Ask an Expert about Glaucoma

Will I have to take these drops forever or will I be able to get off them? I've noticed that lot of people with narrow-angle glaucoma do not have to take medication after laser surgery. Why do I have to keep using the drops?  When will my eyes change color?

Thank you for your question. First, without having examined your eyes or having seen the results of previous exam tests it is difficult for me to give you a completely accurate answer. One thing that we should clarify is the difference between “narrow-angle glaucoma” and “narrow angles/anatomically narrow angles.” You can have anatomically narrow angles without having glaucoma. This can, however, put you at risk for an attack of angle-closure glaucoma. The reason that we typically complete laser peripheral iridotomy (LPI) surgery is to put a hole in the iris and hopefully create a “safety valve” that will prevent angle closure from what we call pupillary block. Pupillary block occurs when the fluid made in the back of the eye cannot get between the lens and the pupil and then into the drainage system in the angle of the eye. When this happens, fluid gets trapped behind the iris and can push it forward and completely close off the angle and drainage system resulting in an acute-angle closure attack. If you simply have anatomically narrow angles and your pressure is normal then you only need the LPI and you will not necessarily need to take glaucoma medications. Other patients have narrow-angle glaucoma. This is a case in which the angle is narrow again, but there is also an increase in eye pressure that has likely caused damage to the optic nerve and some changes in the visual field. In these cases, LPI still needs to be completed, but it will not do anything to treat the pressure problems in most cases. Additional treatment is needed to control the eye pressure.

The only variable that doctors can change to slow or stop the progression of glaucoma is the intraocular pressure. Once a thorough eye exam has been completed, eye doctors often set a target or goal intraocular pressure. To achieve this goal, there are essentially three different tools that they can use to treat glaucoma. There are medicated eye drops (such as the ones that you have been prescribed), laser treatments, and surgical methods to lower the intraocular pressure. The eye doctor will follow the intraocular pressure, vision, visual fields, and the appearance of the optic nerves to see if the glaucoma progression has stopped. If the pressure is not reduced enough or the doctor ever notices advancement in the glaucoma, they will add more medications or use laser techniques or surgery to help lower the intraocular pressure further. Every treatment (whether it is medication, laser, or surgery) has risks, benefits, and alternatives. As your doctor has told you, one of the risks of using a prostaglandin is the possibility of eye color change. When and if this will happen cannot be predicted. You simply have to watch over time. In some people it never occurs, and others notice it relatively quickly after starting the medication. I suggest that you discuss with your doctor what goal intraocular pressure he or she would like to achieve, and this will likely clarify why you are still using eye drops to help lower the intraocular pressure. I wish you the best of luck; it sounds as though you are on the right track.

Thank you for your question. You should always discuss the risks, benefits, and alternatives with your ophthalmologist before undergoing any operation; however, the short answer to your question is yes, you absolutely can have cataract surgery. In fact, you may actually see a benefit and a lowering of your intraocular pressure after cataract surgery. There is a great deal of evidence that suggests cataract surgery can lower intraocular pressure by 1-2 mmHg, and that some glaucoma patients may be able to reduce or stop their glaucoma medications for some time. The reason for the decrease in eye pressure after cataract surgery is not yet known, but there are several studies trying to find the answer. Some people have proposed that the cataract, which is the natural lens in the eye that has become cloudy, may be at fault. Over our lifetime, the natural lens in the eye continues to grow similar to an onion adding layers. As the lens gets bigger, it may crowd the drainage system in the eye causing the pressure to increase (like a sink backing up when the drain gets clogged). Removing the lens may allow the drainage system to expand again and begin to flow better. Other people have proposed that the inflammation caused after the surgery may in fact be of benefit and cause the drainage system to start working better. Finally, some people feel that some of the techniques that we currently use to remove the cataract (i.e., phacoemulsification) may have steps that cause the drainage system to be cleaned and begin flowing better. The true answer is that we don't know; however, we do know it is a real phenomenon. There are some lucky patients (like my grandmother) who used glaucoma drops for years prior to cataract surgery and have never had to restart them again. However, on average, we tend to see the eye pressure staying lower for about one to two years, and then it often increases again over time. It is important that you continue to see your eye doctor for routine exams to check the intraocular pressure, vision, visual fields, and optic nerves because we cannot predict who will need to restart their medications or when this need will occur. I wish you the best of luck.

Thank you for your question. I am sorry that you are having trouble with your eyes. Without having examined your eyes or having seen the results of previous tests, it is a bit difficult to give you an exact answer. The response may depend on what your goal intraocular pressure is. If you are at your goal pressure, but you are simply having difficulty because of the drops, you could try a different combination of drops. Often the irritation to the eyes comes from the preservatives used in the eye drops, and the benzalkonium chloride (BAK) is the one that we see the most problems with typically. Combigan is a combination of an alpha agonist (brimonidine) and a beta blocker (timolol). Azopt is a carbonic anhydrase inhibitor and Travatan is a prostaglandin analog. You are essentially on all 4 drops that eye doctors use regularly to decrease pressure. Timolol comes in a preservative free form and preservative free prostaglandin analogs should soon be on the market as well. Alphagan P has a preservative other than BAK. In essence, it might be possible to change your prescriptions so that you eliminate a large portion of the preservatives going into the eye.

