Macular Degeneration: Symptoms, Types & Treatment

What is age-related macular degeneration?

Age-related macular degeneration (AMD) is a chronic condition that usually appears in people over 60, although in some cases it can develop earlier. But what is the macula? The macula is the central part of the retina, which has the highest concentration of photoreceptors, the cells that receive light and turn it into an image. Photoreceptors are found throughout the retina, but their density decreases towards the periphery. This is why central vision is the part affected when someone develops this condition.

Page contents

1. What is age-related macular degeneration?
2. What are the main causes?
3. What are the symptoms of macular degeneration?
4. What types of macular degeneration are there?
5. How do we know whether someone has macular degeneration?
6. What is the right treatment for macular degeneration?
7. What should I be careful about if I have macular degeneration?
8. Are there eye drops for macular degeneration?
9. New treatments for macular degeneration
10. Frequently Asked Questions about Macular Degeneration

And of course, despite the difficulty this loss of central vision causes in daily life, there is a positive side: peripheral vision will never be affected, so the person will never lose their sight completely. In addition, macular degeneration is not painful at any stage, which means the patient does not experience the unpleasant sensation of pain.

What are the main causes?

At present, the exact cause of age-related macular degeneration is not known.

However, it has been associated with:

• Age: it is more common in people over 65
• Female sex (probably because of longer life expectancy)
• Heredity: genes associated with macular degeneration have already been found, and in some families it is more common than in others. Even so, it is not considered a purely hereditary disease
• Smoking: it significantly increases the likelihood of developing macular degeneration.
• Sun exposure: some studies suggest that high exposure to sunlight over a lifetime may increase the likelihood of developing macular degeneration
• Diet: a large number of studies have shown that a poor diet can be a risk factor for developing the disease.

What are the symptoms of macular degeneration?

Symptoms vary from person to person, but the first symptom is usually distortion of the image. Straight lines look distorted or wavy, which in most cases is easily noticed in daily life. Later, there is difficulty making out details, in other words vision begins to blur.

Difficulty reading, even with reading glasses, is common, since, as we said, the central part of vision is the most affected. If there is a haemorrhage, a dark spot appears in the centre of the person’s visual field, and in rare cases the haemorrhage can be large and extend into the inside of the eye. If this happens, vision drops to very low levels within a very short time, even within hours.

In advanced stages of the condition, as well as in neglected cases, the initial distortion or blurring of vision gives way to a permanent dark area in the visual field.

With proper monitoring and treatment, it is possible to have little or even no loss of vision, depending of course on the type of macular degeneration.

What types of macular degeneration are there?

There are two main types of age-related macular degeneration: the dry form and the wet form. There are, however, also early stages of the condition, in which we speak of early or initial macular degeneration. In these stages the most common finding is the presence of deposits called drusen. With long-term exposure, drusen have a toxic effect on the cells of the retina, which can lead to one of the two advanced forms.

Dry form

This is the most common type. It usually progresses slowly and causes a gradual loss of central vision. It usually takes several years to reach its final stage, in which there is a spot in the centre of the visual field where the patient cannot see. This is also influenced by the fact that one of the two eyes is always ahead in developing the disease, and therefore in losing vision.

Wet form

A small proportion of people with age-related macular degeneration will develop the wet form. In this form, abnormal blood vessels (new vessels, or neovascularisation) grow from the underlying tissues towards the macula. These vessels are not properly sealed, so fluid leaks from them and builds up in the macula, causing oedema (swelling). These vessels also often bleed. Long-standing oedema and haemorrhage lead to scarring and loss of central vision.

The wet form progresses very quickly, which is why a correct and prompt diagnosis is important so that treatment can begin.

How do we know whether someone has macular degeneration?

A simple test that can easily be done at the clinic or even at home is the Amsler grid. The grid consists of straight horizontal and vertical lines and a central dot. The test is done by asking the patient, while looking only at the central dot, to tell us whether the lines look bent at any point, as shown in the image.

The diagnosis is supported by specialised tests such as optical coherence tomography (OCT), as well as fundoscopy or fundus photography, which show changes in the anatomy of the retina. The exact subtype of the condition is confirmed with angiography, which is done either with an intravenous injection of contrast dye or with a more modern technique called OCT angiography. OCT angiography has the advantage that it takes much less time and does not require an intravenous injection of dye, which eliminates the chance of an allergic reaction.

What is the right treatment for macular degeneration?

Worldwide, there is currently a great deal of research into the treatment of both the wet and the dry form. New medicines are being studied for both forms, and Dr. Skouteris has taken part in two international multicentre studies of such medicines for the wet form, as well as in an international multicentre study for the dry form.

