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Elsner AE. 2022 Prentice Award Lecture: Advancing Retinal Imaging and Visual Function in Patient Management and Disease Mechanisms. Optom Vis Sci 2023; 100:354-375. [PMID: 37212795 PMCID: PMC10317306 DOI: 10.1097/opx.0000000000002029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
SIGNIFICANCE Patient-based research plays a key role in probing basic visual mechanisms. Less-well recognized is the role of patient-based retinal imaging and visual function studies in elucidating disease mechanisms, which are accelerated by advances in imaging and function techniques and are most powerful when combined with the results from histology and animal models.A patient's visual complaints can be one key to patient management, but human data are also key to understanding disease mechanisms. Unfortunately, pathological changes can be difficult to detect. Before advanced retinal imaging, the measurement of visual function indicated the presence of pathological changes that were undetectable with existing clinical examination. Over the past few decades, advances in retinal imaging have increasingly revealed the unseen. This has led to great strides in the management of many diseases, particularly diabetic retinopathy and macular edema, and age-related macular degeneration. It is likely widely accepted that patient-based research, as in clinical trials, led to such positive outcomes. Both visual function measures and advanced retinal imaging have clearly demonstrated differences among retinal diseases. Contrary to initial thinking, sight-threatening damage in diabetes occurs to the outer retina and not only to the inner retina. This has been clearly indicated in patient results but has only gradually entered the clinical classifications and understanding of disease etiology. There is strikingly different pathophysiology for age-related macular degeneration compared with photoreceptor and retinal pigment epithelial genetic defects, yet research models and even some treatments confuse these. It is important to recognize the role that patient-based research plays in probing basic visual mechanisms and elucidating disease mechanisms, combining these findings with the concepts from histology and animal models. Thus, this article combines sample instrumentation from my laboratory and progress in the fields of retinal imaging and visual function.
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Affiliation(s)
- Ann E. Elsner
- School of Optometry, Indiana University, Bloomington, Indiana
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2
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Whitmore SS, DeLuca AP, Andorf JL, Cheng JL, Mansoor M, Fortenbach CR, Critser DB, Russell JF, Stone EM, Han IC. Modeling rod and cone photoreceptor cell survival in vivo using optical coherence tomography. Sci Rep 2023; 13:6896. [PMID: 37106000 PMCID: PMC10140056 DOI: 10.1038/s41598-023-33694-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Many retinal diseases involve the loss of light-sensing photoreceptor cells (rods and cones) over time. The severity and distribution of photoreceptor loss varies widely across diseases and affected individuals, so characterizing the degree and pattern of photoreceptor loss can clarify pathophysiology and prognosis. Currently, in vivo visualization of individual photoreceptors requires technology such as adaptive optics, which has numerous limitations and is not widely used. By contrast, optical coherence tomography (OCT) is nearly ubiquitous in daily clinical practice given its ease of image acquisition and detailed visualization of retinal structure. However, OCT cannot resolve individual photoreceptors, and no OCT-based method exists to distinguish between the loss of rods versus cones. Here, we present a computational model that quantitatively estimates rod versus cone photoreceptor loss from OCT. Using histologic data of human photoreceptor topography, we constructed an OCT-based reference model to simulate outer nuclear layer thinning caused by differential loss of rods and cones. The model was able to estimate rod and cone loss using in vivo OCT data from patients with Stargardt disease and healthy controls. Our model provides a powerful new tool to quantify photoreceptor loss using OCT data alone, with potentially broad applications for research and clinical care.
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Affiliation(s)
- S Scott Whitmore
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA.
| | - Adam P DeLuca
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Jeaneen L Andorf
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Justine L Cheng
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | - Mahsaw Mansoor
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Christopher R Fortenbach
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - D Brice Critser
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Jonathan F Russell
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Edwin M Stone
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Ian C Han
- The University of Iowa Institute for Vision Research & Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
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Henle Fiber Layer Mapping with Directional Optical Coherence Tomography. Retina 2022; 42:1780-1787. [PMID: 35504010 DOI: 10.1097/iae.0000000000003514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To perform a macular volumetric and topographic analysis of Henle Fiber Layer (HFL) from retinal scans acquired by directional optical coherence tomography (D-OCT). METHODS 30 healthy eyes of 17 subjects were imaged using the Heidelberg SD-OCT (Spectralis®, Heidelberg Engineering, Heidelberg, Germany) with varied horizontal and vertical pupil entry. Manual segmentation of HFL was performed from retinal sections of horizontally and vertically tilted OCT images acquired within macular 20×20° area. Total HFL volume, mean HFL thickness and HFL coverage area within ETDRS grid were calculated from mapped images. RESULTS HFL of 30 eyes were imaged, segmented and mapped. The mean total HFL volume was 0.74±0.08 mm3 with 0.16±0.02, 0.18±0.03, 0.17±0.02 and 0.19±0.03 mm3 for superior, temporal, inferior and nasal quadrants, respectively. The mean HFL thickness was 26.5±2.9 µm. Central 1 mm macular zone had the highest mean HFL thickness with 51.0±7.6 µm. The HFL coverage which have thickness equal or above to the mean value had a mean 10.771 ± 0.574 mm2 of surface area. CONCLUSION HFL mapping is a promising tool for structural analysis of HFL. Identifying a normative data of HFL morphology will allow further studies to investigate HFL involvement in various ocular and systemic disorders.
