Dynamic light scattering spectroscopy of the retina-a non-invasive quantitative technique to objectively document visual improvement following ocular stem cell treatment.

backgroundA major difficulty in retinal research is the lack of a sensitive and quantitative method to objectively determine the functional ability of the retina. Dynamic light scattering (DLS) spectroscopy is a non-invasive quantitative technique that measures the thermal random motion of particles. DLS technology has been used to predict cataractogenesis in rabbits and detect and monitor diabetes mellitus in humans. The results demonstrated the utility of DLS to noninvasively quantitate subtle changes at the molecular level.

methodsThe Stem Cell Ophthalmology Treatment Study is an Institutional Review Board (IRB) approved clinical study and the largest ophthalmology stem cell study to date. A DLS system has been developed to perform retinal measurements. Using this device, sequential measurements were made in a patient with nonarteritic ischemic optic neuropathy (NAION) who underwent stem cell treatment in the Stem Cell Ophthalmology Treatment Study.

resultsThe patient demonstrated visual acuity and visual field improvements in the absence of observed changes in his fundus or in ocular coherence tomography examinations. Measurements with the DLS device showed significant increases in the diffusion coefficient. The DLS results identified changes that anticipated the improvements in central and peripheral vision for the patient.

conclusionsDLS has been demonstrated to have value in the early detection of molecular responses to interventions involving the retina and appears predictive of improvement in vision following stem cell treatment, irrespective of other imaging studies.