What is it?
Pathology of the macula
The macula is a small area of yellow pigmentation in the center of the retina (it is its thinnest part), which has a high concentration of photoreceptor cells. Despite its small size, it has a great relevance in ocular functions, since it is responsible for the central vision, the vision of the human eye movement, as well as for the most precise vision. In other words, thanks to the macula, it is possible to distinguish small details, colors and faces.
The pathologies of the macular region are characterized by symptoms affecting this central vision, to which only 5% of the retina is dedicated, as opposed to the remaining 95%, which is responsible for peripheral or lateralvision.
Macular hole
It consists of a micro-tear in the macula (central part of the retina), as a consequence of the tension generated by the vitreous gel when it naturally detaches from the retina, to which it is attached. In some cases, the vitreous gel does not separate completely from the retina and remains attached to some areas. These areas of vitreomacular adhesion exert a traction force on the macula that may eventually lead to the formation of a macular hole.
There are different types of macular holes depending on whether they totally or partially affect the thickness of the retina.
The macular hole is usually due to the aging process, although there are also other risk factors that may influence its appearance, such as myopia (in myopic patients it may lead to retinal detachment ), certain eye injuries or a long-lasting ocular inflammatory process.
Symptoms
The visual consequences of this progressive pathology will depend on the degree to which it is present. Although, at first there are no symptoms, it can cause a significant loss of vision.
In an initial phase, during the formation of the macular hole, there is an alteration of vision that results in mild blurred or hazy vision. If the macular hole evolves and enlarges, a dark spot may appear in the central vision, the size of which depends on the area that has been affected, as well as a distortion of the image.
It is very important to detect this disease early, when the formation of the macular hole is still in its initial stages, in order to achieve a better visual recovery. For this reason, if any of these symptoms occur, it is necessary to consult an ophthalmologist immediately for an in-depth study to rule out or confirm the diagnosis.
Treatment
The macular hole has a good prognosis, since it is closed in 90% of the cases.
The treatment of macular hole is always surgical and is performed by vitrectomy. This surgery is based on removing the vitreous, detaching it from the macula and repairing the tear that has occurred. It is also necessary to remove the membranes that grow around the hole and keep it open, to free the retina. At the end, a gas bubble must be introduced into the eye to help it close.
There are cases of small holes that can be treated with an intravitreal injection of ocriplasmin, which releases the traction of the vitreous and closes them without the need for intervention, although they can also heal spontaneously.
2. Age-related Macular Degeneration (AMD)
It is a disease of degenerative origin of the macula (central area of the retina), which causes a progressive deterioration of the tissues of the eye, particularly the retinal pigment epithelium, and is generally associated with aging.
AMD is the leading cause of severe visual impairment over the age of 50 in the Western world. In Spain, this chronic condition affects some 700,000 people (1.5% of the population) and it is estimated that its prevalence will triple within 25 years.
Two types can be distinguished:
- Dry AMD: Occurs in 80% of cases. It is characterized by the slow and progressive loss of vision in the central area of the visual field, while peripheral (lateral) vision is preserved, which allows the patient to defend himself in a familiar environment.
- Wet AMD: It is characterized by the growth of new blood vessels (neovascular membrane) under the macula. Its evolution is rapid and seriously compromises central vision.
The main risk factors for the onset of AMD are age, genetic predisposition, smoking, alcohol, hypertension or high cholesterol levels.
Symptoms
AMD does not cause pain, but may present various visual disturbances affecting the center of the field of vision, such as distorted vision of objects(metamorphopsia), blurred vision, increased sensitivity to light or sudden loss of central vision, among others.
When the disease is in a more advanced stage, the patient reports seeing a dark spot in the area of central vision that may darken and enlarge the more advanced the AMD is.
In order to confirm the appearance of the first symptoms, the patient can resort to the use of a simple test known as the Amsler Grid, which consists of looking at the central point of a grid with one eye and then with the other. If a central spot appears or the grid lines look distorted instead of straight, a complete examination with the ophthalmologist is required.
