Age-related Macular Degeneration AMD - Questions and Answers
This article, written by Dr. Pedro Neves, an ophthalmologist at CPO, serves to inform readers about this pathology that requires special attention due to the high risks it poses to patients' vision if not monitored and treated by a professional.
What is age-related macular degeneration (AMD)?
Age-related macular degeneration, AMD, is a progressive eye disease that affects the macula, the central part of the retina responsible for sharp vision and fine detail. Over time, macular function can deteriorate, leading to loss of central vision, blurred vision or blind spots (called scotomas) in the center of the visual field. This type of vision loss, macular blindness, can affect daily activities such as reading, driving and facial recognition.
Is it a common disease?
Yes. According to the World Health Organization (WHO), age-related macular degeneration (AMD) is one of the leading causes of blindness worldwide. It is estimated to be the third leading cause of blindness globally, affecting almost 196 million people (WHO, 2019). In Portugal, it is estimated that around 400,000 people have some form of AMD, and the prevalence is expected to increase with the ageing of the Portuguese population.
What subtypes of age-related macular degeneration (AMD) are there?
The two main types of age-related macular degeneration, AMD, are dry AMD and exudative/wet AMD. Dry AMD is the most common form and progresses slowly, and can develop into well-defined areas of loss of retinal cell function - atrophy. Exudative AMD is less common, but more severe and progresses rapidly. Exudative AMD occurs when new blood vessels grow under the retina and release fluid or blood, causing permanent damage to the photoreceptor cells in the macula.
What symptoms can appear in IMD?
Patients with age-related macular degeneration, AMD, may develop the following symptoms:
- Blurred central vision
- Decreased ability to see fine details and contours
- Difficulty recognizing faces
- Distorted or wavy straight lines
- A dark or empty area in the center of vision
- The need for more light when reading or working up close
- Altered color vision in central vision
It's important to note that symptoms can be subtle at first, particularly if the other eye has good vision. For this reason, examinations carried out at an ophthalmologist's appointment can help detect AMD early on and allow for timely treatment.
What is the main risk factor for IMD?
As the name suggests, the main risk factor for age-related macular degeneration, AMD, is age. The older you get, the greater your risk of developing some form of AMD. The prevalence of AMD increases from 4.2% in people aged between 45 and 49 to 27.2% in people aged between 80 and 85. The risk of developing more severe forms also increases with age.
Is family history a risk factor for IMD?
Yes, having a family history of age-related macular degeneration (AMD) is one of the risk factors for developing the disease.
Are there any other risk factors for IMD?
Yes. Some risk factors described in the literature are:
- Smoking habits: smokers have up to 3x higher risk of IMD
- Ethnicity: higher risk in Caucasians and people with light eyes
- Diet: diets low in fruit/vegetables and high in fat/cholesterol are at greater risk
- History of cardiovascular disease and/or obesity
- Sun exposure: UV rays associated with greater risk
It should be noted that the presence or absence of risk factors does not guarantee or exclude the possibility of developing IMD. As it is a multifactorial disease, it is only natural that as yet unknown factors are determining factors in this pathology.
How can I prevent age-related macular degeneration, AMD?
There is currently no guaranteed way to prevent age-related macular degeneration (AMD). Intervention in the risk factors mentioned above can reduce the overall risk of the disease developing - primary prevention. However, it is possible to improve the prognosis and sequelae by seeking the earliest possible diagnosis and early access to treatment - secondary/tertiary prevention. To do this, it is important to understand AMD and its symptoms and to have regular eye examinations.
Are there treatments for dry IMD?
There is currently no cure for dry AMD, and this field is the subject of intense pharmaceutical research. The use of some nutritional supplements formulated in clinical trials reduces the risk of progression to severe forms of the disease. Some drugs are currently undergoing clinical trials with results available in the next few years.
Are there treatments for exudative IMD?
Yes. There are treatments that are effective for treating the exudative form of IMD:
- Eye injections with anti-VEGF molecules (most common)
- Photodynamic therapy
- Photothermal laser
In any of the treatment modalities, the aim is to reduce the activity of the abnormal vessels in the retina and the consequent release of fluid. It is important to start treatment quickly, as vision loss can be more severe if the disease is left untreated.
How do eye injections work for the treatment of exudative AMD?
