Scanning interferometry of sunfish cones I Longitudinal variation in single-cone refractive index

Rowe, M. P.; Corless, Joseph M.; Engheta, Nader; Pugh, Edward N.

doi:10.1364/josaa.13.002141

Cited by 8 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with other reports [5, 6, 11] which described the primary defect site to be the RPE with involvement of the outer photoreceptor segments by photochemical and/or photothermal reactions in extended injuries [1, 12]. In laser‐induced retinal injuries in zebra fish the early hyperreflectivity seen in OCT histologically correlates to an early edema, which is followed by disorganization of photoreceptors and loss of nuclei in the outer nuclear layer after one day [13], keeping in mind that OCT images are based on tissue reflectivity and not on tissue or cell types (while reflectivity is amongst other things depending on the complex refractive index of the cellular and extracellular components involved and light scattering) [14, 15]. With en face OCT, we could depict the total two‐dimensional alterations of the EZ and carry out a quantitative analysis of the EZ reformation.…”

Section: Discussionmentioning

confidence: 99%

En Face Optical Coherence Tomography Imaging Ellipsoid Zone Regeneration in Laser-Induced and Solar Maculopathies

Gunzinger

Fasler

Barthelmes

et al. 2019

Case Reports in Ophthalmological Medicine

View full text Add to dashboard Cite

The purpose of the study was to analyze imaging findings in spectral domain en face optical coherence tomography (SD OCT) in patients with laser‐induced and solar maculopathies focusing on the possible regeneration of the ellipsoid zone. In a retrospective case series of 3 patients (4 eyes) with solar maculopathy and 2 patients (3 eyes) with laser‐induced maculopathy who underwent a comprehensive ocular examination, ellipsoid zone (EZ) was segmented from SD OCT data. Evaluation of EZ in en face OCT revealed a hyporeflective lesion surrounded by a hyperreflective border. The area of EZ alteration was measured manually in en face OCT. All patients showed partial EZ regeneration. Mean EZ alteration decreased from 0.12 mm2 (range: 0.05–0.32) at baseline to 0.07 mm2 (range: 0.01–0.22) at last follow‐up (p = 0.018, mean follow‐up: 372 days; range: 115–592). Mean best visual acuity (BVA) improved from 20/36 at baseline to 20/30 (p = 0.018). In conclusion, en face OCT imaging clearly delineated the area of EZ alteration in patients with laser‐induced and solar maculopathies. Follow-up showed significant reformation of the EZ as well as improvement of BVA.

show abstract

Section: Discussionmentioning

confidence: 99%

En Face Optical Coherence Tomography Imaging Ellipsoid Zone Regeneration in Laser-Induced and Solar Maculopathies

Gunzinger

Fasler

Barthelmes

et al. 2019

Case Reports in Ophthalmological Medicine

View full text Add to dashboard Cite

show abstract

“…In addition, the axial scaling of the OCT signal may not be completely linear across the different chorioretinal layers. Since the signal depends in part on the refractive index of tissues (Cheng and Liu, 2010; Drexler et al, 2001; Zhou et al, 2013), layers that are rich in lipids such as the IS ellipsoid or OS may refract light and scale differently than layers that have more aqueous components (Hoang et al, 2002; Rowe et al, 1996). Further, the melanosomes that in part confer the hyperreflective property of the RPE and OC in macaques also allow better distinction of the CC, attenuate the light signal in the OC, and reduce the delineation of the choroidal-scleral junction as compared with humans, where the choroid is less pigmented (Yiu et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

Comparison of chorioretinal layers in rhesus macaques using spectral-domain optical coherence tomography and high-resolution histological sections

