Glaucoma is a progressive disease of the optic nerve which, if untreated, can lead to a narrowing of the vision field, deterioration of the optic nerve and significant, and even permanent, loss of vision. It has no symptoms and therefore it is called “the silent thief” or “silent killer” of the vision.
How frequent does glaucoma occur?
Glaucoma is the second cause of blindness in the world. Previous studies have shown that approximately 2-3% of the population older than 40 years suffer from some type of glaucoma, but is assumed that 50% of cases remain unrecognized. The results of prospective study show that in 2010 the number of people with glaucoma worldwide was 65.8 million, and predictions are that by 2020 that number will be 78.6 million, while in 2040 could grow to 111.8 million. Currently, more than 6 million people in the world are blind as a consequence of glaucoma.
What are the risk factors in the development of glaucoma?
- Population aged 45 years or more
- Presence of glaucoma in the family
- High myopia
- In patients with high blood pressure, hypothyroidism, diabetes
- Frequent and long-term treatment with corticosteroids
- Eye injuries
- Greater representation among people of colour due to the anatomical features of the eye
What causes glaucoma?
Elevated eye pressure is considered a major risk factor for developing glaucoma. Normal values of the eye pressure are in the range of 8-21 mmHg. According to some statistics, upper normal value is 22 mmHg or even 24 mmHg. It should be noted that any increase in eye pressure does not necessarily mean that a person has glaucoma. For example, people with ocular hypertension have a value of intraocular pressure over 21 mmHg with no visible glaucoma damage to the optic nerve or changes in the visual field, but have a slightly higher risk of developing glaucoma disease. But changes in the optic nerve and visual field can occur also in normal and reduced values of eye pressure.
Then we talk about the normotensive and hypotensive glaucoma. Glaucoma is a syndrome which means that in addition to the value of eye pressure, there must be present changes in the optic nerve and visual field.
What are the symptoms of glaucoma?
Symptoms of glaucoma depend on the stage and type of disease, and may be unrecognized for a long time. Unfortunately, often in everyday practice, advanced glaucoma damages are discovered, without even causing any disturbances to that person. Glaucoma is usually detected during the first detailed eye examination at a time when patients feel presbyopic disturbance (age related farsightedness) and come to do the examination to determine diopter of eyeglasses they need to get. After some research, only half of patients with glaucoma are aware of their disease. In the early stages it is usually asymptomatic and therefore is often called the “silent thief” of the sight.
In open angle glaucoma symptoms often do not exist. Often patients come to the clinic only when damage of the optic nerve and changes in the visual field occurred. On the other hand, the symptoms of angle-closure glaucoma can be very turbulent. Some of the symptoms are extremely high eye pressure, significant drop in visual acuity, pain in the region of the eye, headache, nausea and vomiting.
Main types of glaucoma
Open angle glaucoma
Unknown cause. Iridocorneal angle structures through which the aqueous humour goes appear to be normal, but nevertheless the flow of aqueous humour is slowed, it remains in the eye longer than it should which results in increased eye pressure. If left untreated, it compresses and damages the optic nerve.
The cause lies in the anatomy of the iridocorneal angle that is narrow or completely closed which makes difficult the outflow of aqueous humor and damages the optic nerve.
Infantile (congenital) glaucoma
It can occur at birth (congenital glaucoma), and between 3-16 years of life (juvenile glaucoma). Often has a worse prognosis than glaucoma that occurs in adults.
It can occur after eye surgery, eye injuries, recurrent complicated inflammation of the eye, long-term use of corticosteroids, systemic diseases such as diabetes or cataracts.
We have the possibility of performing the overall diagnosis of glaucoma in one day (non-contact and contact measurement of intraocular pressure, corneal thickness measurement – to define the level of intraocular pressure, examination of iridocorneal angle – gonioscopy, preparation and analysis of the field of vision and analysis of the optic nerve – computed coherence tomography (OCT)).
Damage on the optic nerve which is caused by glaucoma before the beginning of the treatment cannot be mended, but it is possible to maintain the current condition and significantly slow down the progression of the disease. Depending on the situation, treatment of glaucoma can involve anti-glaucoma eye drops, laser or surgery. It is also possible to combine these methods.
The treatment most frequently starts with anti-glaucoma drops which allow reduction of intraocular pressure.
Glaucoma is treated with: YAG laser iridotomy and selective laser trabeculoplasty (SLT).
Early detection of glaucoma
Prevention of glaucoma is not possible, but the early detection of disease and its significant slowdown is possible:
- If a member of family has glaucoma, a complete examination of glaucoma should periodically be carried out
- If you more than 65 years, it would be good to control eye pressure every two years, even though you do not feel any symptoms
- If the disease is already detected, it should regularly be checked and prescribed medication should be used