Advanced Multimodal Imaging System Maps Retina Oxygen Levels with Unmatched Precision

A groundbreaking imaging technology has been developed that allows scientists to visualize and measure oxygen levels within the retina with unprecedented detail. This innovative system combines two cutting-edge optical techniques: visible light optical coherence tomography (VIS-OCT), which captures detailed 3D images of retinal microanatomy, and phosphorescence lifetime ophthalmoscopy (PLIM-SLO), which provides precise measurements of oxygen partial pressure (pO₂) in blood vessels.

The retina, known for its high oxygen consumption, is vulnerable to diseases like glaucoma, age-related macular degeneration, and diabetic retinopathy, all of which involve disruptions in oxygen supply. However, noninvasively assessing oxygen levels at the microvascular level has historically been challenging.

Researchers from Johns Hopkins University and the University of Pennsylvania have devised a multimodal system that integrates these techniques to image both retinal structure and oxygen metabolism in live mice. By injecting a specially tailored probe, Oxyphor 2P, into the mice, the team could determine oxygen levels by analyzing changes in phosphorescence lifetime. Simultaneously, the VIS-OCT provided high-resolution images of retinal layers and blood flow, with both systems synchronized to enable accurate spatial correlation.

Initial tests demonstrated that the system could effectively track variations in retinal oxygenation in response to different oxygen inhalation levels. Results showed higher pO₂ in arterioles compared to venules, with capillary measurements falling in between, aligning with known blood oxygen saturation curves. The device's ability to focus at various depths allows detailed mapping of local microvascular oxygenation.

This dual-function imaging platform offers a powerful new way to study how oxygen supply is compromised in retinal diseases and during treatments. Its non-destructive nature permits repeated measurements over time, making it suitable for longitudinal studies in disease models.

Furthermore, the system's capacity for concurrent anatomical and functional imaging could enhance the validation of label-free ocular oximetry methods, refining non-invasive diagnostic tools. Future improvements, such as incorporating adaptive optics, might further sharpen imaging resolution, paving the way for potential clinical applications in human eye health.

This innovative approach promises significant advances in understanding retinal vascular health and developing targeted therapies for vision-threatening diseases.

Source: https://medicalxpress.com/news/2025-10-imaging-retinal-oxygen-unprecedented.html