Glaucoma is a group of eye diseases that affect the optic nerve. As a rule, pathology develops due to increased intraocular pressure (IOP) and is one of the main causes of blindness in the elderly.
This insidious disease often progresses gradually, proceeding completely unnoticed by a patient with glaucoma. A person may not even know about glaucoma until it reaches an advanced form. Loss of vision due to glaucoma is an irreversible change, but at an early stage, the development of the disease can be slowed down or stopped altogether. That is why it is so important to undergo regular ophthalmological examinations.
What is open angle glaucoma?
angle glaucoma (OAG) is the most common form of the pathology. Ophthalmologists warn: with this variety, the risk of complete loss of vision is very high and, unfortunately, it is increasingly occurring in young people. Unlike closed-angle glaucoma, which occurs with attacks, accompanied by redness of the eyes, discomfort and episodes of acute pain, with open-angle glaucoma, vision may not cause inconvenience to the patient and gradually narrow down to complete blindness.
It usually occurs in people who have small eyeballs, a shallow anterior chamber, and a large lens.
Signs and symptoms of open-angle glaucoma are:
- Frequent headaches and eye pain;
- The appearance of rainbow circles or a feeling of fog before the eyes;
- Narrowing of peripheral (lateral) vision;
- Decreased clarity of vision (disturbance of accommodation, visual functions).
If you are familiar with these symptoms, we recommend that you contact an ophthalmologist as soon as possible, diagnose and take action. If you ignore the manifestations of glaucoma, vision can no longer be saved.
Why does open- angle glaucoma develop?
Among the reasons are congenital features of the development of the eye, the impact of external factors, problems with the outflow of intraocular fluid due to degenerative changes in the trabecular (drainage) apparatus. With age, degenerative changes in this system progress, and the symptoms of OAG increase.
Let’s figure out how it works. Our eyes contain a fluid that must circulate properly: the new one enters, the old one is removed. On the border between the cornea and the sclera of the eye there is a limbus – the transition of these anatomical formations from one to another. It is there that the system is located, which is responsible for filtering and draining liquid through microscopic drainpipes. In fact , the open-angle shape is a blockage and stagnation of fluid, which increases pressure in the eye.
The risk group primarily includes people over 60, but it can be encountered at 45 and 35 years. If someone in your family has been diagnosed with this pathology, you should especially carefully monitor the health of the eyes, as the likelihood increases. Since glaucoma is directly related to pressure, it is more common among people with diabetes, hypertension (high blood pressure).
Depending on the nature of the disease, doctors distinguish the following forms of glaucoma:
- Primary open-angle glaucoma (POAG).
- Secondary – a complication against the background of another pathology of the organ of vision, in which intraocular pressure rises, the optic nerve is damaged.
angle glaucoma is:
- Simple, that is, arising against the background of problems with the outflow of intraocular fluid, which is accompanied by impaired blood supply and stagnation of blood flow. This form progresses rather slowly and usually does not affect both eyes at once;
- pigmented. Characterized by the ingress of pigment granules from the iris into the drainage system, they, in turn, cause blockage of the outflow tract;
- Pseudoexfoliative . Usually develops rapidly and causes hypertension. It can be caused by amyloidosis (amyloid degeneration) – protein deposition in the tissues of the iris, lens and ciliary body;
- Glaucoma with normal pressure. Yes, this can happen too. In this case, visual disturbances are caused not by increased ophthalmotonus , but by visual field defects, damage to the optic nerve – the main conduction tract, along which image information is transmitted from the retina to the brain.
As open-angle glaucoma progresses, the following stages of the course of the disease are distinguished:
- I (initial) stage. Some areas of central vision fall out (scotomas appear), while the peripheral boundaries remain normal. On examination, the ophthalmologist may note depressions (excavations) in the optic disc of various sizes and shapes. At this stage, the patient can notice the changes himself only if he is engaged in fine painstaking work that requires perfect and clear vision;
- II (developed) stage. The boundaries of the visual field are narrowed by 10 or more degrees, and the excavation of the optic nerve reaches the edges of its disk. Symptoms are still invisible;
- Stage III – advanced POAG. The view is limited on all sides, that is, peripheral vision is impaired. By closing one of the eyes, the patient may notice problems with orientation in space;
- IV (terminal) stage, when visual functions are already irretrievably lost, the patient can distinguish light from shadow, but is not able to determine the direction of its source.
Diagnosis and treatment of open- angle glaucoma
To catch the moment when vision can still be saved, people over 40 years of age are recommended to have an annual examination for the timely detection of open-angle glaucoma.
To make a diagnosis, the following examinations will be required:
- Visiometry – assessment of visual acuity with and without correction;
- Tonometry – measurement of intraocular tone;
- Biomicroscopy – examination with a slit lamp;
- Refractometry to check the refractive power of the eye
- Ophthalmoscopy to check the condition of the fundus.
If the specialist detects ophthalmohypertension , then he will additionally conduct a study of the visual fields (perimetry), gonioscopy and pachymetry , that is, he will study the structure of the angle of the anterior chamber of the eye and measure the thickness of the cornea. The data obtained may be the basis for the diagnosis of “Suspicion of glaucoma” and re-examination after 2-4 weeks. In order to confirm or refute the diagnosis, it may be necessary to perform tonography , daily pressure measurements, coherence tomography, and additionally contact a neurologist glaucomatologist – a highly specialized specialist in the treatment of glaucoma.
When glaucoma is detected, drug (conservative) therapy is first started. For treatment, antihypertensive drugs are used in the form of eye drops, which reduce pressure and tension. Finding the right medication can take time. First, the patient may have contraindications. A couple of weeks after the start of using the drops, the doctor should evaluate the effect, and if it is not there, replace the drug or supplement it with another one.
It is very important to follow all the doctor’s recommendations for instillation of drugs, especially before the control measurement of the level of IOP. Otherwise, the indicators will be uninformative, and the effectiveness of treatment will not be possible to assess. If you often forget about your medications, set up daily reminders on your phone according to the schedule prescribed by your doctor. Conservative treatment of glaucoma can be combined with courses of vascular therapy to improve blood circulation.
In cases where ophthalmotonus (high blood pressure) remains the same even with the use of drugs, surgical treatment is indicated. Glaucoma surgery is aimed at restoring the circulation of eye fluid, but is not able to restore vision. Surgery is performed using a laser.
For the treatment of OAG perform:
- Laser iridectomy . The essence of the operation is to create artificial perforation to normalize pressure. It is performed in a few minutes under local anesthesia on an outpatient basis using a YAG laser. This method has many limitations and contraindications, the procedure is not performed in case of damage or clouding of the cornea, pronounced edema;
- Laser trabeculoplasty to improve the functioning of the drainage system and restore the outflow of moisture. This type of treatment effectively shows itself in stages I and II of primary open-angle glaucoma, and is also minimally invasive.