Ask an Expert about Glaucoma
I am 30 years old, and in April of 2010 I had my first trabeculectomy in the left eye. The pressure in that eye is now 4, which concerns my doctor. She said that she may need to re-stitch it. I have the same surgery scheduled for my right eye soon; however, due to the low pressure in my left eye, my doctor will be performing the surgery without "mito." What does this mean? [ 12/21/10 ]
Thank you for your question. Trabeculectomies are excellent surgeries, but they come with some drawbacks. One of those drawbacks or possible complications is that the pressure does not drop to the desired target range (i.e., the pressure either remains too high or it drops too low). Every time I discuss this surgery with my patients, I explain that we are making a new drainage system for the eye to help reduce the pressure. We do that by creating a trap door (the trabeculectomy flap) on the white part of the eye (the sclera) and we lift that door up. Once we have the door lifted, we create a hole into the eye so that fluid can exit the eye under the trap door and leak out onto the surface of the sclera. We sew the trap door down for a little while because if we did not, too much fluid might escape and the pressure can be too low. As the healing process occurs the pressure can start to creep up, so we cut a few of those stitches so that the trap door opens a bit more and we can get the pressure to our target. Because most people heal too quickly, we have started using a drug called mitomycin C ("mito") to help slow that healing process. All of our studies indicate that in most cases using that drug increases the likelihood that the surgery will be successful.
Unfortunately, not every person heals the same after a trabeculectomy. Sometimes patients heal too well despite our best efforts. Even though we have used mitomycin and we have cut all of the stitches on the trap door, some patients heal so well that the trap door seals itself back down and fluid cannot exit the eye. This causes the pressure to increase. The opposite can also occur. Sometimes, people simply do not heal well and there is too much fluid that escapes from the trap door. In these cases, we often have to re-stitch the trap door and make it a bit tighter. In addition, because we know that these patients have a tendency not to heal quickly, we may not use the mitomycin C on the second eye (just as your doctor has suggested). If you have a tendency to heal slowly, as you have already proven in the left eye, there is no need for the mitomycin C and using it would simply put you at risk for having pressure that is too low in that eye as well. It sounds like your eye doctor is doing a good job of recognizing your healing pattern and changing his or her plan accordingly. I wish you the best of luck.
After applying timolol and Azopt to my eyes, does water or soap from a bath have any impact on the effectiveness of the eye drops? [ 12/20/10 ]
Thank you for your question. The proper installation and use of eye drops is a very important thing to discuss and demonstrate for patients. Not only can it increase the efficacy of the medication but it also decreases the side effects. The most efficient method of instilling eye drops is to place a drop in the eye and then close the eyes. The other thing that we often teach our patients is to place gentle pressure on the nose just next to the lower part of the eye. Ask your doctor to demonstrate this the next time you are at the office for a visit. This helps block the tear drainage system and does two things:
- First, the drug stays in contact with the cornea longer and allows more absorption into the eye.
- Second, it decreases the amount of the eye drop that drains into the nose and throat. When the medication drains into the nose and throat it can be absorbed into the body, and the risk of side effects from the medication increases.
Finally, we typically tell our patients to wait a full 5 minutes between using different eye drops (in your case timolol and Azopt) or wait 5 minutes after the last drop before cleaning the eyelids or getting water in the eyes (taking a shower or bath). Most of the medication that will be absorbed into the eye will have done so within that 5 minute window. After waiting those 5 minutes, you can gently clean your eyelids. Always avoid getting soap in your eye if possible because it hurts and it is irritating to the eyes.
I am a 31-year-old woman who has glaucoma and was told that I have a defective photoreceptor layer in the retina. What is a defective photoreceptor layer? [ 12/16/10 ]
Glaucoma is a disease that causes damage to the nerve that connects the eye to the brain, called the optic nerve. The optic nerve is composed of retinal nerve fibers, which often thin with glaucoma. The more retinal nerve fibers you lose, the worse your glaucoma. A defective photoreceptor layer can occur in a variety of retinal diseases, and is not usually related to glaucoma. The photoreceptor layer is part of the retina that converts light into an electrical signal, which then travels to your brain. A variety of diseases can cause a defective photoreceptor layer such a retinal dystrophy and retinal degeneration, so the best thing is to ask your eye doctor about what exactly is causing the defective photoreceptor layer.
If someone has had the following procedures and/or treatments in their right eye, can you please talk about what a patient should and should not do in the post-surgical period? Procedures include: phacoemulsification, foldable intraocular lens, trabeculectomy, and mitomycin C. [ 12/09/10 ]
Thank you for your question. You have undergone what we call a combination phaco-trab. Basically, I provide all of my patients with the same general guidelines. The first day, in most cases, will be the most uncomfortable and vision will not be very good. Over time, you should slowly notice less pain and increased vision. If you notice increased redness, decreased vision, increased pain, pus-like discharge, or any bleeding you should be seen by your eye doctor immediately. During the first week, you will need to wear an eye shield at night to keep from rubbing the eye. When you are awake during the first week, you can either wear glasses or your eye shield. No lifting, bending or straining of any type will be allowed. You should not lift anything heavier than a gallon of milk. Your head should stay above your heart at all times (no bending over to tie your shoes or bringing your feet up to your chest to them, for example). You must take all of your medications exactly as prescribed. If you run out of drops, you should contact your eye doctor immediately to get refills. After one week, you will likely begin to change your drop regimen. Follow your eye doctor's instructions very carefully. Often the surgery is not difficult, but the post-operative care of the eye is the primary determinant of success or failure. These are the general guidelines I share with all of my patients, but I also add different guideline based on the individual patient sometimes. You should discuss this exact question with your own eye doctor so that they can add any other restrictions based on your specific case. I wish you the best of luck.
