Chat Highlights
Current Research
February 28, 2001

Norma Devine, Editor

On Wednesday, February 28, 2001, Dr. Jay Katz, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Current Research" 

Moderator:  Dr. Katz, our topic tonight is "Current Glaucoma Research."

Dr. Jay Katz:   Great! Any questions?

P:  What can you tell us about the memantine study? 

Dr. Jay Katz:  Memantine is being used orally in a large study for glaucoma as a neuroprotective agent.  It has been used for Alzheimer's.  There are no results available yet. We are hopeful!  

P:  How is glaucoma related to Alzheimer's?

Dr. Jay Katz:  Nerve cells are dying prematurely in Alzheimer's and glaucoma, maybe as a result of excessive glutamate toxicity in both diseases. 

P:  Would memantine replace all current glaucoma medications?

Dr. Jay Katz:  Memantine would only supplement current glaucoma meds, not replace them.

P:  Are there other drugs that may be neuroprotective? 

Dr. Jay Katz:  Memantine is the only neuroprotective drug being used in glaucoma trials in the U.S., although some glaucoma drugs (Alphagan and Betoptic) may also give "neuroprotection."

P:  How will the effectiveness of memantine be determined?  

Dr. Jay Katz:  The effectiveness of memantine will be established by visual field tests.

P:  How long will the study take?  

Dr. Jay Katz:  The trials are planned for two to four years. 

P:  Will you let us know the results?

Dr. Jay Katz:  I will be delighted to let the group know of any results in the trials.

P:  What research are you involved in?

Dr. Jay Katz:  We are working on drugs that help glaucoma patients by improving blood flow to the optic nerve and there are drugs that may stabilize nerve damage, "neuroprotective drugs."

P:  What do you think of the hypothesis that glutamate may cause nerve damage?  Should we avoid substances like MSG?

Dr. Jay Katz:  Memantine blocks excessive levels of glutamate in nerve tissue, but MSG, orally, does not give high levels in nerve tissue, so it's okay.  

P:  Has there been any success in obtaining epithelial cells from a patient's undamaged eye to replace conjunctival epithelium removed from the diseased eye?

Dr. Jay Katz:  Stem cell transplants for surface disease in the eye have been done, but I am no expert on that.   That is a question for my corneal colleagues.

P:  I have heard that researchers at New York Eye & Ear are working on Phase III testing of a medicine to counteract the tendency for dying cells to trigger apoptosis in neighboring cells. Any word on the status of that trial?

Dr. Jay Katz:  That is probably the Alphagan study, in which we are also participating.  The   results have not been released.  These trials will require years, since glaucoma is so slow in progressing for most treated patients.

P:  Is there anything new on regeneration of the optic nerve?

Dr. Jay Katz:  We are still far from regenerating nerve tissue in the eye, but we are able to grow cells in the lab and that is an important first step.

P:  What causes the excessive glutamate? Is it a hereditary thing?

Dr. Jay Katz:  There are competing signals in the body (ying/yang) that signal survival or death, and the balance determines the fate of cells in the body.   There is a suspected imbalance of signals favoring death of cells in glaucoma. It may be genetic in many cases.

P:  What are "signals."?  

Dr. Jay Katz:  Signals are substances in our body like glutamate, neurotrophins, calcium, nitric oxide, and many others.

P:  So the signals are in the blood, not the tissue?

Dr. Jay Katz:  The signals controlling cell survival are everywhere in the body, not just nerve or blood. 

P:  Should glaucoma patients avoid using MSG? 

Dr. Jay Katz:  Memantine blocks excessive levels of glutamate in nerve tissue, but MSG, orally, does not give high levels in nerve tissue, so it's okay.  

P:  Do you put much stock in research showing magnesium supplements improve visual fields? Magnesium is supposed to be "nature's calcium channel blocker."

Dr. Jay Katz:  Magnesium may prove to be helpful, although I know of only one small study supporting its use in glaucoma.  

P:  If memantine is successful in protecting the optic nerve, will we ALL be advised to use it? Or can patients be tested for excess glutamate?

Dr. Jay Katz:  We are not at the stage to recommend memantine to anyone outside trials, and we can't easily test for glutamate levels in the optic nerve.

P:  Have there been any studies about the long-term side effects of glaucoma medications?  

Dr. Jay Katz:  There have been long- term studies (years).  Most found that patients benefit from lowering eye pressure, but some studies were discontinued because of side effects and ineffectiveness.  

P:  How is visual field progression defined in clinical trials? 

Dr. Jay Katz:  Visual field progression is defined in a variety of ways, including mathematical models and clinical interpretation by masked graders.

P:  Why do you think many of us glaucoma patients have aggressive disease in one eye and only mild symptoms in the other?  Is there an explanation for the imbalance?

Dr. Jay Katz:  That's a good question about the imbalance between two eyes.  Some feel that a difference in circulation or structural support for the nerve may explain a difference in severity between the two eyes.  

P:  Is intraocular pressure the most important factor in glaucoma?

Dr. Jay Katz:  Pressure is an important factor in glaucoma, and the only one we can modify currently in practice.  However, there are definitely other factors, such as impaired blood flow.  

P:  Do you know of any study relating glaucoma and eye pain, especially after a trabeculectomy?

Dr. Jay Katz:  Eye pain after surgery could be due to lots of things: inflammation, drops, bleeding, etc.

Dr. Jay Katz:  What do you all want to hear from your doctors regarding glaucoma?

P:  That a cure has been found!

P:  A cure has been found!

P:  For the first time in my life, I would like a doctor to go over the results of my visual field test with me and give me more information.  

P:  I'd like to hear that as much money will be spent on glaucoma research as on other terrible diseases.

P:  I'd like to hear that there's some hope of restoring some nerve function and visual loss caused by glaucoma.

P:  I want to hear that treatment will do no harm.

Dr. Jay Katz:  Tell your doctors what you wish for and fear the most. No treatment is totally safe, unfortunately.  

P:  Dr. Jay, thank you for sticking with us as we throw all these questions at you. You can tell how eager we are to find an answer. Is there anything we can do to help the researchers?

Dr. Jay Katz:  You can participate in projects that make sense to you.

Moderator:  You can find more information about research at: http://www.willsglaucomaresearch.org.

On March 14, Dr. Wilson discussed "Healthy Lifestyles and Glaucoma" in the Chat room. Click here for highlights of that meeting.

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