Generality
The macular hole is a lesion, similar to an opening, which is formed at the level of the macula and which compromises a person's visual abilities.
The factors favoring and / or triggering the appearance of a macular hole are different. One of the main ones is surely the so-called vitreomacular traction, a circumstance that involves the "draw" of the retina (and of the macula in particular) by the vitreous humor.
The treatment usually consists of the vitrectomy procedure.
Short review of the anatomy of the eye
In the eye (or eyeball ), located in the orbital cavity, three concentric portions can be recognized, which from the outside towards the inside are:
- The external habit (or fibrous frock). Area in which sclera (posteriorly) and cornea reside (anteriorly), acts as an attack for the so-called extrinsic muscles of the eyeball.
It has a fibrous nature.
- The medium tunic (or uvea ). It is a membrane of connective tissue, rich in blood vessels and pigment.
Interposed between sclera and retina, it deals with providing nourishment to the retina, or rather to the layers of retina with which it comes into contact.
Includes iris, ciliary body and choroid.
- The internal habit . It consists of the retina; the latter is a transparent film consisting of ten layers of nerve cells (or neurons), including the so-called cones and rods. Cones and rods are deputies to the visual function.
Figure : anatomy of the eyeball.
What is the macular hole?
The macular hole is an opening at the level of the macula, or the central area of the retina responsible for central vision .
Its presence interrupts the normal retinal continuity - after all it is comparable also to a lesion or a tear - and it is the cause of various sight problems.
WHAT IS MACULA?
The macula (or macula lutea ) looks like a yellow spot about 5.5 millimeters in diameter.
Located beside the emergence of the optic nerve at a distance of about 2.5 centimeters, it represents the retinal area with the greatest visual acuity and the greatest ability to identify details. Furthermore, containing more cones than rods, it is particularly sensitive to light stimuli and color perception. All these features describe the so-called central vision.
At least 4 regions can be recognized in the macula: two of these are particularly important and are identified with the names of fovea and foveola (NB: foveola is the center of the fovea).
As for the vascularization, the fovea has large blood vessels all around and arterioles, venules and capillaries inside it; foveola, on the other hand, is avascularized.
The yellow color that distinguishes the macula is due to the presence of two carotenoids: lutein and zeaxanthin .
STAGES OF A MACULAR HOLE
Not all macular hole conditions are the same: there are more or less severe ones, depending on the size of the opening on the macula and the degree of involvement of the retina.
Experts have identified at least three stages of gravity:
- Stage I or macular hole with foveal detachment . Characterized by an alteration of the region occupied by the fovea, it is the least severe stage of the macular hole. If left untreated, in 50% of the cases it undergoes a further deterioration. In the remaining 50% of patients, on the other hand, it heals spontaneously.
- Stage II or partial thickness macular hole . At this stage, not only the macula but also part of the retina is altered. In fact, the latter is slightly raised compared to where it is. If there is no intervention with adequate therapy, 70-80% of the cases undergo a further deterioration.
- Stage III or full-thickness macular hole . It is the most serious stage, in which a complete lifting of the retina is observed in the area around the macular opening.
Patients who come to this state suffer from severe visual disturbances and, even if subjected to the most powerful treatments, they would not be able to recover the entire visual functionality.
Causes
There are various situations that favor the formation of a macular hole, however it is good to remember that most of the lesions at the level of the macula arise without precise and identifiable causes ( idiopathic macular hole ).
One of the main factors favoring the macular hole is the process of separating the vitreous body from the retina, a process that is also called vitreomacular traction .
UMOR VITREO AND VITREOMACULAR TRACTION
Contained in the so-called vitreous chamber, the vitreous humor (or vitreous body ) is the gelatinous and transparent substance that acts as a support
- for the crystalline lens, in the anterior part of the eyeball;
- for the retina, in the back of the eye.
Colorless and with a constant volume, the vitreous body is made up of 98-99% water and other substances, including: hyaluronic acid, salts, sugars and proteins of various types.
These proteins represent fibers of conjunction between the same vitreous humor and the retina.
With aging, the vitreous humor tends to withdraw and interact less and less with the retina. This process - called posterior vitreous detachment - can determine the phenomenon of vitreomacular traction when the vitreous body, detaching itself from the retina, drags along part of the latter and the macula with it (by means of the protein-binding fibers).
If the act of dragging becomes particularly violent, the retina and macula may suffer a tear or an injury.
In reality, for many people, posterior vitreous detachment has no important consequences; only in some cases, in fact, it leads to a serious vitreomacular event that is harmful to the retina.
OTHER FAVORABLE CONDITIONS
According to experts, in addition to vitreomacular traction, they can also affect the appearance of a macular hole:
- Diabetic retinopathy . It is a condition typical of people with diabetes, in which the vascular system of the retina is damaged.
It can cause various vision problems (loss of vision, blurred vision, blindness, etc.) and exposes those who are affected to disorders such as macular edema, macular pucker, vitreous hemorrhages etc.
