What is Glaucoma?

There has been many definitions for glaucoma but the most accepted one is; it's a combination of Increase IOP, Visual Field changes, and Optic Disk cupping. One of the leading causes for blindness worldwide, and a silent killer of the optic nerve.

Aqueous Humor Cycle:

Aqueous is the clear fluid filling the anterior chamber of the eye. It is produced by the cilliary body into the posterior chamber, flows through the pupil to the anterior chamber then to the Irido-Corneal angle, where it's absorbed via the trabecular meshwork.

Any thing that disrupt absorption or increase production can lead to increase trapping of aqueous with in the eye and increase in IOP (Intraocular Pressure). The normal IOP is ranging from 10-21 mmHg.

Consequences of high IOP:

Increase IOP can put pressure back on the retina causing direct damage to the sensitive light layers of Rods and Cones, it can lead to damage indirectly through pressing on the blood vessels that supply the retina and thus causing ischemic damage to the layers of retina.

Most Glaucoma treatments are directed toward lowering IOP.

 Types and causes of Glaucoma:

Glaucoma is broadly classified into Open-Angle and Angle-Closure, Primary and Secondary.

The list of risk factors is wide; Age over 40, family history, steroids induced IOP elevation, diabetes, and myopia (short-sightedness).

While secondary glaucoma can be caused by conditions like Pseudoexfoliation syndrome, Pigmentary dispersion syndrome, Neovascular glaucoma (angle is closed by formation of new vessels as in diabetes).

Diagnosing Glaucoma:

The glaucoma is commonly silent with no symptoms, yet it may present with headaches, pain in the eye, deterioration of vision. Then, if the physician suspect it he must do the following tests:

-         Measuring the IOP.

-         Visual Field exam.

-         Fundus examination.

IOP measurement is routine on ophthalmic examinations.

Treatment:

REMEMBER.. once you are diagnosed to have glaucoma, it is extremely important to stay on medication and frequent visits to check you IOP. What is lost can not be replaced!

1-     Medical Treatment with drops that lower you IOP. A combination of more than one drop is possible to keep you IOP low.

2-     YAG-Laser iridotomy; an opening in the iris in those with shallow anterior chamber to establish a communication between Anterior and posterior chamber in order to facilitate aqueous drainage.

3-     Trabeculotomy; is a surgical procedure to create a valve like mechanisim that assist in filtering the excess aqueous humor. Is generally performed if medical treatment is insufficient to keep IOP low.

4-     Ahmed Valve implantation; is very effective way to terminate the existence of increased IOP. Ahmed valve is placed on the sclera and under a conjunctival pocket. More details regarding the valve are found in the Procedures section of the website.