AGE RELATED MACULAR DEGENERATION


Dry Age Related Macular Degeneration

The development of this condition is partly influenced by our genes and our lifestyle. It is more common with advancing age whereas it is very uncommon under the age of 60. Degenerative changes in the pigmented cell layer under the macula cause degeneration of overlying light-sensitive cells. This process is called DRY AGE RELATED MACULAR DEGENERATION (Dry AMD) and it tends to be a slowly progressive condition. 

A special form of Dry AMD called Geographic Atrophy is can be particularly debilitating but there is a number of treatments undergoing clinical trials and we hope that there will be some form of treatment which can slow down or stop this disease process. For a list of Dry AMD and Geographic Atrophy trials, click here

Patients with Dry AMD or a family history of this condition should avoid smoking and are encouraged to have a diet rich in dark green leafy vegetables, fruit, fish and follow a balanced diet. Some patients benefit from special vitamin supplements containing specific doses of Zinc, Copper, Vitamin C, Vitamin E, Lutein and Zeaxanthin  (beta carotene is no longer recommended). Omega-3 supplements had no effect on reducing the risk of  vision loss from AMD. Nevertheless, if patients take omega-3 supplements for other reasons, they can continue doing so as they do not appear to cause any harm to the macula. 

Patients with dry AMD should be aware of any new onset of distortion in vision or vision loss, which may herald the onset of Wet macular degeneration. Patients can test themselves regularly, using an Amsler grid. For a copy, click here.


Wet Age Related Macular Degeneration

In some patients, these degenerative changes are followed by the development of abnormal blood vessels, which grow under the macula. These blood vessels can leak fluid, they can bleed or they can cause scarring. As a result, widespread loss of macular light sensitive cells occurs and in the past when there was no effective treatment, many patients had profound loss of central vision. This is called WET AGE RELATED MACULAR DEGENERATION (Wet AMD). 

Since 2006, there have been very effective treatments for Wet AMD. Clinical trials have shown that with early recognition and treatment, 9 out of 10 patients do not lose a lot of vision and around 4 out of 10 patients have marked improvement in vision (3 lines or more on the vision chart). On average, patients gain one line on the vision chart but the aim is to maintain or slow down any deterioration in vision.


Injections for Treating Wet Age Related Macular Degeneration

Current treatments for Wet age related macular degeneration are  in the form of injections inside the eye. These drugs neutralizes a hormone which maintains abnormal blood vessel growth and by eliminating this hormone, we usually achieve temporary regression of these abnormal blood vessels and a reduction in fluid or blood leakage so that any subsequent scarring on the macula is minimised. The effectiveness of the drug inside the eye lasts  for around 4 to 6 weeks so these drugs need to be injected on a regular basis, initially as a three monthly loading course and subsequently according to any signs of the disease flaring up. This is why patients need to be seen on a monthly basis and injected where there are signs of activity (PRONTO Protocol). Patients need on average 7-8 injections per year, according to how aggressive their AMD is. Alternatively, after the initial three monthly doses patient visits can be extended by 2 weeks at a time up to 8 weekly visits, but patients must have an injection at each visit (Treat and Extend Protocol). This later protocol is useful where patients can not attend monthly clinics.


Lucentis Vs Eylea Vs Macugen Vs Avastin

There is a number of available treatments for Wet AMD. They all neutralize a hormone which causes and maintains the abnormal blood vessel growth responsible for Wet AMD. 


Macugen: This was the first drug that was licensed for the treatment of Wet AMD in 2004. Clinical evidence has shown inferior results to other AMD drugs so it is no longer used by the vast majority of retinal specialists. 

Lucentis: It was licensed for the treatment of Wet AMD in 2006. There is ample clinical evidence supporting its efficacy and safety. 

EyleaIt was licensed for the treatment of Wet AMD in 2006. Clinical trials show no difference in efficacy, compared to Lucentis. There is some evidence that its effect may be slightly longer lasting.

