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Latest Questions and Answers
I am a 53-year-old female, who was diagnosed with advanced glaucoma in both eyes, and have had trabeculectomy surgery. The procedure in the left eye was successful; the procedure in the right eye has also been successful, but with complications. Currently, I wear a contact lens bandage patch in the right eye. I am getting ghost images in this eye and the doctor has told me that they are a result of a growing cataract. When is the proper time to remove this cataract? My doctor is currently hesitant to remove the cataract because it is likely to comprise the integrity of the bleb. How long can the cataract remain in the eye without causing further eye damage? Thank you for your excellent responses! [ 10/12/10 ]

Unfortunately, it is difficult to give you an exact answer for your first question. In regard to the first part: “When is the proper time to remove the cataract”, the answer is simply when the cataract becomes “visually significant” and you and your doctor determine that the benefits of doing the surgery outweigh the risks. The hard part of that answer is determining when that that time has arrived (and depending on the patient's tolerance for risk, that time might be different for each patient). Your doctor has reason to be concerned about taking out the cataract. In a bleb that is functioning well, cataract surgery can cause the bleb to fail completely or become less functional after the cataract surgery (this is a known “risk” of cataract surgery in a patient with a functioning bleb). The reason that a bleb may not work as well after cataract surgery is based on the fact that the cataract surgery will cause some inflammation in the eye. With inflammation, scar tissue can form. If scar tissue forms on or near the bleb, it may not continue to function as well. In many cases, if I have a patient with advanced glaucoma and the bleb is functioning well, I try to wait as long as reasonably possible before doing the surgery. The answer to your second question is a lot easier: “How long can the cataract remain in the eye without causing further eye damage?” While there are some rare cases in which a cataract needs to be taken out immediately, in most instances a cataract can remain in the eye forever without causing irreversible damage (although they can get bad enough that you cannot see anything out of them or the doctor has a hard time seeing in). It is similar to having a glass shower door that gets more and more lime/soapy buildup on it. Eventually it is hard or impossible to see out or in, but it does not mean that the shower itself has been damaged.

Eventually cleaning or replacing the door can make things more clear (i.e. having the cataract removed). In many instances, the cataract will get bad enough that you cannot see out of it and you may have trouble do the things that you need to do (eat, cook, dress yourself, etc) or enjoy doing (reading, watching TV, needlepoint, etc). At that point we say the cataract is becoming “visually significant” and we discuss the risks, benefits, and alternatives of having the cataract removed. Once you know the risks and benefits, you will have to determine when you would like to have the cataract removed. If you feel overwhelmed, I suggest that you have family or friends that you trust accompany you during the exam so that you can talk to them about your concerns and they may be able to help you come to a decision. Finally, if you are uneasy, it is also ok to ask for a second opinion from another glaucoma specialist if you think that might help. Best of luck, I know it can be a difficult decision to make.


How can an eye doctor tell if a person has closed-angle or open-angle glaucoma? [ 10/11/10 ]

Thank you for your question. This is something that many of our patients ask. Determining whether the angle of the eye is open or closed is a relatively simple process. It simply takes having an eye doctor do a procedure called a gonioscopy at your next eye exam. This can be done in the normal office exam lane and does not require your eyes to be dilated. We simply use the slit lamp and a special tool called a gonioscopy lens or gonioscopy mirror. The eye doctor will put a couple of numbing drops in your eye, then they will barely touch the gonioscopy lens/mirror to the cornea. Once the gonioscopy mirror/lens is in contact with the cornea, the mirrors on the gonioscopy lens/mirror allow the eye doctor to see the “angle”. It is similar to using mirrors in a periscope to see areas that are not otherwise visible to the naked eye. The “angle” is the area where the cornea (the clear part in the front of the eye) meets the iris (the colored part of the eye). The “angle” is where the trabecular meshwork is located.

