential during this period of acute sensitivity to light.
In addition, the patient may suffer from continuous pain and might be more prone to infections. Many patients develop swelling and thick raised scars that can be cosmetically disfiguring. If the therapy was used to treat wet macular degeneration, the patient might experience eye injury or loss of vision. Another severe complication is the recurrence of the cancer, if the therapy was used to treat cancer. Burns, pain, swelling and scarring of healthy tissue near the treated area, although minimal, can occur. Depending on the target area of the therapy, there can be short-term side-effects such as coughing, pain in the stomach, shortness of breath, difficulty in breathing, difficulty in swallowing and pain experienced while breathing.
Allergic reactions to the photosensitive agents can also occur. Since local anesthesia is used in the procedure, there is always the risk of a reaction to it that can either be mild or fatal. The patient may also have an allergic reaction to any of the medications that are administered before, during and after the therapy.
Although there are several side effects, risks and complications associated with photodynamic therapy, they are generally not experienced by most patients. Even when they are experienced, such undesired reactions are temporary in most instances. If symptoms of infections such as fever, soreness or redness manifest themselves, it's best to seek the advice of the specialist because oral antibiotics can help resolve the infection.