Yiu

Wang

Munevar

et al. 2018

Experimental Eye Research

View full text Add to dashboard Cite

Nonhuman primates are important preclinical models of retinal diseases because they uniquely possess a macula similar to humans. Ocular imaging technologies such as spectral-domain optical coherence tomography (SD-OCT) allow noninvasive, in vivo measurements of chorioretinal layers with near-histological resolution. However, the boundaries are based on differences in reflectivity, and detailed correlations with histological tissue layers have not been explored in rhesus macaques, which are widely used for biomedical research. Here, we compare the macular anatomy and thickness measurements of chorioretinal layers in rhesus macaque eyes using SD-OCT and high-resolution histological sections. Images were obtained from methylmethacrylate-embedded histological sections of 6 healthy adult rhesus macaques, and compared with SD-OCT images from 6 age-matched animals. Thicknesses of chorioretinal layers were measured across the central 3 mm macular region using custom semi-automated or manual software segmentation, and compared between the two modalities. We found that histological sections provide better distinction between the ganglion cell layer (GCL) and inner plexiform layer (IPL) than SD-OCT imaging. The first hyperreflective band between the external limiting membrane (ELM) and retinal pigment epithelium (RPE) appears wider on SD-OCT than the junction between photoreceptor inner and outer segments seen on histology. SD-OCT poorly distinguishes Henle nerve fibers from the outer nuclear layer (ONL), while histology correctly identifies these fibers as part of the outer plexiform layer (OPL). Overall, the GCL, inner nuclear layer (INL), and OPL are significantly thicker on histology, especially at the fovea; while the ONL, choriocapillaris (CC), and outer choroid (OC) are thicker on SD-OCT. Our results show that both SD-OCT and high-resolution histological sections allow reliable measurements of chorioretinal layers in rhesus macaques, with distinct advantages for different sublayers. These findings demonstrate the effects of tissue processing on chorioretinal anatomy, and provide normative values for chorioretinal thickness measurements on SD-OCT for future studies of disease models in these nonhuman primates.

show abstract

“…Photoreceptors may use a relatively high density of cytoskeletal elements to maintain their highly structured, polarized morphology. Crowding by macromolecules may be exceptionally high in the cytoplasm of the IS and OS: interferometric measurements of cytoplasm, which probe particulate density, indicate that the refractive index of the OS is 1.41 ( Sidman, 1957 ) and the core of the myoid region of cones has an index of 1.42 ( Rowe et al, 1996 ). These values contrast with those of cultured mammalian cells, with reported refractive indices in the 1.36 to 1.37 range ( Lanni et al, 1985 ).…”

Section: Discussionmentioning

confidence: 99%

Diffusion of a soluble protein, photoactivatable GFP, through a sensory cilium

Calvert

Schiesser

Pugh

2010

Journal of General Physiology

View full text Add to dashboard Cite

Transport of proteins to and from cilia is crucial for normal cell function and survival, and interruption of transport has been implicated in degenerative and neoplastic diseases. It has been hypothesized that the ciliary axoneme and structures adjacent to and including the basal bodies of cilia impose selective barriers to the movement of proteins into and out of the cilium. To examine this hypothesis, using confocal and multiphoton microscopy we determined the mobility of the highly soluble photoactivatable green fluorescent protein (PAGFP) in the connecting cilium (CC) of live Xenopus retinal rod photoreceptors, and in the contiguous subcellular compartments bridged by the CC, the inner segment (IS) and the outer segment (OS). The estimated axial diffusion coefficients are DCC = 2.8 ± 0.3, DIS = 5.2 ± 0.6, and DOS = 0.079 ± 0.009 µm2 s−1. The results establish that the CC does not pose a major barrier to protein diffusion within the rod cell. However, the results also reveal that axial diffusion in each of the rod’s compartments is substantially retarded relative to aqueous solution: the axial diffusion of PAGFP was retarded ∼18-, 32- and 1,000-fold in the IS, CC, and OS, respectively, with ∼20-fold of the reduction in the OS attributable to tortuosity imposed by the lamellar disc membranes. Previous investigation of PAGFP diffusion in passed, spherical Chinese hamster ovary cells yielded DCHO = 20 µm2 s−1, and estimating cytoplasmic viscosity as Daq/DCHO = 4.5, the residual 3- to 10-fold reduction in PAGFP diffusion is ascribed to sub-optical resolution structures in the IS, CC, and OS compartments.

show abstract

Scanning interferometry of sunfish cones I Longitudinal variation in single-cone refractive index

Cited by 8 publications

References 18 publications

En Face Optical Coherence Tomography Imaging Ellipsoid Zone Regeneration in Laser-Induced and Solar Maculopathies

En Face Optical Coherence Tomography Imaging Ellipsoid Zone Regeneration in Laser-Induced and Solar Maculopathies

Comparison of chorioretinal layers in rhesus macaques using spectral-domain optical coherence tomography and high-resolution histological sections

Diffusion of a soluble protein, photoactivatable GFP, through a sensory cilium

Contact Info

Product

Resources

About