Glaucoma is an Eye Disorder

Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye(s) and progressing to complete blindness if untreated.  It was not until 1705 that the difference between Cateract and Glaucoma were understood   The word "Glaucoma" comes from a Greek word meaning "opacity of the crystalline lens

There are two main categories of Glaucoma "open angle" and "closed angle". Closed angle glaucoma can appear suddenly and is often painful; visual loss can progress quickly, but the discomfort often leads patients to seek medical attention before permanent damage occurs. Open angle, chronic glaucoma, tends to progress at a slower rate and patients may not notice they have lost vision until the disease has progressed significantly 

Glaucoma is associated with increased pressure of the fluid in the eye (above 21 mmHg or 2.8 kPa).  In cases where the intraocular pressure (IOP) is constantly raised without the associated nerve damage the term 'ocular hypertension' is used. On the other hand the term 'low tension glaucoma' is used for the typical visual field defects when associated with a normal or low IOP. The nerve damage involves loss of retinal ganglion cellsin a characteristic pattern.

Glaucoma is called the "silent thief of sight" because the loss of vision normally occurs gradually over a long period of time, and is sadly often only recognized when the disease is quite advanced and the damage cannot be reversed. It is the second leading cause of blindness in the World. 

Glaucoma affects one in 200 people aged fifty and younger, and one in 10 over the age of eighty. In some populations, only 50% of patients with primary open angle glaucoma actually have elevated ocular pressure. Those of African descent are three times more likely to develop primary open angle glaucoma People with a family history of glaucoma have about six percent chance of developing glaucoma Elderly people have thinner corneal thickness.they are also at higher risk for primary open angle glaucoma.

It is possible to arrest the development or slow the progression of Glaucoma with the use of eye drops. In some cases surgery may be used. Poor compliance with medications and follow-up visits is a major reason for vision loss in glaucoma patients.