With age-related macular degeneration recognized as the leading cause of blindness in the aging population, developing drugs to combat the eye disease has become a priority for many pharmaceutical companies.
While there is no cure for macular degeneration, there are several drugs on the market used to treat the most severe form of the eye disease, wet macular degeneration. There is no drug to treat dry macular degeneration.
What drugs are available to treat wet macular degeneration?
The most commonly used drug treatments are:
Lucentis or ranibizumab is what an angiogenesis inhibitor used to halt the formation of new blood vessels and treat wet macular degeneration.
Vision loss in patients diagnosed with wet age-related macular degeneration occurs when abnormal and leaky blood vessels form, damaging the macula. This area of the eye is responsible for central vision and.
Lucentis is injected into the vitreous portion of the eye and as an antibody fragment that inhibits the growth of new blood vessels it stops the leaking blood vessels and slows the growth of new ones. However as the human body continually produces the protein responsible for new blood vessels, patients suffering from wet macular degeneration must receive additional injections of Lucentis.
The most common side effects noticed with using Lucentis include haemorrhaging of the membrane that covers the white part of the eye (conjunctiva), floaters, eye pain, increased pressure in the eye and inflammation of the eye. Some serious eye conditions such as retinal detachment, retinal tears and endophthalmitis has occurred as well.
Approved originally as a cancer drug, Avastin or bevacizumab has become a popular off-label drug for treating wet macular degeneration.
Manufactured by the same company as Lucentis, Avastin works in much the same way, inhibiting the growth of abnormal and leaking blood vessels associated with wet macular degeneration. It is injected into the vitreous portion of the eye just like Lucentis and must be given at regular intervals throughout the treatment for the eye disease.
While Avastin has not been FDA approved for treating macular degeneration it has become a drug of choice by many eye care professionals because of its cost. Lucentis treatments cost approximately $2000 per injection while Avastin treatments cost approximately $50 per treatment. The ongoing debate over using avastin or lucentis has recently surfaced again.
While experts argue Avastin holds more risks for the patients, some have argued sicne it is delivered in much smaller doses than if used to treat cancer, it is perfectly safe. Many eye care professionals feel Avastin is just as effective at treating wet macular degeneration as Lucentis.
Side effects of using Avastin to treat macular degeneration are very similar to those experienced with Lucentis. However, it should be noted not all the side effects are known because Avastin has not been studied or approved for use in the eye.
In recent months, several patients using Avastin to treat their macular degeneration have experienced total blindness. However, it should be noted this was not directly attributed to the drug but rather the process of splitting the dose of the cancer drug into smaller amounts to be used in the eye.
Macugen or pegaptanib is another of the drugs used to inhibit the growth of blood vessels associated with wet macular degeneration.
Macugen is injected directly into the vitreous portion of the eye and works in much the same way as both Avastin and Lucentis, inhibiting the formation of new blood vessels prone to leak behind the macula. Ongoing injections are required with this treatment as well.
The most common side effects associated with Macugen included inflammation of the eye, blurred vision, cataracts, bleeding, swelling of the eye, spots or floaters, and eye discomfort.
Visudyne or verteporfin was one of the first drugs developed to treat wet macular degeneration. It is used as part of a treatment known as photodynamic therapy.
With Visudyne, the drug is injected into the arm and travels trough the body. It is absorbed by the abnormal blood vessels growing under the macula and when a low-intensity, cold laser is directed into the retina, the drug activates. It will then destroy the abnormal blood vessels.
While photodynamic therapy will not restore loss vision, it can help stabilize the vision of an individual suffering from wet macular degeneration.
Treatments of visudyne typically take place over a period of 2-3 years and are administered every three months as needed to prevent the growth of the abnormal blood vessels associated with wet macular degeneration.
Future Drug Treatments for Macular Degeneration
With macular degeneration being seen as one of the major causes of vision loss in the elderly population, research into other drugs is continually occurring.
A new drug, Eylea has shown great promise and is awaiting final approval of the FDA.