Age-related macular degeneration (AMD)

Anatomy of the retina and macula

The retina is responsible for processing the incoming light. The so-called sensory or visual cells, cones and rods, convert the incoming light into electrical impulses and transmit these via the optic nerve to the brain. Finally, the picture is displayed here. It is therefore a very complex, anatomical and neural process.

In the center of the retina is the place of the sharpest vision (macula). At this point of the retina, the visual cells are particularly sensitive and are present in large numbers, therefore the best possible light processing is possible with this site. Likewise, here is a yellow dye in the tissue, which protects the cells from harmful light, the short-wave UV light. Due to this yellowing, this spot is sometimes called „yellow spot“.

Definition of age-related macular degeneration

As „age-related“ refers to such changes, which are usually seen from the 50th to 60th year of life in heaped form on the surface of the retina and especially the macula. In exceptional cases, there are also macular degeneration in younger years. Real degeneration occurs when deep tissue layers are included beneath the macula, ie within the adjoining choroid or retinal pigment epithelium.

Age-related degeneration is usually expressed in drusen (greasy deposits) or pigment epithelial shifts. This process is primarily provoked and driven by the lifelong exposure to UV light. In the process, waste products, which normally degrade the eye on its own, are stored away, increasingly causing a poorer tissue structure and a deterioration in vision.

Age-related macular degeneration (AMD) is thus a disease at the site of sharpest vision, the macula.

Who gets an AMD and when?

Basically, every person is exposed to the risk of age-related macular degeneration throughout their lives, as they are always exposed to UV light.

However, whether the individual ever gets an AMD can not be predicted with certainty. Even a possible course is fundamentally very complex. Known risk factors are mainly the UV influence (too little sun protection), but also the family disposition, smoking, increased blood lipids, high blood pressure, diabetes and arteriosclerosis.

Forms of AMD

Dry macular degeneration / with drusen (yellowish spots)

Dry AMD is characterized mainly by the change in the macula due to metabolic waste products, which are stored in the tissue (drusen). However, in this form there is no leakage of tissue fluid, hence called „dry form“.

The dry form is much more common and mostly pronounced. It progresses less quickly. However, it is also more difficult to treat and may also have far-reaching consequences for the patient in terms of possible visual limitations in the final stage. The only treatment option is the intake of micronutrients.

Wet macular degeneration / neovascularization in the retina

In wet AMD, the organism sends a vascular endothelial growth factor („VEGF“), which stimulates the regeneration of vessels within the retina and the macula.

The basically quite reasonable biological principle that the new blood vessels accelerate the removal of the leftover waste products causes more harm than good at this tiny spot. Namely, the newly formed blood vessels are less stable, often rupture and lead to leakage of tissue fluid. This causes the retina to swell as a result (edema), causing the actual damage. In the final stage and in the absence of any treatment, swelling can lead to large areas of scar tissue in the macula, which then result in massive discomfort. The patient usually notices rapidly after the appearance of wet AMD visual changes in a variety of forms.

How do you notice an AMD?

The impairment is always dependent on the shape and severity of the present AMD. The dry form is barely noticed at the beginning and in the course usually rather small, since the progression is very slow. Only in the end stage and with increasing scarring of the macula, vision is severely impaired. The wet form, however, is perceived faster because acute lines are warped, faces are no longer recognized or reading is no longer possible. Similarly, patients often speak of a permanent black spot in the center of vision.

Diagnosis at AMD

Control of the ocular fundus by reflection

In addition to a routine measurement of visual acuity / visual performance, the macula is examined enlarged with a magnifying glass with an enlarged pupil. Any changes, such as drusen or pigment shifts, as well as new types of tissue formation or even edema, can be diagnosed.

Optical Coherence Tomography – OCT

By taking an image with an OCT numerous cross-sectional images of the retina are made, which allow the view under the surface of the retina. In the end, new types of tissue alterations and edema occur. No other investigation provides comparable details. Based on this imaging procedure, therapeutic approaches can be defined and tissue structures can be differentiated. Also in the follow-up of an AMD, whether dry or moist, the OCT should always be used for the reasons mentioned above.

Fluoreszeinangiografie

This image allows to detect and document leaks of blood vessels following administration of a dye by means of a special camera. It is an additional prerequisite to capture the location of the liquid outlet and represent the areal extent of the exit. However, since it is an invasive diagnosis with possible side effects such as allergic shock or intolerance, OCT is now the recommended diagnostic tool.

