What is the Difference Between Open and Closed Angle Glaucoma?
Glaucoma is a disease caused by a disturbance in the balance of production and outflow (hydrodynamics) of intraocular fluid, which is accompanied by an increase in intraocular pressure – IOP. Glaucoma can appear immediately after the birth of a child (congenital) or over time (acquired), against the background of certain diseases (diabetes mellitus, hypertension, atherosclerosis). Acquired glaucoma often occurs after 40 years, but it can also appear at a young age. In addition to the above, there is also secondary glaucoma, when the cause of increased IOP is other eye diseases or complications during their treatment.
Types of glaucoma
There are 2 types of glaucoma: open-angle and closed-angle. The most popular type of glaucoma is open-angle, this pathology occurs most often in patients. With open-angle glaucoma, the circulation of the intraocular fluid is disturbed, but the structure of the anterior chamber angle remains normal. In the closed-angle form of glaucoma, the angle of the anterior chamber of the eye overlaps, therefore, the pressure inside the eye increases. This is the main difference between the two types of glaucoma. Now we will review each type of this disease in more detail.
The exact cause of open glaucoma is unknown. But doctors believe that it is associated with dysfunctions of the eye drainage system. Most often, if a patient has an initial degree of glaucoma, then it does not manifest itself in any way, therefore, one can suspect this disease only later. With moderate and severe degrees of open-angle glaucoma, the field of vision from the side of the nose is narrowed, and intraocular pressure increases. The patient can also have the following symptoms:
- gray optic nerve head;
- bending of blood vessels along the edges of the nerve;
- changes in the vessels of the retina and conjunctiva;
- optic disc.
How is open-angle glaucoma treated? If a person is diagnosed with this disease, then he or she needs to be fully examined immediately. An ophthalmologist will measure intraocular pressure and visual acuity, and prescribe glaucoma eye drops – some of them are even available over the counter.
Most often doctors prescribe Bimatoprost 0.03%. This product belongs to anti-glaucoma drugs that improve the outflow of aqueous humor along the uveoscleral pathway. Generic Bimatoprost is available at Trust Pharmacy, so you can buy it online. The drug relieves the symptoms of the disease 4 hours after application. The maximum effect is observed after 8-12 hours and lasts up to 24 hours. The patient needs to place 1 drop in the affected eye in the evening. If the drug is used more often, the effectiveness of therapy decreases. If you skip the next dose, you need to continue treatment in a standard dose.
If Bimatoprost ophthalmic solution does not help and the symptoms worsen, then surgical treatment may be indicated. One should bear in mind that the operation is aimed only at reducing intraocular pressure, and not at improving vision and curing the disease.
Angle-closure glaucoma can be caused by several factors: heredity, age-related features of the visual organs, etc. The disease can proceed in an acute and chronic form. The acute form of glaucoma is usually accompanied by severe pain, headaches, nausea or vomiting, red eyes. Intraocular pressure also rises. In this case, treatment cannot be postponed since even a slight delay is fraught with loss of vision.
Patients with the chronic form of the disease complain of redness of the eyes, blurred vision, headaches. Intraocular pressure often remains normal but it is often higher in the affected eye. Treatment can be conservative or surgical. Conservative treatment includes eye drops and special antibiotics. In the second case, laser surgery is indicated. Using a laser, a doctor makes a hole in the iris of the eye, which helps to ensure drainage of fluid and normalize pressure in the eye.
A simple measurement of intraocular pressure will not identify the disease. It is necessary to study in detail the fundus and the optic nerve head, as well as examine the visual fields, that is, conduct a thorough diagnostic examination.
Doctors use a whole range of modern computerized equipment to diagnose open-angle or closed-angle glaucoma:
- examination of the visual field (using a computer perimeter);
- measurement of refraction (the ability of the optical system of the eye to refract light rays);
- measurement of intraocular pressure;
- ultrasound examinations;
- determination of the depth of the anterior chamber of the eye and the thickness of the lens (since often the cause of high pressure is the displacement or enlargement of the lens);
- gonioscopy (evaluates the internal drainage system of the eye).
All theses diagnostic methods make it possible to identify the initial signs of glaucoma that occur before changes in the field of vision and to stop the pathological process.
Forecast and prevention
It is very important to start treatment of the disease in the early stages when pathological changes occurring in the structures of the visual apparatus can be corrected and the most positive results achieved.
With the spontaneous course of glaucoma and the absence of adequate therapy, the prognosis of the disease is unfavorable, soon it leads to partial or complete blindness.
Prevention of open-angle or closed-angle glaucoma consists in early diagnosis – for this, it is necessary to regularly visit an ophthalmologist, especially if you are over 40, as well as if you are at risk. If you have glaucoma, you should be examined by an ophthalmologist every 6 months and receive recommendations for treatment.