Glaucoma is a leading cause of preventable vision loss and blindness in adults in the United States and Canada and the second leading cause of blindness in the World.
What is Glaucoma?
Glaucoma is actually a group of eye diseases that cause damage to the optic nerve due to an increase in pressure inside the eye or intraocular pressure (IOP). When detected in the early stages, glaucoma can often be controlled, preventing severe vision loss and blindness. However, symptoms of noticeable vision loss often only occur once the disease has progressed. This is why glaucoma is called “the sneak thief of sight”. Unfortunately, once vision is lost from the disease, it usually can’t be restored.
Treatments include medication or surgery that can regulate the IOP and slow down the progression of the disease to prevent further vision loss. The type of treatment depends on the type and the cause of the glaucoma.
Prevention is possible only with early detection and treatment. Since symptoms are often absent, regular eye exams which include a glaucoma screening are essential, particularly for individuals at risk of the disease. While anyone can get glaucoma, the following traits put you at a higher risk:
- Age over 60
- Hispanic or Latino descent, Asian descent
- African Americans over the age of 40 (glaucoma is the leading cause of blindness in African Americans, 6-8 times more common than in Caucasians.)
- Family history of glaucoma
- People with severe nearsightedness
- Certain medications (e.g. steroids)
- Significant eye injury (even if it occurred in childhood)
Signs and Symptoms of Glaucoma: Due to a buildup of pressure in the eye, glaucoma causes damage to the optic nerve which is responsible for transmitting visual information from the eye to the brain. How does glaucoma affect your vision?
Types of Glaucoma: There are a number of types of glaucoma, some more acute than others. Learn about the common types of glaucoma and the differences between them.
Diagnosis and Treatment of Glaucoma: Early detection and treatment of glaucoma is essential to stopping or slowing the disease progression and saving vision. Treatment can include medicated eye drops, pills, laser procedures and minor surgical procedures depending on the type and stage of glaucoma.
Signs and Symptoms of Glaucoma
The intraocular pressure caused by glaucoma can slowly damage the optic nerve, causing a gradual loss in vision. Vision loss begins with peripheral (side) vision, resulting in limited tunnel vision. Over time if left untreated, central vision will also be affected which will increase until it eventually causes total blindness. Unfortunately any vision that is lost from the optic nerve damage cannot be restored.
What are the Symptoms?
Typically, glaucoma sets in without any symptoms. At the early onset of the most common type of glaucoma “open angle” glaucoma, vision remains normal and there is no pain or discomfort. This is why the disease is nicknamed the “sneak thief of sight”.
An acute type of glaucoma, called angle-closure glaucoma, can present sudden symptoms such as foggy, blurred vision, halos around lights, eye pain, headache and even nausea. This is a medical emergency and should be assessed immediately as the intraocular pressure can become extremely high and cause permanent damage within hours.
Types of Glaucoma
The primary forms of glaucoma are open-angle and narrow-angle, with open-angle being the most common type.
Primary open-angle glaucoma (POAG) gradually progresses without pain or noticeable vision loss initially affecting peripheral vision. By the time visual symptoms appear, irreparable damage has usually occurred, however the sooner treatment starts the more further vision loss can be prevented. When untreated, vision loss will eventually result in total loss of side vision (or tunnel vision) and eventually total vision loss.
Normal-tension glaucoma or low-tension glaucoma is another form of open-angle glaucoma in which the intraocular pressure remains within the normal level. The cause of this form of glaucoma is not known, but it is believed to have something to do with insufficient blood flow to the optic nerve, causing damage. Individuals of Japanese descent, women and those with a history of vascular disease or low blood pressure are at higher risk.
Angle-closure glaucoma can be a sudden increase in eye pressure causing severe pain, blurred vision, halos, nausea and headaches. The pressure is caused by a blockage in fluid at the front of the eye which is a medical emergency and should be treated immediately. Without prompt treatment to clear the blockage vision can be permanently lost.
Congenital glaucoma is an inherited form of the disease that is present at birth. The babies are born with a defect that slows the normal drainage of fluid out of the eye and are usually diagnosed by the time they turn one. In these cases there are typically some noticeable symptoms such as excessive tearing, cloudiness or haziness of the eyes, large or protruding eyes or light sensitivity. Surgery is usually performed with a very high success rate of restoring full vision.
Secondary glaucomas are complications that develop from eye surgeries, injuries or other medical conditions such as cataracts, tumors, or a condition called uveitis which causes inflammation. Uncontrolled high blood pressure or diabetes can result of another serious form called neovascular glaucoma.