I have heard of a new procedure called canaloplasty; it is apparently like an angioplasty for the eye to relieve pressure. Is this a sound procedure? [ 12/08/10 ]
Thank you for your question. Canaloplasty is a newer procedure developed and promoted by the company iScience. There are many well regarded ophthalmologists doing this procedure, and I was trained to complete these surgeries during fellowship. I have assisted in approximately 8-10 cases, but have not yet signed any of my patients up for the procedure. It is a surgically sound procedure and it does lower the intraocular pressure in most cases. Often this is accompanied by either no bleb (like a traditional trabeculectomy) or there is a very low, nearly imperceptible bleb. My only concern, and the concern of many other ophthalmologists, is the longevity of this type of procedure. In our hands, we had excellent results for approximately 1 year but then had a few patients that had pressures begin to increase again. Other patients continued to do well after 1 year. The long-term data is not yet out since this is a newer procedure, and we are awaiting that data to come out in the medical literature. Overall, it is a sound procedure, but just like any other procedure, we need longer-term data before any definitive projections on long term success can be made. If you are interested in the procedure, I suggest that you discuss the risks, benefits, and alternatives of canaloplasty, for your particular case, with your eye doctor.
Is there an over-the-counter eye drop that I can use? My prescription is too expensive and my insurance does not cover it. [ 12/07/10 ]
Thank you for your question. I am sorry that you are having difficulty obtaining your prescription medication. This is a problem for many of our patients. Unfortunately, there are no over the counter medications to treat glaucoma. All the medications that have a proven benefit must be obtained with a prescription from an eye doctor. There are several alternatives that I can suggest, however. Ask your doctor if there are any generic drugs available. If you are taking a beta blocker, you should be able to obtain the generic timolol at Walmart or CVS, etc. for $4/month. Generics for the prostaglandin analogs (Xalatan, Travatan, and Lumigan) will most likely be available within 1 year and will hopefully be much cheaper that than they are now. There are also generics for some of the combination medications (Cosopt, for example). If no generics are available, I suggest that you first determine if you qualify for assistance under Medicare or Medicaid. Next, if you served in the armed forces, you may qualify for benefits through the Veterans Administration Hospitals. Often, these hospitals are staffed by the same physicians that staff the large well known University hospitals. Finally, if you do not qualify for Medicare, Medicaid, or VA benefits, see if there is a free/reduced fee clinic at either your county hospital or somewhere in the state. These clinics are often run by medical universities and their residency training programs, where you will be seen by multiple specialists at different levels of training during a single visit. These may include medical students, residents, fellows or a fully trained-board certified ophthalmologist. Finally, the drug companies often have free drug programs for those that cannot afford the medication. Ask your eye doctor to find out if the company that makes your medication has this type of program. They will require you to provide evidence of your income and last year's taxes, but I have a lot of patients that qualify. They are great programs, and many of the drug companies do not get enough credit for establishing these types of programs for our patients. I hope this gives you some direction and new avenues to consider for obtaining your medications. If these do not work, I suggest that you discuss this with your eye doctor. It may be possible to recommend a surgical procedure that can reduce the number or drops that you need to take. This is an option that could be discussed.
I have normal-tension glaucoma with optic nerve damage in my right eye that has caused a loss of peripheral vision. I need cataract surgery and have two different conflicting answers on what is best to do. One specialist says that I should have cataract surgery and endoscopic cyclophotocoagulation at the same time. Another specialist suggests having cataract surgery and trabeculectomy at the same time. What is the difference in these two glaucoma surgeries and which is the safest? [ 12/06/10 ]
Thank you for your question. Unfortunately, without having personally examined your eyes, knowing your eye history, or personally looking at the results of your eye tests from your previous office visits, it would be nearly impossible for me to make a recommendation on which of these two alternatives to pursue. I can tell you that combination cataract surgery and ECP (endoscopic cyclophotocoagulation) or combination cataract surgery and trabeculectomy are both excellent options for our glaucoma patients that also have visually significant cataracts. I have done both of these combinations in many of my own patients in the past depending on their individual presentations and individual cases.
