Glaucoma is typically not something you notice or feel until it’s too late. Glaucoma is essentially optic nerve damage within the eye most often due to the pressure being high inside the eye. When the pressure gets too high, it damages the optic nerves and potentially destroys some of the nerve fibers that run from the eye to the brain that allow you to see. This optic nerve damage can lead to tunnel vision and eventual blindness.
We look at a lot of data to decide if patients have glaucoma. This includes eye pressure readings, optic nerve appearance and the status of peripheral or “side” vision. Other tests include cornea thickness measurement (a thicker cornea is better), retinal nerve fiber layer thickness measurements, cornea hysteresis (a firmer cornea is better), electro-diagnostic testing to check the integrity of the optic nerves from the retina to the brain, etc.
The eye gets its pressure from a production of a fluid called the aqueous humor from an area called the ciliary body and its processes. This fluid leaves the eye via several drainage routes. This fluid is necessary to keep the eyes round and taut and provides nutrition for certain ocular tissues. It also helps to defend against pathogens.
There are several categories of glaucoma including:
1) Primary Open Angle Glaucoma where there is an open, normal appearing anterior chamber angle and raised intraocular pressure with no other underlying disease.
2) Pigmentary Glaucoma which is a type of inherited open-angle glaucoma where pigment from the iris clogs the drainage leading to an increase in eye pressure
3) Normal Tension Glaucoma is a unique condition in which optic nerve damage and vision loss have occurred despite a normal pressure inside the eye. Treatment includes pressure lowering drops and a good look at modification of blood pressure and optic nerve perfusion in addition to neuro-protective drops.
4) Narrow Angle Glaucoma: this occurs suddenly, when the iris is pushed or pulled forward. This causes blockage of the drainage angle of the eye where the trabecular meshwork allows outflow of fluids.
Treatment for glaucoma includes eye drops, laser and surgery.
1) Eyedrops can reduce production of fluid in the eyes or increase the outflow of fluids from the eyes.
2) Laser includes Selective Laser Trabeculoplasty (SLT) that uses laser energy that is applied to the drainage tissue in the eye. This starts a chemical and biological change in the tissue that results in better drainage of fluid through the drain and out of the eye.