Glaucoma affects more than a million people in Spain and is the second cause of vision loss. On the occasion of World Glaucoma Day, on March 12, we report on the types of glaucoma, bearing in mind that it is a silent disease in its initial stages.
Vision of a person with glaucoma. Photo provided by the Gómez-Ulla Ophthalmological Institute
Glaucoma, of which four different types stand out, is an irreversible damage to the optic nerve whose most relevant cause is often high intraocular pressure, which means the progressive loss of peripheral vision.
In most cases and in the initial stages, “the patient does not experience any discomfort or symptoms until a permanent and irreversible alteration of vision occurs”, explains the president of the General Council of Colleges of Opticians-Optometrists (CGCOO), Juan Carlos Martínez Moral.
In this way, he recommends going to an annual review, since “cases of blindness could be reduced by one 90%“.
Who does it affect?
According to the CGCOO, people over forty are more likely to develop glaucoma, although it can appear at any age.
For his part, the Gómez-Ulla Ophthalmological Institute focus on the genetic predisposition of this disease, as a person with a family history of glaucoma is up to nine times more likely to suffer from it.
They also remember that children are not exempt from suffering from this eye condition either.
The types of glaucoma
In this way, it is important to know the different types of glaucoma that exist. From the Spanish Society of Glaucoma (SEG) point out the four main:
Open angle glaucoma
Is the most common type of glaucoma and the main risk factor is the elevation of intraocular pressurealthough family history or high myopia can also contribute to its appearance.
Depending on whether there is another disease that causes it, it is classified into primary or secondary. In the case of secondary glaucoma it can be caused by ocular or non-ocular diseases.
Diagnosis and treatment
In most cases this type of glaucoma is asymptomaticthis is why it is known as silent blindness, so it is advisable to go to the ophthalmologist for an annual check-up.
It usually consists of a medical treatment with drops that reduce intraocular pressure.
Angle-closure glaucoma
It occurs in those eyes where the outflow of the aqueous humor (the liquid that the eye produces) is compromised when the iris obstructs the chamber angle (forms the cornea, sclera and iris). It is more common in small and farsighted eyes.
symptoms
This type of glaucoma can occur acutely, intermittently or chronically:
- acute: severe pain, blurred vision, nausea, vomiting and heavy sweating. It can be confused with a gastrointestinal picture.
- Intermittent: episodes of blurred vision, with halos around lights and headaches.
- chronic: it is asymptomatic, with a painless rise in intraocular pressure and damage to the optic nerve and visual field.
diagnosis and treatment
The diagnosis is obtained from the inspection of the chamber angle with the gonioscopy.
As for the treatment, it requires one peripheral iridotomy with laser, which consists of creating a small hole in the iris that allows the recirculation of the aqueous humor that has been blocked.
Neovascular glaucoma
It’s a special kind of secondary glaucoma relatively common and serious that occurs as a result of the formation of new blood vessels in the iris. These end up causing a obstruction to the circulation of aqueous humourwhich triggers an increase in eye pressure (ocular hypertension).
Central retinal vein occlusion and diabetes mellitus are the main causes.
symptoms
In the most serious phase appears:
- Significant pain.
- Decreased vision.
- Corneal edema (fluid retention).
- Distortion in the shape of the pupil.
- Redness and congestion of the anterior sector of the eye.
Treatment
It is fundamentally based on the control of ocular hypertension, retinal oxygen deficiency and pain.
The panretinal photocoagulation is the most used procedure through the application of laser to induce the regression of the new glasses.
Congenital glaucoma
It is a set of diseases characterized by the existence of anomalies which cause an increase in the internal pressure of the eye, damaging the optic nerve.
The most frequent form usually occurs in the first months of the child’s life or in early childhood (before the age of three), and between 80 i 90% of the cases are sporadic.
symptoms
- Increase in the size of the eye (buphthalms)
- Corneal endothelium breaks (Haab’s striae).
- Corneal edemacausing tearing, photophobia and blepharospasm (inability to keep the eyes open when there is light).
diagnosis and treatment
In most cases it is necessary to explore it under sedation in the operating room.
In addition, it requires surgery that is usually repeated several times, depending on each case.