Early detection is important
Treatment options depend on the type and stage of macular degeneration. Whilst there is presently no cure, early detection is vital to save sight. The earlier you seek treatment, the more likely you are to have a better visual outcome compared to those who wait.
Macular degeneration can cause many different symptoms. Difficulty with your vision should not be dismissed as part of 'getting older'. In its early stages macular degeneration may not be obvious to you but can be detected with an eye test before any visual symptoms occur. Early detection may allow you to take steps to slow the progression of macular degeneration.
What tests are used to diagnose macular degeneration?
Eye examination
An eye care professional may use eye drops to dilate your pupils to give a better view of the retina at the back of the eye.
Amsler grid
The Amsler grid may be used to detect distortion in vision where straight lines appear wavy or bent and to see if there are dark spaces or empty patches in the vision.
Optical Coherence Tomography (OCT)
OCT is a standard investigation for the diagnosis and ongoing management of wet macular degeneration. It is a non-invasive imaging technique that uses light to produce very high resolution cross sectional images of the retinal layers. Repeated tests are usually necessary to monitor disease activity.
Fluorescein angiography (FA)
FA is sometimes used to investigate wet macular degeneration. It involves injecting fluorescein dye into a vein in the arm to image the blood circulation at the back of the eye. As the dye circulates through the choroidal and retinal blood vessels, a camera with a special filter is used to take a series of photographs over about 10 minutes. The dye highlights any abnormalities of or damage to the blood vessels.
What treatments are available?
Currently there are no medical treatments for dry macular degeneration. However a considerable amount of research is being conducted to find a treatment. There are a number of medical treatments available for wet macular degeneration. These treatments do not cure the disease but aim to stabilise vision and maintain the best vision for as long as possible. In some people, treatment can improve vision. Treatment options for wet macular degeneration should be discussed with an eye specialist.
Anti-VEGF drugs
In wet macular degeneration, blood vessels are prompted to grow under the retina by a protein called vascular endothelial growth factor (VEGF). These vessels can bleed, leak fluid and cause scarring under the retina leading to rapid vision loss that if left untreated becomes permanent. To slow or stop this process, various drugs that block VEGF (called anti-VEGFs) can be used.
Treatment usually begins with monthly injections for 3 months. In order to maintain control of the disease, injections are usually required indefinitely. Several anti-VEGF drugs are in use, namely Bevacizumab (Avastin), Aflibercept (Eylea) and Ranibizumab (Lucentis).
Avastin
(Bevacizumab)
Bevacizumab was primarily developed, tested and approved to decrease new blood vessel growth associated with cancer. It is highly effective and used worldwide for treating wet macular degeneration. It is not funded by Pharmac because it is not registered for the treatment of macular degeneration as it was not designed for use in the eye; however, each DHB funds it as a treatment for wet macular degeneration. Bevacizumab is typically used as the initial treatment of wet macular degeneration in New Zealand.
Eylea
(Aflibercept)
Aflibercept is now the second-line agent for the treatment of wet macular degeneration and is registered for use in the eye, and funded by Pharmac but with availability restricted. Aflibercept is similar to bevacizumab and ranibizumab but works slightly differently to them. It binds to VEGF significantly more strongly than both the other agents and also binds PIGF. After a loading phase of three monthly injections, aflibercept only needs to be injected every two to three months, rather than monthly, as it is longer acting than bevacizumab.
Lucentis
(Ranibizumab)
Ranibizumab is very similar to bevacizumab. It is derived from the same parent molecule but is much smaller and has been pharmacologically altered to provide stronger binding to VEGF than bevacizumab. Ranibizumab was specifically formulated and registered for use in the eye. It costs significantly more than bevacizumab and is restricted to third-line use in New Zealand by Pharmac for wet macular degeneration.
Photodynamic therapy (PDT)
This is a 2-step process combining a light-activated drug called Visudyne (verteporfin) with light from a cold laser directed onto the abnormal area of retina. Once activated, the drug causes the abnormal vessels to close off. PDT does not cause direct damage to the surrounding retina. Therefore, it can be used to treat new vessels that are under the centre of the macula (fovea).
Several treatments are needed to keep the leaking blood vessels closed and stop the progression of wet macular degeneration. Close follow up and monitoring is needed to determine if further treatment is required.
Unlike anti-VEGF drugs with which the vision is usually maintained, patients undergoing PDT continue to lose vision in the first 6 months. Their vision then stabilises so that the eye does not progress to severe vision loss.
PDT is now rarely used to treat ordinary wet macular degeneration. It is sometimes used in conjunction with an anti-VEGF drug to treat a type of macular degenerationcalled polypoidal choroidal vasculopathy (PCV) as some of these cases do not settle completely with anti-VEGF treatment.
Laser photocoagulation
This treatment consists of a concentrated light beam of high-energy thermal light that is directed onto the retina to destroy and seal leaking blood vessels. It is not painful. The laser not only destroys the abnormal vessels but also destroys retina adjacent to them. Therefore it may only be used for treating new vessels that are not under the central part of the macula.
Laser photocoagulation is only used for a small percentage of patients with wet macular degeneration. Close follow up is required as there is a 50% recurrence rate.
Nutrition and supplements Fact Sheet
The Age Related Eye Disease Studies (AREDS I and II) are 2 major clinical trials that identified a specific formula of antioxidants including high dose zinc that significantly reduced the relative risk of progression of macular degeneration and delayed vision loss. The daily amounts of these are:
Zinc 80 mg
Copper 2 mg
Vitamin E 400 IU
Vitamin C 500 mg
Lutein 10 mg
Zeaxanthin 2 mg
More information is contained in MDNZ’s Nutrition and Supplements fact sheet. Any changes in diet or lifestyle should be undertaken in consultation with your doctor.
Preview the brochure by downloading a pdf here