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Yuhas PT, Ciamacca ML, Ramsey KA, Mayne DM, Stern-Green EA, Ohr M, Zimmerman A, Hartwick ATE, VanNasdale DA. Foveal Phase Retardation Correlates With Optically Measured Henle Fiber Layer Thickness. Front Med (Lausanne) 2022; 9:846738. [PMID: 35492328 PMCID: PMC9051020 DOI: 10.3389/fmed.2022.846738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/23/2022] [Indexed: 01/21/2023] Open
Abstract
This study quantified and compared phase retardation distribution in the central macula with the thickness of the Henle fiber layer (HFL). A scanning laser polarimeter (SLP) was used to acquire 20° × 40° macular-centered images, either with fixed corneal compensation or with variable corneal compensation, in two cohorts of clinically normal subjects (N = 36). Phase retardation maps from SLP imaging were used to generate a macular cross pattern (fixed compensation) or an annulus pattern (variable compensation) centered on the macula. Intensity profiles in the phase retardation maps were produced using annular regions of interest at eccentricities from 0.25° to 3°. Pixel intensity was averaged at each eccentricity, acting as a surrogate for macular phase retardation. Directional OCT images were acquired in the horizontal and vertical meridians in all subjects, allowing visualization of the HFL thickness. HFL thickness was manually segmented in each meridian and averaged. In both cohorts, phase retardation and HFL thickness were highly correlated in the central 3° assessed, providing further evidence that the source of the phase retardation signal in the central macula is dominated by the HFL and that the center of the macula on cross sectional imaging corresponds closely with the center of the macular cross on SLP imaging.
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Affiliation(s)
- Phillip T. Yuhas
- College of Optometry, The Ohio State University, Columbus, OH, United States,*Correspondence: Phillip T. Yuhas
| | - Marisa L. Ciamacca
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Keith A. Ramsey
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Danielle M. Mayne
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | | | - Matthew Ohr
- Department of Ophthalmology and Visual Sciences, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - Aaron Zimmerman
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | | | - Dean A. VanNasdale
- College of Optometry, The Ohio State University, Columbus, OH, United States
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Elsner AE, Walker BR, Gilbert RN, Parimi V, Papay JA, Gast TJ, Burns SA. Cone Photoreceptors in Diabetic Patients. Front Med (Lausanne) 2022; 9:826643. [PMID: 35372411 PMCID: PMC8968172 DOI: 10.3389/fmed.2022.826643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose Cones in diabetic patients are at risk due to metabolic and vascular changes. By imaging retinal vessel modeling at high magnification, we reduced its impact on cone distribution measurements. The retinal vessel images and retinal thickness measurements provided information about cone microenvironment. Methods We compared cone data in 10 diabetic subjects (28–78 yr) to our published norms from 36 younger and 10 older controls. All subjects were consented and tested in a manner approved by the Indiana University Institutional Review Board, which adhered to the Declaration of Helsinki. Custom adaptive optics scanning laser ophthalmoscopy (AOSLO) was used to image cones and retinal microcirculation. We counted cones in a montage of foveal and temporal retina, using four non-contiguous samples within 0.9–7 deg that were selected for best visibility of cones and least pathology. The data were fit with a two parameter exponential model: ln(cone density) = a * microns eccentricity + b. These results were compared to retinal thickness measurements from SDOCT. Results Diabetic cone maps were more variable than in controls and included patches, or unusually bright and dark cones, centrally and more peripherally. Model parameters and total cones within the central 14 deg of the macula differed across diabetic patients. Total cones fell into two groups: similar to normal for 5 vs. less than normal for 2 of 2 younger diabetic subjects and 3 older subjects, low but not outside the confidence limits. Diabetic subjects had all retinal vascular remodeling to varying degrees: microaneurysms; capillary thickening, thinning, or bends; and vessel elongation including capillary loops, tangles, and collaterals. Yet SD-OCT showed that no diabetic subject had a Total Retinal Thickness in any quadrant that fell outside the confidence limits for controls. Conclusions AOSLO images pinpointed widespread retinal vascular remodeling in all diabetic eyes, but the SDOCT showed no increased retinal thickness. Cone reflectivity changes were found in all diabetic patients, but significantly low cone density in only some. These results are consistent with early changes to neural, glial, or vascular components of the retinal without significant retinal thickening due to exudation.
