Exudative maculopathy (or wet macular degeneration) is one of the two forms of macular degeneration (wet and dry), being the rarer form (10% cases) and also the more serious.
Age-related macular degeneration (AMD) is a disease associated with aging, which affects the macula, the central portion of the retina that is necessary for the clear vision of what you watch. It is the leading cause of severe central vision loss (legal blindness) after age 55.
Maculopathy is characterized by the progressive loss of central vision, often bilateral, which severely limits visual function.
The set of adjacent structures such as the retinal pigment epithelium, Bruch’s membrane, and the choriocapillary located below the macula undergo changes due to aging. The physiological passage of oxygen and nutrients from the choroid to the retina becomes difficult and at the same time, the debris deriving from the photoreceptors that are normally metabolized and eliminated by the retinal pigment epithelium accumulate to form deposits under the pigment epithelium itself.
Risk Factors for Age-related Macular Degeneration
The causes of age-related macular degeneration are not yet fully known, but risk factors have been identified:
- Age. It is the main risk factor. In Italy, it is estimated that about 1.5 million people between 50-60 years old, 1 million between 60 and 70 years old, and 2 million over 70 years old suffer from one of the two forms of this pathology.
- Diet. Cells in the macula are particularly susceptible to free radical damage. People who take low amounts of antioxidants are at increased risk of developing maculopathy.
- Sunlight. Cell damage from sun exposure can lead to macular deterioration over time.
- Smoke. It increases the risk of macular degeneration by more than double.
- Inheritance. You may have a higher risk if one or more close relatives have maculopathy.
- Gender and race. A 75-year-old woman is twice as likely to develop the condition as a man of the same age.
Symptoms and Diagnosis
This disease can go almost unnoticed in the early stages, especially if only one of the 2 eyes is affected. There is a reduction in central vision, a blurring of words in reading, a dark or blank area in the center of the field of view, and the distortion of straight lines. The distortion of the images is a frequent symptom onset of the wet form and one must push an urgent eye examination because of this. Defects of the central visual field and image distortion can be verified with a simple test, the Amsler grid (Amsler test).
Among the fundamental exams we have:
- the measurement of visual acuity
- fundus examination in biomicroscopy
- OCT (Optical Phase Coherence Tomography), which allows you to view the different layers of the retina
Fluorangiography uses a blue light fluorescent substance (fluorescein) to detect foreign bodies in the eye. This test can also detect damage to the cornea.
The Amsler test is useful as a self-check of macular function and is based on the search for any deformations or defects of the grid. If the grid appears deformed, consult your ophthalmologist immediately. Below is how the Amsler test is performed. Wear reading glasses if necessary.
- cover the left eye with the palm of the hand
- hold the test at a normal reading distance with the right hand
- fix the vision at the point at the center of the grid with the right eye
- be careful if you observe deformed, distorted, broken lines; or a dark spot
- repeat the same procedure on the other eye
Macular Degeneration Therapy
Until some time ago, the only treatment options were based on Argon laser photocoagulation and photodynamic therapy. In my current practice, I have been able to use all the therapies with which more or less effective results can be obtained which are also connected with the operator’s preparation in handling these methods.
Intravitreal injections of anti-angiogenic drugs. Anti-VEGF drugs. Bevacizumab (Avastin®).
In recent years, it has been discovered that the protein that is mainly responsible for the growth of new vessels is called VEGF (vascular endothelial growth factor). Thanks to this discovery, antibodies have been developed that can block VEGF and therefore, neovascularization.
The research has produced sophisticated drugs that, when administered with intravitreal injections (inside the eye), aim to block the growth of neovascularization and facilitate the reabsorption of retinal exudation. (also read what anti-VEGF drugs are).
Avastin® should not be used in the treatment of dry macular degeneration, non-proliferative diabetic retinopathy, and diabetic macular edema.
The Argon laser requires a trained operator to achieve good results, but on experienced hands, it can be very effective. The Argon laser has a photocoagulation action. It is performed on an outpatient basis, under topical anesthesia, after having dilated the pupil. It can be a little annoying, though it is good that patients who have to undergo the Argon laser treatment are accompanied because the pupil dilation is maximal.
It is used when the newly formed vessels occupy the center of the macula and have certain characteristics. In photodynamic therapy, a photosensitive substance (verteporfin) is injected into a vein that adheres to the endothelium of the newly formed vessels. The deposited verteporfin is then activated with a non-thermal laser, and the resulting reaction leads to the closure of the abnormal vessels due to thrombosis. The adjacent retina is not damaged. As a rule, multiple treatments are required over a period of 1-2 years.