What is it?
Though there are various forms of glaucoma they all result in a loss of vision due to damage of part of the retina called the retinal nerve fiber layer and ultimately the optic nerve. Glaucoma may be associated with high intraocular pressure though this is not always true, in contrast to previous thought. Many forms of glaucoma can occur with the eye pressure never exceeding what is considered “normal.” We take glaucoma very seriously because the vision loss is slow, progressive and most importantly irreversible.
How is Glaucoma Diagnosed?
Many things are taken into consideration when making the diagnosis of glaucoma.Family history, age, race, prescription, and overall health can all affect one’s risk of developing glaucoma. During the eye examination observation of the optic nerve and the nerve fiber layer, the drainage system, the intraocular pressure, corneal thickness and visual fields are all assessed.
Optic Nerve & Nerve Fiber Layer
Think of the optic nerve as the conduit for nerve impulses between the retina and the brain. It is composed of hundreds of thousands of nerve axons. These nerve axons originate within the retina and are called the retinal nerve fiber layer when they are within the eye. Our doctors will examine both the optic nerve and the retinal nerve fiber layer. We look at many characteristics of the optic nerve, the most important being what is termed as the cup to disc ratio. This is a number between a 0 and a 1 with the higher number being of greater risk. As glaucoma progresses the number gets larger as more and more of the nerve fibers that travel through the optic nerve are damaged. There are also many technological advances in the field of glaucoma that are allowing us to assess changes at a cellular level and detect changes many years earlier than in the past. The most advanced technology called ocular coherence tomography (OCT) is utilized at ECC to assess changes in the optic nerve and nerve fiber layer.
The eye is a dynamic organ in that it is filled with a fluid called aqueous humor that is continually being produced and drained from within the eye. The intraocular pressure (discussed below) is a function of the balance of fluid production and drainage. During your exam one of our doctors will examine the drain if the eye using a special diagnostic lens.
Intraocular Pressure & Corneal Thickness
Tonometry, or more commonly 'eye pressure", is also assessed. We know that IOP is only one of the risk factors for the development of glaucoma and "normal" pressures are very specific to each person's situation. The intra-ocular pressure varies throughout the day and in affected by both the drainage system (mentioned above) and the central corneal thickness. The corneal thickness will also be evaluated during your exam with a small ultrasonic device.
In later phases of the disease various specialized peripheral fields tests are also employed. These tests evaluate the degree of functional vision loss that is occurring with the progression of the disease.
What Do We Notice?
Unfortunately, for most forms of glaucoma there are no symptoms. Because it is a slow and progressive disease most people are never aware that they have glaucoma until significant damage is already occurred.Because of this, we recommend annual exams to monitor the optic nerve for change
How Often Should I be Seen?
Due to the slow and lack of symptoms patients who are at greater risk will be seen at least annually.Patients who are diagnosed with glaucoma may be seen as often as 6 week interval depending on the severity of the disease.
How do We Treat This?
The primary method of treatment at this time is eye drops. There are various forms of eye drops that can be used to reduce the pressure in the eye. Currently there is no medical treatment to protect the optic nerve or reverse damage that has already been done. As the disease progresses surgery may be necessary. There are various forms of surgery that may be recommended depending on the type or severity of glaucoma. The non-invasive procedures include laser therapy called either Selective Laser Trabeculoplasty (SLT) or Argon Laser Trabeculoplasty (ALT). Both of these facilitate an increase in the rate of fluid draining from with in the eye without ever actually opening the eye. Invasive procedures include a trabeculectomy. Ask one of our doctors about more details on these and other surgical options.