Retina Specialists Auckland New Zealand

Photodynamic Therapy

Photodynamic therapy (PDT) uses a light-activated dye (Verteporfin) and a special non-thermal laser. The entire process takes about 20 minutes and is relatively painless.
The Verteporfin dye is injected via an intravenous infusion into the arm and selectively accumulates in the abnormal blood vessels. Shining a non-burning laser at the abnormal blood vessels activates the drug, producing free radicals, which selectively destroy the abnormal blood vessels. Importantly, because the laser is non-burning, the overlying retina is not destroyed. . These abnormal blood vessels tend to reopen and further treatment may be required after 3 months. On average people require between 4 and 6 treatments over two years. PDT results in a highly selective treatment. Its selectivity reduces damage to surrounding tissue, allowing for re-treatment.

Results from clinical trials using PDT with verteporfin in AMD have shown the ability to stabilize vision, confining retinal damage and slowing down vision loss, it does not restore vision in eyes that have suffered longstanding vision loss or have already been significantly damaged by AMD. Early recognition of symptoms is important as the greatest benefit is achieved when PDT can be given in the early stages of the disease.

Side effects
Verteporfin causes light sensitivity up to 48 hours after injection and bright sunlight can cause a serious photosensitive reaction. Patients are advised to wear dark sunglasses and stay indoors and away from direct sunlight for 48 hours. Normal, low-level indoor light is O.K. Other side effects include decreased vision (if some of the normal blood vessels are accidentally shut down as well), a mild headache, dizziness and a drop in blood pressure.
Because of the nature of Age-related Macular Degeneration, a number of people may continue to suffer progressive visual loss from AMD in spite of treatment.

Lucentis
(Ranibizumab)

In wet AMD, abnormal blood vessels grow under the retina and leak blood and fluid. This causes rapid damage to the macula, the portion of the eye responsible for fine, detailed central vision. Lucentis (ranibizumab) is a novel drug that closes down these blood vessels by inhibiting VEGF-A, a protein that is believed to play a critical role in the formation of new blood vessels. In clinical trials on patients with wet AMD, it was found to prevent further visual loss in 90 - 95% of patients. Up to a third of patients in the trials also experienced an increase in their vision following treatment – something not seen before in the treatment of AMD.

Lucentis was approved by the United States FDA in June 2006. It is not yet registered for use in NZ by medsafe, but is available on a named patient basis under Section 29 of the medicines act.

Currently Lucentis is only approved for use in age-related macular degeneration. However, many other diseases in the eye may also be treatable with Lucentis, and at Retina Specialists we are currently involved in an international clinical trial of Lucentis for diabetic macular oedema.

The medication is delivered by injection into the vitreous jelly which fills the eye. The injections need to be repeated monthly for the first 3 months, following which the frequency may be reduced, although close monitoring of the eye will still be required, and further injections are likely.

More information about Lucentis is available on the following websites:
www.agingeye.net/mainnews/lucentis.php
www.gene.com/gene/products/information/tgr/lucentis

Avastin
(Bevacizumab)

In wet AMD, abnormal blood vessels grow under the retina and leak blood and fluid. This causes rapid damage to the macula, the portion of the eye responsible for fine, detailed central vision. Avastin (bevacizumab) is an antibody that inhibits VEGF-A, a protein which plays a critical role in the formation of new blood vessels. It was developed for use in cancer, but has gained in popularity as a treatment for AMD as it is very closely related to Lucentis, a medication shown to be extremely effective for AMD in clinical trials. Early results suggest similar results with Avastin, at a much lower medication cost.

In addition to wet AMD, other conditions of the eye such as retinal vein occlusions and diabetic retinopathy are characterised by excess blood vessel growth and leakage, and these may also be amenable to treatment with Avastin.

The medication is delivered by injection into the vitreous jelly, which fills the eye. Close monitoring is required, with examinations every month, and repeat injections are likely.


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	Photodynamic Therapy Photodynamic therapy (PDT) uses a light-activated dye (Verteporfin) and a special non-thermal laser. The entire process takes about 20 minutes and is relatively painless. The Verteporfin dye is injected via an intravenous infusion into the arm and selectively accumulates in the abnormal blood vessels. Shining a non-burning laser at the abnormal blood vessels activates the drug, producing free radicals, which selectively destroy the abnormal blood vessels. Importantly, because the laser is non-burning, the overlying retina is not destroyed. . These abnormal blood vessels tend to reopen and further treatment may be required after 3 months. On average people require between 4 and 6 treatments over two years. PDT results in a highly selective treatment. Its selectivity reduces damage to surrounding tissue, allowing for re-treatment. Results from clinical trials using PDT with verteporfin in AMD have shown the ability to stabilize vision, confining retinal damage and slowing down vision loss, it does not restore vision in eyes that have suffered longstanding vision loss or have already been significantly damaged by AMD. Early recognition of symptoms is important as the greatest benefit is achieved when PDT can be given in the early stages of the disease. Side effects Verteporfin causes light sensitivity up to 48 hours after injection and bright sunlight can cause a serious photosensitive reaction. Patients are advised to wear dark sunglasses and stay indoors and away from direct sunlight for 48 hours. Normal, low-level indoor light is O.K. Other side effects include decreased vision (if some of the normal blood vessels are accidentally shut down as well), a mild headache, dizziness and a drop in blood pressure. Because of the nature of Age-related Macular Degeneration, a number of people may continue to suffer progressive visual loss from AMD in spite of treatment. Lucentis (Ranibizumab) In wet AMD, abnormal blood vessels grow under the retina and leak blood and fluid. This causes rapid damage to the macula, the portion of the eye responsible for fine, detailed central vision. Lucentis (ranibizumab) is a novel drug that closes down these blood vessels by inhibiting VEGF-A, a protein that is believed to play a critical role in the formation of new blood vessels. In clinical trials on patients with wet AMD, it was found to prevent further visual loss in 90 - 95% of patients. Up to a third of patients in the trials also experienced an increase in their vision following treatment – something not seen before in the treatment of AMD. Lucentis was approved by the United States FDA in June 2006. It is not yet registered for use in NZ by medsafe, but is available on a named patient basis under Section 29 of the medicines act. Currently Lucentis is only approved for use in age-related macular degeneration. However, many other diseases in the eye may also be treatable with Lucentis, and at Retina Specialists we are currently involved in an international clinical trial of Lucentis for diabetic macular oedema. The medication is delivered by injection into the vitreous jelly which fills the eye. The injections need to be repeated monthly for the first 3 months, following which the frequency may be reduced, although close monitoring of the eye will still be required, and further injections are likely. More information about Lucentis is available on the following websites: www.agingeye.net/mainnews/lucentis.php www.gene.com/gene/products/information/tgr/lucentis Avastin (Bevacizumab) In wet AMD, abnormal blood vessels grow under the retina and leak blood and fluid. This causes rapid damage to the macula, the portion of the eye responsible for fine, detailed central vision. Avastin (bevacizumab) is an antibody that inhibits VEGF-A, a protein which plays a critical role in the formation of new blood vessels. It was developed for use in cancer, but has gained in popularity as a treatment for AMD as it is very closely related to Lucentis, a medication shown to be extremely effective for AMD in clinical trials. Early results suggest similar results with Avastin, at a much lower medication cost. In addition to wet AMD, other conditions of the eye such as retinal vein occlusions and diabetic retinopathy are characterised by excess blood vessel growth and leakage, and these may also be amenable to treatment with Avastin. The medication is delivered by injection into the vitreous jelly, which fills the eye. Close monitoring is required, with examinations every month, and repeat injections are likely.