Amsler test

The Amsler grid (Amsler test) is primarily used as a rapid screening method and can be given to the patient as well as home. However, a specific diagnostic does not replace the Amsler grid.

Therapy of AMD

What can one do against the AMD?

Every patient is individual, every macular degeneration is different. Only the ophthalmologist can tell you, after a thorough examination, what the state of AMD is and what you can do basically as prevention and therapy.

Preventive measures

The fundamentally healthy lifestyle, as it is important for so many areas of the body, should also be mentioned here. Above all smoking, as well as the unhealthy nutrition are in the foreground. Resulting sequelae such as diabetes and hypertension often lead to later AMD.

Micronutrients

A number of findings suggest that the regular intake of certain natural substances (so-called antioxidants) can favorably influence the course of some forms of AMD.

These substances are:

  • Resveratrol
  • Lutein
  • Zinc
  • Zeaxanthin,

Important here is the pure processing of the substances within your extraction, as well as the correct composition in terms of bioavailability in the body. For example, it is known that when zinc is used, copper should always be co-processed to avoid copper deficiency. This principle is very complex. Your ophthalmologist will be able to explain the differences and recommend the right preparation to your heart.

UV protection

The same purpose, namely the protection of the macula from harmful short-wave blue UV light components, is achieved by wearing a corresponding pair of sunglasses. This should allow as little light as possible and also to be worn continuously, even in low light. However, it should be noted that sunglasses can never be completely and 100% UV-protective.

In cataract surgery, it is important to be mindful of the UV absorption spectrum of the lens when selecting the new lens. Although all intraocular lenses in Germany are provided with UV protection, the standard variants usually only with an insufficient. In cataract surgery, however, the patient has the option of selecting a UV protective lens. If possible, a photochromic lens should be chosen, because a permanent yellow lens can in turn lead to visual impairment. With a photochromic lens, a lens that adapts to the light conditions, you have both the 100% UV protection (unlike sunglasses), as well as the security to always get the best possible color and contrast vision. This currently represents the best care within cataract surgery in terms of age-related macular degeneration.

Treatment

Dry AMD

Unfortunately, a drug treatment of dry AMD does not exist. However, scientific studies, such as the so-called AREDS 1 + 2 study, provide information that the intake of micronutrients with the already mentioned ingredients have a positive influence on the progression of the disease.

Moist AMD

The elimination and equal sclerotherapy of the newly formed blood vessels and / or the resulting edema is basically the goal in the treatment of wet AMD. Not only must the liquid that has already formed be eliminated, but also the re-emergence of further liquid must be prevented. In the best case, massive visual deterioration due to scar formation is prevented and partially also provided with preventive care. This can be achieved by means of:

Intravitreal injections (IVOM)

The introduction of drugs injected into the inside of the eye (vitreous) has set a milestone in the treatment of wet AMD in recent years. These drugs work against certain messenger substances (VEGF), which lead to the new formation of unwanted blood vessels. This treatment method has established itself worldwide as the standard in wet macular degeneration.

The drug is given over a longer period of time in repeated sessions under sterile conditions. In ophthalmology, only Lucentis® is approved as a drug. In part, Avastin® is used as an alternative, but this represents an off-label treatment and is urgently to be discouraged.

The drug develops over several weeks its effect. A complete cure is not achieved here either. In order to achieve a consistently good prognosis, all other factors must be improved. However, the drug can stop the acute process, remove fluid and have a mild protective effect.

Help for the visually impaired

Increasing visual aids can effectively improve vision in everyday life and are an adequate remedy for advanced macular degeneration from a legally required level of vision. We are happy to give you recommendations and arrange contacts to specialized opticians.

Conclusion

1. AMD never leads to blindness

Although central vision is sometimes severely impaired and recognition of faces and reading is no longer possible, degeneration always „only“ affects the central visual field. The periphery remains untouched, whereby at least one orientation will always be given. Although this gives the sufferers little comfort, it is true that a complete blindness, such as in glaucoma, can be excluded.

2. Early diagnosis very important

A regular ophthalmologist’s diagnosis and examination as described above should be done every year, regardless of age. This is important for all prepositions. It should be noted that macular degeneration can be treated if it is detected and treated early enough. Nowadays there are many more possibilities with micronutrients than they were years ago.

3. Exploit medical possibilities

The medical possibilities by means of intravitreal injection are today far advanced. With timely therapy, a progression of the findings should always be avoided.