Under normal circumstances, the majority of the fluid that is created inside the eye must exit the eye by passing through the trabecular meshwork. Once it is through the trabecular meshwork, it then goes through several channels before draining back into the bloodstream. If the trabecular meshwork is visible on gonioscopic examination, we call this an “open” angle. If the trabecular meshwork is blocked by scar tissue or the iris, this is called a “closed” angle. This is how we determine whether patients have “open-angle glaucoma” or “closed-angle glaucoma.” The procedure is simple, quick, and does not hurt. It is very possible that your doctor has already done this exam and you simply did not realize it. I suggest you ask your doctor if they completed a gonioscopy and whether you have open or closed angle glaucoma.


I had a pressure of 34 in one eye and the doctor put me on Azopt eye drops 3 times a day. Is it necessary to see a doctor about glaucoma? My pressure is normal as measured in the treatment of retinopathy. Thank you! [ 10/08/10 ]

This is slightly difficult to answer since I have not examined your eyes myself and it forces me to make some assumptions. Judging from your question, I assume you are not talking about primary open angle glaucoma. I assume that you mean that you are being treated for diabetic retinopathy. If the diabetes is not well controlled, one of the side effects is new blood vessel growth inside the eye. Often, these blood vessels are found growing on or near the retina in the back of the eye; however, it is possible that the new blood vessels are also growing in the front of the eye.

Often these blood vessels will begin growing on the iris (the colored part of the eye) and eventually they may grow into the area of the trabecular meshwork where the fluid normally drains out of the eye. If these blood vessels begin to prevent the aqueous fluid from draining out of the eye, the pressure will build up. We call this neovascular (i.e. “new vessel) glaucoma. If the pressure was 34, then you absolutely need to continue seeing an eye doctor regularly to ensure that the pressure goes down.

It is possible that the Azopt drops will help, but your eye doctor should have a backup plan ready in case it does not. Initially, you can be seen by the retina specialist that is following your diabetic retinopathy, but if the pressure does not come back to normal, I would suggest asking your retina specialist if they are comfortable treating the increase in pressure or if they will be referring you to a glaucoma specialist. In many cases, I recommend that the retina specialist take care of the diabetic retinopathy while working with a glaucoma specialist that can treat the neovascular glaucoma. I suggest that you ask your eye doctor what plan they have in place to treat the increase in eye pressure.


I am 49 years old and have been an insulin-dependent diabetic for about 20 years. Macular degeneration runs in my family (my maternal grandma had it and so does my mother). I have noticed a spot on my right eye in the last week. I use my left eye dominantly so I don’t know how long it’s been there. It’s like looking at something bright and then looking away, except the spot isn’t as dark. It’s a long spot, kind of like a cloud. I can see through it, but is blurry. I don’t know if this is sign of glaucoma, macular degeneration or something else entirely! I already have severe nerve damage in my feet and calves. Do my symptoms sound like I have either or both of these eye diseases? Thank you for your time. Blessings! [ 10/01/10 ]

Thank you for your question. Because I did not complete a dilated examination of your eyes, it is very difficult to give a completely accurate assessment. First, I would say that it is most likely not related to macular degeneration. Because you are under the age of 50, this would be quite rare. In addition, these are not the usual presenting signs of glaucoma either. It is possible that this could be related to diabetic retinopathy. If you have had a small bleed from a vessel in the back of your eye, you could be seeing the shadow of the blood. The only way to really know is to go to your eye doctor for a dilated examination. If this is not related to the diabetes, my next best guess is that you may be simply noticing "floaters" for the first time. Floaters are simply pieces of debris or condensed vitreous that are elevated slightly above the retina and cast a shadow on the retina as light passes through the eye. If you think of your retina like the grass in your yard, the blades of grass are like the photoreceptors in the retina that detect light. If you held a piece of string over the grass in the sunlight, the shadow of the string would be cast onto the blades of grass. This is how you end up seeing floaters. Floaters are relatively common in most people. They can come as a natural process of aging and are most often seen between the ages of 60-65, but can occur earlier or later. This is usually related to a process in which the vitreous or gel inside the eye begins to condense and pull away from the attachments to the back of the eye along the retina, retinal vessels, optic nerve, and the front part of the eye called the vitreous base. As it slowly pulls away from the retina, you can get the sensation of flashing lights. This change in the vitreous is normal as we age and is known as a posterior vitreal detachment. It is often associated with flashes of light and onset of seeing new floaters. Any time new flashes of lights or new floaters are seen, you should have a dilated eye exam to make sure there is no evidence of a retinal tear. While retinal tears are rare in these cases, they are important to diagnose and treat appropriately. Because of your specific history of diabetes, I would let your doctor know that you are having these symptoms, as they may wish to dilate your eyes and make sure there is nothing else going on. In either case, these do not sound like symptoms of glaucoma.


