Content

Introduction

Glaucoma, according to some sources, affects over 55 million people on earth and is a leading cause of visual impairment after cataracts; in Italy, it is estimated that about one million people are affected, but it is estimated that half of the patients are unaware of it.

It is an eye disease that gradually, slowly but severely, damages the optic nerve causing changes in the visual field with limitations in the external field of vision (peripheral vision).

The lesion of the optic nerve causes a progressive alteration of the visual field, which tends to gradually narrow until its complete disappearance (Video).

Glaucoma is typically characterized by an increase in pressure inside the eye (intraocular pressure, IOP) due to the lack of outflow of the transparent and colorless liquid that fills that portion of the eye (aqueous humor). However, there are also forms, more rare, in which the IOP is not elevated.

In the eye there are regulatory mechanisms that tend to keep the pressure inside it more or less constant. Normal values ​​are between 16 mmHg (millimeters of mercury) and 21 mmHg. We therefore speak of ocular hypertension in the presence of values ​​higher than 21-22 mmHg.

Lowering the IOP can reduce the risk of damage to the optic nerve and visual field.

There are four main types of glaucoma:

  • primary open-angle glaucoma, the most common form of chronic glaucoma. It progresses very slowly, affecting the older population and causing a gradual reduction in peripheral vision
  • closed-angle glaucoma, form that interests the adult.It is less common than open-angle glaucoma, and can occur slowly (chronic form) or can develop rapidly (acute form) with a sudden and painful increase in ocular pressure following the failure of the aqueous humor to drain.
  • secondary glaucoma, a form that occurs mainly as a result of certain diseases such as diabetes, arterial hypertension, but also as a consequence of the intake of certain drugs, of some ocular or intracranial tumors, proliferative and haemorrhagic diseases, or of wounds and trauma ( often sports) that involve closing the corner
  • congenital glaucoma, a form that affects infants or very young children. It is caused by an abnormality of the eye that causes photophobia (discomfort in the light) and excessive tearing. It is rare because it occurs in about 1 in 30,000 births.

The visual limitation and loss of vision caused by glaucoma can be prevented as long as the disease is detected (diagnosed) and treated as soon as possible. It is therefore very important to undergo regular eye checks, which include measuring the intraocular pressure so that you can discover the disease in the early stages when it is not yet causing any disturbances (symptoms). A correct and timely treatment helps, in fact, to slow down or stop the disease.

It is recommended that you have your eye pressure checked annually from the age of 40 if you have no risk factors, and more frequently if you are at high risk or are over 65, even if there are no symptoms.

Symptoms

The signs and disorders (symptoms) caused by glaucoma are variable and occur only in the most advanced and terminal stages of the disease:

  • primary open-angle glaucoma: it is the most common type (60-70% of cases), often causing little obvious discomfort as it develops very slowly and is often linked to aging.Frequently, people do not realize that their vision has been damaged because the first part of the eye to be affected is the external field of vision which will present with blotches or blind spots. It is therefore advisable to have an eye examination. at least annually or more frequently if recommended by your doctor
  • closed-angle glaucoma- develops rapidly, often causing severe discomfort (symptoms) such as intense pain and redness of the eyes, severe headache, nausea and vomiting, blurred vision, halos around lights, loss of vision in one or both eyes . The disturbances are not constant. They can last for an hour or two before disappearing again. But each time they occur, vision is damaged a little more. It is therefore important to seek immediate medical attention if you notice that you have any of these discomforts because starting treatment right away can prevent further damage.
  • secondary glaucoma: have disorders caused by other diseases or by eye treatments, such as the use of drugs. It can cause blurred vision with halos around the lights
  • congenital glaucoma: it is rare and affects very young children. Young age often makes it difficult to recognize disorders (symptoms) such as: large eyes due to ocular pressure that tends to expand them, excessive tearing, sensitivity to light (photophobia), eyes that move in jerks, eyes that appear to appear watery, strabismus

Causes

The front (anterior chamber) of the eye is filled with an aqueous substance called aqueous humor, a fluid that, in a healthy eye, flows constantly inside the eye, between the anterior and posterior chambers of the eye, maintaining the correct pressure.

Glaucoma occurs when the drainage tubes (trabeculae) inside the eye are slightly blocked, preventing aqueous humor from flowing properly.

When fluid cannot flow freely, the pressure inside the eye rises and can damage the optic nerve (the nerve that connects the eye to the brain) and nerve fibers in the retina (the light-sensitive nerve tissue that lines the eye). the back of the eye).

It is often unclear why drainage pipes become blocked or what causes the pipes to clog.

