Ask An Expert: Your Questions About Glaucoma Answered
Online Health Chat with Dr. Shalini Sood
July 10, 2012
Cleveland_Clinic_Host: Glaucoma is a condition characterized by degeneration of the optic nerve (the vision nerve) and impaired eyesight caused by increased pressure within the eye. The pressure comes from a buildup of the ‘aqueous humor’, a clear fluid that helps nourish the eye. In glaucoma, this fluid does not drain properly and results in increased pressure. In turn, this pressure damages and deteriorates the nerve that transmits images to the brain. The effects of glaucoma range from slight vision loss to total blindness. Although glaucoma treatment cannot restore lost vision, it can help prevent additional vision loss from occurring. Understanding glaucoma symptoms, regular screening and early detection is essential to preserving vision.
For More Information
Cleveland Clinic’s Cole Eye Institute is ranked among the top ophthalmology programs in the country by U.S. News & World Report, making us the top-ranked program in Ohio. We are among an elite group of dedicated, comprehensive eye institutes. Our fully integrated model helps us provide patients with quick and easy access to specialty and subspecialty care for a wide spectrum of eye conditions—from the routine to the complex. Cleveland Clinic’s Cole Eye Institute continues to expand its quality ophthalmic care to several locations throughout Northeast Ohio, allowing patient access to ophthalmologists closer to their homes.
To make an appointment with Dr. Sood or any of the other specialists at the Cleveland Clinic’s Cole Eye Institute, please call 216.444.2020 or call toll-free at 800.223.2273, ext. 42020. You can also visit us online at www.clevelandclinic.org/eye
About the Speakers
Shalini Sood, MD joined the glaucoma staff of the Cleveland Clinic’s Cole Eye Institute in 2011. She received her medical degree from Albany Medical College in Albany, N.Y. She completed her residency in ophthalmology at the University of Illinois at Chicago Medical Center and a fellowship in glaucoma at the Emory Eye Clinic in Atlanta, Ga. Her specialty interests include general ophthalmology and glaucoma.
Let's Chat About Scoliosis
Cleveland_Clinic_Host: Welcome to our Online Health Chat with Cleveland Clinic expert Dr. Shalini Sood. We are thrilled to have her here today for this chat. Let’s begin with some of your questions.
Signs and Symptoms of Glaucoma
robineaze: Over 10 years ago my husband was told by an eye doctor that he may have glaucoma. He is now 53 years old and cannot see well. He has to wear sunglasses outside because of the light. Is this a symptom of glaucoma? He does not have any health insurance; I would also like to know if there is any medical assistance to help him get his eyes checked.
Dr__Sood: Sensitivity to light is not a typical symptom of glaucoma, but it could be related to other ocular issues including cataracts. There are programs available through the pharmaceutical companies to help patients with financial issues. At the Cleveland Clinic we have financial advisors who you may be able to speak to about receiving care at our institution. The number is 216.445.6249. Our physicians would be happy to work with him.
Hypnoz: What is the danger zone for eye pressure? What happens if eye pressure gets too close to this?
Dr__Sood: The danger zone for eye pressure may be different for each individual depending on if one has glaucoma damage already or not. Typically pressures greater than 40 mmHg in a normal individual is extremely high, and needs to be emergently treated with drops, oral medications, laser or surgery. If the pressure gets too high, this could lead to irreversible vision loss.
Family History of Glaucoma
robtoby: I have two questions: First, my family does not have any history of glaucoma. However, my brother was recently diagnosed with it and is now on eye drops. Does that make me a higher risk candidate? Second, if one has pressure in the upper teens (approaching 20 mmHg), does that signal a precursor to possibly getting glaucoma, and is there anything to be done proactively?
Dr__Sood: Having a sibling with glaucoma increases your risk of glaucoma by three-fold, so I would strongly suggest you have an eye examination by an ophthalmologist soon.
