My sister has been told that she has glaucoma and has been given three different types of eye drops as well as tablets to manage her eye pressure, which is currently at 46. Although she has been taking the drops for a while, the eye pressure is not coming down. Would you have any idea why the medication is not working and could there be anything else causing this high eye pressure? She will now have to undergo a trabeculectomy operation and she is very scared. [ 11/01/10 ]
Thank you for submitting your question. I am sorry that your sister is going through all of this. Without having examined your sister's eyes personally, it is difficult for me to give an exact answer to your question. Unfortunately, there are many different types of glaucoma that patients can get (primary open-angle glaucoma, angle-closure glaucoma, diabetic neovascular glaucoma, and traumatic angle-recession glaucoma, for example). Sometimes, depending on the type of glaucoma that a patient has, medications do not work as well for one form of the disease as they do another.
The other problem is that even in the same type of glaucoma, for example all patients with primary open-angle glaucoma, individuals respond differently to the treatment. I have some patients that need one drop a day for the rest of their lives and they never have any further problems. I have patients like your sister who try all of the medications, yet none of them seem to work. Unfortunately, we are still trying to find out what causes all of these different types of glaucoma and how to best treat each of them. It sounds as though her doctor has tried all of the drops, but they have not worked for her. The next options are either using a laser or surgery to try and treat the glaucoma. Unfortunately, with a pressure of 46, I am not sure that the laser would be sufficient. I would agree that a surgery (trabeculectomy or glaucoma shunt tube) would be the best next step. If the pressure is not lowered, your sister will eventually lose her sight in that eye. I know undergoing surgery can be very scary, but the good news is that most patients do very well. I suggest that she have a discussion with her eye doctor about the risks, benefits and alternatives of having trabeculectomy surgery. Because she is scared, this conversation may take some time, but discussing all of her fears may help put her more at ease. You might consider writing down her questions for the doctor so that you do not forget any. I wish you the best of luck.
I believe that Xalatan will be available in a generic version in November of 2010. Do you know the name of the generic version? [ 10/19/10 ]
Thank you for your question. Many glaucoma specialists and our glaucoma patients are anxiously awaiting the release of a generic version of Xalatan (or any of the prostaglandin analogs). To my knowledge, the generic for Xalatan will not be available until after March 2011, although I may be incorrect about that. I am mainly going by a July 6, 2004 decision by Judge Stanley R. Chesler of the United States District Court for the District of New Jersey. The legal finding was that Pharmacia's patent on formulations and uses of latanoprost (Trade Name Xalatan) covered under U.S. patent# 5,296,504 that expires in March 2011 was valid, infringed upon and enforceable against Par (a drug company trying to make a generic). Further, the court issued an injunction blocking the approval of Par's drug application until the March 2011 expiration of patent #5,296,504 (the Xalatan Patent). Simply put, I would assume that any other generic produced before March 2011 will be found to infringe upon the Pharmacia's patent on Xalatan. The generic will most likely be sold under the compound name Latanoprost and will likely still be 0.005% concentration. I do not yet know who will distribute the generic, but it will be someone other than the Pharmacia & Upjohn Company Division of Pfizer, Inc, New York, NY 10017 as they are the parent company that makes Xalatan.
I am a 24-year-old male and was diagnosed with glaucoma in my right eye. I have been told that I may lose sight in my eye. What are the chances that glaucoma will affect my other eye? [ 10/18/10 ]
Thank you for your question. Unfortunately, without having examined your eyes myself or having seen the results of your previous tests, I cannot give you an accurate estimation of the chances that you will eventually develop glaucoma in your left eye. There are many things that I would need to know. First, developing primary open angle glaucoma at the age of 24 would be quite unusual (although not impossible). Therefore, I would have to assume it is caused by some other reason. If the glaucoma is secondary to trauma in the eye, then there is no increased risk of developing glaucoma in the left eye compared to the average person (unless it also had trauma). If the glaucoma is caused by new blood vessel growth secondary to diabetes (i.e. neovascular glaucoma), then it is possible that the new vessels could begin growing in the left eye as well. This may increase your risk for developing glaucoma in that eye. As I said, unless I knew more, I could not give you an accurate assessment. I suggest that you discuss the cause of your glaucoma with your eye doctor and ask them the risk of developing glaucoma in the left eye. Because they are familiar with your case and your history, they should be able to give you an accurate assessment of the risk of developing glaucoma in the left eye.
