Glaucoma Clinical Trials
Chat Highlights
August 25, 2004

Norma Devine, Editor

On Wednesday, August 25, 2004, Dr. Elliot Werner, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Glaucoma Clinical Trials."

Moderator:  Welcome, Dr. Werner.  The topic tonight is glaucoma clinical trials. 

P:  Dr. Werner, what is a clinical trial?

Dr. Elliot Werner:  A clinical trial is a controlled experiment in which a diagnostic test or, more often, a treatment, is tested on human subjects to determine if it is worthwhile.

P:  How are people selected for a clinical trial?

Dr. Elliot Werner:  Usually, a set of requirements called "inclusion criteria" is determined.  The criteria define the types of patients that would be eligible for the trial.  The criteria include diagnosis, age, gender, and more.  Then the subjects may be recruited from doctors' practices, or clinics, or by publicly advertising for volunteers.

P:  Do the volunteers always know they are part of a clinical trial?

Dr. Elliot Werner:  Yes.  All subjects in clinical trials must give informed consent, must clearly understand that they are part of a trial, that whatever is being tested has not been proven to be beneficial, and may have unknown or unexpected adverse effects.

P:  What distinguishes clinical trials from protocols?

Dr. Elliot Werner:  A protocol is a standard way of administering a treatment that usually is known to be effective.  For example, protocols are often used in treating cancer, where certain combinations of drugs and radiation are used, because they seem to be effective.  A trial tests something about which the effectiveness is unknown.  The purpose of the trial is to find out whether or not it works. 

P:  Is a trial different from a study? 

Dr. Elliot Werner:  A "study" is a more general term than a "trial."  Almost anything can be a study.  A clinical trial is usually a much larger and more formalized study, with well-defined and standardized procedures. *

P:  Are clinical trials conducted to gain FDA (Food & Drug Administration) approval of a drug?

Dr. Elliot Werner:  Most clinical trials are not carried out to get a drug approved for sale.  That is confusing even to those of us involved in research.  The FDA has certain standard procedures that drug companies must follow to get a drug approved for sale.  When I think of a clinical trial, I usually think of one designed to test a particular treatment in a particular disease that is not necessarily sponsored by a drug company or designed to get a specific drug to market.

P:  Are clinical trials conducted at different places? 

Dr. Elliot Werner:  Many clinical trails are "multicenter."  For example, the Ocular Hypertension Treatment Trial (OHTS), in which I am an investigator, takes place at over 20 centers around the country.

P:  Do you know of any glaucoma clinical trials now underway?

Dr. Elliot Werner:  Several important glaucoma clinical trials are either underway or were recently completed.  The OHTS tested treatment versus no treatment in ocular hypertension.  The Advanced Glaucoma Intervention Study (AGIS) and another study, called CIGTS (Collaborative Initial Glaucoma Treatment Study), tested the effectiveness of surgical treatments for glaucoma. The Normal Tension Glaucoma Treatment Study (NTGTS) tested treatment versus no treatment for normal-tension glaucoma. 

P:  Are clinical trials different from drug trials?  

Dr. Elliot Werner:  I guess the term "clinical trial" can have broader meaning than I have been giving it.  Certainly, drug trials  would be considered a form of clinical trial.  We usually tend in our own minds, however, to distinguish between drug-company trials, which are designed to get a drug to market, from trials that are sponsored by government agencies or private foundations that do not have profit as one of their motivations.

P:  Do clinical trials test only those drugs already approved by the FDA?

Dr. Elliot Werner:  Most controlled clinical trials that are not sponsored by a drug company would be testing drugs already approved, but not necessarily.  Most trials testing non-approved drugs would be drug-company trials.

P:  The National Institutes of Health (NIH) site shows 16 studies currently recruiting for glaucoma.*  Those studies would not include those at teaching universities doing their own studies, would they?

Dr. Elliot Werner:  The NIH would probably only list those studies that are funded by the NIH.  If a study were funded by some other agency, I'm not sure the NIH would list it in its  publications.

Moderator:  Glaucoma clinical trials being conducted at Wills are described at the web site:   http://willsglaucomaresearch.org/keystudies.html

P:  How are donor eyes used in research obtained?  

Dr. Elliot Werner:  Donor eyes are often used in research of one sort or another.  Donor eyes are often obtained through a central eye bank that distributes them to appropriate sites.

P:  Many patients are uncertain about whether to undergo ALT (argon laser trabeculoplasty), which can only be repeated twice, or the more recent SLT (selective laser trabeculoplasty), which supposedly can be repeated more often than ALT.  How long will it take before doctors and patients know how often SLT can be repeated and whether it is safer and more effective than ALT?  

Dr. Elliot Werner:  I would guess a long time.  Answering that question will require a very large and long-term clinical trial.   To  my knowledge, no such trial is underway. 

P:  Do you think SLT is better than ALT?

Dr. Elliot Werner:  There is no good evidence now that SLT is any more effective than ALT, or that it is safer or more effective as a repeat treatment.

P:  Doctor Werner, before you leave, would you please tell us how, when you feel discouraged or depressed, you cope with those emotions?

Dr. Elliot Werner:  Whenever I feel down, I remember something attributed to Mark Twain.  He was looking out a window at a pounding rain storm.  A friend asked him if he thought it would stop.  Twain replied, "It always does."

Moderator:  Thank you, Dr. Werner.  Enjoy your drive to Maine in the morning. 

*Editor's Note:  "In Phase I trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.  In Phase II trials, the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.  In Phase III trials, the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it with commonly used treatments, and collect information that will allow the drug or treatment to be used safely.  In Phase IV trials, post marketing studies delineate additional information including the drug's risks, benefits, and optimal use." (National Institutes of Health.  http://www.clinicaltrials.gov)

End of highlights for August 25, 2004.

On September 1, the glaucoma chat support group discussed "Sources of Support" in the Chat room. Click here for highlights of that meeting.

Click here for the most recent glaucoma chat highlights and links to the chat archives.

Click here for upcoming glaucoma chat events.