How to watch ganglion cells in the DARC?

Abstract

Abstract Purpose: Assessment of neuroprotection in vivo is difficult. DARC (Detection of Apoptosing Retinal Cells) is a newly devised, non‐invasive real‐time imaging technique using confocal laser scanning ophthalmoscopy to visualise single retinal nerve cell apoptosis in vivo. Methods: DARC allows longitudinal study of disease processes, which has not previously been possible. The implications of this novel technique include its application to glaucoma as a powerful new clinical tool with which to diagnose and identify patients with early disease, before they lose vision. Furthermore it may serve as a surrogate biomarker, providing real‐time information that could dramatically reduce the duration of glaucoma clinical studies, which currently have to use visual field status as a key endpoint and determinant of outcome. Results: We have been able for the first time to image changes occurring in neuronal cell apoptosis over hours, days and months, and show effects depending on the magnitude of the initial apoptotic inducer in several experimental models of neurodegeneration. Conclusions: More importantly, by using the eye as a “window” onto the brain, DARC opens the door to directly observing effects of therapeutic strategies in neurodegenerative disorders, by allowing for the study of potential neuroprotective drugs using meaningful endpoints that are based on the direct assessment of neuronal death in vivo. We have already assessed several neuroprotective agents using DARC including neuropeptide approaches.