I am 45 years old and had trabeculectomies in both eyes around 2 years ago. I know that the key for the bleb to keep functioning is for the fistula to stay open. In theory, wouldn't a poorly functioning trabecular meshwork, (one that is really clogged up), force more fluid through the fistula and help keep the bleb functioning? [ 10/15/10 ]
Thank you for the interesting (but quite complex) question. The full answer is beyond the scope of this blog and would take a full discussion of fluid dynamics, eye physiology, and glaucoma pathophysiology to answer appropriately. I will do my best to try to give you an adequate answer; however, I am afraid this answer may not be 100% accurate due to the constraints of time and length. Answering the question as written is difficult, so I am going to try to clarify it a bit by changing it slightly. First, “Would a poorly functioning trabecular meshwork force more fluid through the fistula?” The answer is likely yes. The fluid will primarily take the path of lesser resistance until that pathway is at its maximal outflow capacity. If the trabecular meshwork is completely clogged, there are essentially two methods left for the aqueous fluid to escape. If there is a trabeclectomy, the aqueous can go through the fistula to the conjunctival bleb and be reabsorbed. Otherwise it may be absorbed through a second pathway that uses the ciliary body for reabsorption (the uveoscleral outflow pathway). Continued flow though the fistula and into the bleb is important for its continued functioning; however, is by no means the only factor in determining whether the bleb will continue to function or fail.
Further, the goal of trabeculectomy surgery is not to create a functioning bleb, the goal of trabeculectomy surgery is to lower intraocular pressure to a point that the optic nerve damage does not progress (i.e. if the bleb is perfectly functional but not sufficient to get the pressure low enough by itself, then the glaucoma will continue to progress, and we have not met our actual goal). So if you asked me “If a trabeculectomy has been completed, would you be better off completely blocking the trabecular meshwork at the same time so that all of the fluid is forced through the bleb in an attempt to keep the bleb functioning better.” The answer to that is probably not. After a trabeculectomy is completed, some fluid continues to escape through the trabecular meshwork (the conventional pathway), some travels though the uveoscleral pathway, and some through the fistula to the bleb. All three of these pathways are utilized in concert to give us the best chances of achieving the goal of maintaining the intraocular pressure at a lower target goal. I hope this comes close to answering the question. Best of luck.
If I need eyeglasses to see well, does that mean that I will develop glaucoma later in life? [ 10/14/10 ]
Thank you for your question. The easiest answer that I can give you is “Absolutely Not”. While there is some growing evidence that needing to wear glasses, whether you are hyperopic (far sighted) or myopic (near sighted), may put you at a slight increased risk of developing certain types of glaucoma (i.e. hyperopia is associated with a higher incidence of angle closure in some patient populations), this in no way indicates that because you wear glasses you will absolutely develop glaucoma in the future. In fact, the vast majority of people wearing glasses never develop glaucoma. Similarly, the fact that someone does not wear glasses is not a guarantee that they cannot develop glaucoma. In short, your glasses prescription cannot predict whether or not you will eventually develop glaucoma; but someday with more research, we might be able to understand how a person's glasses prescription changes their risk of developing glaucoma.
I had Lasik surgery to correct my vision approximately 4 years ago, and would like to know if that procedure could have caused my glaucoma? [ 10/13/10 ]
Currently, there is no evidence in the literature to indicate that Lasik surgery can cause glaucoma. At times, we will occasionally see patients that have a slight increase in pressure just after surgery if they have to use steroid eye drops to help reduce inflammation; however, this usually goes away after stopping the steroid eye drops (we call this steroid induced glaucoma). To our knowledge, simply having Lasik surgery does not directly cause glaucoma nor does it put you at an increased risk of developing glaucoma in the future.
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.