Most people have heard of the eye disease called Glaucoma, however the majority are unaware of what makes Glaucoma such a threatening eye problem. Unlike many other eye diseases, conditions or problems Glaucoma most often begins without any symptoms or obvious loss of vision. In this way it is quite insidious and, if not diagnosed early in its course, will lead to progressive unnoticed vision loss. This is what makes Glaucoma an eye disease to be diagnosed and reckoned with early in its course.
Glaucoma is actually a broad term that is used to characterize a broad range of eye problems that damage the optic nerve and potentially cause loss of vision. Most people share the common belief that Glaucoma is simply due to a high pressure within the eye. The pressure inside the eye is called Intraocular Pressure (IOP) and generally falls within some normal range. While a high Intraocular pressure certainly can be one cause of Glaucoma, and in fact is the most common cause of Glaucoma, a high IOP is not the only cause of Glaucoma by any means. There are numerous causes of Glaucoma and the more common ones are discussed in the following text. No matter what the cause, all Glaucomas share a common factor-if not diagnosed early, treated properly and controlled, they will result in permanent vision loss and potentially blindness.
Glaucoma is a leading cause of blindness for patients between the ages of 18-65 years of age-in fact it is only second to cataracts. It is believed that only half of the people who have Glaucoma actually know that they have it. Over 2.25 million Americans over the age of 40 years old have Primary Open Angle Glaucoma, which will be discussed here. National studies estimate that between 3-6 million people in the United States have higher than normal Intraocular Pressure, without obvious clinical signs of damage to the optic nerve. Thus it is likely that there are another million people who may have Glaucoma, but have not yet been diagnosed because they do not have access to eye care or even Glaucoma screenings. Just in the United States, there are approximately 100,000 patients who are believed to be legally blind from glaucoma.
As mentioned above, the most disturbing characteristic of Glaucoma is that the course of the eye disease, beginning with its slow onset and lack of visual symptoms is likely to go unnoticed by patients unless they are consistent about having routine eye examinations with Glaucoma testing. It is entirely possible to have a higher than normal Intraocular Pressure (IOP) and vision loss and simply not know it. As an absolute minimum clinical care standard, patients over 50 years of age who have no previous family history of Glaucoma or other general health conditions such as diabetes or high blood pressure should be evaluated for Glaucoma every two years. If there is any family history of Glaucoma at all, or any other general health problems, patients should be evaluated for Glaucoma every year beginning at 40. Further, there is considerable risk for siblings of those who have Glaucoma. The Nottingham Glaucoma Study demonstrated that siblings of Glaucoma patients are at particularly high risk for developing Glaucoma by the age of 70 and should be repeatedly screened on an annual basis.
Causes & Types of Glaucoma
In the normal eye, there is a constant production and drainage of fluid called Aqueous Humor. This production and drainage is balanced so as to maintain a “normal’ Intraocular Pressure (IOP).
Aqueous Humor is produced by the Ciliary Body, a structure positioned just behind the Iris, or colored part that is visible. Aqueous Humor is normally drained through a structure called the Trabecular Meshwork, which is a tissue meshwork located at the base of the Iris. Any time there is a disturbance in either too much Aqueous Humor being produced or too little fluid being drained, there is a rise in pressure. It is best to have an equilibrium of Aqueous Humor fluid so that a “normal” pressure in the eye is created.
Primary Open Angle Glaucoma
By far, the most frequently diagnosed type of Glaucoma in the United States is Primary Open Angle Glaucoma (POAG). Patients with Primary Open Angle Glaucoma, typically demonstrate an increase in Intraocular Pressure (IOP) upon routine measurement. The increased Intraocular Pressure (IOP) results from either too much Aqueous Humor being produced or too little being drained as mentioned above. This fluid buildup within the closed space of the inside of the eye elevates the pressure. It is this raised pressure (IOP) that can cause permanent changes and even damage to the optic nerve resulting in vision loss. The optic nerve is the connection between the retina and the brain and is responsible for communicating visual images. Once the optic nerve is damaged, it is not able to carry this visual images, resulting in vision loss. This is why it is so important to monitor, detect and control Intraocular Pressure (IOP). If left untreated, an elevated Intraocular Pressure (IOP) may, over time, cause slow progressive, permanent damage to the optic nerve that can result in blindness.
