What exactly is the macula?
The retina is a thin layer of tissue in the back of the eye (playing the role of photographic film to capture visual information). The macula is the central portion of the retina, a thin layer of photosensitive cells and nerve fibers. The macula is the point at which light is focused when you look at an object, it is responsible for sharp vision (details of objects) and for color vision.
What is age-related macular degeneration (AMD)?
It is a degenerative condition of the macula. The exact etiology of the disease remains unknown to date. It appears with aging usually in people over 60 years and is one of the most serious causes of vision loss worldwide. In the early stages of AMD, substance deposits are generated under the retina. These deposits are called Drusen and they are usually visible to the opthalmologist during the examination of the eye fundus. In most cases Drusen do not lead to severe vision impairment.
In yet advanced stages of AMD, a decrease in vision is large, and in the final phase of the disease can lead to legal blindness (visual acuity less than 01/10). In AMD the patient maintains a part of their peripheral vision.
The Amsler grid is a useful tool (special graph) for self-examination.
Causes / Symptoms
- yperiosis radiation (sunlight)
- blurred vision
- central scotoma (the patient permanently sees a dark spot in the center)
- metamorphopsia (distorted vision)
- contrast sensitivity reduction (contrast sensitivity)
- reduced visual acuity (visual acuity)
There are two basic forms of age-related macular degeneration (AMD):
- dry form (also known as non-exudative or atrophic form): This form is substantially more prevalent but less dangerous. It is caused by aging, thinning and atrophy of the macula. Symptoms are “blanks” or scotomas in the central vision. Although there are no pharmaceutical or surgical treatments for this form of AMD (except some special food supplements), optical devices such as magnifiers can help these individuals to harness their peripheral vision and to better manage their daily lives
- wet form (also known as exudative form): although less frequent, the wet (exudative) form of AMD is responsible for 90% of severe vision loss cases. Wet AMD is so named because it is characterized by the generation of abnormal choroidal vessels (neovascularization), under the macula. The new vessels are generally poor and brittle, resulting in a leakage of fluid and blood. This leak creates lesions, which destroy the light-sensitive cells of the macula and have as a final result in scarring of the area and the loss of central vision. From the first signs of which are presented to the patient at the earliest stage of wet AMD are metamorphopsia and blurred vision. Straight lines are shown distorted, curved or jumbled together
Treating dry AMD
How is dry (non-exudative) AMD treated?
- healthy and balanced diet
- nutritional supplements (vitamins C, E, minerals, zinc) slow the progression of the disease)
- regulation of the blood pressure
- reducing smoking
Treating wet AMD
How is wet (exudative) AMD treated?
Today there are various therapeutic approaches that have proven effective for the treatment of wet AMD in selected cases.
- Photocoagulation with laser: with a high intensity laser, causing heat to burn and destroys abnormal new vessels, the development of the disease is limited. The result is a small scotoma in the visual field, but is usually much less severe than the loss of vision that would exist if no photocoagulation was applied
- Photodynamic therapy: a photosensitive substance, the Verteporfin (Visudyne CIBAVision), is administered intravenously, selectively retained by pathological new vessels and is activated by a special laser (not producing heat and does not burn the retina). When activated, it causes thrombosis, obstruction and destruction of neovascularization, without affecting the adjacent tissue, thereby limiting the progression of the disease
- Intravitreal injection: the latest development in the treatment of the wet form. This is an injection in the eye, injecting a specific drug that inhibits the activity of the VEGF. Factor The VEGF (Vascular Endothelial Growth Factor), favours the development of pathological, abnormal vessels, i.e. neovascularization. The main drugs used today are the Lucentis (Ranibijumab) and Avastin (Bevacijumab). The injection (injection) is performed under local anesthesia and sterile conditions in a specially equipped sterile operating room. The whole process is painless, quick and does not need stay in a hospital or clinic. About a month later, the doctor will determine the treatment effect. Typically, most patients need one injection a month, during the first three months and afterwards, one to three more injections, through the next nine months. Probably need combination with photodynamic therapy or cortisone injection, depending on the evaluation of the doctor to reduce the duration and the better treatment efficacy
What exactly is the macular hole?
The macular hole is essentially a retinal tear, particularly in the macular region. The disease leads to loss of central vision and involves large groups, as usually occurs after 60 years of age. For the treatment of macular hole, surgery is required (vitrectomy), but in some cases it may be healed automatically. The traction exerted on the retina, the area around the macula is the dominant cause of the condition. This attraction can be caused by the adhesion of the vitreous on the retina, of membranes grown on the retina (macular film) or adhesions between the vitreous and the retina (retinal-vitreous traction). Some of the risk factors for causing the macular hole are: high myopia, macular edema, inflammations of the vitreous, inflammations of the retina, or an injury of the eye.
The main symptoms of the disease are as mentioned above, the loss of central vision, central scotoma with the deformation of objects. The relevant examination carried out is the spectral optical coherence tomography (Spectral Optical Coherence Tomography or S-OCT) with pupil dilation (mydriasis), where, usually, there is a loss of retinal layers. The fluorescein angiography can also give useful results.
What is diabetic macular edema;
The diabetic macular edema (DME) occurs when fluid accumulates in the retina’s layers and specifically in the macular region. This accumulation of fluid occurs due to a local disturbance of the wall of blood vessels leading to their increased permeability. The DME can occur at any stage of development of diabetic retinopathy and is one of the major causes of reduction of visual acuity of diabetic patients (affects about 30% of people suffering from diabetes for many years). The visual impairment due to DME varies depending on the type and duration of diabetes if not promptly treated, in 20% – 30% of patients, mild vision loss occurs. With proper treatment, the swelling subsides, but there are cases resistant to any form of treatment. Several studies show that about 0.6% of the general population suffers from macular edema.
Types of diabetic macular edema:
Causes & risk factors:
- diabetic retinopathy
- elevated levels of glycated hemoglobin
- arterial hypertension
- diabetic nephropathy
- retinal vein thrombosis
- duration of diabetes
- retinitis pigmentosa
- blurred / unstable vision / floaters
- image distortion
- reducing sensitivity to contrast (contrast sensitivity)
- disturbances in colour perception
- scotoma (visual field defects)