What Is Glaucoma and How Did I Get It?

by Charles Blotnick MD 

Patients often ask “what is Glaucoma and how did I get it?” 

Glaucoma is a disease where the pressure inside the eye builds up and damages the vision nerves.  It effects over 3 million Americans and 70 million people worldwide.  Glaucoma is considered the leading cause of irreversible blindness in the U.S. and the world.  90% of those are over the age of 40. 

The eye behaves like a sink, fluid is produced and then drains out.  If the fluid (called Aqueous Humor) does not drain out fast enough then the pressure inside the eye will rise.  The increased pressure directly damages the vision nerves in the back of the eye called the optic nerve.  For this reason, most patients will have no symptoms until their vision is almost gone. 

There are 2 main forms of glaucoma, Open angle and Angle closure.  The open angle form is far more common (over 90%) and is associated with a gradual rise in pressure.  It is painless so patients may not know they have glaucoma until it is too late.  Angle closure on the other hand is a sudden rise in pressure and is usually painful.  It is considered an ocular emergency and needs to be treated immediately by an eye doctor. 

We know there are several risk factors to develop glaucoma.   

  1. Age over 60 (or 40 for African Americans) 
  1. Family History of glaucoma (brother, sister, mother, father) 
  1. Having high eye pressure 
  1. Having a thin cornea (there is a simple test in the office to measure corneal thickness) 

Other lower risk factors include: 

  1. Diabetes 
  1. Being near-sighted 
  1. Prior eye injury 
  1. Long term use of steroids (oral, topical or nasal inhaler) 

It is important to note that your daily blood sugar or blood pressure levels do NOT correlate with your actual eye pressure.  Also, eye pressure varies through-out the day and is often higher in the morning.  For this reason, it is sometimes necessary to check the eye pressure several times during the day (called a diurnal curve).  

There are several tests we perform in the office before we can confirm the diagnosis of glaucoma.   

  1. Visual Acuity 
  1. Intra-ocular Pressure or IOP (there are several different devices to measure pressure but Goldmann Applanation is consider the most reliable) 
  1. Visual Field (this is a machine used to detect loss of your peripheral vision, which is the first area of the vision to be damaged) 
  1. Corneal thickness (called pachymetry) 
  1. Inspect the drainage channels (called gonioscopy) 
  1. Analysis of the Optic Nerve (by photography and OCT thickness) 
  1. ERG (electroretinography) is a newer test to measure the electrical response of the retinal cells 

If your doctor at Metrolina Eye Associates decides that you do have glaucoma, there are several ways to treat the disease.  There are 3 general categories 

  1. Eye drops 
  1. Laser treatments in the office 
  1. Surgical drainage 

Look for another blog in the future with more information on glaucoma treatments. 

Charles Blotnick MD