How is age-related macular degeneration diagnosed?
Even though there are self-tests that you can use to check if you suspect age-related macular degeneration (AMD), only an experienced ophthalmologist can make a reliable diagnosis. But how exactly does the examination work? We will explain the most important steps in diagnosing AMD in a way that is easy to understand.
Diagnosis AMD – An ophthalmologist examines a patient.
Pre-existing and Concomitant Diseases in Age-Related Macular Degeneration
In his practice, the ophthalmologist will first ask you about any symptoms you have already noticed, for example blurred writing or a cloudy spot in your field of vision. This can be an indication of damage to the macula . It is also particularly important for the doctor that you not only describe your direct symptoms, but also discuss other illnesses that could potentially affect your eye health. This typical step in the examination of the patient's medical history is called anamnesis. Signs of diabetes or high blood pressure (hypertension) are important. Both illnesses have a damaging effect on the retina: high blood pressure means that the small blood vessels in the retina are exposed to unusually high pressure and can become damaged. Patients with diabetes, on the other hand, are at risk of developing what is known as diabetic retinopathy, in which the fine blood vessels in the retina are also irreparably damaged.
Eye test provides evidence of age-related macular degeneration
After an initial assessment of your symptoms and previous illnesses, the ophthalmologist will use further diagnostic tools to determine AMD as the cause. This includes a visual acuity test (visual acuity determination), which you have probably experienced many times before: You will be asked to read out letters in which the characters get smaller and smaller from top to bottom. If the characters are no longer recognizable above a certain size, the ophthalmologist can use corrective lenses to test whether the person has normal vision. So that he does not have to juggle half a dozen pairs of glasses, he uses a so-called phoropter, a device with which he can slide lenses with different prescriptions in front of the eye. For another test, the ophthalmologist uses grid lines to determine whether there is distorted vision (the technical term for this is metamorphopsia). You can easily carry out this so-called Amsler grid line test yourself using templates from the Internet.
Diagnosis AMD – A doctor adjusts the phoropter.
Endoscopy of the fundus of the eye for AMD diagnosis
You may also have experienced an examination of the back of the eye (so-called funduscopy). This involves putting a drop of medication into the eyes, which dilates the pupils. This allows the doctor to examine the retina more effectively using optical examination equipment and thus detect pathological changes. He is particularly looking for drusen, which are deposits under the retina that often occur in AMD. Be careful: the eye drops will continue to work for several hours after the examination - so protecting your eyes with sunglasses is particularly important after an ophthalmoscopy.
Measuring the intraocular pressure to rule out glaucoma
Measuring the intraocular pressure is also a familiar procedure for many patients. The ophthalmologist will also carry out this examination in order to rule out glaucoma as the cause of your symptoms. To determine the intraocular pressure reliably, the doctor must apply a drop of anesthetic into the eye and then measure the pressure directly in the eye using a measuring plunger. The technical term for this is applanation tonometry. This is completely harmless, but somewhat uncomfortable for many patients. However, eye pressure can now also be measured using a puff of air. This procedure is called non-contact tonometry.
Diagnosis AMD – An ophthalmologist during the examination.
Detecting wet macular degeneration with fluorescein angiography
In order to detect wet age-related macular degeneration, the ophthalmologist uses what is known as fluorescence angiography. This procedure allows him to determine whether new blood vessels have developed, as is characteristic of wet age-related macular degeneration: blood cells and other substances emerge from the new, brittle veins, which can damage the sensitive retinal cells. In order to better examine the blood vessels, the ophthalmologist injects a dye into the arm vein, which is distributed throughout the body - and thus also reaches the eye. There, the doctor can then document changes with a special camera. The patient excretes the harmless dye via the kidneys.
Optical Coherence Tomography in Age-Related Macular Degeneration
Another possible examination is so-called optical coherence tomography (OCT). In this examination, the doctor uses a special laser that is harmless to the eye. The light from the laser is reflected differently by the different layers of the retina. A computer then calculates a three-dimensional image of these cell layers from these reflections. The resulting image shows thickenings or fluid accumulations that are typical of age-related macular degeneration. A newer procedure is optical coherence tomography angiography (OCT-A). This method can be used to display the blood flow in the retinal vessels and the draining blood vessels.
Checking eye metabolism with fundus autofluorescence
Fundus autofluorescence is a procedure that makes it possible to visualize deposits of metabolic products (lipofuscin) in the eye. The main focus is on observing the structure of the retinal pigment epithelium. This layer of cells in the retina is responsible for supplying the light-sensitive cells (photoreceptors) and for disposing of metabolic products. In the procedure, light with a specific wavelength is beamed into the eye and its reflection on the retina is recorded with a camera. Lipofuscin reflects the light differently than surrounding areas. If fundus autofluorescence shows an uneven distribution of deposits or a lack of them, this is a clear sign of a degenerative disease process.
,%20only%20an%20experienced%20ophthalmologist%20can%20make%20a%20reliable%20diagnosis.%20But%20how%20exact...){kind=link}