Glaucoma Research Community and FDA Look to the Future, II: NEI/FDA Glaucoma Clinical Trial Design and Endpoints Symposium: Measures of Structural Change and Visual Function

Abstract

At this daylong NEI/FDA Glaucoma Clinical Trial Design and Endpoints Symposium planned collaboratively by the NEI, the FDA, and glaucoma experts, the researchers and clinicians described OCT, stereophotography, SLP, and CSLO criteria for identifying clinically significant structural change related to glaucoma progression and treatment that is greater than that expected from normal aging and is associated with future visual function changes. The FDA presented its position on using the structural metrics for detecting progression of glaucoma in clinical trials of glaucoma drugs and devices. The position of the FDA is that it is the responsibility of the glaucoma research community to establish definitions of glaucoma progression and consensus about structural–functional relationships that characterize early, moderate, and late stages of the disease. With that, the FDA would be willing to accept a structural parameter as the basis for an approval of a drug or device to treat glaucoma. Dr. Chambers emphasized that any definition presented by the glaucoma community must have clinical relevance for the patient. Once researchers establish definitions empirically, the FDA will evaluate them. The FDA is also willing to consider drugs or devices for subgroups of patients with glaucoma. The agency reiterated its position from an earlier NEI/FDA clinical trial design and endpoints symposium that it will consider PROs as endpoints in clinical trials in ophthalmology. The key to using PROs is developing well-defined and reliable instruments. Similarly, the key to using structural endpoints in clinical trials of glaucoma is establishing an association with visual field measurements that the FDA already accepts as a surrogate functional metric that in turn strongly predicts a functional change that will be important in a patient's everyday life. It is anticipated that using optic disc and retinal structural characteristics in clinical studies of drugs and devices for detecting and treating glaucoma progression will reduce the time and cost of clinical trials and the burden of vision loss related to glaucoma.