Ophthalmic Diseases - Glaucoma
The glaucoma is a leading cause of blindness in Portugal, especially in older people. Fortunately, the loss of vision caused by glaucoma is preventable if detected in time.
The glaucoma is a disease of the optic nerve in which it is affected by the increase of intra-ocular pressure, decreased irrigation and other factors . These changes cause a typical loss of the visual field as well as macroscopic changes of the optical nerve (excavation), wich help define this disease.
The amendment more suggestive of glaucoma is the disruption in visual field, since there may be glaucoma with Intraocular pressure "normal" (below 21 mmHg) or excavation of the great optic nerve without glaucoma. It is understood by excavation, the optic nerve that has no nerve fibers.
There are basically 2 types of glaucoma:
Chronic open-angle glaucoma - It is without doubt the most common (90%) and it results in a loss of efficiency of the zone of disposal of aqueous humor. This disorder will lead to an increase of intraocular pressure with consequent damage to the optic nerve. The injury develops slowly and is painless
The acute angle closure glaucoma - Blocking sudden-area outlets with large increase intraocular pressure (> 45 mHgm) and causing; blurred vision, headache, eye pain, domestic areolas with colors, nausea and vomiting, red eye, etc.. The treatment of glaucoma acute attack constitutes an emergency in ophthalmology.
The usual chronic glaucoma, the most frequent, may pass unnoticed by the patient. Unfortunately it doesnt give pain, decreased visual acuity initially and when the patient realizes that if something is not right, then it is because the disease is already well advanced. For these reasons it is imperative to early diagnosis in order to avoid a loss of vision that is totally avoidable. Thus, it becomes mandatory, from 40 years in the outpatient ophthalmology, eye measure intraocular pressure (tonometry), evaluate the optic nerve (ophthalmoscopy), inspect the drainage angle of the eye (gonioscopy).
Where there is suspicion, further examinations are important:
Visual fields - This examination is made using techniques increasingly refined and precise. Currently it´s used computerised perimeters who study the sensitivity of each point tool. In glaucoma the loss of visual field begins to cover the peripheral and only later amendments are central. Examination of the visual fields is the only test that can detect early changes that easily go unnoticed to the patient.
Optical tomography of the nerve - computerized test that measures the anatomical changes of the optic nerve, very useful for monitoring the progress of excavations of glaucoma
In the treatment of glaucoma its always necessary to remember that:
- The existing injuries can not be reversed.
- The current treatment is very effective and is designed to prevent or stop the trend of injuries from glaucoma.
- Treatment is chronic, that is for life, only the ophthalmologist can stop or change therapy (never do that by your own initiative!).
The basis of the treatment of glaucoma is to lower the intraocular pressure. Most patients can lower the intraocular pressure only using eye drops. If this fails it is possible to do laser therapy.
Alternatively, treatment is surgery:
Trabeculectomy - Creation of a new exit from the aqueous humor in order to lower the intraocular pressure. Although the complications of modern surgery are rarely serious, they may occur, as with any surgical intervention. For this reason, the surgery is indicated when the risk of injury optic nerve caused by glaucoma, is larger than the surgical risk.
Because of this disease causing blindness, which is avoidable, and not give symptoms in the early stages, treatment is more effective in the early stages.
Go to the ophthalmologist every 1-2 years if:
- You have more than 39 years.
- Some family member has glaucoma.
- If you have myopia.
- If you are from African origin.
- If at anytime suffered a serious eye injury.
- If you take medicines, anxiolytics, tranquillisers corticosteroids.
- If you suffer from cardio-vascular disease.
If you have glaucoma do not forget:
Never stop treatment without the order of the ophthalmologist.
Treatment is chronic, its forever.