I have heard that the Japanese have an increased risk of developing glaucoma. Is this true of all Asians or just Japanese people? Is this increased risk related to diet or genetics? By the way, I do have Chinese ancestry. [ 09/29/10 ]

Thank you for your question. Individuals of Asian descent are at higher risk of developing glaucoma; however, the exact type of glaucoma that each population is at greatest risk for is slightly different. Evidence in the literature suggests that individuals of Japanese descent are at a higher risk of normal-tension glaucoma while individuals of Chinese ancestry are at a higher risk of angle-closure glaucoma. Individuals of Asian ancestry are most likely at an increased risk of developing glaucoma for many different reasons. As we learn more, I am almost positive we will find that genetics plays a very large roll in determining our risk of developing one specific type of glaucoma instead of another. In addition, individuals of Asian ancestry may have an anatomic predisposition to developing angle closure. In many Asian individuals, the drainage angle of the eye is narrower than some other races. This may put them at an increased risk. In general, I would suggest that you have a complete exam by an eye doctor that is comfortable also completing a gonioscopy. After the gonioscopy, the doctor should be able to tell you if the drainage angle is narrow and puts you at higher risk of developing angle-closure glaucoma. In addition, the doctor will also look at the optic nerve and check the eye pressure to determine if there are any other signs of glaucoma.


A recent article reported by Dr. Dexter Leung of the Chinese University of Hong Kong found via a brain scan that there was an increased incidence of silent cerebral infarct blockage in small blood vessels of the brain in people with normal-tension glaucoma. I have normal-tension glaucoma and my mother had vascular dementia. My glaucoma is progressing even though my pressures are controlled so I am looking at other causal factors. However, when I asked my consultant about brain scans for silent cerebral infarcts, I was told that they could not be detected by a scan. What are the tests and treatments for silent cerebral infarct? I would like to have this scan, if possible. [ 09/28/10 ]

Thank you for your question. I read over Dr. Leung's article and found it very interesting. I will continue to follow this research and think it may provide us with some promising information regarding normal-tension glaucoma. Let me first directly answer your questions as best I can. As a disclaimer, the questions that you ask are probably best answered by a neurologist or a radiologist; however, I will give you my best understanding of current neurological and neuroradiological practices.

What are the tests and treatments for silent cerebral infarct? Different studies have placed different limits on what they consider positive evidence of a silent cerebral infarct. It appears that most studies rely on magnetic resonance imaging (MRI) of the brain to look for silent cerebral infarcts. These were studies specifically looking for the incidence of silent cerebral infarcts in normal patients or certain populations of patients. To my knowledge, neurologists do not recommend screening MRIs in normal patients and we as ophthalmologists do not yet recommend MRIs as a diagnostic tool in our glaucoma patients. In terms of treatments, any patient at risk of cerebrovascular disease (vascular dementia, atherosclerosis, stroke, etc.) should be monitored and treated for high blood pressure, high cholesterol, and diabetes among other things. If you are concerned about your individual risks of cerebrovascular infarcts, I suggest you speak with your primary care physician or a neurologist to determine the best course of action.

While Dr. Leung puts forth an interesting hypothesis, I think it is important to establish a more clear body of evidence to support the findings. I would assume similar studies are now being created to reproduce his results at other institutions. Every study has its strengths and weaknesses. I was a bit concerned by a few of the limitations of this study. First, this group used CT scans instead of MRI to define silent cerebral infarcts. It is my understanding that CTs are not as accurate when looking for silent cerebral infarcts. Second, he used Anderson's criteria rather than more conservative measures to define visual field progression. I would rather see slightly different criteria for progression. The study only enrolled Chinese patients, so it is very possible the outcome could be different in Caucasian, African American, African, Indian, or Hispanic patients. Finally, I would need to discuss whether or not the appropriate statistics were used in this analysis and if the results were interpreted correctly. In all, I agree this is a very interesting and promising study, it simply needs confirmation by a few other studies before we would ever recommend that our patient begin getting MRIs to look for silent cerebral infarcts.


