The most common type of glaucoma is Primary Open Angle Glaucoma (POAG).  This occurs when the angle of the eye is open anatomically, but there is an excess of fluid in the anterior chamber of the eye.  This elevated pressure can lead to damage of the optic nerve, resulting in vision loss.  This is the most well-known type of glaucoma.  There are other types of glaucoma that are explained in the videos below. 

• Narrow Angle Glaucoma: The angle where fluid drains is limited, so the pressure builds up. Often a laser surgical procedure called a Laser Peripheral Iridotomy is performed.  This makes a small opening in the iris to allow another route for fluid outflow. 
• Closed Angle Glaucoma: The angle is completely closed, so the pressure can elevate very quickly causing rapid vision loss. This is an emergent condition and needs immediate treatment. Symptoms are an acute onset of severe eye pain, a very red eye, tearing, nausea and vomiting, headache, blurred vision and haloes around lights. 
• Secondary Glaucomas: This can be from injury, certain medications, inflammatory conditions or secondary to other disorders. For instance, some patients are steroid responders, meaning steroids make their eye pressures elevate dramatically.  If you are on long term steroid treatment for any condition, make sure you get regular eye exams.  Steroids can also cause early onset cataracts and other ocular problems.  
• Normal Tension Glaucoma:  In this type, the pressures are within the normal range, but the optic nerve still becomes damaged.  
• Pigmentary Glaucoma: In patients with Pigmentary Dispersion Syndrome, the pigment from the iris flakes off and can intermittently block the angle, causing a block in outflow and resultant pressure spikes. This is a common type of secondary gluacoma. 
• Ocular Hypertension: With Ocular Hypertension, there is no apparent damage to the anatomy or function of the nerve, but intraocular pressures are higher than normal.  These patients need to be monitored carefully, and often on treatment to prevent damage in the future.