Chat Highlights
New Glaucoma Medications
May 9, 2001

Norma Devine, Editor

On Wednesday, May 9, 2001, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "New Glaucoma Medications." 

Moderator:  Tonight's topic is New Glaucoma Medications, something that interests all of us.

Dr. Wilson:  Good evening all. Sorry to be late. Had a call at 8:30 p.m. 

P:  What's the difference between prostamides (e.g., Lumigan) and prostaglandins (e.g., Xalatan)?

Dr. Wilson:  Very little. It's all part of trying to get around the Pharmacia patent for Xalatan that includes a lot of prostaglandin analogues.

P:  Has Lumigan been compared to beta blockers in aphakic patients?  If so, what were the results in this subgroup?

Dr. Wilson:  Lumigan did somewhat better in IOP control, but may cause edema in the retina that timolol does not.

Moderator:  Besides Lumigan and Travatan, what other new drugs are there?

Dr. Wilson:  Rescula is slightly older than the two you mention, but there is nothing else new out there for glaucoma.

P:  Why is the Xalatan bottle only half full when new?

Dr. Wilson:  They want you to get only about four to six weeks' of the medicine. 

Moderator:  Rescula is "Xalatan light?"

Dr. Wilson:  Xalatan-Lite.  Very like Xalatan. It is a knock-off.  

P:  Lumigan does not sting. Why can't they make Trusopt not sting?

Dr. Wilson:  You will have to ask them.  I can't tell you.

P:  For those of us with NTG (normal-tension glaucoma), it seems likely that IOP is a symptom more than a cause.  Is there anything being developed for improved circulation for the optic nerve that is not IOP-focused?

Dr. Wilson:  Yes.  Allergan is trying memantine as a neuroprotector that does not affect eye pressure.

P:  Can Xalatan cause retina edema, like Lumigan?

Dr. Wilson:  Yes, in some people it can.

P:  Is it true that Lumigan improves both trabecular (the usual route) and uveoscleral (the alternative route) outflow and Xalatan only the latter?

Dr. Wilson:  Probably not.  They probably both have an effect on trabecular outflow, although not nearly as much as the effect on uveoscleral outflow (i.e., outflow between the muscles in the wall of the eye).

P:  How do allergy meds such as Allegra-D, Nasalcrom, and Azmacort affect glaucoma?

Dr. Wilson:  Allegra and Nasalcrom will not affect glaucoma.  Azmacort is a nebulized corticosteroid, and if it gets into the bloodstream in sufficient quantities it will cause a pressure rise in the eye.

P:  Is it likely that memantine will be approved in the near future?

Dr. Wilson:  No, the study itself should take about five years and we are only one year into it.

P:  Where is memantine being tested and how do I get into the trial?

Dr. Wilson:  You could write to Allergan in the Irving, California, area; they  should be able to tell you the nearest city.  

P:  Are there studies being done on blood pressure and circulation and NTG?  If so, where and how does one ask to be a part of a study?

Dr. Wilson:  The major studies on blood circulation are being conducted by Dr. Alon Harris at the University of Indiana Medical Center in Indianapolis.

P:  Is memantine available in Europe?

Dr. Wilson:  Yes, it is. My ex-fellows over there have given it lukewarm reviews, at best.

P:  What is the problem with Travatan and pregnancy?

Dr. Wilson:  Travatan may cause miscarriages.  Xalatan and Lumigan are also suspect, in my book.

P:  Can you explain what memantine is, please?

Dr. Wilson:  Memantine is a substance that theoretically protects the nerve fibers from damage in the face of noxious stimuli.

P:  Does an insufficient supply of blood to the optic nerve cause loss of sight?  

Dr. Wilson:  That is one theory. 

P:  Is memantine similar to Xalatan?

Dr. Wilson:  No.  Memantine has no effect on IOP (intraocular pressure), as Xalatan does.

Moderator:  Do the new meds have fewer side effects than the old ones?

Dr. Wilson:  Both Travatan and Lumigan advertise more power than Xalatan, but that may come at the cost of more red eyes and mild discomfort.

