What is Glaucoma?
Glaucoma represents heterogenic group of relatively common optic neuropathies, which are manifested through higher ocular pressure, progressive damage of the ocular nerve, deterioration of ganglion retina cells and defects in the vision field.
Glaucoma is one of the leading blindness causes in the world. According to the World Health Organization, 105 million people suffer from this optic neuropathy while 5 million people are blind because of it.
What causes glaucoma?
Glaucoma occurs due to higher generation of eyewash or disorder in the drainage of the eyewash from the eye. Eyewash is the liquid that is generated in the eye and leaves the eye through the part called chamber angle.
Since eye is a closed structure, if there is a blockage of the chamber angle, flow of the eyewash is disabled and ocular pressure rises, affects optic nerve and causes damage.
What are different types of glaucoma?
Most common categorizing of different types of glaucoma in everyday clinical practice is: primary, secondary, and congenital. Primary glaucoma can be open angle glaucoma (glaucoma simplex) and closed angle (glaucoma angular). Open angle glaucoma (POAG) can also have ocular hypertension and normotensive glaucoma.
Secondary glaucoma occurs due to a number of other ocular disorders that can lead to higher values of ocular pressure: eye inflammation, changes in the lens (overripe and swollen cataract), eye injuries, changes in the eye caused by diabetes, hypertension…
Congenital glaucoma occurs as a consequence of the embryogenesis disorder.
Main risk factors for glaucoma are:
- Higher intraocular pressure (higher than 20 mmHg)
- Age (over 40)
- Central corneal thickness
- High myopia
- Systematic diseases – including diabetes, migraine, and bad circulation
- Environmental factors
Symptoms and signs:
In most cases, open angle glaucoma has no symptoms at the beginning so it is discovered by accident during regular ophthalmic examination. That means that people don’t know they have glaucoma while their optic nerve is deteriorating.
Usually, patients schedule appointments late once they realize their vision is getting impaired or blurred, they see rainbow colors, they feel fatigue and pain in eyes, defects in view field, and headache. Unfortunately, changes that have occurred on the optic nerve are irreversible at that point.
Closed angle glaucoma develops very slowly in two thirds of patients, without showing any symptoms before difficulties happen.
A lot of patients experience sudden jump in the intraocular pressure and the state called acute glaucoma attack.
Those states require urgent medical assistance! It is very important to recognize the symptoms:
- Vision blurriness
- Strong eye pain
- Rainbow colored circles around the source of light
- Nausea and vomiting
If you have any of these symptoms, immediately see your ophthalmologist. If acute glaucoma attack is not treated immediately, blindness can occur!
How to discover glaucoma?
Regular eye examination is the best way to detect glaucoma. Measuring ocular pressure is not enough to discover glaucoma. One way that definitely discovers glaucoma is the complete ophthalmologic examination.
- Tracking of the intraocular pressure (tonometry curve)
- Inspection of the chamber angle (gonioscopy)
- Examination of the optic nerve (ophthalmoscopy)
- Inspection of the view field (computerized perimetry)
- Measuring cornea thickness (pachymetry)
- Measuring the thicknesses of the neuroretinal rim and layer of the retinal nerve fiber (optic coherent tomography – OCT)
How is glaucoma treated?
Glaucoma is a progressive chronic optic neuropathy that, once diagnosed, requires lifetime monitoring and treating. That includes use of eye drops medicine or, in case that maximum doze of medicine does not regulate the disease, surgical or laser treatment
Prescribed therapy must be done every day the way your ophthalmologist prescribed.
Open angle glaucoma laser intervention (trabeculoplastica) uses special laser to affect trabeculum (part where eyewash is flowing) which improves the flow of the eyewash and reduces ocular pressure.
Closed angle glaucoma intervention (iridotomia) uses special laser to affect peripheral part of the iris, makes small opening in the tissue and enables additional drainage of the eyewash.
These two methods are done in hospital under local anesthesia without preoperative preparation.
If the maximum use of the anti-glaucomatous therapy does not regulate disease, surgical treatment is used. All anti-glaucomatous surgeries have a goal of finding a balance between generation and drainage of the eyewash.
Today, drainage implants like Ahmed’s valvulator Express implant are more and more used.
Vision loss can be prevented
Glaucoma is a progressive chronic optic neuropathy that, once diagnosed, requires lifetime monitoring and treating. For the adequate treatment, cooperation between a patient and a doctor is necessary.
- Regular ophthalmologist examinations, at the beginning once a month then every 3 months
- Inspection of the vision field every 6 months
- OCT once a year
If you use two or more types of eye drops, the period between the uses of those should be 5 to 10 minutes.
Glaucoma cannot be cured, however it can be controlled and permanent blindness can be avoided if discovered in the early stages and treated appropriately.