Can depression cause glaucoma? [ 09/27/10 ]

Thank you for submitting your question. This is a very interesting topic for patients with glaucoma. Currently, there is no evidence to indicate that depression can cause glaucoma. However, research in the field of neuroscience is truly in its infancy. There are many things that we do not yet understand about how the brain works. It is possible that over time, we may eventually find a link. While there is no evidence that depression can cause glaucoma, the opposite is likely very true. We have a growing body of evidence to suggest that our patients with glaucoma may have an increased risk of developing depression and/or anxiety. This is not hard to imagine considering how dependent many of us are on our eye sight. The thought of having a disease that can potentially cause the loss of vision can be frightening. In addition, patients with advanced glaucoma and loss of vision often lose the ability to complete their activities of daily living independently (grocery shop, drive to appointments, cook, etc). Our patients often feel they are a burden to family members or friends because they must rely on them for assistance. This can easily lead to feelings of anxiety and depression. If you have any of these feelings, do not hesitate to discuss this with your eye doctor. We understand that having glaucoma can have impacts on our patients' lives beyond just the loss of sight. There are resources in the mental health area that can offer patient assistance, so do not hesitate to ask your eye doctor for help if you believe you are experiencing depression or anxiety as a result of having glaucoma.


I have open-angle glaucoma. It has been suggested by my doctor that I have tube surgery on my eyes. Can you give me some more information on this type of surgery? [ 09/24/10 ]

Thank you for your question. A glaucoma tube or glaucoma shunt is a two-part device that is used to reduce intraocular pressure. The plate of the shunt is placed between the white part of the eye (the sclera) and the conjunctiva (the "saran wrap" layer surrounding the sclera). The shunt tube is then routed from inside the eye to the shunt plate. This allows the fluid to be drained off, hence lowering the pressure. There are many different types of shunts, but the two most common are the Baerveldt shunt (a non-valved shunt) and the Ahmed shunt (a valved shunt). Each of these shunts comes in different sizes. Valved and non-valved shunts each have advantages and disadvantages, and the choice of which to use and which size to use is often dependent on the patient and the need. I am often asked "What are the short-term and long- term outcomes of glaucoma shunt surgery?" and "What are the possible complications of glaucoma shunt implant surgery?" To answer those questions completely would take a very long time. There are individual studies that are published that show the short-term and long-term effectiveness and complication rates of of Baerveldt 250, Baerveldt 350, Baerveldt 500, Ahmed S-2, and Ahmed FP-7 shunts as well as others (but these are the most commonly quoted and used in practice). Without knowing which your history and type of glaucoma that you have, it is impossible to give you a completely accurate estimate of the effectiveness or complication rates associated with each shunt. Complications most commonly listed are cornea decomposition, formation of choroidals (blood or fluid between the white part of the eye and the retina), double vision, uveitis, a membrane on the retina that can cause it to wrinkle, retinal detachment, blockage of the tube, the pressure being too low, bleeding, erosion of the tube through the conjunctiva (tube exposure), loss of vision, etc. The rate of those complications varies. I suggest that you have a discussion with your surgeon before the surgery regarding the risks, benefits and alternatives of having the shunt surgery.


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Disclaimer: The information provided here is a public service of the BrightFocus Foundation and should not in any way substitute for the advice of a qualified healthcare professional; it is not intended to constitute medical advice. Please consult your physician for personalized medical advice. BrightFocus Foundation does not endorse any medical product or therapy. All medications and supplements should only be taken under medical supervision. Also, although we make every effort to keep the medical information on our website updated, we cannot guarantee that the posted information reflects the most up-to-date research.

Some of the content in this section is adapted from other sources, which are clearly identified within each individual item of information.

Last Review: 04/28/13


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