Non-invasive in vivo imaging and methods for treating type I diabetes

A method for drug development comprising:

• (a) contacting engrafted pancreatic islets that have been transplanted into the anterior chamber of the eye of a live test animal with:
• (i) one or more test compounds, and
• (ii) one or more fluorophores;
• wherein the one or more fluorophores are perfused into the anterior chamber of the eye, and wherein the one or more fluorophores fluorescently labels calcium ions in cells of the engrafted pancreatic islets;
• and
• (b) performing non-invasive fluorescent imaging on the eye of the test animal, wherein the engrafted pancreatic islets are imaged through the cornea without removing the engrafted pancreatic islets from the eye,
• wherein the fluorescent imaging is used to detect test compound-induced changes in intracellular calcium concentration within multiple individual cells in the engrafted pancreatic islets, wherein the changes identify those test compounds that may provide a therapeutic benefit to the engrafted pancreatic islets.