In vivo super-resolution retinal imaging through virtually structured detection

Son

Kim

et al. 2018

Exp Biol Med (Maywood)

Self Cite

Age-related macular degeneration (AMD) is the leading cause of severe vision loss and legal blindness. It is known that retinal photoreceptors are the primary target of AMD. Therefore, a reliable method for objective assessment of photoreceptor function is needed for early detection and reliable treatment evaluation of AMD and other eye diseases such as retinitis pigmentosa that are known to cause photoreceptor dysfunctions. Stimulus-evoked intrinsic optical signal (IOS) changes promise a unique opportunity for objective assessment of physiological function of retinal photoreceptor and inner neurons. Instead of a comprehensive review, this mini-review is to provide a brief summary of our recent in vitro and in vivo optical coherence tomography (OCT) studies of stimulus-evoked IOS changes in animal retinas. By providing excellent axial resolution to differentiate individual retinal layers, depth-resolved OCT revealed rapid IOS response at the photoreceptor outer segment. The fast photoreceptor-IOS occurred almost right away (∼ 2 ms) after the onset of retinal stimulation, differentiating itself from slow IOS changes correlated with inner neural and hemodynamic changes. Further development of the functional IOS instruments and retinal stimulation protocols may provide a feasible solution to pursue clinical application of functional IOS imaging for objective assessment of human photoreceptors. Impact statement Retinal photoreceptors are the primary target of age-related macular degeneration (AMD) which is the leading cause of severe vision loss and legal blindness. An objective method for functional assessment of photoreceptor physiology can benefit early detection and better treatment evaluation of AMD and other eye diseases that are known to cause photoreceptor dysfunctions. This article summarizes in vitro study of IOS mechanisms and in vivo demonstration of IOS imaging of intact animals. Further development of the functional IOS imaging may provide a revolutionary solution to achieve objective assessment of human photoreceptors.

Section: Discussionmentioning

confidence: 99%

Functional optical coherence tomography of retinal photoreceptors

Son

Kim

et al. 2018

Exp Biol Med (Maywood)

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“…24 Recently, we demonstrated the feasibility of the line-scanning strategy for rapid VSD-based super-resolution imaging of both isolated retinas 25 and intact frog eyes. 26,27 Figure 4 shows the experimental setup and representative in vivo super-resolution images captured with 127 frames/s speed. As shown in Figure 4(b), the VSD-based SLO enabled unambiguous observation of individual retinal photoreceptors (Figure 4(b1)) and ganglion fibers (Figure 4(b2)).…”

Section: In Vivo Super-resolution Ophthalmoscopy Of Animal Retinasmentioning

confidence: 99%

“…As shown in Figure 4(b), the VSD-based SLO enabled unambiguous observation of individual retinal photoreceptors (Figure 4(b1)) and ganglion fibers (Figure 4(b2)). 26 By providing high-spatial (µm) and high-temporal (∼10 ms) resolutions, the VSD-based super-resolution SLO has been used to validate in vivo monitoring of transient retinal phototropism evoked by oblique light stimulation. 27…”

Section: In Vivo Super-resolution Ophthalmoscopy Of Animal Retinasmentioning

confidence: 99%

Super-resolution ophthalmoscopy: Virtually structured detection for resolution improvement in retinal imaging

Wang

et al. 2020

Exp Biol Med (Maywood)

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Quantitative retinal imaging is essential for advanced study and clinical management of eye diseases. However, spatial resolution of retinal imaging has been limited due to available numerical aperture and optical aberration of the ocular optics. Structured illumination microscopy has been established to break the diffraction-limit resolution in conventional light microscopy. However, practical implementation of structured illumination microscopy for in vivo ophthalmoscopy of the retina is challenging due to inevitable eye movements that can produce phase artifacts. Recently, we have demonstrated the feasibility of using virtually structured detection as one alternative to structured illumination microscopy for super-resolution imaging. By providing the flexibility of digital compensation of eye movements, the virtually structured detection provides a feasible, phase-artifact-free strategy to achieve super-resolution ophthalmoscopy. In this article, we summarize the technical rationale of virtually structured detection, and its implementations for super-resolution imaging of freshly isolated retinas, intact animals, and awake human subjects.

“…Here, we demonstrated for the first time in vivo observation of TRP using a custom-designed super-resolution ophthalmoscope [20]. The custom-built digital ophthalmoscope employed virtually structured detection (VSD) to achieve a sub-cellular level of spatial resolution, and it combined a rapid line-scanning strategy to realize a millisecond level of temporal resolution.…”

Section: Introductionmentioning

confidence: 99%

In vivo observation of transient photoreceptor movement correlated with oblique light stimulation

Liu

Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XVI

2018

Self Cite

Rod-dominated transient retinal phototropism (TRP) has been observed in freshly isolated retinas, promising a noninvasive biomarker for high resolution assessment of retinal physiology. However, in vivo mapping of TRP is challenging due to its fast time course and sub-cellular signal magnitude. By developing a line-scanning and virtually structured detection based super-resolution ophthalmoscope, we report here in vivo observation of TRP in frog retina. In vivo characterization of TRP time course and magnitude were implemented by using variable light stimulus intensities.