Abstract
Purpose :
Transscleral flood illumination of the retina with adaptive optics (AO-TFI) allows the observation of several retinal structures at cellular level, especially those invisible with regular transpupillary illumination such as retinal pigment epithelium (RPE). This suggests the assessment of structures affected early in diseases and the possibility to quantify them. Herein, the use of AO-TFI was investigated for the first time to assess human RPE before and after selective retinal therapy (SRT) in vivo.
Methods :
SRT was performed in patients with diabetic retinopathy using the research device Spectralis Centaurus (optoLab, Bern University of Applied Sciences, CH) which is based on a modified imaging platform (Spectralis, Heidelberg Engineering, DE), extended with a prototype SRT treatment laser (Meridian Medical, CH). Beside multimodal standard imaging, laser lesions were evaluated using RPE and photoreceptor (PR) images acquired with the Cellularis Discovery device (EarlySight, CH).
Results :
Using the infrared live camera and the mobile fixation target integrated in the Cellularis Discovery device, the peri macular applied SRT laser spots could be localized and imaged with a 6.7°×6.7° field-of-view. Initial results demonstrate that AO-TFI is very sensitive to clearly detect morphological alterations in the RPE after laser application. Especially at one-month follow-up, SRT lesions showed a strong hyperreflectivity, similar to those observed with standard infrared imaging. This corresponded to a slight dune-shaped RPE thickening in OCT B-scans. In contrast, photoreceptors in the laser-treated areas showed hardly any abnormalities in high-resolution images.
Conclusions :
AO-TFI combined with regular transpupillary illumination allows high-resolution label-free in vivo images of the RPE and PRs on a same location, after laser treatment. Therefore, AO-TFI might become an important imaging modality in the future to gain a deeper understanding of tissue remodeling and regeneration processes such as RPE regeneration and rejuvenation after SRT. In addition, the Cellularis Discovery device could possibly help to assess the impact of laser treatments on the PRs located above the RPE. Furthermore, this novel imaging modality could possibly be used prior to laser treatments to evaluate ideal target sites i.e. in the treatment of early AMD.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.