If changing medications is not an option, your next choices are likely either laser treatment (SLT, for example). If this does not work, then surgical intervention is likely the only option left. If your pressure dropped too low with a conventional trabeculectomy, then you can always discuss the use of a glaucoma tube implant, canaloplasty, trabectome, or a few of the other new surgeries available with your ophthalmologist.

I wish you the best of luck and I hope you can find a good solution.

SLT, or selective laser trabeculoplasty, is not an outdated treatment of glaucoma. Indeed, sometimes it is offered as a first-line treatment if patients do not want to take medications or are intolerant of them. It may also be used as an adjunctive therapy before moving to more aggressive surgical treatment.

SLT is a laser treatment that increases the outflow of fluid from the eye thereby lowering eye pressure. There are currently trials ongoing comparing its efficacy as a primary treatment to currently used glaucoma medications. It is a relatively low risk procedure with great benefit if it is effective, and an important procedure in your doctor's toolbox to help treat glaucoma.

Thank you for your interesting questions. Laser peripheral iridotomy is a relatively low risk procedure; however, that being said, it is a preventive technique and no one can really predict whether your mother will actually have an attack of angle-closure glaucoma. It is difficult to undergo a laser procedure when you do not feel any symptoms or have any problems, but I usually counsel my patients that the risks of the procedure are relatively low, whereas the potential benefit can be high. With regards to one eye or both eyes undergoing the procedure on the same day, eye doctors may offer the option of either to their patients. Some patients would rather complete the iridotomy on one day, while others would rather have the procedure performed on separate days. The latter is certainly a reasonable option if you are worried about any of the risks associated with the laser treatment, and you can discuss the pros and cons of this further with your mother's eye doctor.

• Have you ever heard of performing a trabeculectomy on someone whose pressure reading is only 13?
• Is damage to the optic nerve likely based on an eye pressure of 13?
• Wouldn't it be rather difficult to finesse this procedure so as to obtain an eye pressure reading of 10 from reading of 13 that I now have? Thank you.

Thank you for your interesting question.  I am happy to hear that you have been following up with your ophthalmologist for over 40 years to manage your glaucoma. 

For many glaucoma specialists, trabeculectomy is the surgery of choice when targeting eye pressures in the single digits or low teens.  However, I cannot answer your question about whether your optic nerve is being damaged at an eye pressure of 13 mmHg, although it certainly possible, as we know that the more damaged an optic nerve is, the lower the pressure needs to be.  This can only be answered by careful review of your optic nerves, visual fields, office visit eye pressures, and optic nerve imaging studies you have had over time.  Luckily, as you have experienced, your glaucoma does not sound like it is damaging your nerves on a rapid time scale.  Therefore, it is reasonable to have a discussion with your surgeon about whether your glaucoma has truly progressed at an eye pressure of 13 mmHg. 

The other issue to consider is that you are using a fair amount of eye drops to control your eye pressure, and even though your eye pressure may measure 13 mmHg in your doctor's office, that is only a “snapshot,” and it is possible that your eye pressure is fluctuating over the course of the day.  There is some evidence to suggest that trabeculectomy surgery blunts eye pressure fluctuations, which may be important in glaucoma progression. 

With regards to your last question, trabeculectomy is often the surgery of choice to bring a pressure reading from 13 to 10, and is often successful.  I frequently tell my patients that the key to success is the post-operative management of the trabeculectomy “bleb,” which may require sutures that needing cutting or injections that can help reduce scarring.

Thank you for your question. It is not clear to me whether you actually have hypotony, a condition in which low pressure causes decreased vision, or whether you might have “low-pressure” or “normal-tension” glaucoma, a condition in which there is characteristic optic nerve damage despite having a “normal” eye pressure. If it is the latter, the only treatment we currently have for these forms of glaucoma is to lower eye pressure, even when the pressure is “normal,” and this may be why our doctor prescribed Travatan Z. I hope this answered your question.

Thank you for your question.  It sounds as though your mother has quite a complex set of problems.  Given all of her issues (glaucoma, cornea issues, and retina problems) it would be nearly impossible for me to give you any accurate answers without having seen the results of previous exams or tests, and previous operative reports to understand what surgery was done. In addition, I would need to also do an exam myself to see what type of “weeping” you are talking about.   

In general, this will not likely have anything to do with the macular degeneration as that is a problem with the retina on the inside of the back of the eye. The term “wet macular degeneration” refers to the fact that there is bleeding in the retina and has nothing to do with moisture or weeping at the front of the eye.  “Weeping,” whether it is tearing, mucus, or purulent discharge is almost always related to the front surface of the eye (the cornea or conjunctiva/sclera).  To specifically address the “weeping” it would depend on the consistency of the fluid coming from the eye.  If it is watery, it may simply be that her tear ducts are clogged and she has tearing (epiphoria).  This is less likely considering that you say her nose runs when she has this problem.  Sometimes the eye drops that we use can irritate the eyes a bit and cause watering themselves.  In addition, the doctor can also test to ensure her tear drainage system is working and he can also determine if she is making too many tears naturally.  If the “weeping” is thicker, it is important to determine whether it is related to an allergic reaction to one of the glaucoma medications (this could also account for the redness).  It would also be important to rule out the possibility of an infection as well.  Sorry I could not be of more help, but in these cases it is difficult to be of more assistance without personally seeing the patient.  I wish you the best of luck.