The retina takes on the function of imaging in the eye – similar to the film in a photo camera. One must think of the eye as a spherical organ that is covered by a protective skin, the dermis (med. Sclera). Where the light enters the eye – in the area of the pupil – this protective cover is transparent. This transparent window is the cornea of the eye. The inner lining, that is the layer on the back inner wall of the eye, is the retina. It is a highly complex nerve tissue with a thickness of 1/10 to 1/3 millimeter. It serves as a projection surface for all perceived images and passes them on to the brain via the optic nerve, where the impressions are processed.
The macula is the area for the sharpest view. Macular means spot, namely the spot of the sharpest vision. It is often referred to as the yellow spot on the retina because the yellow protective pigments are only present in the macula. The macula plays a major role when we want to fixate something precisely, for example when reading or when we want to recognize faces.
Macular disorders are manifested by reduced visual acuity and typically also by distortions in perception. Letters or parts of words sometimes fail when reading, occasionally it appears to those affected as if letters were jumping, faces are distorted and barely or not at all recognizable and lines or edges can appear wavy or warped. Reading is no longer possible if there are major changes.
Since the rest of the retina is still functional in most cases of macular diseases, those affected can still see in the external field of vision. Many things can still be perceived, so that, for example, orientation in rooms may be possible or smaller objects in the external field of vision may be noticed. However, if the person concerned wants to look at this object closely and tries to fixate it, the object disappears, since the image of the object falls on the diseased macula when looking closely.
This strange way of seeing can then cause irritation in the immediate social environment. “He / she always says he / she can’t see anything, and he / she also sees a stain on the floor”. It is therefore important that family members understand how vision can change in the course of a macular disease and how the visual impairment is not questioned.
AMD, DMO, CMO (vascular occlusions, uveitis)
The macula lutea, the so-called yellow spot on the retina, is the location of the sharpest vision and lies on the optical axis of the eye exactly in the middle of the retina. Diseases in this region of the retina can therefore severely impair visual acuity.
Macular diseases can already occur in adolescents, for example in the context of adolescent or juvenile macular degeneration. These macular degeneration are based on genetic factors. Effective therapies are not available.
The most common form of macular degeneration is the one associated with increasing age, namely age-related macular degeneration (AMD).
There are two main types of AMD:
The disease primarily affects people over the age of 50. That is why we speak of age-related macular degeneration. We still don’t know exactly what factors lead to macular degeneration. There are some indications that the light to which we are all exposed for a lifetime plays an important role. When light hits tissue, light oxidation creates aggressive oxygen atoms, the so-called radicals, which can damage the cells of our body. Therefore, dark-skinned people who have more protective pigment appear to be less at risk of AMD than fair-skinned people.
Inheritance factors may also play a certain role. However, it is not necessarily the case that children also develop AMD if this disease has occurred in the parents.
Large studies indicate a connection with smoking. It was shown that smokers are more likely to get AMD than non-smokers.
Cataract surgery does not appear to affect the course of an AMD. For a long time, it was believed that cataract surgery could worsen it. However, there are no clear indications for this.
Reading disorders can be the first signs of AMD. There can be a fail of individual letters or parts of words. Sometimes a dark spot can be noticed, especially in the morning after getting up or when the person has looked at a bright surface. Twists or waves can appear on lines, door edges, window frames. Over time, it becomes more difficult to fixate objects precisely. Contrasts increasingly lose sharpness and colors lose intensity.
The symptoms at a glance:
In the course of an AMD, it is important to recognize the possible transition from a dry form to a moist AMD in good time. We have effective treatment methods available for this situation today. Modern diagnostic methods, especially examinations with optical coherence tomography (OCT) or fluorescein angiography, make it possible to quickly and reliably detect a wet AMD.
One focus of our practice is the individualized treatment of AMD diseases. Prof Koss is an internationally sought-after expert and is therefore currently the youngest professor in German ophthalmology due to his services in the treatment of AMD. In this regard, Prof. Koss gave a lecture at the annual training of the Herzog Carl Theodor Eye Clinic at the Nymphenburg Palace in January 2017.