GLAUCOMA

Glaucoma is a condition that can lead to damage to the eye’s optic nerve and result in blindness.  It can be a serious threat to vision.  There is a process in the eye that maintains the pressure at a normal level to keep the eye full and round.  The front chamber (Anterior Chamber) is filled with clear fluid somewhat like the plasma component of blood.  Fluid is slowly pumped into the anterior chamber and slowly drains out into the blood stream.  With glaucoma, there can be a problem with fluid not flowing out of the eye quickly enough.  Internal pressure can rise and press upon the optic nerve which is the weakest part of the eye.  It is somewhat like squeezing a balloon … the neck or tip of the balloon is pushed out as the internal pressure increases.

Following are some of the routine tests done to check and monitor glaucoma. 

Tonometry:  Tonometers are any of the instruments that measure the internal pressure in the eye.  If glaucoma is suspected we often prefer to check the pressure at several times during the day.  We can also teach patients how to measure their own pressures and loan them the appropriate instrument to take home with them. 

Pachymetry:  This is an instrument used to measure the thickness of the cornea.  When we know the exact thickness of the cornea, we can more easily calibrate the pressure measurements for individual eyes.

Evaluation of the Internal Eye:   The interior structures of the eye can be evaluated, with special emphasis on the optic nerve (see diagram above and below).  This can be done with special instruments, including digital photography and scanning laser tomography.  Digital photography gives a two dimensional record of the appearance of the optic nerve and scanning laser tomography gives a three-dimensional record along with exact measurements of the structure and anatomy of the optic nerve.  We also use a special lens and microscope to evaluate the area in the eye that often becomes clogged and causes the pressure to rise (the angle where fluid exits).  This is called gonioscopy. 

Above left is a normal optic nerve.  The nerve on the right is glaucomatous.

The same optic nerve affected by glaucoma as viewed in 3-D frames by scanning laser.

Peripheral Vision:  We routinely do screenings for any abnormal blind spots in the fields of vision.  When patients have glaucoma or are suspected of possibly having or developing visual field problems we can test with state of the art visual field testing devices.   

Fields of vision in beginning glaucoma.  Note the emerging blind spots (dark areas)

Glaucoma Information from The National Eye Institute, which is the Federal government's lead agency for vision research.

Glaucoma Facts