A study on human subjects with transscleral optical phase imaging (TOPI) (Conference Presentation)

Purpose: Retinal diseases are the major cause of blindness in industrialized countries. A forecast reported that an estimated number of 196 million people will be affected by age related macular degeneration by 2020. While tremendous effort is made to develop novel therapeutic strategies to rescue retinal neurons and retinal pigment epithelium (RPE), optimal means to evaluate the effects of such treatments and diagnose the disease are still missing. Methods: We developed an imaging modality, called transscleral optical phase imaging (TOPI), which is able to resolve the individual human RPE cells in-vivo with the help of adaptive optics. The technology is based on oblique flood illumination and provides cellular resolution. The resulting 16 Hz-imaging speed, 5.7° × 5.7° field of view system allows for the visualization and the quantification of RPE cells within 2 seconds. Thanks to the approval from the ethic committee (CER-VD N°2017-00976), we conducted a study on 7 healthy human participants, with different skin pigmentations, 3 men and 4 women having an average age of 26 years. In all subjects, the RPE cell layer could be imaged and cell density could be quantified. Results: We show the RPE density and area analysis for 7 healthy subjects. The results of the analyses show comparable values to those found in the literature. Conclusion: The results of the study on healthy subjects demonstrate that TOPI is able to image and quantify in-vivo the human RPE cells, within a time frame of a few seconds (typically 2 seconds). The next step is to transfer the technique into a clinical environment.