Glaucoma
Glaucoma ranks among the most hazardous diseases leading to complete sight loss. It affects people from 40 years of age and older, and its incidence increases with age. Currently, the number of people affected by glaucoma is estimated at 64.3 million, and it is assumed that this number will increase to 76 million people by 2020. In 2040, it will affect 111.8 million people.The main cause of glaucoma is the impairment of the optic nerve as a result of increased intraocular pressure. The development of the disease is affected by a number of factors. Predominantly, age and genetic predisposition increase the risk of developing this disease. For individuals with a family history of glaucoma it is advisable to undergo a genetic examination.
The risk of disease formation can be predicted by discovering the presence of potential disease-causing genes involved in the development of glaucoma, and its onset may be delayed or prevented by early detection.
Causes
Glaucoma is a disease caused by a number of disease conditions with a different pathogenesis that cause increased intraocular pressure, producing regressive changes in the retina. Increased intraocular pressure is one of the key factors involved in the development of glaucoma.
An increased value of intraocular pressure is the major risk factor in glaucoma development, but this disease occurs even in cases when intraocular pressure values are low and stable. In this case, it is called normal-tension glaucom.
Developmental anomalies in the structure of the eye (changes in the structure of the chamber angle, or hypermetropic eyes) have a great impact on the development of glaucoma as well. Due to eye injury, intraocular inflammation, surgery, or as a result of pseudoexfoliation syndrome (PXF), the advanced phase of glaucoma development, referred to as secondary glaucoma, may occur.
Pathophysiology
Glaucoma is a disease in which the degeneration and necrosis of the optic nerve transmitting visual information from the retina to the visual centers in the brain occur. Impairment of the optic nerve is caused by increased intraocular pressure inside the eye that may indicate early or advanced glaucoma. The increased intraocular pressure may have various causes, for example, infection, poor regulation of intraocular fluid formation, or clogging of drainage channels.
There are two basic types of glaucoma:
Primary angle-closure glaucoma arises due to the closure of the chamber angle (place where the intraocular fluid drains). As the fluid cannot drain, it accumulates in the eye, and this disorder leads to a distinct increase in intraocular pressure. Angle-closure glaucoma occurs in anatomically predisposed eyes (eyes with an inherently narrower chamber angle and a smaller cornea). Normal drainage of the intraocular fluid is most commonly acutely blocked by the iris, and the intraocular pressure often increases to extreme values. It manifests itself by acute attacks leading to acute angle-closure glaucoma (glaucoma angulare acutum).
The second type is primary open-angle glaucoma. The mechanism of its formation is not precisely known, but there is evidently excessive production of intraocular fluid that is not sufficiently drained. The onset and course of open-angle glaucoma is slow. It proceeds asymptomatically over a long time frame, and it manifests itself in a sudden deterioration of vision. Impairment that occurs in the optic nerve is, unfortunately, irreversible. For this reason, early detection of the disease is very important. Both eyes are often affected.
Treatment
Glaucoma can be treated by using drugs, which reduce the intraocular pressure, or by undergoing laser intervention or surgery.
Early diagnosis and glaucoma treatment play an important role in the development of the disease, and it may slow down its course in some cases.