Eye injections to treat age-related macular degeneration, AMD, are called anti-VEGF intravitreal injections. This is an injection into the vitreous gel of the eye of an antibody designed to block the VEGF molecule - a molecule produced by the abnormal vessels that develop in the retina. Blocking this molecule both inhibits the release of fluid/blood by these vessels and prevents or reverses the progression of these vascular lesions.
What are the treatment regimens? When does it end?
Unfortunately, exudative IMD has no final curative treatment. For this reason, when improvement and stability of the disease is achieved, the next challenge is to try to maintain the best possible result with the minimum number of injections, knowing that the need for treatment is ongoing. Treatment regimens are individualized and can be adapted to the characteristics of the disease and the patient.
- Start of treatment - loading dose of fixed monthly injections
- Maintenance phase - regime that can be one of the following:
- Fixed regimens: monthly/monthly treatments or other periodicity, regardless of disease activity;
- Pro re nata reactive regimens: treatments carried out only when there is a reactivation of the disease;
- "Treat and extend" regimens : periodic treatments which, according to the activity of the disease, are carried out at increasingly longer intervals.
There are advantages and disadvantages to each regimen, which should be discussed with your ophthalmologist for further clarification.
What is the surgical technique like? Is it painful? What care should I take after the injection?
It is administered under local anesthesia, in the same way as most cataract surgeries, for example. Before the injection, the skin and eye are disinfected. After placing a speculum to help keep the eye open, the injection is made into the pars plana (the area of the eye wall where it is safe to inject). For most patients, the process is quick and only mild discomfort occurs in the following hours. The use of antibiotic eye drops is not currently recommended, but the use of lubricants for comfort is encouraged. Although some discomfort may occur on the day of the injection, most patients resume their normal, unrestricted lives the day after the procedure.
Are there any risks involved in intravitreal injections?
Yes. Intravitreal injections are quick and safe, but invasive procedures, which is why they are only performed by an ophthalmologist and in safe conditions - usually in an operating room. As with any eye procedure, the risks include the possibility of infection, retinal damage or eye bleeding.
Is there any surgery to treat IMD permanently?
As a direct treatment for age-related macular degeneration, AMD, the answer is no. No clinical trials have shown good results with invasive surgical approaches. Rarely, exudative AMD can cause severe bleeding in the retina or inside the eye, which may require surgery.
On the other hand, cataract surgery is still indicated after assessing the risk-benefit of the intervention, in order to preserve the remaining central vision and peripheral vision. Intraocular implantation of macular magnification to aid reading in patients with AMD can also be performed in candidates.
Does IMD cause total blindness?
No, age-related macular degeneration, AMD, rarely causes total blindness, understood as the loss of all central or peripheral vision. However, it can cause significant loss of central vision, called macular blindness, which can make activities such as reading or driving difficult. Usually peripheral vision, which allows orientation in space and part of the activities of daily living, is preserved.
Is there any way I can monitor the appearance of symptoms at home?
Yes. The simplest way to carry out a self-examination is to use the Amsler grid. The Amsler grid allows you to detect mild symptoms, and the examination is carried out on each eye in isolation. If a patient develops retinal disease, one of the symptoms they may notice is distortion in the lines or a lack of detail in the grid.
Amsler Grid - Portuguese Version
An altered test on the Amsler grid is unlikely to be caused by refractive problems (e.g. outdated glasses) or cataracts, and should always prompt a full examination by an ophthalmologist.
How important is an eye examination by an ophthalmologist in this context?
Regular eye examinations are crucial for detecting AMD early and monitoring its progress. Early detection allows for more effective treatment and can slow down or even prevent the progression of the disease, preserving your vision. The ophthalmologist can prescribe tests, such as retinography or OCT (optical coherence tomography), which make it possible to diagnose and stage the disease, as well as its progression.
I have partial loss of central vision. How can I try to improve my reading ability?
Reading ability can be aided with one or more of the following options, among others:
- Magnifying glasses: portable illuminated or fixed magnifying glasses
- Digital magnification devices
- Electronic reading devices with zoomable text
- Text-to-speech reading devices
- Macular magnification lens implant surgery
It is important to note that any of these options means adapting to an installed disability, requiring learning and motivation on the part of the patient.
If you have been diagnosed with age-related macular degeneration, AMD, or have symptoms related to those mentioned in this article, make an appointment with CPO - Clínica Privada de Oftalmologia at 213105650.
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