Surrogate endpoints in clinical trials: Ophthalmologic disorders


  • Dr. Argye Hillis,

    Corresponding author
    1. Texas A&M University and Scott and White Memorial Hospital/Scott, Sherwood and Brindley Foundation, Temple, TX 76508, U.S.A.
    • Scott and White Hospital, Temple, TX 76508, U.S.A.
    Search for more papers by this author
  • Daniel Seigel

    1. National Eye Institute, National Institutes of Health, Bethesda, MD 20892, U.S.A.
    Search for more papers by this author


We examined three examples of surrogate observations in ophthalmology. The first'represents a simple case: the status of one eye is used as a surrogate for the (unobservable) status of the opposite eye in the same individual. The second and third examples represent possible extrapolation of long term results on the basis of early changes. These examples are used to illustrate the assumptions intrinsic in the use of surrogate variables.