Clinical Trial Primer

Clinical Trial Primer

Posted under Eye Health, Low Vision Info

Recent reports on the safety and long-term side-effects of a clinical trial that was listed at for macular degeneration has raised lots of questions on how clinical trials work and who should consider becoming a participant.  Here are some of the basics of clinical trials to provide you with a better understanding of how research works and what are the issues one should consider before signing a consent form.  First is a database of clinical trials being conducted throughout the world.  The listing of a study does not mean that the FDA or any other overseeing organization has provided its approval.


The purpose of a clinical trial can be one of two – either interventional or observational.  An interventional study is investigating a device, a drug or a behavior – such as diet.  The study may be introducing a new drug and comparing it to an established one or comparing the new drug to no treatment at all.  An observational study is doing just that, observing a specific patient population or disease to see perhaps what lifestyle choices contribute to or prevent a certain health condition.


The sponsor of a clinical trial is the entity who is responsible for the research and financially supports the study drug, device and team of investigators.  It could be a pharmaceutical company, an academic medical center, a non-profit group like BrightFocus Foundation, or a government agency, like the National Eye Institute.  In some cases it can be patient funded which means the patient pays for all the testing and treatment fees.


It is important to know what phase the clinical trial is in.  There are commonly 4 Phases starting with Phase 1 seeking to study the safety of a drug, a device or a procedure.  Phase 1 allows for only a very small number of participants until safety can be determined.   Phase 2 allows for more eligible participants and seeks to get a better understanding of efficacy.

Principal Investigator

The principal investigator is the person responsible for the entire study and oversees it even if there are multiple study site locations.  Typically this role of oversight is a medical doctor.

Institutional Review Board

The Institutional Review Board (IRB) is a group of health professionals whose job is to ensure that the rights and welfare of of the participants are protected.  Institutions that do not have an IRB can use one from an outside source.

Informed Consent

Signing an Informed Consent involves an exchange of information, knowledge and questions between the participant and the interviewer. There needs to be a verbal explanation of the study, an opportunity to get questions answered, and assurance that the patient comprehends the presented information on the intervention, along with risks, benefits and long or short term side effects.


To find out more how clinical trials work go to here:

Learn About Clinical Trials


Leslie Degner, RN, BSN