World Glaucoma Week, a silent disease

World GlaucomaWeek (World Galucoma Week) is celebrated from March 8 to 12. In our facilities at the General Hospital of Catalonia we will carry out free eye examinations from 9 am to 3 pm, throughout the week, with one objective, to detect the disease.

This degenerative disease of the optic nerve is characterized by the progressive loss of nerve fibers, which is manifested by a gradual loss of visual field. As the disease evolves, a series of changes are produced in the optic nerve, which are visible in the fundus exploration. If the disease is left untreated, all nerve fibers may be lost and blindness may result.

Glaucoma is a common disease that affects 2% of the population over 40 years of age and 15% of those over 60 years of age. As it does not produce symptoms, the patient does not know he/she has it until the vision loss is very advanced.

Why is it produced?

Glaucoma is considered a multifactorial disease, i.e., there is no known primary cause of the disease. So far the best known and most treatable cause is elevated eye pressure, which causes mechanical damage to the optic nerve. But there are other causes such as genetic predisposition, vascular damage, low blood pressure or metabolic dysregulation.

How does it manifest itself?

Glaucoma is a progressive disease, which is why, in most cases, it does not cause symptoms in its early stages. Instead, as the disease progresses, patients notice a loss of central vision in the later stages of the disease. Another sign of advanced disease is difficulty in light adaptation, in which partial blindness occurs when the patient moves from a dark to a bright place or vice versa.

Severe pain occurs only in the acute attack of glaucoma, which may be accompanied by redness, nausea, vomiting and blurred vision from the onset. It is produced by a different mechanism than chronic glaucoma, which is what we are talking about today.

Diagnosis of glaucoma

Early diagnosis of glaucoma prevents visual impairment. It is very important that people who suffer from it undergo a periodic review, as it can worsen without the patient noticing anything.

Diagnostic tests.

• PACHIMETRY Measures the thickness of the cornea of the eye.
• TONOMETRY Measures the intraocular pressure of the eye by means of a warm blast of air.
• OCT OFTALMOSCOPY It helps us to measure parameters of the optic nerve that will allow us to detect changes or progression in this structure if the disease progresses.
• PERIMETRY A test of the visual field that informs us about the visual function and possible losses or defects caused by the disease.
• GONIOSCOPY This test determines whether the angle where the iris meets the cornea is open and wide or narrow and closed.

It should be noted that, despite slowing the progression of the disease, the lost vision does not recover. That is why it is advisable to have a complete eye examination for people over 40 or 45 years of age. In these examinations, the intraocular pressure of the eyes should be measured and checked for possible alterations in both the optic nerve and visual function.

On the other hand, it is essential to review the risk factors that may predispose to glaucoma and closely monitor each case, in order to treat the disease early. These risk factors are:

• Be over 60 years old.
• Having first-degree relatives affected by glaucoma.
• Being of black race.
• Other ocular diseases.

Glaucoma treatments

There are several ways to treat glaucoma, depending on its evolution and severity.

EYE DROPS

This is the first step. Its function is to reduce the amount of fluid produced by the eye or increase its drainage, which helps to reduce eye pressure.

SURGERY

Surgery is performed when eye drops and lasers have not been successful in lowering intraocular pressure. It consists of the creation of a fistula that communicates the interior of the eyeball with the subconjunctival space, thus relieving intraocular pressure and draining the aqueous humor out of the eyeball.

NON-PERFORATING DEEP SCLERECTOMY

Non-penetrating sclerectomy will remove the remainder of the scleral lamina down to the trabecular membrane.

TRABECULOCTOMY

It differs from the previous surgery in that the trabeculectomy will resect the full thickness of the sclera and trabeculum, so the penetration to the globe is complete. Even a small perforation is made at the level of the iris root. The flow rate achieved by this method is higher.

SCLEROTRABECULECTOMY WITH OR WITHOUT EXPRESS VALVE IMPLANTATION

It is an intermediate surgery between the two previous ones. Instead of resecting the base of the sclera and trabeculae, a valve is placed that penetrates to the interior of the eyeball. As filtration is performed through the filter, the outflow is more constant and regulated.

MINIMALLY INVASIVE GLAUCOMA SURGERY (MIGS)

MIGS (Micro Incisional Glaucoma Surgery) is a set of glaucoma surgeries in which an intraocular drainage device is implanted. The objective of these minimally invasive surgeries is to achieve greater safety than conventional or filtering surgeries. The conjunctiva is not altered, thus avoiding the fibrosis that closes filtering surgeries and inducing less tissue disruption. Therefore, there is less postoperative inflammation, as well as a sufficient decrease in blood pressure to stabilize the glaucoma in those patients who do not require more aggressive reductions.

On March 12, the OMIQ Institute will celebrate World Glaucoma Day, with a single objective: to raise awareness of this chronic disease.