Angle Closure Glaucoma
Angle Closure Glaucoma is found much less frequently than Open Angle Glaucoma, but is nonetheless quite important as it has the ability to produce considerable vision loss in a short period of time. Angle Closure Glaucoma is characterized by closure or blockage of the drainage structure of the eye-the Trabecular Meshwork. The Trabecular Meshwork is actually a tiny tissue filter, that if blocked by a change in size or shape of the tissue, will cause the Intraocular Pressure to elevate. In instances where the meshwork becomes blocked abruptly, it will cause a sudden rise in the Intraocular Pressure (IOP). This sudden rise in pressure can cause pain, redness, blurred vision and if left untreated permanent loss of vision.
While there can be a number of causes of Angle Closure Glaucoma, it is most often caused by anatomical changes within the internal structures of the eye. Angel Closure Glaucoma is considerably more common in farsighted eyes, which tend to be smaller and in patients between the ages of 45-60 years of age where the Crystalline Lens is beginning to swell. During your general eye exam if the eye doctor observes or measures a narrowed angle, he or she will perform an additional examination procedure called Gonioscopy to fully visualize the meshwork and the angle in order to carefully assess your predisposition to Angle Closure Glaucoma. This test is performed by placing a special contact lens on the eye and then using the slit lamp biomicroscope to fully examine the meshwork and the angle. In the event that you are at risk for Angle Closure Glaucoma or in the event that you have Acute Angle Closure Glaucoma, the most effective form of treatment is to use a Laser to produce a small opening or hole in the Iris so that Aqueous Humor can quickly and efficiently drain from the eye by preventing the Trabecular meshwork from being blocked.
Glaucoma Risk Factors
Glaucoma is a well studied eye disease and fortunately we know many of the factors that can predispose patients to being at risk. Some of these factors by themselves are highly predictive and others are more important when combined with other risk factors
- Increased Intraocular Pressure-Anyone who has been found to have an elevated Intraocular Pressure (IOP) at a Glaucoma screening or as part of a general eye examination is considered to be at risk for developing Glaucoma.
- Age-The incidence of Glaucoma increases as we get older. Typically the incidence of Glaucoma become much more noticeable above the age of 40 years old. This is why routine eye examinations with Glaucoma evaluation are recommended every 2 years above the age of 40 if there is no other family or medical history and more often if there is a preexisting history of Glaucoma in the family or other predisposing heath factors.
- Race - African-Americans to have certain genetic factors that cause a higher likelihood of developing Glaucoma.
- Myopia-In general patients who are nearsighted have anatomical features that may increase the risk of Glaucoma.
- Hypertension-Those patients who are being medically treated for high blood pressure may be at greater risk for Glaucoma due to the lowering of the blood pressure within the optic nerve.
- Diabetes-Anyone being treated for diabetes is considered to be at greater risk for Glaucoma due to the general circulation problems associated with diabetes.
- Family History-Family history of Glaucoma is a very significant risk factor. If any other family members have been diagnosed with Glaucoma, your risk of developing Glaucoma increases considerably. This is particularly true for siblings of Glaucoma patients, who according to the Nottingham Glaucoma Study, as previously mentioned, have a 5-fold increase in risk for developing Glaucoma.
Treatment of Glaucoma
Glaucoma is in almost all cases, treatable. Thanks to advances in medical treatment for Glaucoma, Laser treatment for Glaucoma and Surgical Treatment for Glaucoma, there are many options depending on the severity and the actual clinical response you may have to each. The following text is limited to treatment of Primary Open Angle Glaucoma, as it is the most common type of Glaucoma. Primary Open Angle Glaucoma is treated by the three different approaches above depending on the severity of the disease and the ability of each treatment option to slow or halt the disease progression.
