Tracción vitreo-macular, agujero macular y membrana epirretiniana
Vitreo-macular traction Macular Hole and Epiretinal membrane
Macula, Why is so important?
The macula is the central part of the retina. It is anatomically located in the center of the eye and it is responsible for central vision, the ability to recognize faces and to read.
Despite representing a very small part of the retina as a whole, it contains the cells and the structure that allows the most complex visual functions.
If the macula is affected by a problem, the result can be tragic, since we could definitely lose these abilities and that is why ophthalmologists have a lot of respect for the diseases that affect this small area of the eye. Among these diseases are the 3 that we treat in this text.
Eye structure
The eyeball is a sphere whose back walls form the retina, so the retina has an oval shape, as if it were a dome. If we compare it with a movie screen we could say that the wall of the cinema is the wall of the eye and the canvas where the image is projected is the retina.
The retina, therefore, is a thin layer strongly adhered to the eye inside.
But what keeps it stuck?
There are two mechanisms; On the one hand there is” the glue” that joins it to the wall of the eye that is produced at the intercellular level and on the other, the Vitreous, which is a jelly-like substance that fills the eye inside and is firmly attached to the retina keeping it in place. It fulfills a support function therefore.
Normally the vitreous cortex, which constitutes the outer part of the vitreous, is firmly adhered to the inner walls of the eye, and therefore, in direct contact with the retina.
Vitreous detachment
With age, mainly after 40 years the vitreous degenerates and becomes more liquid, having no longer the same consistency tends to collapse, separates from the retina in some areas and tracts in the parts where it still remains stuck.
This process is a normal phenomenon of aging, therefore it affects us all.
Retinal Vitreous Traction Syndrome
On certain levels this detachment is not total and this residual adhesion can have bad consequences for our eye health.
We could say that the complete vitreous detachment is the best thing that can happen to us since if it is completely separated it does not exert tension on the retina and does not damage it.
The vitreous traction can be at the base of the vitreous, and can cause a retinal tear or rupture and consequently retinal detachment, this topic will be dealt with later.
But if the traction occurs in the Macula, which we have previously defined, then we talk about Vitreous-Macular Traction Syndrome, in which we observe, as in the retina Vitreous Sclera scheme, an adhered zone (vitreous cortex) and another that pulls that is not detached causing deformity of the retina that the patient will perceive as blurred vision or distorted vision (crooked lines) Traction.
Traction
Partial release
Before a macular traction of this type the patient can perceive:
- Distorted vision (larger, smaller, deformed objects ...)
- Flashes
- Blurry vision
- Loss of sharpness
On certain occasions the process resolves spontaneously, the vitreous ends up
completely detaching, the traction disappears and does not require any action.
At other times, especially when there are symptoms such as those mentioned above,
the patient must undergo surgery to release that traction and improve.
Full Macular Hole
The macular hole can be considered an advanced degree of Traction Syndrome where the force exerted is such that it breaks free by breaking the retina during this
resolution.
This is probably the least desired situation. The patient then perceives a black spot in the center of his visual field and loss of acuity that is variable but always severe.
This pathology can also be treated surgically by releasing traction in the area surrounding the hole. In most cases the hole is closed with this procedure.
But it is convenient for the patient to know that the closure of the hole does not mean the restoration of vision, although in most cases it does occur over the months following the treatment.
Epiretinal Membrane
The epiretinal membrane is a formation of an elastic and semi-translucent nature that is located on the surface of the retina. In this pathology there is no vitreoretinal traction, but a total vitreous detachment and the membrane is located in direct contact with the retina.
Its frequency is approximately 2% in people over 50 and increases with age. In most cases the cause is unknown. In this case, the difference with the Vitreous Traction that we have talked about before is that the detachment has been complete, however a dense membrane is formed on the surface of the retina, which when contracted deforms the retina and therefore there is no upward traction, as in the tractional syndrome, but tangential, that is, sideways, causing wrinkling of the retina on which it is located. The symptoms are similar to those of vitreomacular Traction syndrome.
What symptoms should alert me to these pathologies?
The main visual symptoms are image deformity and blurred vision.
There are other pathologies that cause these same symptoms, but it will be the ophthalmologist who with complete recognition and imaging tests can answer the questions.
The bottom image is called Amsler Grid, it serves as a reference to know if a certain pathology is affecting the Macula.
Simple the patient should look at the center of the image, the central point and see if the lines of a certain sector appear crooked. If this occurs, it would be convenient to be evaluated by an ophthalmologist.
And if the diagnosis is confirmed?
There are two possible attitudes:
- Observation and review: sometimes patient follow-up is required evaluating possible changes that may require a different attitude or sometimes the picture can be resolved spontaneously with the release of traction. This follow-up is mainly carried out with a test known as Optical Coherence Tomography that allows us to observe the morphology and traction on the macula and track the changes that occur.
- Surgery: On other occasions a surgical intervention is necessary to release the traction and prevent the process from getting worse. The surgery is called Vitrectomy. Through small incisions in the eye, instruments are introduced that allow the membranes and tractions to be released and removed on the macula and reduce symptoms.
Is the intervention painful?
Although the patient perceives a certain degree of discomfort during the application of anesthesia, the surgery itself is not painful.
What is the postoperative period?
The surgery lasts approximately 30-45 minutes in most cases. It is usually performed with local anesthesia and a certain degree of sedation and the patient can return home after the intervention following a series of recommendations that basically consist of relative rest without making any effort or sudden movements.
In a few days you can live a practically normal life by resuming your daily activity.
What is the final visual result?
It is difficult to predict and very variable from one patient to another.
There are cases of almost complete visual recovery and others where the improvement is less obvious.
If we know that with surgery we stop the progression of the disease and with it the associated visual loss. We also know that the perception of bent objects and crooked lines improves and even disappears.
You have to be patient because recovery is not immediate, it occurs over the following months and even years. Generally the greatest recovery occurs in the first 3 to 4 months.