- A strong myopia
- A retinal detachment
- Best's disease . Also known as vitelliform macular dystrophy, it is a very rare hereditary disease that causes a retinal degeneration involving mainly the macula. Patients begin to experience the first symptoms (loss of central visual acuity, inability to recognize colors, etc.) during childhood or adolescence.
- An ocular trauma
- Conditions of cystoid macular edema or macular pucker
Epidemiology
The macular hole is an eye condition that most frequently affects people aged 60 and over.
According to the latest surveys, it mainly affects women. In fact, it would appear that the number of female patients is twice that of male patients.
Symptoms and Complications
The macular hole generally begins with a slight symptomatology. Then, as the size of the opening on the macula increases, it leads to increasingly evident and serious symptoms.
The typical manifestations of the initial phase consist of:
- Central vision blurred and / or distorted.
- Inability to see straight lines correctly. These, in fact, appear undulating or arched.
- Difficulty reading small fonts.
The classical disorders of the advanced phase, instead, are:
- Loss of sight. In particular, reduced ability to see objects and people both at large and at a small distance.
- Reduced ability to recognize the details of what is being observed.
- Worsening of vision blurring and / or distortion.
- View of one or more black spots in the center of the visual field.
The macular hole is a completely painless condition.
MONO OR BILATERAL?
Generally, people suffer from one-eyed macular hole ( unilateral macular hole ). However, there are cases in which the disease affects both eyes ( bilateral macular hole ).
COMPLICATIONS
If left untreated or inadequately cared for, a macular hole can greatly reduce a person's vision, with serious repercussions on everyday life.
For example, it may be impossible to read or drive a vehicle.
WHEN TO REFER TO THE DOCTOR?
If you experience one or more of the aforementioned symptoms, you should contact your doctor or an ophthalmologist, an eye disease expert immediately.
An early diagnosis of macular hole can avoid unpleasant consequences and makes treatments more effective.
Diagnosis
In general, to diagnose the presence of a macular hole, ophthalmologists use:
- An examination of the fundus
- A computerized optical tomography (OCT)
- A retinal fluorangiography
EXAMINATION OF THE EYE BACKGROUND
The examination of the ocular fundus allows to view the internal structures of the eyeball.
It can provide various interesting indications, but often, for a better final evaluation, it is necessary to resort to more specific examinations.
COMPUTERIZED OPTICAL TOMOGRAPHY (OCT)
Computerized optical tomography ( OCT ) is a reliable and non-invasive diagnostic test that provides very precise scans of cornea, retina, macula and optic nerve.
For a total duration of 10-15 minutes, it is performed using an instrument that emits a laser beam without harmful radiation. Obviously, the patient should be made to sit in front of this instrument.
The latest generation OCTs work very well even without having to give the patient eye drops for pupil dilation.
RETINAL FLUORANGIOGRAPHY
Retinal fluorangiography (or fluorescent retinal angiography ) is a photographic diagnostic procedure that allows the identification and study of vascular diseases of the eye.
It is based on the use of a dye, fluorescein, which, after being injected into a vein, spreads in a circle.
Thus, the diffusion of fluorescein is followed by means of an instrument - the retinograph - capable of taking real photographs (or frames) of the blood flow inside the retinal vessels.
The exam has a duration of about 10 minutes and, at the time of dye administration, could be slightly annoying.
Treatment
There are two possible treatments for the macular hole: vitrectomy and the injection of ocriplasmin (or jetrea).
While vitrectomy is feasible in any situation and represents the main method of treatment, the injection of ocriplasmin is indicated exclusively for cases in which the opening on the macula is subsequent to vitreomacular traction.
VITRECTOMY
Vitrectomy is the surgical procedure of total or partial removal of the vitreous body, carried out in order to fix a vision problem.
In the case of a macular hole, after removal of the vitreous humor, the ophthalmologist works to "fix" the lesion on the macula and to replace the retina in its natural position.
To know in detail what the whole vitrectomy procedure involves, it is advisable to consult the article on this page.
Vitrectomy in its highlights:
- Duration from 1 to 3 hours.
- It can be performed under general or local anesthesia.
- After the operation, scrupulously follow the doctor's instructions, in particular those concerning the insertion of the gas or oil bubble.
- Eye drops are expected to prevent infections from arising.
- Main complications: cataract and retinal detachment.
Figure: state in which an eye undergoes a vitrectomy. The redness and swelling generally last a couple of weeks; after which the situation returns to normal.
Also after the operation, it is highly probable that the vision is blurred for 4-6 weeks; however it is a completely normal consequence.
OCRIPLASMINA INJECTION
Ocriplasmin - injected only once as a single dose - favors the non-violent separation of the vitreous body from the retina, in cases of vitreomacular traction.
It is, in fact, an enzyme that breaks down proteins that connect the vitreous humor to the retina.
According to the latest statistical studies, it would be successful in about 40 patients out of 100 (with, obviously, a macular hole due to vitreomacular traction).
Also in this case, to know the indications and contraindications of ocriplasmin, it is advisable to consult the article present at this link.
Prognosis
After closing the opening on the macula, the eye recovers most of its visual functions. However, it is fair to remember that the effectiveness of the therapy is strongly affected by the size of the macular hole at the time of diagnosis.