In general, the goal of cataract surgery is to remove a cloudy lens and implant a new clearer lens so that it maximizes your chances of getting clearer vision. The primary risks that I discuss with my patients having cataract surgery are pain, bleeding, infection, decreased vision, need for further surgery, loss of the eye, or death. Each of these risks has different probabilities. The risk of post-operative discomfort (gritty feeling in the eye, etc) in the few hours after surgery is probably near 95%. When you make an incision on the eye, it cannot be avoided. It is usually short lived and by the next day most patients having just cataract surgery feel back to normal. The risk of death is probably 1 in a million or more, but when any type of anesthesia is administered there is always the risk of death. The potential for all of the other risks fall somewhere in between. The goal of endocyclophotocoagulation is to use a laser to destroy the ciliary body. The ciliary body is responsible for making the fluid inside the eye that keeps the eye blown up like a water balloon. I tell my patients that glaucoma is like having a sink that has a drain that does not work well and a faucet that is constantly dripping too fast and filling the sink up. Essentially the ciliary body is like the dripping faucet and the trabecular meshwork is like the clogged drain. Our treatments do one of two things:
- Turn down (or turn off) the faucet
- Open up or create a new drain
The ECP turns off the faucet by destroying the ciliary body. The tricky part is doing enough to turn down the faucet but not turn it off completely. That is a risk of the surgery (the pressure dropping too low). Overall, the risks of endocyclophotocoagulation are pain, bleeding, infection, inflammation, decreased vision, eye pressure dropping too low, eye pressure increasing because of inflammation or other causes, double vision, need for further surgery, loss of the eye, and death. The goal of a trabeculectomy is to provide a new drainage system for the fluid (i.e., we are building a new drain for the sink). If that new drain works too well, we can have pressure that is too low again and if the drain does not work well enough the pressure may not be low enough. The risks for trabeculectomy are nearly the same as those for ECP (probably slightly different rates of complications because the procedures are different). Again, I suggest that you discuss your particular case with your eye doctor and they can give you a better idea of the risks, benefits, and alternatives in your particular case. Hope this answers the first part of the question.
Discussing all of these risks can sound a bit dramatic considering that most of our patients do perfectly fine and have great outcomes. However, the second part of the question touches on a key issue that all of our patients need to understand. Every surgery that we do has potential risks and potential benefits. I never tell any of my patients that any surgery is "safe." Surgeries just have greater or lesser risks. Your job is to determine when the potential benefits outweigh the potential risks (this is when you should decide to go ahead with surgery). I often tell my patients that if a surgery carries a 1 in 1 million chance of going blind, it sounds "safe." However, if you are the one person that does go blind, you will not care about the other 999,999 that have good outcomes. You will just be upset that your surgery did not go well. That is why you need to understand the risks associated with each surgical option and you need to have a reasonable expectation of the benefit that you plan to get out of it. If you have end-stage glaucoma, you cannot expect to come out of a surgery with perfect vision. The benefit that we may be able to offer is simply slowing or stopping the progression of the vision that you have lost in the past. You need to discuss the risks of each combination surgery with your eye doctor because they know your individual case the best and be able to provide an accurate goal of the benefits that you may receive from the surgery. You always have the alternative plan of doing nothing and waiting, but this can also carry a risk of causing progressive vision loss and blindness as well, if the glaucoma worsens. Again, your goal is to determine when you think the potential benefits of surgery outweigh the risks.
I had an Ahmed implant with a shunt 9 weeks ago. The eye pressure is now down to 24, and my vision with glasses is good; however, there is never a day without discomfort. I also now have ‘flashes’ in both eyes that were never present prior to the shunt surgery. I would appreciate your input. [ 11/18/10 ]
Thank you for your question. Let's divide this into two separate pieces. First, after having a glaucoma implant procedure, it is not uncommon to experience some discomfort. While glaucoma implant surgery is not the most technically difficult procedure, it is still a surgical procedure that requires a healing period. While the majority of patients notice the discomfort for less than a month, I have also had patients that take several months until they no longer notice problems. This often depends on how quickly you heal. In general, almost everyone eventually recovers without any problem or the need to revise the surgery (although there are exceptions to every rule). I would discuss this with your doctor and describe the discomfort to them. If you are having a scratchy feeling, that may be related to a small piece of suture that still present and may be poking underneath the eyelid. That can easily be fixed in the office. If you are simply noticing a 'fullness' in the area of the implant, it may simply need to allow the implant to encapsulate (heal) fully. Again, that can take anywhere from 1 to 3 months depending on how quickly your body naturally heals, if you are taking steroids, etc. Finally, if your eye pressure is “down” to 24 that is still a bit high for someone with glaucoma. I would be curious to know if the pressure is elevating throughout the remainder of the day causing you some discomfort. You may need to have your pressure taken at different times of the day to determine if the pressure is going up beyond 24 sometimes.
The second part of your question is difficult to answer without examining your eyes. You can have flashes of light for many different reasons, but if it is in both eyes, it is most likely not related directly to the surgery and the timing may just be coincidental. In general, flashes of light or new floaters are 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. This is known as a posterior vitreal detachment and 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. Another possibility is that these lights could be related to migraine headaches. Often patients describe a shimmering or jagged line in their peripheral (side) vision that grows for approximately 5-10 minutes and then slowly goes away. For many people with migraine headaches, this is the "prodrome" or "visual aura" that happens just before the migraine headache starts. I suggest you have an eye exam to help determine the cause of the flashes of light. It is most likely benign, but we cannot know that until a dilated exam is completed.
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Last Review: 04/28/13