Macular edema is an accumulation of fluid in the human eye. The fluid accumulation, the edema, is located in the area of the yellow spot. As a result, visual disturbances and, in particular, blurred vision occur.
What is macular edema?
Macular edema is a swelling of the retina. Tissue swells, particularly in the area of the macula. The macula is a small area in the center of the retina. Because most of the photoreceptors are located here, the macula is the site of the sharpest vision. Light falling on an object is partially reflected and then enters the eye. The light is focused by the cornea and the lens. Thus, the light falls on the center of the retina, on the macula. Here lie numerous light-sensitive sensory cells, so-called photoreceptors. The sensory cells convert the incoming light signals into electrical signals. These electrical signals are then transmitted to the brain via the optic nerve. This then assembles the signals from the eye into a finished image. In macular edema, a circumscribed swelling and vesicle-like accumulation of water occur under or in the so-called pigment epithelium of the retina. There are four stages of macular edema. Thus, there is focal, clinically significant, diffuse, and ischemic macular edema.
Causes
There are numerous causes of macular edema. For example, swelling of the macula can occur with retinitis or uveitis. Retinitis is an inflammation of the retina that is usually caused by infections with certain bacteria or viruses. Borrelia, Toxoplasma gondii or the cytomegalovirus are possible triggers of retinitis. Retinitis can also occur with certain hereditary diseases. In uveitis, the middle skin of the eye (uvea) is inflamed. A frequent cause of macular edema is also vascular damage of the retina caused by diabetes mellitus. This is called diabetic retinopathy. Due to the increased sugar levels in diabetes mellitus, the small blood vessels in particular, such as the capillary vessels of the retina, are damaged. This leads to swelling in the area of the retina and thus also to damage to the retina. This damage often goes unnoticed at first. However, diabetic retinopathy is the most common cause of blindness in Europe. Retinal vein occlusion can also cause congestion, resulting in macular edema. Such retinal vein occlusion occurs when a blood clot (thrombus) forms in the vessel or is washed in from another vessel. Risk factor for the development of retinal vein occlusion is arterial hypertension. Diabetes mellitus or certain forms of glaucoma also increase the risk of thrombus formation in blood vessels.
Symptoms, complaints, and signs
Macular edema usually develops gradually and remains asymptomatic for a long time. With smaller deposits, affected individuals experience problems perceiving contrast or color. In this phase, however, patients can usually still see sharply without any problems. Only in the case of advanced macular edema can visual acuity be reduced. Since macular edema affects the area of sharpest vision, the visual disturbances also occur preferentially in the central area of the field of vision. Those affected then complain of blurred, blurred or distorted vision. Altered color perception may also occur. There may also be dark spots or red haze in the visual field. Some patients also report a kind of gray curtain in the visual field. Even at the first noticeable signs, there is a risk that the disease will progress to blindness. The symptoms affect patients in many activities of daily living. Thus, there may be problems with reading, watching television, or driving.
Diagnosis and disease progression
Diagnosis always begins with a detailed medical history taken by the ophthalmologist. Here, the existing complaints and the temporal course of the disease are discussed. Pre-existing conditions, such as high blood pressure or diabetes mellitus, are also inquired about by the physician. Using various examination techniques, the doctor is able to detect pathological changes in the eye and thus make a diagnosis. With simple eye tests, the ophthalmologist can also examine visual acuity and contrast and color perception.Using a special ophthalmoscope, he can also take a close look at the back of the eye and thus also at the patient’s retina. In macular edema, typical deposits, vascular changes or even hemorrhages are visible here. Such an ophthalmoscopy is also called funduscopy or opthalmoscopy and is part of every detailed examination by an ophthalmologist. In addition to funduscopy, a so-called fluorescence angiography is often performed. This uses a special dye and a special camera to make the retinal vessels visible. Optical coherence tomography also allows the ophthalmologist to visualize the individual layers of the retina. This allows fluid deposits to be detected at an early stage.
Complications
As a rule, macular edema causes discomfort in the eyes. Visual disturbances develop and the affected person usually can no longer see sharply. Furthermore, double vision or veil vision may also occur. The patient’s quality of life is significantly limited and reduced by macular edema. Not infrequently, sudden visual complaints also lead to depression or other psychological limitations. Furthermore, the disease can negatively affect the perception of colors. Spots appear in the visual field, which can make everyday life more difficult. Especially in children, macular edema can significantly restrict and delay development. Due to the macular edema, the affected person is limited in his everyday life in many activities and also in work. The treatment of this disease usually depends on the underlying disease. There are no particular complications. Various medications or surgical interventions can alleviate or completely resolve the symptoms. The patient’s life expectancy is not limited or reduced by macular edema. In severe cases, treatment with a laser can also be performed. This also does not usually result in any particular complications.