Treatment
AMD cannot be prevented because it is linked to the natural aging process. Therefore, it is advisable for the patient to have regular check-ups with the ophthalmologist after the age of 50, since early diagnosis can prevent the disease from leading to blindness in many cases. As a preventive measure, it is also advisable to adopt certain healthy habits related to food care ( healthy and varied diet) and tobacco consumption.
Current treatments for macular degeneration focus on combating the wet form of AMD. For some years now, intravitreal injection of anti-angiogenic drugs, whose action blocks the progression of neovascular membranes, has been indicated. This is an outpatient treatment that is performed under topical anesthesia and requires a very strict follow-up of the patient. In general terms, this type of treatment manages to stop vision loss in 90% of cases.
On the contrary, there are others in which it will be more advisable to opt for direct laser photocoagulation or surgical treatment to remove the neovascular complex.
3. Macular edema
Macular edema is a swelling of the retina at the level of the macula, which is the part responsible for central and detailed vision. This complication is due to irritation of the blood vessels that irrigate the retina and cause fluid leaks. As a result of these leaks, fluid accumulates in the macula and impairs its proper function. The result of this complication is a mild or severe loss of vision, although peripheral vision is maintained in many cases.
Although the causes of macular edema can be multiple, the risk of developing it is usually associated mainly with complications of ocular pathologies such as diabetic retinopathy, age-related macular degeneration (AMD), venous thrombosis (obstruction in the retinal veins) or uveitis. Occasionally, it may be a consequence of an ocular surgery procedure.
Regular check-ups with the ophthalmologist are essential to detect macular edema early and treat it as soon as possible. In the case of diabetic patients, this control should be stricter in order to reduce the probability of suffering it. It is estimated that approximately 25% of diabetic patients may develop some degree of retinopathy.
Symptoms
When macular edema develops, it can cause symptoms in central vision, such as blurred vision, distorted vision of straight lines, and a feeling of darkening of images in the center of the visual field.
Treatment
The treatment of macular edema will depend on its origin and degree of evolution.
Depending on the characteristics of each patient, there is the option of pharmacological treatment with eye drops, intraocular injections of antiangiogenic agents, which reduce the formation of new abnormal blood vessels (neovascularization) and prevent fluid loss, as well as laser photocoagulation. In severe cases surgery (vitrectomy) may be necessary.
4. Macular epiretinal membrane (MER)
The epiretinal membrane (ERM) is the proliferation of fibrous tissue that grows on the macular surface, forming a kind of mesh that alters its functionality. When this membrane, which is attached to the retina, contracts, it induces a certain degree of distortion in the retina.
Generally, the epiretinal membrane develops as a result of a posterior vitreous detachment. Over the years, the vitreous humor may separate from the retina, allowing the passage of cells through it, which stimulates the appearance of this tissue.
Other less frequent causes are intraocular inflammation, retinal detachment or severe ocular trauma. These membranes are more common after the age of 50, but can appear at any age.
In case of any of the symptoms described above, it is very important to see an ophthalmologist for a fundus examination to determine the degree of opacity of the epiretinal membrane, as well as the distortion it is causing in the retina.
Symptoms
This pathology is usually asymptomatic when it is in an incipient stage or the symptoms may be very subtle. In fact, many people who have macular epiretinal membrane are unaware of it.
However, in some patients, sometimes there is a contraction of the membrane that wrinkles the retinal area to which it is attached, reducing their central vision. As the membrane progresses, the symptoms that appear are diverse: blurred vision, deformation of objects(metamorphopsia), appearance of a spot in the central vision, luminous flashes(photopsia), among other manifestations.
Treatment
When this pathology produces a progressive loss of vision, becoming disabling for the patient, surgical treatment(vitrectomy) is indicated to remove this abnormal tissue. Once the tissue that is compromising visual quality is removed and released from the surface of the macula, vision slowly begins to recover. This surgery is usually performed under local anesthesia on an outpatient basis.
However, in most cases a surgical solution is usually not necessary.
Other pathologies
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