P:  How many meds do doctors try before suggesting surgery?

Dr. Wilson:  That varies.  Most will try at least the three most effective: beta-blockers, prostaglandins, and Alphagan.

Moderator:  In glaucoma, what are the noxious stimuli that memantine is to protect against?

Dr. Wilson:  High pressure, decreased circulation, loss of neurotrins, and growth factors that help to ensure the health of the ganglion cells in the retina, as well as the released chemicals from surrounding injured cells.

P:  Which one of the prosta-anythings do you prefer to use at this time?

Dr. Wilson:  I'm trying them all.  From the studies done so far, it seems that Travatan may have a slight edge in effectiveness among African Americans compared to whites, which is something we see with no other kind of medicine, laser, or surgery.

P:  Is Lumigan considered a real winner, adequate, lukewarm, or what, based on the studies?

Dr. Wilson:  At this point Lumigan and Travatan need to prove that they offer something more than Xalatan, the proven medication, does.

P:  I know you can measure pressure, but is there a way to tell if you have decreased circulation?

Dr. Wilson:  Yes, color Doppler and other blood-flow machines can measure, grossly, blood flow to the eye.

P:  What meds are you and your colleagues currently testing at Wills, and do they work along a different line than the meds coming out now?

Dr. Wilson:  No, they do not. We are testing memantine as part of a national study, and other medicines in children. 

P:  The only eye drop I am using now is Pred Forte in my left eye, but for the last two weeks my eyes are really sore.  Could that be from allergies?  My eyes are very sensitive.  Is there a drop that would help and be safe for me to use?  

Dr. Wilson:  You would need to be examined to see if allergies are the cause of your problems.  If so, there are many new meds to pick from to help.

P:  Xalatan did not seem to work for me, but Trusopt and Lumigan seem to.  It seems to me doctors will use whatever works, and everyone is different, right?

Dr. Wilson:  Yes. 

P:  There seems to be a connection between NTG and those near-sighted folks with vitreous humour collapse and retinal tears. 

Dr. Wilson:  Yes, glaucoma may be more common or more progressive in myopes.

P:  Sometimes, about half-an-hour after using my drops, I taste something acrid.  Is that the medicine coming down my sinus area into my throat, and is it okay?

Dr. Wilson:  Yes, but we would rather you kept the drop in the eye. One way to do that is to cover the duct in the lower lid that carries drops into the nose and throat.

P:  Sometimes I have nosebleeds.  Is that from over 20 years on five kinds of meds?  

Dr. Wilson:  Probably not.  More likely its from dry heat and cracking of the nasal mucosa.  However, I cannot rule out an effect from the drops.    

P:  Is the idea with drops to get and keep them in the pocket under the eye, or should the drop be spread over the eyeball by blinking after depositing the drop in the lower pocket?

Dr. Wilson:  Spread over the cornea where they are absorbed into the eye.  

P:  Is there something I can do to minimize the stinging before I use the drops? 

Dr. Wilson:  I advise my patients that if the stinging is excessive, they can put a drop of artificial tears in the eye five minutes before the medicine. This may coat the eye and leave less of the cornea bare to the slightly acidic nature of drops.

P:  Do you think glucocordical steroids cause high IOP just by modulating the TIGR gene expression, or are there other sinister forces at work?

Dr. Wilson:  Wish we knew.  

Moderator:  Do you think that glaucoma meds will ever come in a pill form?

Dr. Wilson:  Yes, especially the neuroprotective agents. 

P:  Which artificial tears do you recommend? 

Dr. Wilson:  I usually suggest Refresh Tears or GenTeal Tears.

P:  Do you recommend the single-use tears?

Dr. Wilson:  No,  they're too expensive and hard to use.  I use the two I mentioned above because the preservative either evaporates quickly after hitting the eye or presents less problem to the eye.  Sorry, gang.  Have to go to bed.  Falling asleep at the monitor here. Have a great week.

On May 16, Dr. Wilson discussed "Normal Tension Glaucoma Research" in the Chat room. Click here for highlights of that meeting.

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