The most important risk factors for glaucoma are:

  • advanced age over 60 years: in this age group, the risk of developing the disease becomes higher
  • eye surgery or traumasthe repeated of the eye: Sports activities such as boxing or football can be the cause of traumatic glaucoma which can occur immediately after the trauma or even years later
  • family predisposition: Having direct relatives, such as a parent, brother or sister with glaucoma, increases the risk of developing the disease 4 to 9 times compared to the normal population
  • diabetes, heart disease, hypertensionPeople with these diseases may be at increased risk for glaucoma
  • myopia: nearsighted people are more likely to develop primary open-angle glaucoma
  • reduced corneal thickness: a reduced thickness of the cornea (less than 500 microns) increases the risk of developing the disease
  • prolonged intake of cortisone drugs, especially locally (topically)

Diagnosis

It is important to have regular eye exams at least once a year and especially after the age of 40 so that eye diseases such as glaucoma can be diagnosed and treated as soon as possible, especially if you have a close relative who is already affected. from the disease.

Glaucoma usually damages the peripheral vision of the eye and then slowly affects the central vision as well.

To ascertain (diagnose) glaucoma it is essential to undergo some instrumental tests, all painless and fast enough, such as:

  • pressure measurement inside the eye (tonometry): a drop of anesthetic eye drops (analgesic drug) and dye is placed in the eye. Then, the pressure of the eye (intraocular) is measured by means of a device that measures tonometry (the tonometer) which can work by a light contact or by means of a light puff of air (air tonometer). Tonometry can diagnose ocular hypertension (OHT), a risk factor for chronic open angle glaucoma
  • corneal thickness measurement: the thickness of the cornea is measured because it can influence intraocular pressure
  • gonioscopy: it is an examination of the anterior outer edge of the eye, between the cornea and the iris (the colored part of the eye). This is the area where the eye fluid must drain. Gonioscopy can help determine whether this angle is open or closed (locked)
  • visual field examination (perimetry): check for missing vision areas. During the examination, a sequence of light points is shown that must be identified. If you can't see light in your peripheral vision, glaucoma has damaged your vision
  • evaluation of the optic nerve: the optic nerve connects the eye to the brain. After instilling eye drops to dilate the pupils, the patient's eyes are examined with some optical instruments to assess whether the optic nerve has been damaged by glaucoma

In case of suspected glaucoma it is important to evaluate the causes, the degree of development, the damage caused in order to choose the most suitable treatment.

Therapy

Although incurable, glaucoma can be well controlled with adequate therapy aimed at reducing intraocular pressure.Any visual damage caused by glaucoma cannot be repaired, so it is important to find out as soon as possible (diagnose it early) and start treatment right away to prevent further damage.

Initially, eye drops are used to lower intraocular pressure. Treatment will have to continue throughout life.

When medical therapy is no longer sufficient, laser treatment is used or surgery is performed. This gradual treatment procedure is possible when the diagnosis is made in the early stages of development and the glaucoma progresses slowly. In severe cases it recurs. immediately to laser or surgical treatment.

Use of eye drops

The choice of eye drops depends on the stage of the disease, the general state of health, the possible intake of other drugs, the "resistance" to their side effects.

They are used to favor the outflow of the aqueous humor in the eye, consequently reducing the intraocular pressure which will tend to return to normal values.

If prescribed by your doctor, it is important to use eye drops even in the absence of visual impairment as, if left untreated, glaucoma can cause permanent vision loss.

If you use two different types of eye drops, you will have to wait a few minutes between the administration of the first and that of the second. It will also be necessary to follow the doctor's advice, even in the case of contact lenses use as the eye drops could deposit in the lenses, damaging the eyes.

If the therapy based on eye drops is not enough, medicines can be used by mouth (oral route), even if for limited periods of time.

Types of eye drops

Among the drugs for the treatment of glaucoma, the most used are beta-blockers and prostaglandin analogues.

Beta blocker drugs

Used once or twice a day they can cause unwanted effects (side effects) such as: stinging or burning sensation in the eye, dry eyes, itchy eyes. Beta blockers should not be used in case of asthma or heart problems.

Prostaglandin analog drugs

Usually used once a day, they are used to treat glaucoma in the event that beta blockers cannot be taken.

The main side effects may include: red eyes, darker iris, longer, thicker and darker eyelashes, eye pain and irritation, red and swollen eyelid edges, dry eyes, headache, sensitivity to light.

Carbonic anhydrase inhibitors

They are used both as an alternative to beta-blockers (for allergic, intolerant or hypersensitive patients), and as a complement to a therapy with the same beta-blocker drugs (in the absence of contraindications for the patient).

Used usually two or three times a day, they can cause: bitter taste in the mouth, nausea, dry mouth, eye irritation.

Sympathomimetic drugs

Used with caution in people with high blood pressure (arterial hypertension) and heart disease, they are used twice a day and can cause pain and redness in the eyes.

Laser treatment (Trabeculoplasty)

Used in the treatment of open-angle glaucoma, the operation lasts a few minutes, is painless, non-invasive and usually does not involve risks and complications. A brief twinge of pain or heat may be felt during the procedure. The operation consists in applying an anesthetic pain-relieving eye drops in the eye and placing a special lens in front of the cornea while the laser will make small holes inside the bulb allowing the fluid to flow out of the eye, reducing its pressure. at a laser treatment you may still need to use eye drops.