Based on current evidence, the wet form is treated with intravitreal injections (injections into the eye) and, in some cases, with a laser treatment called photodynamic therapy. Intravitreal injections deliver a type of medicine called anti-VEGF. These agents have an anti-angiogenic action, meaning they stop the growth of the abnormal new vessels and cause them to scar down (fibrosis). The aim is to reduce the oedema and improve vision.

By using the monitoring and treatment protocols applied at Oxford University Hospital, we aim to offer the best possible outcome in terms of the patient’s final vision.

In certain subtypes of age-related macular degeneration, photodynamic laser therapy can be beneficial. Photodynamic therapy is an older treatment carried out by an intravenous injection of a light-sensitive agent that is activated by the laser. This leads to closure of the growing new vessels, and it is now proven to be extremely useful in certain subtypes.

As for the dry form, management is supportive, while a new form of treatment, photobiomodulation (PBM), shows promise. According to clinical studies, this treatment may be beneficial in the dry form by reducing drusen and, under certain conditions, improving visual acuity.

For patients whose disease has advanced and who have had low vision for a long time that is not improving, low vision aids can be of great help. These aids make the most of the remaining vision using various types of magnification, lighting and other methods that make the central blind spot (scotoma) seem smaller.

Surgery for age-related macular degeneration with good results has not yet been established. Many attempts have been made with telescopic intraocular lenses and other methods, but the results are not yet satisfactory. There are, however, other conditions of the macula apart from age-related degeneration that could be improved with surgery, such as a macular hole or an epiretinal membrane, again under certain conditions.

Dr. Skouteris, who works with doctors at Oxford University Hospital and is in contact with the international community, keeps constantly up to date with new research developments and can at any time inform you about them and how they apply to your own case.

What should I be careful about if I have macular degeneration?

The course of macular degeneration does not depend only on treatment at the clinic. Some everyday choices affect how it progresses:

• Stopping smoking. Smoking is the most important risk factor that we can change, and it speeds up the progression of the disease.
• Diet. Green leafy vegetables such as spinach and broccoli, fruit, pulses and fish rich in omega-3 are associated with a lower risk of progression. The Mediterranean diet is a good basis.
• Amsler grid. Check each eye separately, wearing your reading glasses, once or twice a week. If the lines look bent or faded, or a shadow appears, contact your ophthalmologist immediately.
• AREDS2 supplements. The combination of vitamins, zinc, lutein and zeaxanthin from the AREDS2 study reduces the risk of progression only in certain stages of the disease. They should be taken only on the advice of your ophthalmologist, who will judge whether they will benefit you.
• Keeping blood pressure, cholesterol and weight under control, as they affect the health of the blood vessels of the eye.
• Sunglasses with UV protection in bright light.

Patients receiving intravitreal injections should stick to their schedule of visits, even when their vision seems stable.

Are there eye drops for macular degeneration?

At present there are no approved eye drops that treat or stop macular degeneration. Drops do not reach the back of the eye, where the macula is, in sufficient amounts. That is why medicines for the wet form are given by intravitreal injection, directly into the inside of the eye.

Eye drops may be used for other reasons: artificial tears for the dry eye that is often present in older age, antiseptic drops during the injection procedure, or dilating drops for the examination. None of these affects the progression of the disease.

Products promoted as “eye drops for macular degeneration” have no proven benefit. Research into treatments in drop form continues, but until there are proven results, regular monitoring with optical coherence tomography (OCT) and starting treatment promptly when needed remain the way to preserve vision.

New treatments for macular degeneration

The treatment of macular degeneration is evolving, with the aim of fewer visits for the wet form and treatment for the advanced dry form as well.

Wet form: less frequent injections

Newer anti-VEGF agents act for longer or on several mechanisms at the same time. In suitable patients they allow injections to be spaced further apart, in some cases up to every three or four months, once the disease has stabilised. The interval is adjusted individually based on the OCT findings, using the “treat and extend” protocol. Sustained-release implants and gene therapies are also being researched.

Dry form: geographic atrophy

For geographic atrophy, intravitreal injections that slow the spread of the damage have been approved in some countries. They do not restore vision that has been lost, they require frequent injections and their availability varies from country to country.

The new treatments are not suitable for everyone. The choice is made after a full examination, based on the form and stage of the disease. See how intravitreal injections are given and the aftercare instructions following an intravitreal injection.

Frequently Asked Questions about Macular Degeneration

Medically reviewed by: Dr. Vasileios Skouteris MD, FEBO