PDT is a two-step treatment primarily used for certain types of wet age-related macular degeneration (AMD). First, a light-activated drug called verteporfin is infused into a vein in your arm over about 10 minutes. Second, about 15 minutes after the infusion starts, your doctor will shine a non-thermal ("cold") red laser directly onto the leaky blood vessels in your macula for some seconds. The laser activates the drug only in that precise area, causing the abnormal vessels to seal without damaging the overlying retina. The laser itself is not hot and is not felt by the patient.
Before procedure
You must arrange for transportation, as you will be light-sensitive.
Wear long sleeves, pants, a wide-brimmed hat, and sunglasses for your appointment.
Inform your doctor of all medications, especially if you take blood thinners, and allergies.
After procedure
Strict Light Protection is Critical: The drug remains in your system for 24-48 hours. You must avoid direct sunlight and bright indoor light (e.g., from dental lamps, surgical lights, tanning beds) to prevent severe skin burns. Stay indoors in dim light.
You can gradually resume normal activity after 2 days, but continue to protect your skin and eyes from bright sun for 5 days.
Vision may be blurred for a few days. Use any prescribed eye drops.
Complication and alarm signs
The main risks are related to the drug: severe sunburn (if light precautions aren't followed), back pain during infusion, and allergic reactions. Eye-specific risks include temporary vision loss, increased scarring at the treatment site, or blockage of a healthy blood vessel (rare).
Seek immediate medical help if you experience: Signs of an allergic reaction (hives, difficulty breathing, chest tightness) during or after infusion. Contact your eye doctor if: You notice a sudden, significant drop in vision or severe eye pain in the days following treatment.