The Glaucoma Research Foundation (GRF) Patient Summit highlights the latest in glaucoma treatment advances, giving patients practical information to help them live their best lives with the condition. In this seventh recording from the fourth annual GRF Patient Summit, Angelo P. Tanna, M.D., the Vice Chair and Director of Glaucoma for Northwestern University Feinberg School of Medicine’s Department of Ophthalmology, reviews the basics of clinical trials, recent findings, and clinical trial participation.*

Clinical trial basics (0:52)

A clinical trial is a research study that tests the safety and effectiveness of a new treatment on human volunteers, though long-term effects can only be determined once a drug or other therapy has been on the market for some time.

High-quality clinical trials generally involve:

• Randomization, or randomly assigning patients to at least two groups—a treatment arm and a control arm, where controls may be given a standard drug or a placebo (an inactive substance) for comparison, and
• Masking, where the patients don’t know who is receiving the treatment, or neither the patients nor the investigators know (double-masking, or double-blind).

In the United States, a new drug or other therapy must pass through three clinical trial phases prior to approval by the Food and Drug Administration (FDA).

• Phase I trials are small studies on dosing safety and effectiveness.
• Phase II trials are larger studies and involve more people.
• Phase III trials are even larger and are the “gold standard” for approving new treatments. 

Phase IV occurs after FDA approval, where a treatment is monitored for ongoing safety and performance after being made available in the commercial marketplace.

Why clinical trials are needed (9:43)

The Cypass® Micro-Stent is a good example of why we need high-quality testing and continued monitoring of new treatments for better and safer patient care. In a two-year clinical trial without a comparison group, the Cypass was seen to lower eye pressure by 7-8 mmHg. Once the device was implanted during cataract surgery, however, compared with a group that had cataract surgery with no implant, the device yielded only a small improvement.

Though the FDA approved the implant, they charged the manufacturer with continued safety monitoring. After five years, people who had undergone both cataract surgery and implantation had more corneal cell death than those who had only undergone cataract surgery. The FDA recalled the device.

Trial ethics and participant protection (13:26)

When a clinical trial is designed, it undergoes an ethics review by a human research ethics committee. Similarly, a data safety monitoring committee analyzes clinical trial data as the trial is underway to make sure no group is being harmed.

Participants themselves have several layers of protection in Western medicine:

• The Declaration of Helsinki, 
• Ethics committee oversight (U.S.), and
• HIPAA (U.S.)

Regulatory bodies today have much stricter control over protocols than they did 20 years ago, to ensure participants are safe and know the risks involved in the research.

Important clinical trials (15:00)

There have been a number of important glaucoma clinical trials yielding significant results.

Latanoprost for open-angle glaucoma (15:06)

In a U.K.-based, randomized, placebo-controlled trial with over 500 participants, researchers were able to establish in only two years that latanoprost protected the visual field in people with glaucoma. “This is the strongest proof that we have that lowering eye pressure helps,” Tanna says.

Ocular Hypertension Treatment Study (15:54)

The landmark Ocular Hypertension Treatment Study is “probably the most important clinical trial in terms of what we have learned,” Tanna says. His takeaways:

• “Treatment definitely reduces the risk” of glaucoma in patients with high eye pressure.
• After five years, only about 10% of patients with high pressure developed glaucoma.
• After 20 years, delayed eye drop treatment did not make people worse.

Most importantly, he says, we learned five risk factors that could predict future glaucoma:

• Elevated eye pressure
• Thinner corneas
• Older age
• Damaged visual field despite normal test scoring
• Enlarged optic nerve cup

Measuring these risk factors allows clinicians to calculate a person’s five-year risk of developing glaucoma, and determine the next steps.

Selective laser trabeculoplasty (SLT) versus eye drops (19:00)

A U.K. clinical trial called LiGHT examined SLT versus eye drops as the best front-line treatment for newly diagnosed high eye pressure and glaucoma patients. 

• After three years, only a “slight advantage” with SLT was found. 
• After six years, however, SLT was proven “conclusively” to be superior to eye drops.

How you can help (19:47)

Tanna and Northwestern University are involved in a large, federally funded clinical trial called COAST (Clarifying the Optimal Application of SLT Therapy) to determine the best dose of SLT and whether yearly low-dose SLT is better than regular-dose treatment on an as-needed basis. The trial is currently recruiting newly diagnosed glaucoma patients who haven’t already been treated. You can contact Dr. Tanna at atanna@northwestern.edu or go to coasttrial.org for more information.

*Glaucoma Research Foundation. (2022, August 16). Clinical Trials in Glaucoma: What We Have Learned [Video file]. Retrieved from https://www.youtube.com/watch?v=a340UWNlX7s