Purchase this article with an account.
Mathieu KUNZI, Timoth� Laforest, Laura Kowalczuk, Francine F Behar-Cohen, Christophe Moser; Transscleral optical phase imaging (TOPI) of human retinal pigment epithelium. Invest. Ophthalmol. Vis. Sci. 2019;60(9):4741.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Numerous studies have shown a morphological change of retinal pigment epithelium (RPE) cells in age-related macular degeneration, diabetic retinopathy, uveitis, and other chronic retinal diseases suggesting the high importance of these cells in the disease development state. However, no clinical mean to observe and quantify RPE cells is currently available, preventing the diagnostics and evaluation of potential treatment effects. We developed a new eye imaging modality, called transscleral optical phase imaging and conducted a proof-of-concept study on humans to show the ability to image and quantify in-vivo RPE cells.
Our technology combines an innovative transscleral retinal illumination coupled to a full-field adaptive optics high-resolution imaging system. Infrared illumination beams are projected directly on the sclera, and the transmitted light provides an oblique illumination of the eye fundus. This illumination prevents strong light reflection at the photoreceptor interface, revealing the underlying RPE layer. A study aimed at imaging the RPE layer with our experimental TOPI device was performed on 7 healthy participants.
High-resolution images of the RPE layer were obtained in all participants, enabling counting and a morphology analysis (density, area) of the cells. The acquisition time necessary to observe the RPE layer was between 2 and 5 seconds. The resulting numbers are comparable to the values found in the literature, both from in vivo and histological measurements.
The results of the study demonstrate the possibility to image and quantify in-vivo human RPE cells using TOPI, within a few seconds. It is, to our knowledge, the only technique demonstrated to image the RPE with high contrast, cellular resolution and fast enough to be compatible with a clinical examination. It therefore makes the technology promising for evaluating early state of retinal diseases and monitor treatment effects.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
Fig. 1.In vivo RPE of a human volunteer. (A) SLO (Optos) image of Subject S7 left eye fundus. The yellow square illustrates the position of the TOPI image.(B)TOPI image of the RPE layer. The individual RPE cells appear in dark with bright edges.
Fig. 2. In vivo RPE TOPI images of seven healthy volunteers (S1 to S7). (Left) TOPI images of the left eye of each volunteer taken at different eccentricities from the fovea. Scale bars = 0.12°. (Right) RPE cell area (Top) and density (Bottom).
This PDF is available to Subscribers Only