Pigmentary glaucoma is a rare form in which pigment from the iris sheds and clogs the drainage of fluid from the eye resulting in inflammation and damage to the eye and drainage system. .
Treatment of glaucoma is dependant upon the severity and type of glaucoma present.
Glaucoma Diagnosis and Treatment
During a routine comprehensive eye exam to check for glaucoma, your eye doctor will dilate your eye to examine the optic nerve for signs of glaucoma and will also measure the intraocular pressure (IOP) with an instrument called a tonometer. Tonometry involves numbing the eye with drops and then gently pressing on the surface of the eye to measure the pressure. Since your IOP can fluctuate throughout the day and glaucoma can exist without elevated IOP this is not enough to rule out the disease. If there are signs of the disease, further testing will be performed.
Digital Retinal Imaging & OCT Scans
We use cutting-edge digital imaging technology to assess your eyes. Many eye diseases, if detected at an early stage, can be treated successfully without total loss of vision. Your retinal Images will be stored electronically. This gives the eye doctor a permanent record of the condition and state of your retina.
This is very important in assisting your Optometrist to detect and measure any changes to your retina each time you get your eyes examined, as many eye conditions, such as glaucoma, diabetic retinopathy and macular degeneration are diagnosed by detecting changes over time.
The advantages of digital imaging include:
- Quick, safe, non-invasive and painless
- Provides detailed images of your retina and sub-surface of your eyes
- Provides instant, direct imaging of the form and structure of eye tissue
- Image resolution is extremely high quality
- Uses eye-safe near-infra-red light
- No patient prep required
Digital Retinal Imaging
Digital Retinal Imaging allows your eye doctor to evaluate the health of the back of your eye, the retina. It is critical to confirm the health of the retina, optic nerve and other retinal structures. The digital camera snaps a high-resolution digital picture of your retina. This picture clearly shows the health of your eyes and is used as a baseline to track any changes in your eyes in future eye examinations.
Optical Coherence Tomography (OCT)
An Optical Coherence Tomography scan (commonly referred to as an OCT scan) is the latest advancement in imaging technology. Similar to ultrasound, this diagnostic technique employs light rather than sound waves to achieve higher resolution pictures of the structural layers of the back of the eye.
A scanning laser used to analyze the layers of the retina and optic nerve for any signs of eye disease, similar to an CT scan of the eye. It works using light without radiation, and is essential for early diagnosis of glaucoma, macular degeneration and diabetic retinal disease.
With an OCT scan, doctors are provided with color-coded, cross-sectional images of the retina. These detailed images are revolutionizing early detection and treatment of eye conditions such as wet and dry age-related macular degeneration, glaucoma, retinal detachment and diabetic retinopathy.
An OCT scan is a noninvasive, painless test. It is performed in about 10 minutes right in our office. Feel free to contact our office to inquire about an OCT at your next appointment.
Visual Field Testing
A visual field test measures the range of your peripheral or “side” vision to assess whether you have any blind spots (scotomas), peripheral vision loss or visual field abnormalities. It is a straightforward and painless test that does not involve eye drops but does involve the patient’s ability to understand and follow instructions.
An initial visual field screening can be carried out by the optometrist by asking you to keep your gaze fixed on a central object, covering one eye and having you describe what you see at the periphery of your field of view. For a more comprehensive assessment, special equipment might be used to test your visual field. In one such test, you place your chin on a chin rest and look ahead. Lights are flashed on, and you have to press a button whenever you see the light. The lights are bright or dim at different stages of the test. Some of the flashes are purely to check you are concentrating. Each eye is tested separately and the entire test takes 15-45 minutes. These machines can create a computerized map out your visual field to identify if and where you have any deficiencies.
VISUCAM®PRO NM feature legendary ZEISS optics and non-mydriatic color fundus photography enabling our optometrist to photograph through pupils as small as 3.3mm. Offering you superior comfort, more efficient eye exam and improved eye care.
Treatment for glaucoma depends on the type and severity of the disease and can include medication such as eye drops or pills or laser or traditional surgery.
Medication and drops to lower IOP are often the first resort for controlling pressure-related glaucoma. These drops may have some uncomfortable side effects, but compliance with the treatment plan is essential for preserving vision and halting the progression of the disease.
Surgical procedures are designed to control the flow of fluids through the eye by either decreasing the amount of fluid produced or improving the drainage. Your doctor may decide that a combination of surgery and medication will be the most effective in many cases.
It cannot be stressed enough that the most effective treatment for glaucoma happens when the disease is detected and treated early before significant vision loss occurs. Any vision that is lost can not be restored. This is why the best prevention is awareness by knowing your risks and taking responsibility by having your eyes examined on a regular basis.