Having a higher eye pressure than 21 mmHg is typically a potential risk factor for glaucoma. This is a red-flag to ophthalmologists that a glaucoma work-up should be performed to determine whether a patient has glaucoma. If there is no sign of damage, the patient is followed as an ocular hypertensive with regular follow-up.
Usually a pressure greater than 21 mmHg is a risk factor, but one-third of patients with glaucoma have normal pressures of less than 21 mmHg. So, having normal pressures does not, unfortunately, preclude one from developing glaucoma. All patients should have regular eye exams since glaucoma is often asymptomatic until significant damage has occurred.
Rolf: I have heard that sons inherit glaucoma from their mothers and daughters inherit it from their fathers. Is this true? Should my son get screened for glaucoma?
Dr__Sood: This is not true. If you have a parent with glaucoma, your risk increases by twofold, and if you have a sibling, that increases your risk by threefold. African Americans are also at increased risk. If you have glaucoma, then I would recommend any siblings and children also be screened.
Rolf: If there is a genetic link (inheriting from one parent or another), is this something that could actually be prevented?
Dr__Sood: Risk factors for glaucoma include family history (most commonly), certain ethnic groups (African-Americans and Latinos), diabetes or myopia (near-sightedness). Other than regular screening and living a healthy lifestyle, there are not specific measures to be taken to prevent glaucoma.
madeupname: When I go for regular eye exams, how are they screening for glaucoma?
Dr__Sood: First, by checking the eye pressure and, second, by clinically looking at the nerve with a dilated exam. It is important to have regular dilated exams. The frequency depends on age and family history.
kownt: How young can you be at risk for glaucoma?
Dr__Sood: Glaucoma can affect newborns, children and young adults through the elderly. Signs and symptoms vary for the different age groups. High pressure is more often seen the younger the onset. If there are any concerns of blurred vision or family history of glaucoma, one should see an ophthalmologist.
jacks: With no warning signs of glaucoma, at what age should you start being tested?
Dr__Sood: Everyone should have regular eye examinations, even if you do not wear glasses or contacts. Typically, eye exams are performed at least twice during your 20s and 30s, thereafter every two to three years. If there is a family history of eye disease, your ophthalmologist may recommend more frequent examinations.
Eyeprobs: What is the difference between optic nerve atrophy and glaucoma?
Dr__Sood: Optic nerve atrophy is a clinical description of the appearance of the optic nerve indicating loss of tissue. Glaucoma is a clinical diagnosis. You can see optic nerve atrophy with glaucoma when it is advanced, but optic nerve atrophy may be due to other causes. The ophthalmologist must look at the whole clinical picture to determine the reason for the optic nerve atrophy.
Almich1: I am a patient with glaucoma since I was baby. I have been using eye drops in order to control the pressure in my eyes. Two weeks ago, I started seeing a blur in my vision. I checked the pressure in a hospital and it was normal. Some information I found on the Internet stated that the blur is because of scratches in cornea, and there is no specific treatment for this case. Is there information that may help me, or could this be possible? Would the glaucoma be the cause, or could there be other factors at play here?
Dr__Sood: I would strongly recommend you see your ophthalmologist or schedule to see a glaucoma specialist. It is true with congenital glaucoma one can have ‘Haab's striae’ that can blur vision. But, with this being a new symptom, it is important for you to have an evaluation soon to screen for any other potential causes.
Types of Glaucoma
medinakv: What is the difference between open-angle glaucoma and closed-angle glaucoma?
Dr__Sood: These terms refer to the anatomy of the drainage system of the eye. Your ophthalmologist is able to visualize the area and determine if the drainage is open or closed leading to those classifications. Treatment is tailored to which type is present. The majority of patients in the United States have open-angle glaucoma.
medinakv: What causes people with normal eye pressure to get glaucoma?
