Glaucoma Medications
Chat Highlights
November 18, 2009

On Wednesday, November 18, 2009, Dr. Michael Pro, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Glaucoma Medications".

Moderator: Welcome back Dr Pro. Our topic this evening is Glaucoma Medications.

P: Why do drops burn, sting and make eyes water when beginning a glaucoma medication but disappear over time? How long does it take for the side effects to dissipate?

Dr. Pro: There are several reasons that the drop may sting. First the pH of the drop may be different than that of the tears. Drops may be slightly acidic and sting a bit for that reason (not so acidic that they could hurt the eye of course). Next, the medication itself could be a bit irritating. In fact, that is one of the factors that is investigated when a new drop is investigated by a drug company. Some drops could cause redness due to vascular dilatation. Over time these side effects often wear off. Just like many things, we either get use to the stinging and just don't notice, or your eye becomes less sensitized to the irritation and doesn't react as strongly.

P: Can you explain a little how pilocarpine works?

P: Oh, I was on that and my pupils were pinpoints.

Dr. Pro: OK, there are several major classes of drugs. Pilocarpine is a drug in the miotic group, meaning that is causes constriction of the pupil. This helps to improve outflow of aqueous from the eye which lowers the IOP.

P: What classification of glaucoma drops cause the most initial problems for patients?

Dr. Pro: Well, some of the older drugs were much worse and really caused awfully red eyes; pilocarpine was one. Today it seems that some of the prostaglandins like Lumigan or Travatan can cause some initial redness.

P: I notice using Alphagan P makes my eyes very blurry, and I see a glare. Is this uncommon?

Dr. Pro: Let me start by saying that I see all sorts of side effects with all sorts of drops. What is great for one person may not be for another. Generally glare is from surface irritation, or disruption of the normal smooth tear film. Any drop can cause that, as can Alphagan. You need to discuss your symptoms with your doctor; however, as he or she may want to evaluate you.

P: I tried Xalatan in one eye for a month. When I returned to my doctor I told her I was going to wear one false eyelash to the appointment and say "This stuff works great!" Seriously, I use it in both eyes; it lowers my pressure and my lashes are growing, but I get a hot flash about 15 min after I use the drops. Have you ever heard of this before?

Dr. Pro: It's true; Xalatan and any of the prostaglandins can cause longer eyelashes. I have not heard of the hot flash, but as I said patients can experience all sorts of different side effects.

P: My physician just added Trusopt to my regiment (Travatan and Timoptic). His reading of my pressure reflected no change. He said it's genetics that is keeping my pressure higher. What have you seen as to the role genetics plays against the value of these series of medications?

Dr. Pro: Let's begin by saying that every person has a unique biochemistry and so no one drug is uniquely tailored to you. So it's true that what works to lower the IOP in one person may not work for you. Unfortunately right now there is no genetic test that can tell us what the ideal glaucoma drop is for any patient. It is a bit of trial and error, but each drug that is FDA approved is tested against a large group of patients so we have very good data regarding the average IOP reduction and the average percentage of patients who respond to a given medication.

P: Can you discuss some of the more serious side-effects? After four days on Cosopt, I experienced extreme slowing of my heart and a very sluggish beat. After four more days, my doctor changed me to Trusopt, dropping out the timolol. Does this mean that I should steer clear of all of the beta blockers, or might another one be less of a problem?

Dr. Pro: Great point! Timolol 0.5% is one of the drugs in Cosopt, the other being Trusopt. Cosopt is a combination drop; the other available in the U.S. is Combigan. There are other combination drops in other countries.

Timolol is a beta blocker. A serious side effect is slower heart rate as well as lower BP and shortness of breath. This side effect does not happen to most patients, but may be more common in ill persons of asthmatics (breathing problems). There are beta blocker drops that were developed to avoid the cardiac problems—Betoptic S is one of these—however even these cardio-selective beta blockers can cause problems in some patients, so it may be necessary to avoid the class altogether in sensitive patients.

Alphagan can cause drowsiness, but does not normally slow the heart rate like a beta blocker.

P: I understand some drops cause ptosis. If that is true, what is the time range to improve ptosis once the eye drops have been eliminated? Mine is rather severe, but I am still on Pred Forte.

