Image Gallery

Blood flow in a single capillary path is imaged without contrast agents. Top A single blood cell travels through a capillary (dashed green trace). Movement of this cell over time is highlighted with yellow arrows. The centerline profile of the capillary is "flattened" to show displacement and plotted over time (spatio-temporal plot, bottom). Change in displacement, dx, divided by change in time, dt reveals the velocity of cells. Blood velocities ~0.3-3 mm/second were measured by this method. Image field is 60 µm wide in top images.

Through-focus video of the trilaminar vascular layers of the living mammalian retina, imaged with adaptive optics

Non-invasive measurement of blood flow in a retinal arteriole.

High resolution image of retinal capillaries

Retinal pericytes, imaged ex vivo with a microscope

Green pericytes surround capillaries of the living eye (imaged with AOSLO).

Pericytes (green) surround vessels of the eye (blue).

Sparse arrangement of horizontal cells imaged with label-free split-detection. Guevara et al. 2015. PDF

Phase-contrast image of red blood cells inside a retinal capillary in the living mammal. Guevara et al. 2016. PDF

Red blood cells parachute through retinal capillaries seen with label-free split-detection imaging. Imaging with fluorescein shows labeled plasma with gaps when blood cells pass. Guevara et al. 2016. PDF

Red blood cell packing and flow in capillaries of the living eye. Guevara et al. 2016. PDF

Pericytes labeled in a transgenic animal show microvascular network of the living retina.

Split-detection in different layers of the retina shows the multilayered arrangement of photoreceptor somas and inner and outer segments below. Guevara et al. 2015. PDF

With AOSLO, we can observe three distinct capillary stratifications in the mouse retinal circulation. The above image shows a through-focus capture of three distinct capillary stratifications. Image field is 5 degrees of visual angle, ~150 microns across.

3D rotational image of pericytes and vessels imaged with AOSLO.

Vessels of the primate retina color coded by vessel angle.

The microvascular network imaged without contrast agents. The movement of single blood cells creates a spatio-temporal flicker. Motion contrast imaging reveals active perfusion in the vessels surrounding the fovea.

A binary mask showing perfused vessels surrounding the fovea of the primate. Vessel angle is coded by color.

Fluorescent ring of ganglion cells serving the foveal cones. These cells are expressing the calcium indicator GCaMP, which allows cell responses to be monitored optically.

Phase map of ganglion cell responses to a 0.2Hz drifting grating visual stimulus presented to the foveal cones.

Human Retinal Diseases: Image of rods and cones

Human Retinal Diseases: AMD Geographic Atrophy

Time-lapse imaging of retinal microglia in vivo. Schallek et al. ARVO e-abstract 2017

Time-lapse imaging of retinal microglia in vivo. Schallek et al. ARVO e-abstract 2017

Immune Cell Imaging: In vivo flow cytometry. Joseph et al. ARVO e-abstract 2016

Two-photon Imaging of the Retina: Two-photon ex vivo image of photoreceptors in macaque macular region

Two-photon Imaging of the Retina: In vivo macaque photoreceptor TPEF intensity (a) and corresponding AOFLIO (b) images displaying mean lifetime.

Two-photon Imaging of the Retina: Two-photon in vivo image of GFP-labeled ganglion cells in mouse. The two images are axially separated by 5µm

Two-photon Imaging of the Retina: Ex vivo two-photon microscopy image of ganglion cells below the nerve fiber layer

Two-photon Imaging of the Retina: Reflectance (left) and two-photon excited fluorescence (right) image of the photoreceptor mosaic in the living macaque eye. The main source of fluorescence is most likely all-trans-retinol.

Two-photon Imaging of the Retina: The image shows two-photon excited fluorescence captured from photoreceptors in the living macaque eye where selective S cone damage was induced at different time points.