Dr__Sood: We are still uncertain as to the etiology or reason for ‘normal pressure’ glaucoma. There are thoughts that low blood pressure may lead to poor circulation to the optic nerve, leading to damage. Also, normal tension glaucoma patients have been found to be more likely to have migraines. This has led us to believe there may be a vasospastic component to normal tension glaucoma, and, again, loss of blood flow to the optic nerve.
medinakv: You used the term vasospastic in a recent answer. Could you please define vasospastic?
Dr__Sood: Blood vessels tightening like a spasm.
Normal Eye Pressure
majorie: What is normal eye pressure? What would be considered good eye pressure to maintain if you are on medications for glaucoma?
Dr__Sood: Normal eye pressure is typically 21 mmHg or less. The target eye pressure that you are referring to is an individual number based on your clinical exam and ancillary testing. It is best to discuss with your ophthalmologist what they consider to be your target pressure or target range.
As Glaucoma Progresses
serendipity: Does glaucoma cause blindness?
Dr__Sood: Advanced glaucoma can cause blindness. Early detection is the key and that is why it is critical for patients to have regular eye examinations. The earlier the detection, the earlier the treatment—and the more likely we are able to preserve excellent lifetime vision for our patients.
stefan: I was diagnosed with glaucoma recently, but have had no symptoms. Should I be concerned about losing my vision in the future?
Dr__Sood: Glaucoma is typically asymptomatic. Follow-up with glaucoma patients is critical. Thankfully, glaucoma is a slowly progressive disease. Typically, we follow up with our patients every three to four months with diagnostic testing at least once a year. This follow-up allows us to detect change and, hopefully, treat it before significant damage has occurred. The bottom line is, with close follow-up you should have a very good prognosis for good vision.
so_lucky: My mother has been diagnosed with preglaucoma and has been given a choice between two different medicines. Both have side effects. Between Istalol® and Xalatan®, which do you think has the less side effects or has lesser of the bad side effects?
Dr__Sood: Both medications are excellent medications and are administered once a day. Istalol® is usually once in the morning and Xalatan® is once at night. Xalatan® has more ocular side effects such as redness, increased pigmentation of the lid, or even iris and increase length in lashes. Istalol® has more potential systemic side effects such as lower heart rate and shortness of breath. The ophthalmologist has to weigh your mother's other medical issues when deciding which may be the better option for her.
medinakv: I've recently read about selective laser trabeculoplasty (SLT). I've been seeing a Cleveland Clinic ophthalmologist for high eye pressure. Even with latanoprost drops, I have readings of 17 to 18 mmHg. Would I be a candidate for this procedure? How safe is it? Is there a potential downside? How successful is the treatment?
Dr__Sood: Your physician will be able to help navigate your treatment. First, another eye drop may be an option for you in controlling pressure, if this pressure is not sufficiently low. SLT is a relatively safe procedure for patients with open-angle glaucoma, but not indicated for patients with closed-angle glaucoma. The laser targets the drainage system of the eye to allow greater outflow of fluid and potentially lower the eye pressure. The downside is that it does not work in all patients. Your physician, when looking at your anatomy and determining your target pressure, would best decide whether this is a good option for you.
Marti: When should a person consider having glaucoma implant surgery?
Dr__Sood: This is a question best answered by an ophthalmologist who has been following a patient for glaucoma over time. Glaucoma implant surgery or tube shunt is a surgical intervention that we reserve for patients with uncontrolled pressure or advancing disease, despite maximal medical therapy. Usually, I reserve tube shunt surgery for patients who have failed with trabeculectomy surgery or are not good candidates for trabeculectomy surgery.
moondance77: I was diagnosed with narrow angles. My pressure was 23 mmHg and 22 mmHg a week ago. I am a 62-year-old white female. The doctor said I should have laser surgery, with an incision in each iris to prevent pressure build up. If not, I could run the risk of a glaucoma attack and lose some or all of my eyesight. Are there any other options?
