Clinical trials are the essential human phase of testing new drugs, procedures, or therapies for diseases, including inherited eye diseases. They are conducted only after promising preliminary results have been gathered from initial pre-clinical research, such as studies conducted in vitro (in test tubes or petri dishes) and in animal models.
How Clinical Trials Are Conducted
Clinical trials are highly structured studies typically conducted at specialized medical centers, hospitals, and university settings that possess established research capabilities.
Research Teams and Protocol A multidisciplinary research team oversees the trial, often including physician-scientists, research nurses, technical medical support staff, and administrators.
Once a drug or treatment has shown effectiveness in the lab, the decision to proceed to human testing is made. Every clinical trial adheres to a strict protocol—a detailed, written plan that meticulously documents the study’s goals, research methods, materials, procedures, and duration.
Participant Selection Participants, or test subjects, are carefully chosen based on established inclusion and exclusion criteria. These criteria, which vary by study, ensure that the selected population—based on factors like age, disease status, and general health—will best support the study’s goals and yield meaningful data.
Ethics and Oversight
Participation in a clinical trial is voluntary. Researchers have an ethical obligation to be completely transparent with participants about any potential risks. Before starting, every participant must provide Informed Consent—a written agreement that outlines the study plan, associated risks, and duration. Research team members must be available to address any questions or concerns from the participant and their family.
To ensure participant safety and rights, human clinical trials in the United States are subject to very strict ethical protocols. They must be approved and continuously monitored by an Institutional Review Board (IRB) and the U.S. Food and Drug Administration (FDA). These governing bodies ensure the trial maintains an appropriate benefit-to-risk balance for all participants.
Benefits of Participation
- Access to cutting-edge treatments: Participants may receive promising therapies not yet available to the public.
- Expert medical care: Trials are often led by specialists and researchers who are among the most knowledgeable in their fields.
- Contribution to future care: Participants help advance medical knowledge that may benefit others with the same condition.
- Potential personal benefit: Some participants experience improvement in their own disease as a result of the treatment.
Risks of Participation
- The Unknown: Despite prior animal research, human responses may differ. Side effects, complications, or lack of benefit remain uncertain until the trial is complete.
- Time and Travel: Participation often requires multiple visits over months or years. The travel, testing, and waiting can be time-consuming and physically tiring.
- Costs: Research staff can help determine whether a participant’s insurance will cover testing or treatment. Out-of-pocket costs vary by study type, treatment status, and insurance coverage.
- No Guarantees: Clinical trials are designed to explore effectiveness and safety—not to provide assured treatment success.
Clinical Trial Phases
Clinical trials proceed through a four-stage, stepwise process known as phases. Each phase depends on the successful completion of the previous one, characterized by increasing dosages and a growing number of participants.
| Phase | Primary Goal | Key Characteristics |
| Phase I | Safety | Tests small dosages on a small group of participants (often healthy volunteers or those with the disease). The focus is identifying the safest dosage range and monitoring for serious side effects. |
| Phase II | Efficacy (Effectiveness) | If Phase I shows acceptable safety, this phase expands to a larger group of people with the disease. Researchers adjust dosages and monitor to determine if the drug or treatment has a beneficial effect. |
| Phase III | Expansion and Confirmation | With favorable results from the first two phases, this phase enlists a large cohort of participants. The goal is to confirm the effectiveness, monitor for side effects over a longer term, and compare the new treatment to the current standard of care (if one exists). |
| Phase IV | Post-Market Surveillance | After the drug or treatment has been approved by the FDA and is available to the public, this phase involves continuous monitoring. Researchers gather long-term data on the drug’s effectiveness, potential side effects in diverse populations, and optimal use. |
Clinical trials are the cornerstone of medical progress. For individuals with eye diseases—especially those with limited existing treatments—participating in a trial can be both a personal opportunity and a meaningful contribution to the future of vision care.