When should you see a doctor?
If changes in vision occur, it is advisable to consult a doctor. If there is decreased vision, blurred vision, or blurred contours that are in the field of vision, a doctor should be consulted. Special medical tests are necessary so that the cause of the disorders can be determined. If there are changes in color perception, there is also a need for action. As soon as the person affected notices in everyday life that his color definition differs from that of his fellow human beings, a visit to the doctor is recommended. In these cases there is no spontaneous healing and non-treatment can result in blindness. In case of headache, a feeling of pressure in the eye or inside the head, as well as irritability, a visit to the doctor is necessary. If the affected person suffers from a faster fatigability of vision, needs more strength of the eye muscles to adjust the visual acuity or if there are more accidents in everyday life due to the limited vision, a doctor must be consulted. Spots or shadows in the field of vision are another indication of an existing irregularity. If a haze is perceived in the field of vision, a visit to the doctor is necessary so that there is no deterioration in vision. If fellow human beings perceive an increased clumsiness of the affected person, they should address him or her about it and point out the need for a visit to the doctor.
Treatment and therapy
Basically, to treat macular edema, the underlying disease must be treated. Thus, metabolic optimization in diabetes mellitus or blood pressure reduction in hypertension can halt the progression of the disease. Various agents for the further treatment of macular edema are still being researched. An agent based on a so-called bisindolylmaleimide seems to be promising. In focal macular edema, laser photocoagulation may also be used to prevent further deterioration of vision.
Outlook and prognosis
The prognosis of macular edema is usually favorable. Once the causative disorder is identified, medical therapy takes place. Without treatment, an increase in symptoms and adverse health effects can be expected. In an unfavorable course, the quality of life is considerably reduced due to the limitation of vision. The risk of accidents increases and everyday obligations can no longer be fully met.Once the individual consults a physician, various medical tests are used to determine the causes of the edema. There are various treatment approaches that can be used according to the individual specifications. In addition to the administration of medications, surgical intervention may also be used. Although this is associated with risks, it is nevertheless a routine procedure that is usually trouble-free. Only rarely do complications or other adversities occur that lead to a delay in the healing process. Under optimal conditions, the patient can be discharged from treatment within a few weeks as symptom-free. Vision is restored. Nevertheless, the patient should attend regular check-ups in the further course to prevent recurrence of symptoms. In particular, patients diagnosed with diabetes are well advised to attend follow-up examinations at continuous intervals for a positive prognosis.
Prevention
Diabetics can prevent macular edema with well-controlled blood glucose levels. In addition, regular visits to the ophthalmologist are mandatory for diabetics. However, all other individuals should also have their eyes examined regularly and see an ophthalmologist immediately if they experience vision problems.
Follow-up care
Because the development of macular edema is often due to an underlying disease, affected individuals are generally involved in long-term treatment with a physician to prevent the occurrence of further complications or other complaints. An early diagnosis usually always has a very positive effect on the further course of the disease. The possibilities of aftercare are thus largely limited to regular visits to a doctor. In the event that vision has already been severely affected, aftercare is aimed at minimizing visual complaints. The affected person should therefore refrain from excessive exertion or stressful activities in which the eyes are over. moderately strained, such as hours of computer work and, if necessary, seek a visual aid. The correct adjustment is subject to an expert ophthalmologist in this case.
What you can do yourself
Depending on the cause of the macular edema, adjusting daily behaviors and self-help measures can help alleviate symptoms and prevent recurrence, a reoccurrence of macular edema. In many cases, the primary cause is primary or idiopathic arterial hypertension and type 2 diabetes mellitus, both of which promote damage to small and narrow vessels such as capillaries, allowing tissue fluid or even blood to leak. Adjustment of everyday behavior consists primarily of careful adjustment of blood sugar levels and consistent reduction of blood pressure to tolerable levels. In both cases, relaxation techniques that promote the reduction of stress hormones and give priority to parasympathetic nerve impulses serve to support drug therapy. For example, conscious breathing exercises, self-hypnosis and Far Eastern relaxation exercises such as Tai Chi, Qi Gong and yoga are beneficial. The regularly performed exercises serve to initiate self-repair mechanisms for the damaged vascular system via the parasympathetic nervous system. The danger of retinal vein occlusion in the area of the macula is thereby reduced. Retinal vein occlusions are the main causes of leakage of tissue fluid in the area of sharpest vision.
