A significant portion of our practice is devoted to the treatment of glaucoma, with a number of our physicians having undergone specialty training in the area of glaucoma. Our physicians offer the latest glaucoma diagnostic, laser and surgical technologies.
If you are interested in learning more about glaucoma, please call 516.731.4800 or 516.358.2300 to make an appointment.
In order to understand glaucoma, it helps to understand how the eye functions. There are approximately one million nerve fibers in the back of the eye that absorb light signals and allow us to see. Visual signals are transmitted to the brain from these nerve fibers to the brain via the optic nerve. Glaucoma is a chronic condition in which loss of these optic nerve fibers and damage to the optic nerve leads to a loss of mid-peripheral vision.
Many patients who have glaucoma have elevated intraocular pressure (pressure inside the eye). Elevated intraocular pressure is not related to elevations in blood pressure. There is a subset of glaucoma that occurs in the absence of elevated pressure called low or normal tension glaucoma. Emerging data continues to suggest that there are pressure-independent components that may contribute to the development of glaucoma such as autoimmune disease, decreased cerebrospinal fluid (the fluid that surrounds the brain) pressure, thyroid disease, cardiovascular disease and abnormal blood supply to the optic nerve. Although research is underway to understand and treat pressure-independent causes of glaucoma, the majority of accepted current treatment aims to slow the progression of glaucoma by lowering intraocular pressure.
Most people cannot detect elevated intraocular pressure or loss of mid-peripheral vision until glaucoma is quite advanced, which makes screening for glaucoma by an experienced physician extremely important. Glaucoma is not curable but it is treatable with topical drops, laser and surgery if needed. Patients with glaucoma tend to have the best prognosis when they are identified and treated early in the disease process.
Glaucoma is the leading cause of blindness in the United States, although blindness is largely preventable with early detection and treatment. Although glaucoma can occur in infants and children, glaucoma is most common in adults and becomes increasingly common as we age. Risk factors for glaucoma include African American race, myopia (nearsightedness) and hyperopia (farsightedness), and a family history of glaucoma. Since glaucoma is most easily treated at its early stages and is usually asymptomatic until its late stages, periodic monitoring with a complete, dilated examination by a trained Ophthalmologist is recommended for most adults and some children.
A complete assessment for glaucoma involves a thorough discussion of pertinent personal and family medical history. After a vision assessment, examination of the front part of the eye using a special instrument called a slit lamp is undertaken. This includes measuring the intraocular pressure and an evaluation of the drainage system of the eye with a technique called gonioscopy. It is important to remember that measurement of a normal intraocular pressure at one time does not mean that intraocular pressure is not elevated at other times. Therefore, a dilated examination to observe the appearance of the optic nerve is critical to the accurate diagnosis of glaucoma. Photographs and technical imaging may be performed to document and analyze the appearance of the optic nerve. If a person is felt to be at risk for glaucoma, a systematic assessment of their peripheral vision will be performed and analyzed.
It is important to remember that glaucoma is actually the end result of a number of different diseases. It represents the final pathway of a number of conditions that can affect the eye. Our trained physicians can identify the underlying cause of glaucoma with a thorough examination to provide the best treatment possible.
The most common type of glaucoma is one in which the eye is anatomically normal. The only abnormality is a particular appearance of the optic nerve and, oftentimes, an elevation of intraocular pressure. This type of glaucoma is termed primary open angle glaucoma (POAG). Although the drainage system in the eye that is responsible for draining fluid and maintaining normal eye pressure appears unremarkable, we know that it is probably malfunctioning on a microscopic level. There is a subset of POAG in which intraocular pressure is not elevated termed normal tension glaucoma (NTG). The presence of NTG proves that glaucoma results also from pressure-independent factors that might include autoimmune disease, abnormal blood supply to the optic nerve and abnormal cerebrospinal fluid pressure.
If there are abnormalities contributing to glaucoma noted on examination, glaucoma is considered "secondary" rather than primary. There are many forms of secondary glaucoma. If the drain is visibly obstructed leading to elevated intraocular pressure it is termed angle closure glaucoma (ACG). Glaucoma can result from the accumulation of an abnormal collagen-like material (pseudoexfoliative glaucoma) or pigment (pigment dispersion glaucoma). Advanced forms of diabetic eye disease and other vascular disease can lead to neovascular glaucoma in which abnormal growth of blood vessels obstruct the natural drain. The presence of other eye disease such as inflammation inside the eye (uveitis) or the use of chronic steroids can lead to glaucoma.
Anatomically narrow angle (or narrow angle) is a relatively common finding on ophthalmic examination. Narrow angles become increasingly common as we age and can be diagnosed with a relatively painless and simple technique called gonioscopy in which a small contact lens is used to examine the eye.
In order to understand narrow angles it helps to understand how the fluid system in the eye works. The eye constantly produces a fluid called aqueous humor from a structure called the ciliary body. It is important to remember that aqueous humor is entirely separate from the tears and the blood. The aqueous fluid drains from the eye at a location termed the "angle". The angle is so named because it occurs at the junction of the cornea (the clear front part of the eye) and the iris (the colored part of the eye).
As we age, the lens inside of our eye grows. The lens sits behind the iris and, because of the growth of the lens inside the eye, the angle tends to narrow as we age. This becomes important when the angle becomes narrow enough to allow the iris to actually touch the very delicate drain. Repeated touching can lead to scar tissue, which can lead to elevated intraocular pressure and predispose to glaucoma. This scenario is most common in people with hyperopia (farsightedness) because they have a slightly shorter than average eye leading to crowding of the structures inside the eye, however, it can occur in people with myopia (nearsightedness) as well.
Treatment generally includes placement of a microscopic hole in the iris using a laser in the office called laser iridotomy. Laser iridotomy is relatively painless and takes approximately 5 minutes to complete. The presence of this tiny laser hole allows fluid to circulate normally in the eye, thereby opening the angle and preventing scar tissue and elevation of intraocular pressure that can lead to glaucoma. In some cases additional laser is necessary to complete the opening of the angle.
Many patients with narrow angles discover the condition when they are undergoing a routine eye examination. They are often understandably alarmed and concerned with the diagnosis, particularly because they usually have no symptoms or complaints. Remember that a diagnosis of narrow angles is not the same as a diagnosis of glaucoma. Many people with narrow angles do not have elevated intraocular pressure with damage to their optic nerve consistent with glaucoma. While narrow angles can eventually lead to glaucoma, the early treatment and diagnosis of narrow angles can help prevent glaucoma, and treatment by a trained physician is relatively straightforward.