Abstract
Purpose :
Monitoring real-time cell stress and apoptosis in-vivo is a critical unmet need in retinal degeneration diseases. This study aims to assess the feasibility of using the PSVue® 794 molecular probe for live staining of retinal apoptosis cells in response to different laser treatments. Our goal is to understand the temporal and progressive alternations in retinal cells, providing valuable insights into retinal disease progression and potential treatment strategies.
Methods :
A non-human primate model underwent retinal injury induced by either continued (PurePoint, Alcon) or micropulse laser (IQ 532®, Iridex), both operating at 532-nm wavelength, with variations in laser power settings. Following the laser treatment, PSVue® 794 (0.5ml of 1mg/mL) was intravenously administered to label the retinal apoptotic cells. Real-time scanning laser angiography, complemented by SD-OCT, was employed to dynamically capture the fluorescence staining in retinal cells. Quantitative analysis of fluorescence intensity was conducted to characterize the progression of retinal injury up to 1 month.
Results :
PSVue® 794 effectively stained retinal cell during stress and apoptosis in response to diverse laser treatments, as confirmed by real-time imaging displaying a significant increase in fluorescence intensity. Following a one-time intravenous application, PSVue® 794 was cleared from retinal blood vessels within 10 minutes. Positive staining was observed at the laser spots under both continuous laser (200-400mW, 200ms duration) and micropulse laser conditions (1500-2000mW, 330ms duration, 2% duty cycle) which persisted for up to 1 month. However, under high power continuous laser conditions (600-800mW, 200ms duration), scar tissue formation and negative PSVue staining occurred after 1 week due to cell death. Conversely, in low power micropulse laser conditions (800-1200mW, 330ms duration, 2% duty cycle), the native RPE layer remained undamaged, resulting in negative staining from the outset.
Conclusions :
Our study highlights the effectiveness of PSVue® 794 in real-time imaging of retinal cell stress and apoptosis in a laser-induced non-human primate model. This dynamic monitoring enhances our understanding of retinal injury progression, paving the way for targeted therapeutic interventions and personalized treatment approaches in advancing ophthalmic care.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.