Age-Related Macular Degeneration (AMD)

Promising new treatments for wet AMD and the ever evolving diagnostic imaging of the macula have enhanced our management of this disease far better than what we did a decade ago. Dry AMD often is the earlier stage of the disease that can cause either slow but progressive loss of central vision or transform into the more severe wet AMD. In wet AMD abnormal blood vessels sprout from breaches in the Bruch’s membrane (the layer behind the retina) cause oedema (water-logging), bleeding and distortion of the retinal architecture. This often results in sudden and dramatic distortion or loss of vision. Targeted treatment involving starving these vessels of their growth factors, encourages them to regress. Prevention still has a key role in patients who have dry AMD as well as in first degree relatives by focussed attention to the modifiable risk factors detailed in the “Role of Diet & Vitamin Supplements” section.

Role of Diet & Vitamin Supplements

Diet is a significant modifiable risk factor (besides smoking cessation and avoidance of excessive UV light exposure) in the prevention of progression of AMD. There are several vitamin/nutritional supplements available in the market and patients often ask me as to which formulation to take. The composition of vitamins/nutrients varies between preparations and there are in excess 20 products on the market. A high dose combination of vitamins and anti-oxidants has been found to be helpful in selected patient groups in slowing down the progression to more advanced AMD by the AREDS trial that was published in 2001. A further list of antioxidants that have since been shown to keep the macula healthy, has been studied in the AREDS 2 trial.  Addition of these extra vitamins had not been of much more benefit and lower doses of vitamins used in the initial trial has been shown to be just as good. My recommendations are these:

  • Not to take any form of vitamin pills if you are a current or ex-smoker. β carotene in the preparations increase the risk of lung cancer in smokers. Even preparations that are labelled as being safe for smokers, the degree of relative safety is uncertain as molecular structure of Leutein (found in many preparations) resembles that of β carotene and a similar risk may exist although unknown yet.
  • Have a balanced diet with a regular intake of green leafy vegetables like spinach, kale, broccoli and brussels sprouts as well as orange coloured peppers. Dietary sources of vitamins and anti-oxidants are much lower in concentration in comparison to the strength of pills. However it is well known that natural suppliments in diet are better absorbed than ingestion of synthetically manufactured vitamins.
  • Bausch and Lomb, Vitabiotics, Alcon and Macuvision are some of the manufacturers who make these supplements and they cost around £15 for a month’s supply.

Investigations

Ocular Coherence Tomography (OCT)

OCT is a relatively new technology that has changed the landscape of retinal investigation in the recent years. It is a non invasive imaging modality that uses a special light to scan the layers of the retina and finds its use in the management of Glaucoma, AMD, diabetic retinopathy and other macular diseases. The images take only a few minutes to acquire and the latest generation of OCT machines offer unsurpassed 3-D resolution to accurately identify the anatomy at different layers inside the human retina.

Fundus Fluorescein Angiography (FFA)

FFA has been around for a few decades providing valuable information for retinal specialist on the blood circulation of the retina. It involves an injection of a fluorescent dye through a vein in the arm. Within a few seconds the dye enters the general circulation of the body including the retinal circulation. Photographs of the retina are taken using special filters in rapid sequence, so that the blood vessels are observed as they fill up with the dye. Upon evaluating the series of photographs, your consultant is able to identify abnormal vessels as in AMD, leakage from vessels or absence of circulation in conditions such as diabetes or retinal vein occlusion.

From a patient’s perspective, the photographs would be taken for 5-10 minutes following the injection. They are then asked to be seated for a further hour for observation. The cannula that had been inserted into the vein for the purpose of injecting the drug, would then be removed and the patient sent off home.

Fluorescein also colours the skin (often with a lovely tan!) which fades away over a few days. Fluorescein is excreted by the kidneys and patients are asked not to be concerned to see a change in the colour (a bright yellow) of their urine for a few days afterwards as it is one of the ways by which the dye leaves the body. It is quite a safe drug although as with any drug that is being injected into the body it can be allergic to some people. A transient nauseating feeling is common and rarely patients experience a more severe allergic response. Although is possible in theory, a serious anaphylactic reaction resulting in death has not been observed in one large reported series of 100,000 patients who had FFA.

Indocyanine Green Angiography (ICG)

Treatment Options

Intravitreal therapy (Lucentis/Eylea)
Background

Lucentis (Ranibizumab) is the prototype drug in use for intravitreal therapy. It involves a series of injections of the drug into the eye using a very fine needle. The injections often start off at monthly intervals for the first few months and tailored to response following that period. Lucentis and more recently Eylea (Aflibercept) have been approved ny NICE for treatment of wet AMD.

The Procedure

The procedure is done under strict aseptic conditions. The surface of the eye is made quite numb with local anaesthetic drops. The skin around the eye is then cleaned with antiseptic and drapes are applied. A speculum (a thin metal clip) is used to keep the eyelids apart. Further antibiotic/antiseptic solutions are applied on the eye surface. A very fine needle is used to inject the drug into the eyeball. This is followed by a retinal examination after which antibiotics are instilled and a sterile dressing applied.

Alternative treatment options

Argon laser photocoagulation and phodynamic therapy are options in specific circumstances.

What happens if you don’t have this treatment?

The disease is likely to worsen often leading to an irreversible loss of vision.

The Benefit

The treatment is likely to improve the retinal disease and result in a better chance of retaining good or better vision.

The serious or frequently occurring risks
  • Infection or severe inflammation inside the eye
  • Increased eye pressure
  • Closure of the blood circulation of the nerve of sight
Photodynamic therapy
Argon laser photocoagulation

External Resources

National Eye Institute (NEI)

NEI is a part of National Institutes for Health which is a US governmental organisation funded to promote high quality research into sight-saving treatment. They have a very high profile amongst the ophthalmic community owing to the landmark clinical trials that they have set-up and funded.
http://www.nei.nih.gov/health/maculardegen/armd_facts.asp

Royal National Institute of Bind people (RNIB)

RNIB is a leading UK charity founded in 1824 and their website is the largest source of information available on the internet on blindness and partial sightedness. They also run a useful helpline.
http://www.rnib.org.uk/eyehealth/eyeconditions/conditionsac…

Macular Disease Society (MDS)

MDS is the largest specialist charity for patients with macular disease in the UK and they offer support and advice to patients with macular disease. They also sponsor research projects on the disease.
http://www.maculardisease.org