Avastin: This drug was formulated by the same company that made Lucentis. Avastin is normally used in the treatment of colon, lung and breast cancer by injection into the bloodstream through a vein. It s not licensed for injection in the eye but worldwide, it is the most widely used medication for treating wet age related macular degeneration. It is used in the same way as Lucentis with the same amount of drug injected inside the eye. A large clinical trial on around 1000 patients in the USA has demonstrated that Avastin is as effective as Lucentis in preventing vision loss from wet AMD. The reason patients chose this off lisence treatemnt over lisenced drugs is the cost. In Cyprus, the cost of one injection of  Avastin is 1/3 of that of Lucentis or Eylea.


Safety of the drugs used for Wet AMD

All these drugs appear to increase the risk of stroke, heart attack and internal bleeding (brain, gut). Any differences in safety between these drugs is not proven. There are questions whether Avastin causes more bleeding complications, compared to the other medications but there is no definite clinical evidence. The study on 1000 patients comparing Avastin and Lucentis found more bleeding incidents in patients that took Avastin but another study looking at 146942 Medicare patients in the USA found no differences in bleeding incidents, heart attacks and stroke between patients taking Macugen, Avastin or Lucentis. 


Conclusion on the choice of treatment: Lucentis and Eylea are the gold standard in treating Wet age related macular degeneration but in cases where the cost of treatment can not be met, Avastin is a very good alternative, which is equally effective to Lucentis. Macugen does not give as good outcomes as the other three drugs. 


How is Wet AMD managed and what should I expect during my treatment?

Following a detailed history, accurate vision measurement on a LogMAR Chart and an examination of the eye, including the macula, the doctor will perform an OCT Scan, which is a non-invasive test that provides microscopic cross sections of the macula to assess  and measure the changes caused by AMD and to serve as a baseline for future comparison. In order to make a definitive diagnosis of Wet AMD and identify its subtype, an angiogram is performed. One or two types of dye (Fluorescein with or without Indocyanine Green) are injected through a vein on the back of the hand and the flow of these dyes is observed through scanning laser imaging photographs and video as it circulates through the eye. The abnormal blood vessels of the Wet AMD light up and the pattern and timing will differentiate the Wet AMD into Classic, Occult, RAP, Polyp, forms, which carry a different outlook and may have variations in their management.

The treatment of Wet AMD consists of three initial monthly injections of the chosen medication. A fourth injection is given for the Classic subtype as the initial trials demonstrated continuing improvement in vision up to the fourth injection before the vision stabilised. From there on, the structure and function of the macula is assessed on a monthly basis using vision assessment, clinical examination and OCT Scan. If there is evidence of ongoing activity or relapse, another injection is administered. If the status of the macula is stable with no evidence of disease activity, no injection is given and the patient is seen one month later. It is difficult to predict how many injections will be required and this is related to the subtype of AMD with Classic and RAP subtypes requiring more injections than the Occult subtype. In the CATT trial, patients (all sybtypes) required on average 7 for Lucentis and 8 for Avastin (including the first 3 injections). The treatment does not stop in the first year. Patients should carry on attending appointments for continuing observation and injections when required. 

Uncommon types of Wet AMD may require additional treatment with Photodynamic Therapy (a laser-activated drug administered via an injection into a vein). 

In summary:

Treatment for Dry AMD:

STOP SMOKING

Eat plenty of vegetables, fish, fruit and follow a balanced diet. For advanced Dry AMD, specialised nutritional supplements should be taken following the advice of your doctor.

For more severe Dry AMD, vitamin supplements with special formulations may help reduce the risk of progressing to more advanced disease

Be aware of any changes in vision that may signal the onset of wet AMD.


Treatment for Wet AMD:

STOP smoking if your other eye does not have Wet AMD

EARLY RECOGNITION - See your doctor if you develop distortion or vision loss

All the above in dry AMD to reduce the risk of the other eye becoming affected + specialised vitamin supplements

Fluorescein +/- indocyanin green Angiogram to differentiate bewteen subtypes of Wet AMD

Specialist follow-up with clinical examination, OCT Scan and treatment using Lucentis or Avastin

Uncommon subtypes of Wet AMD may require Photodynamic therapy

Use specialised nutritional supplements are very important if the other eye does NOT have wet AMD