Medical Treatment of Glaucoma
Open Angle Glaucoma is most often treated with eye drops. There are many types of eye drops available that can lower the Intraocular Pressure (IOP). By using a single type of medication or sometimes 2 eye drops in combination, more than 80% of the patients with Open Angle Glaucoma can be successfully treated. These eye drops work by either decreasing the amount of fluid being produced inside the eye or by increasing the rate of drainage of fluid from the eye. For most patients, using the eye drops as prescribed-1-2 times per day it is possible to control the Intraocular Pressure (IOP) and slow or even halt the loss of vision. Unfortunately, some patients experience side effects of these eye drops and it makes the use of eye drops a poor treatment option. Also, some patients are unable to achieve adequate control with eye drops alone and require Laser treatment in addition to the eye drops in order to maintain control.
Laser Treatment of Glaucoma
Laser Treatment for Glaucoma has become an important treatment option for many patients. Whereas in the past, Laser Treatment for Glaucoma was considered a “last resort” before Glaucoma Surgery, to day thanks to advances in lasers, using a laser treatment in conjunction with the eye drop treatment or sometimes even using the laser treatment as the primary treatment are excellent options to help maintain control and slow or stop the progression of the disease.
In fact, today laser treatment for Glaucoma is widely used to help prevent vision loss and is becoming a Glaucoma treatment of choice for many patients who have problems with eye drops or are unable to use them properly. Argon Laser Trabeculoplasty (ALT) is a glaucoma laser treatment that helps to reduce the Intraocular Pressure (IOP) by creating more productive drainage of fluid through the Trabecular Meshwork. Unfortunately, for some patients, the effect of ALT decreases over time, rendering it ineffective. This is a problem as ALT cannot be repeated.
Another type of Laser Treatment for Glaucoma is called Selective Laser Trabeculoplasty (SLT). This type of laser treatment is quickly becoming the preferred treatment for Glaucoma for a number of important reasons. First, SLT appears to be considerably more gentle on the eye. Second, should the effect decrease over time, SLT can be repeated several times in order to control the pressure and slow or halt the progression of the disease. SLT is becoming an important treatment option not only for Glaucoma patients who are unable to use eye drops and obtain control, , but as a primary treatment to help Glaucoma patients avoid needing eye drops altogether. Dr. D’Ambrosio Jr. performs SLT right in the comfort and convenience of the D’Ambrosio Eye Care offices in Lancaster.
Surgical Treatment of Glaucoma
For a small number of patients, even with the maximum medical therapy they can achieve with Glaucoma eye drops and Laser Treatment for Glaucoma, it is still not possible to achieve good stable control and stop the progression of the disease. For these patients there are surgical procedures including removing a tiny piece of the Trabecular Meshwork or even implanting a microscopic Glaucoma valve that can be performed to help reduce and stabilize the Intraocular Pressure (IOP) and prevent vision loss.
Glaucoma is a very complex eye disease, and not simply an elevated Intraocular Pressure (IOP). Nonetheless, when detected early it can be successfully treated. D’Ambrosio Eye Care and their staff, under the medical direction of Dr. Francis D”Ambrosio Jr. perform the full scope of advanced technology diagnostic testing and treatment, as well as taking the time necessary to provide each patient the personal education needed to fully understand their condition and get the best possible outcomes for their patients. If you or a family member or friend have not had a recent screening and examination for Glaucoma, please take a moment to request an appointment.
D’Ambrosio Eye Care under the direction of Boston Ophthalmologist Francis D’Ambrosio Jr., M.D. provides diagnosis and treatment of Glaucoma in greater Boston Massachusetts and is conveniently located for Massachusetts Glaucoma patients from Lancaster, Acton, Gardner, Athol, Clinton, Harvard, Fitchburg, Westminster, Templeton, Worcester, Milford, Marlborough, Boxborough, Westborough, Lowell, Lexington, Leominster, Lunenburg, Shirley, Winchendon. Sterling, Littleton, Boylston, Hudson, Berlin, Bolton, Stowe, Sudbury, Chelmsford, Groton and Concord Massachusetts. To schedule an appointment for a Glaucoma Examination please call us at 1.800.325.3937.
