Glaucoma is a group of diseases that affect the optic nerve (the part of the eye that carries the images we send to the brain). The optic nerve is made up of many nerve fibers, like an electric cable containing numerous wires. When damage to the optic nerve fibers occurs blind spots may develop. Although raised intraocular pressure is a significant risk factor for developing glaucoma there is no set threshold for intraocular pressure that causes glaucoma. One person may develop nerve damage at a relatively low pressure, while another may have high eye pressure for years and yet never develop damage. Untreated, glaucoma can lead to permanent damage to the optic nerve and visual field loss that may, in severe cases, progress to blindness. Glaucoma has been named the “silent sight thief”. Much like high blood pressure, you often do not have symptoms from it and therefore do not realize that it is causing damage. Worldwide it is the second leading cause of blindness. Glaucoma affects one in two hundred people aged 50 and younger and one in ten over the age of 80. People with a family history of glaucoma have about a 6% chance of developing the disease.
Types of Glaucoma
Chronic Open Angle Glaucoma
This is the most common form of glaucoma. The drainage angle of the eye becomes less efficient over time and pressure within the eye can gradually increase causing damage to the optic nerve. The chances of developing open angle glaucoma increases with age. Diabetics and patients of African descent are three times more likely to develop primary open angle glaucoma.
Angle Closure Glaucoma
Angle closure glaucoma develops because of the underlying anatomy of the eye. Some eyes are formed with the iris (the colored part of the eye) too close to the drainage angle. In these eyes the iris can block the drainage angle completely and cause a rapid acute increase of pressure inside the eye. The symptoms of an acute angle closure glaucoma attack are severe eye pain, headache, halos around lights, nausea, and vomiting. This is a true eye emergency and if these symptoms occur it is imperative that the person be seen immediately. Angle closure glaucoma can be prevented with a laser procedure called a laser peripheral iridotomy or laser PI procedure. If upon examination, you were detected to have a narrow anterior chamber angle, this procedure can be done as a preventative measure to avoid an acute angle closure glaucoma attack and possible ocular damage. For more information on the YAG Laser Peripheral Iridotomy click here.
Screening for glaucoma is performed as part of a standard ocular examination that you will receive in our office. Specific testing for glaucoma should include measurements of the intraocular pressure, fundoscopic examination of the optic nerve looking for thinning of the optic nerve, pachymetry testing of corneal thickness, visual field testing, and retinal nerve fiber analysis in the way of an HRT or OCT analysis.
How Glaucoma is Treated
Although intraocular pressure is only one major risk factor of glaucoma, lowering the pressure via pharmaceuticals, laser or surgery is currently the mainstay of glaucoma treatment. Typically topical medications or SLT (Selective Laser Trabeculoplasty) treatment are the first line of therapy. If intraocular pressures are not adequately controlled with these interventions then surgery may be recommended. Glaucoma is usually well controlled with eyedrops taken once or twice daily. However, for these medications to work they must be taken regularly and continuously. It is also important to inform all of your other doctors about eye medications that you may be using.
SLT (Selective Laser Trabeculoplasty)
This modern advance in glaucoma therapy can be used as an alternative to topical drops or in addition to them. It is a safe and simple five minute in office laser treatment that effectively reduces the pressure in the eye for most patients with glaucoma.
SLT laser presented a significant advancement over the other lasers that have been used for open angle glaucoma over the last two decades. The benefit of the SLT laser is that is causes no structural damage to the eye and is completely repeatable. It works by stimulating the body’s own healing response to lower your eye pressure.