by Age-related macular degeneration (AMD) is a condition that affects the central area of the retina called the macula. The macula is responsible for central vision that is needed for activities like reading, driving, and recognizing faces. Over time, AMD can damage the macula and cause a loss of central vision. There are two main forms of AMD – dry AMD and wet AMD. Dry AMD is more common but wet AMD is a more severe form that can cause rapid and severe vision loss.
Wet AMD is caused by the formation of new, abnormal blood vessels under the macula. These vessels are very fragile and often leak blood and fluid, causing damage to the macula. Traditional treatments for wet AMD revolved around attempting to destroy or seal off these abnormal blood vessels through laser therapy or surgery. However, these methods were often ineffective or only temporary. A new treatment method called photodynamic therapy (PDT) was developed that utilized the properties of light-activated drugs to selectively target and treat the abnormal blood vessels.
Verteporfin as the First PDT Drug
In 2000, the photosensitizing drug Visudyne was approved by the FDA to be used with PDT for the treatment of wet AMD. Verteporfin under the brand name Visudyne, was the first PDT drug approved specifically for this application. Prior to Visudyne, PDT had shown promise for wet AMD but available photosensitizers were not selective enough and caused damage to healthy retinal tissue as well. Visudyne was found to be much more effective and safer than earlier generations of PDT drugs.
How Visudyne PDT Works
Visudyne is administered via injection into the bloodstream. It selectively accumulates in the abnormal blood vessels of the macula but not normal healthy vessels. Around 15 minutes after injection, a low-power laser light is applied directly to the macula using a special lens placed on the eye. The light activates the Visudyne, which then produces a chemical reaction that selectively damages the abnormal blood vessels. This causes the fragile vessels to seal off and leak less. While it does not cure wet AMD, Visudyne PDT helps reduce fluid leakage, shrink abnormal vessels, and stop further vision loss in the majority of cases when performed early.
Clinical Studies and Benefits of Visudyne Therapy
Numerous large-scale clinical trials were conducted in the late 1990s to evaluate the safety and efficacy of Visudyne PDT compared to other wet AMD treatments. The Treatment of AMD with Photodynamic Therapy (TAP) studies recruited over 600 patients worldwide and showed that Visudyne PDT stabilized or improved vision in over 90% of cases after 3 years compared to just 50-60% for standard laser photocoagulation therapy.
Subsequent extended follow-up studies continued to demonstrate Visudyne benefits for slowing vision loss from wet AMD out to 5 years. Additional research indicated that treating wet AMD as early as possible and following a strict schedule of Visudyne PDT retreatment every 3 months helped optimize long-term outcomes. This established PDT with Visudyne as the standard-of-care first-line treatment for wet AMD over other modalities from 2000 onward.
Role of Verteporfin Alongside Emerging Therapies
While Visudyne PDT remained the primary therapy for many years, newer treatment approaches started emerging in the mid-2000s. Anti-VEGF injections such as bevacizumab, ranibizumab, and aflibercept were shown to be even more effective than PDT at stopping vision loss from wet AMD. These drugs selectively inhibit vascular endothelial growth factor, a protein that promotes abnormal blood vessel growth. Anti-VEGF therapy is now the standard first-line treatment in most cases instead of Visudyne PDT.
However, Visudyne still maintains an important role for certain wet AMD patients who are poor candidates for repeated monthly injections or who fail to respond sufficiently to anti-VEGF drugs alone. Combination PDT with Visudyne plus anti-VEGF therapy has also demonstrated benefits over monotherapy in some clinical trials. Visudyne PDT also continues to be used in developing countries and regions without widespread access to regular intravitreal injections. Its one-time light activation makes it better suited to certain healthcare situations compared to the frequent injections required by anti-VEGF therapy alone.
the discovery and development of verteporfin represented a significant advancement over prior technologies for photodynamic treatment of wet AMD. As the first drug approved specifically for this application of PDT, Visudyne helped standardize and optimize the delivery of this novel therapeutic approach. Over a decade as the primary treatment for wet AMD, Visudyne helped thousands of patients maintain functional vision. While newer therapies like anti-VEGF drugs are now first-line, Visudyne still plays an important role both on its own and in combination with other treatments. Its approval in 2000 marked a revolution in options for managing one of the leading causes of blindness worldwide.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
Money Singh is a seasoned content writer with over four years of experience in the market research sector. Her expertise spans various industries, including food and beverages, biotechnology, chemical and materials, defense and aerospace, consumer goods, etc.