Dr__Sood: In this case, the two options are to proceed with laser surgery or not. There are no medication options. One in 100 patients with narrow angles may develop an acute angle closure attack, which as your ophthalmologist stated, could lead to significant loss of vision. The laser iridotomy to which you are referring to is a short laser procedure with minimal side effects compared to the benefit of avoiding an angle closure attack. It would be best to discuss the risks and benefits further with your ophthalmologist.
waterboy: I wanted to know the benefits of laser surgery versus eye drops (Lumigan®) for glaucoma. Is there a permanent cure?
Dr__Sood: Laser surgery is performed in the office and with the selective laser trabeculoplasty (SLT) laser, it may repeated. Not all patients respond sufficiently to the laser and still may need to be on medication therapy. Additionally, not all patients are good candidates for laser therapy. The anatomy of the drainage should be open, and there should be enough pigment for the laser to be effective. There are long-term financial savings of having laser instead of medications. The course of therapy would best be determined by your ophthalmologist to discuss why laser may or may not be a good option for you.
Valleyview: Can laser treatment for neovascular glaucoma be done through a four- to five-stage cataract, which in the past had not precluded fairly decent vision? Does the cataract have to be removed first?
Dr__Sood: There are various treatment options for neovascular glaucoma, which most often is surgery. Treatment modalities to control the pressure may be done at the same time as cataract surgery, if it is indicated. A thorough discussion with your ophthalmologist of all options would be best.
FortWayne: Is there a preference to performing trabeculectomy versus canaloplasty surgeries? Is there a reason why which one is better, if one is?
Dr__Sood: Trabeculectomy surgery has been utilized for many decades, but does have potential risks involved. These include hypotony or very low eye pressure and the lifetime risk of infection at the surgical site. Due to these risks, there are a number of newer surgical procedures including canaloplasty that attempt to decrease these risks. In canaloplasty, the surgeon places a suture through Schlemm's canal, which is a channel located behind the drainage system of the eye. This helps open this anatomical area and improve outflow, decreasing eye pressure. It avoids creating a ‘bleb’ or the surgical site that is created in trabeculectomy surgery that puts patients at risk for infection. The limitation of canaloplasty is the pressure lowering is usually limited to mid-teens while with trabeculectomy surgery we often can achieve pressures in the low teens or single digits. Therefore, canaloplasty is more often utilized in patients with only mild or moderate disease, and trabeculectomy is for moderate to severe disease.
Rare Symptoms After Surgery
gsl: An 80-year-old friend had glaucoma surgery for increased eye pressure two years ago. He has flaking of the cornea with intense eye pain and sensitivity in light and tearing that occurs almost every day. He often cries in pain when this happens and goes to bed to close his eyes since it hurts so bad. The eye drops he takes do not seem to help. What happened? Why hasn't this healed and what can be done to ease his eye pain? Any advice you have would be appreciated.
Dr__Sood: This is a difficult question to accurately answer without actually seeing the patient. I suspect that the flaking of the cornea may be a separate issue. Glaucoma affects the internal drainage system of the eye and not typically the cornea—unless one had extremely high pressures that I would not expect after surgery. He may need to have another evaluation to determine other potential treatments.
Diet and Glaucoma
blutto: How can diet affect glaucoma?
Dr__Sood: There is no specific diet that affects glaucoma, although we encourage all patients to eat a healthy diet with green leafy vegetables, high antioxidants and omega 3.
Cleveland_Clinic_Host: I'm sorry to say that our time with Cleveland Clinic expert Dr. Shalini is now over. Thank you Dr. Sood for taking your time to answer our questions today about Glaucoma.
Dr__Sood: Thanks for taking the time to chat with me today. These were great questions! I hope you got the answers you were looking for.
To make an appointment with Dr. Sood or any of the other specialists at the Cole Eye Institute, please call 216.444.2020 or call toll-free at 800.223.2273, ext. 42020. You can also visit us online at www.clevelandclinic.org/eye
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