The Eye Clinic: Learn about clinical trials

Basics of Clinical Trials

What is a clinical trial?

Clinical trials are medical research studies in which people volunteer to participate. A clinical trial is used to evaluate the safety and effectiveness of a new procedure, medication, or device to prevent, diagnose, or treat an eye disease or disorder.

Generally, medical research begins in laboratories. After a treatment shows promise in the laboratory, it is tested in a study to determine if it will be beneficial for the patients.

A clinical trial could test the effectiveness of a new drug for age-related macular degeneration or a new surgical technique for cataract removal.

What are the types of clinical trials?

The following four types, or phases, of clinical trials exist:

  • Phase I clinical trials test a potential new treatment in a small number of volunteers to determine the best dosage and identify potential side effects.
  • Phase II clinical trials test a potential new treatment in a larger number of volunteers to learn more about how the body responds to the treatment, the optimal dose of the treatment, and how the treatment affects a certain eye condition.
  • Phase III and IV clinical trials may include hundreds or thousands of volunteers around the country. These studies compare a new treatment with existing treatments or no treatment to determine if the new treatment works better, the same, or not as well. Phase III clinical trials are conducted to get the new treatment approved by regulatory agencies. Phase IV clinical trials are conducted after approval to understand more about the treatment.

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