Photodynamic Therapy (PDT) for Wet AMD

Wet age-related macular degeneration occurs when fragile, abnormal blood vessels grow beneath the macula, the central part of your retina responsible for sharp, detailed vision. These vessels leak fluid and blood, which can quickly damage the macular tissue and cause rapid vision loss if left untreated. Unlike the dry form of AMD, wet AMD progresses faster and requires prompt medical intervention.

You may notice symptoms such as blurry or distorted central vision, straight lines appearing wavy, a dark or empty spot in your central field of view, or difficulty recognizing faces. Early detection and treatment can help slow vision loss and preserve the sight you still have.

Photodynamic therapy combines a light-activated medication called verteporfin with a targeted laser to close off leaking blood vessels. We first inject the verteporfin into a vein in your arm, and the drug travels through your bloodstream and accumulates in the abnormal vessels in your eye. When we apply a low-energy laser to the treatment area, it activates the medication and causes the abnormal vessels to close. These abnormal vessels, called choroidal neovascularization or CNV, grow from the layer beneath your retina rather than from the retina itself.

The treatment preferentially targets the abnormal vessels while aiming to minimize effects on surrounding tissue, though some changes to nearby structures such as the retinal pigment epithelium and underlying blood supply can occur.

• The medication preferentially accumulates in rapidly growing abnormal blood vessels
• The laser light triggers a chemical reaction that seals the leaking vessels
• The treatment targets the abnormal vessels with relative selectivity
• The procedure occurs during a single treatment session

In 2025, we typically reserve photodynamic therapy for select situations where it may offer specific advantages. PDT is sometimes used for polypoidal choroidal vasculopathy, a subtype of wet AMD that may respond well to this approach, often in combination with anti-VEGF injections. Your ophthalmologist may also consider PDT if you have certain patterns of predominantly classic choroidal neovascularization, or in selected cases to help reduce the frequency of anti-VEGF injections when combined with other therapies.

The decision depends on the specific type, location, and size of your abnormal vessel growth, which we identify through advanced imaging. We will carefully evaluate your individual case to determine whether PDT aligns with your treatment goals. Most patients with wet AMD today receive anti-VEGF injection therapy as the primary treatment because it has proven more effective at improving and maintaining vision in clinical studies.

Anti-VEGF injections have largely replaced photodynamic therapy as the standard treatment for wet AMD in 2025. These injections block vascular endothelial growth factor, the protein that signals abnormal blood vessel growth, and they often improve vision rather than simply slowing its decline. Patients receiving anti-VEGF therapy generally experience better visual outcomes and may need treatments every one to three months depending on their response.

PDT does not typically improve vision but may help stabilize it in certain cases. While PDT treatments may be needed less frequently than anti-VEGF injections, they also carry a unique requirement for strict light avoidance for 48 hours after each session. Your retina specialist will discuss which treatment option best suits your specific type of wet AMD, your overall health, and your lifestyle needs.

For two full days after your PDT treatment, you must avoid direct sunlight and very bright indoor lighting. The verteporfin remaining in your skin and eyes will react to intense light exposure and can cause painful burns or blisters if you expose yourself to bright light sources. Normal indoor ambient lighting is safe and should be used rather than sitting in darkness.

You can use typical indoor lighting and most household activities are fine as long as you avoid direct bright light. This means you can watch television, use a computer or phone, and read with normal lamps, but you should not use very bright task lights or sit in direct sunlight coming through windows. Do not go outside during daylight hours unless you are fully protected with appropriate clothing and eyewear.

If you must go outside during the 48-hour light-sensitive period, you need complete protection from UV and visible light. Wear long sleeves, long pants, gloves, a wide-brimmed hat, and dark wraparound sunglasses that block both UV rays and reduce visible light transmission. Choose tightly woven, opaque fabrics that do not allow bright light to penetrate to your skin.

• Select clothing made from tightly woven, opaque fabrics
• Cover all exposed skin including your hands, neck, and face
• Use dark wraparound sunglasses that block UV and significantly reduce visible light
• Avoid reflective surfaces like water, snow, or white concrete
• If outdoor exposure is necessary within the 48-hour window, full protection is essential even during less bright times of day

After 48 hours have passed since your treatment, most patients can resume normal light exposure without special precautions. If you notice unusual burning, stinging, or redness when you return to normal lighting, contact our office for guidance. The photosensitivity period is generally complete by this point.

You can typically return to work and other regular activities once the 48-hour period has ended and your vision has stabilized. Your normal routine can resume as you feel comfortable.

We will schedule your first follow-up appointment about one to two weeks after PDT to assess how your retina is responding to treatment. During this visit, we may repeat OCT imaging to measure any reduction in retinal fluid and check whether the abnormal vessels are closing. Your vision may continue to change during the first few weeks as the treatment takes full effect.

Additional follow-up visits occur every few months to monitor your condition long-term. Some patients need repeated PDT sessions if new vessel growth appears or if the initial treatment does not fully control the leakage. We may also recommend transitioning to or adding anti-VEGF therapy if PDT alone does not adequately preserve your vision.

Contact our office immediately if you experience severe skin burns or blistering after inadvertent light exposure, as this may require medical treatment. You should also call right away if you develop sudden new vision loss, a dramatic increase in floaters or flashes of light, eye pain, or severe redness. These symptoms could indicate complications that need prompt evaluation.

While serious complications are rare, we want you to understand which changes require urgent care versus those that are expected as part of normal recovery. When in doubt, always call our office for guidance rather than waiting until your next scheduled appointment.