Dr. Pro: Well, surgery can also cause ptosis. It is possible to have long-standing ptosis after glaucoma surgery, especially a tube shunt. Pred Forte is also known to cause ptosis. Discontinuation may improve the situation. You may want to discuss that with your glaucoma specialist.

P: Phospholine iodide work well for me and I heard they stopped making it, but now it seems it may still be available. Do you know anything about this?

Dr. Pro: I think it is available, but it may be that you have to reach out to the manufacturer directly. I no longer use it, so I would have to ask you to discuss the situation with the glaucoma specialist who has been prescribing it.

P: Could you say what the practical value is of pursuing medications that exist in other countries (as you stated)? I'm a fan of the FDA.

Dr. Pro: Well, let's begin by saying that there is no drug for glaucoma that is not available in the U.S. The FDA is often criticized, but in this case the only difference right now is in the availability of certain combination meds, such as a prostaglandin (like Travatan) combined with a beta blocker, but you get the same effect by taking those drops separately. The advantage in getting drugs from Canada, or wherever, is in cost.

P: I have Open Angle Glaucoma and am on Lumigan .03percent which is keeping my pressure in check. I have Asthma and my doctor wants to have me take Advair. Can I take it for a short while without causing too much damage? Or is there another medication of this type that would be a better plan for me?

Dr. Pro: I get this question a lot. Advair contains an inhaled steroid. As many of you know steroids can raise the IOP in glaucoma patients, but the most common route for this is in steroid eye drops or steroid injections into the eye. The next most common route is long term oral steroids. Much further down are inhaled steroids. It's certainly possible to raise the IOP, but unlikely. You need to tell your eye doctor about your new medicine. He or she may want to see you sooner if you are not due for a whole year.

P: Are there any exciting new treatments in development? Any new drops? Any new oral medications? How about stem cells or some other way to regenerate the optic nerve?

Dr. Pro: There are always new items being researched. Last year I participated in a study of a new class of drops for glaucoma, but the bar was set so high by the prostaglandins like Xalatan, Travatan, and Lumigan in terms of lowering the IOP with a very good safety profile, that every new drop is expected to be as good.

There are no new oral medications that I know of. Stem cells remain a bit off in the distance (I assume you mean optic nerve regeneration) because the optic nerve is just so complicated.

P: The American Journal of Ophthalmology has had a number of articles on ibopamine to "increase" pressure for hypotony patients. Have you heard of this, and if so, can you share your thoughts?

Dr. Pro: I don't know the article and would have to check into that. I think the medication is a sympatholimetic which causes dilation and is often used in hypotony to help deepen the anterior chamber. It can certainly be challenging to treat chronic hypotony.

P: Have you seen any value from patients taking the antioxidant supplement Alpha Liptic Acid along with their prescription medications?

Dr. Pro: For glaucoma, no supplement has been proven beneficial. That doesn't mean that they are harmful, just may not help and can get expensive.

P: At what age is it considered safe for children to use glaucoma medications?

Dr. Pro: It depends on the medication. We can use beta blockers and carbonic anhydrase inhibitors in infants, and prostaglandins in the very young. We generally avoid alphagan until a child is older (8 or so) as it can cause lethargy. No glaucoma drug is specifically tested on children, but we do have years of experience to guide us in these extremely challenging cases.

P: Why do drugs cost so much for some and not for others depending on insurance company or where they live? Why don't they cost the same for all?

Dr. Pro: A topic for a whole chat! Basically the U.S. system is insurer driven. Each insurer negotiates a preferred rate for a specific drug (how much the insurer will pay the drug company for the drug). So a drug like Xalatan may be very expensive on one plan but more affordable on another.

P: I have been using pirbuteral acetate in the form of an auto-inhaler for years, and much more often recently. Could that also be an inhaled steroid contributing to my glaucoma?

Dr. Pro: That is not an inhaled steroid, but is a bronchodilator and I am unaware of problems with glaucoma associated with that med.

Moderator: Thank you so much doctor. It was an excellent chat!

Dr. Pro: Good night everyone!

On December 2, Dr. Pro discussed "Glaucoma Risk Factors" in the Chat room. Click here for highlights of that meeting.

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