Surgery (Trabeculectomy)

It is performed to limit the progression of glaucoma when pharmacological treatments are no longer sufficient or tolerated by the patient. It is an intervention that creates a passage ("bypass") between the inside of the eye and the external part, thus allowing the excess aqueous humor present inside the eye to flow out and decreasing the pressure.

Prevention

Although diet and way of life have no correlation with the development of glaucoma, some suggestions can help promote and take care of eye health while also helping to control high eye pressure.

As a general rule:

  • make a complete visit to the ophthalmologist every year starting at the age of 40 and every two after the age of 65. More frequently if you are at high risk of glaucoma
  • follow a healthy diet. This can definitely help keep you healthy although it won't stop your glaucoma from getting worse. Several vitamins and nutrients are important for eye health such as those found in green leafy vegetables and fish
  • practice regular physical activity. Exercise helps reduce eye pressure in open angle glaucoma
  • limit caffeine, as drinking beverages with large amounts of caffeine can increase eye pressure
  • drink only moderate amounts of fluids at any given time during the course of a day. Drinking a liter or more of any liquid over a short period of time may temporarily increase eye pressure.
  • sleep with your head raised slightly helps reduce intraocular pressure during sleep
  • learn about your family's health history and, in particular, that relating to eye health since glaucoma tends to be a hereditary disease. If you are an "at risk" individual, you may need more frequent eye doctor checks
  • protect your eyes carefully, as serious eye damage can lead to glaucoma

Living with

Having glaucoma does not mean limiting your life as it is sufficient to follow a few simple precautions and slightly change your habits.

In the world, half of people with glaucoma don't even know they have it. If they were aware of it, they could become precious "ambassadors", encouraging relatives and friends to regularly undergo a check-up at an ophthalmologist to have their eye pressure and optic nerve checked.

If the disease is ascertained (diagnosed) at an early stage, you can keep its evolution under control and continue to live satisfactorily, remembering, however, to undergo regular eye examinations.

In addition to physical health, the emotional and psychological aspects of a disease must be taken into account. Being able to share your fears, feelings and worries with a family member, friend or, even better, with other people affected by the same disease, can certainly be of great help and relief.

People with glaucoma can continue to live a normal life, although some activities such as driving or playing certain sports may be difficult. Even in summer, the heat and outdoor activities for those suffering from glaucoma can present some difficulties. Loss of visual ability to distinguish extremely fine details, glare problems, sensitivity to light are some possible effects of glaucoma that could interfere with some activities.

However, it is enough to adapt and organize yourself to find the best solution.

The use of sunglasses with sun or gradient lenses (preferably yellow, amber or brown) can certainly help in cases of glare thanks to a considerable reduction of the phenomenon.

As a rule, air travel has no effect on eye pressure, in the case of long journeys, however, it is advisable to have artificial tears to prevent dry eyes. People who have undergone eye surgery for less than a month however, they should consult their medical specialist before flying.

Glaucoma and driving

Some eye drops used for the treatment of glaucoma can contribute to aggravate vision problems such as loss of sensitivity to contrast, glare phenomena, sensitivity to light. It is therefore necessary to protect the eyes from light, both natural and artificial, by using photochromic lenses.

In more advanced forms of the disease it is recommended to stop driving, especially if you notice phenomena such as:

  • loss of lateral vision, a problem that could make visibility difficult and the ability to react in time to avoid other vehicles, pedestrians or obstacles
  • adaptation to light, the eyes take some time to get used to the strong sunlight or the glare of the headlights at night
  • blurred vision, it can become difficult to distinguish images well and to notice movements such as, for example, those of passing cars or pedestrians crossing the street

Pregnancy and glaucoma

Fortunately, eye pressure tends to decrease during pregnancy due to hormonal changes. It is always advisable, however, to discuss with your specialist to choose the most suitable drug during the first months of gestation, the entire period of pregnancy and the subsequent phase of breastfeeding. The data relating to the impact on the fetus of the drugs used for the treatment of glaucoma are not yet well known. These drugs, in fact, not only act on the eye but affect the whole organism.

In-depth link

Italian Association of Glaucoma Prevention

Editor'S Choice 2022

Benzene

Benzene

Benzene is a chemical that can cause cancer in humans. It is present in the environment. How to avoid being exposed to it as much as possible

BPH

BPH

Prostatic hypertrophy or benign prostatic hyperplasia (BPH), consists of the enlargement, common in men over 50, of the prostate

Food pyramid

Food pyramid

The Food Pyramid is a chart designed to illustrate how to maintain a complete and balanced diet.In Italy, the weekly pyramid of the Italian lifestyle was developed to indicate the amount of food but also of physical activity