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Zouache MA. Variability in Retinal Neuron Populations and Associated Variations in Mass Transport Systems of the Retina in Health and Aging. Front Aging Neurosci 2022; 14:778404. [PMID: 35283756 PMCID: PMC8914054 DOI: 10.3389/fnagi.2022.778404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 01/13/2022] [Indexed: 11/17/2022] Open
Abstract
Aging is associated with a broad range of visual impairments that can have dramatic consequences on the quality of life of those impacted. These changes are driven by a complex series of alterations affecting interactions between multiple cellular and extracellular elements. The resilience of many of these interactions may be key to minimal loss of visual function in aging; yet many of them remain poorly understood. In this review, we focus on the relation between retinal neurons and their respective mass transport systems. These metabolite delivery systems include the retinal vasculature, which lies within the inner portion of the retina, and the choroidal vasculature located externally to the retinal tissue. A framework for investigation is proposed and applied to identify the structures and processes determining retinal mass transport at the cellular and tissue levels. Spatial variability in the structure of the retina and changes observed in aging are then harnessed to explore the relation between variations in neuron populations and those seen among retinal metabolite delivery systems. Existing data demonstrate that the relation between inner retinal neurons and their mass transport systems is different in nature from that observed between the outer retina and choroid. The most prominent structural changes observed across the eye and in aging are seen in Bruch’s membrane, which forms a selective barrier to mass transfers at the interface between the choroidal vasculature and the outer retina.
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Ni S, Khan S, Nguyen TTP, Ng R, Lujan BJ, Tan O, Huang D, Jian Y. Volumetric directional optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2022; 13:950-961. [PMID: 35284155 PMCID: PMC8884206 DOI: 10.1364/boe.447882] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/14/2022] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Photoreceptor loss and resultant thinning of the outer nuclear layer (ONL) is an important pathological feature of retinal degenerations and may serve as a useful imaging biomarker for age-related macular degeneration. However, the demarcation between the ONL and the adjacent Henle's fiber layer (HFL) is difficult to visualize with standard optical coherence tomography (OCT). A dedicated OCT system that can precisely control and continuously and synchronously update the imaging beam entry points during scanning has not been realized yet. In this paper, we introduce a novel imaging technology, Volumetric Directional OCT (VD-OCT), which can dynamically adjust the incident beam on the pupil without manual adjustment during a volumetric OCT scan. We also implement a customized spoke-circular scanning pattern to observe the appearance of HFL with sufficient optical contrast in continuous cross-sectional scans through the entire volume. The application of VD-OCT for retinal imaging to exploit directional reflectivity properties of tissue layers has the potential to allow for early identification of retinal diseases.
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Affiliation(s)
- Shuibin Ni
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Shanjida Khan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Thanh-Tin P. Nguyen
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Ringo Ng
- School of Engineering Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Brandon J. Lujan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Ou Tan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon 97239, USA
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Butler JM, Maruska KP. Opsin Expression Varies with Reproductive State in the Cichlid Fish Astatotilapia burtoni. Integr Comp Biol 2021; 61:240-248. [PMID: 33972997 DOI: 10.1093/icb/icab058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Animals use visual communication to convey crucial information about their identity, reproductive status, and sex. Plasticity in the auditory and olfactory systems has been well-documented, however, fewer studies have tested for plasticity in the visual system, a surprising detail since courtship and mate choice are largely dependent on visual signals across taxa. We previously found reproductive state-dependent plasticity in the eye of the highly social cichlid fish Astatotilapia burtoni. Male A. burtoni increase their courtship, including multicomponent visual displays, when around ovulated females, and ovulated females are more responsive to male visual courtship displays than non-ovulated females. Based on this, we hypothesized that ovulation status impacts visual capabilities in A. burtoni females. Using electroretinograms, we found that ovulated females had greater visual sensitivity at wavelengths corresponding to male courtship coloration compared with non-reproductively-receptive females. In addition, ovulated females had higher neural activation in the retina and higher mRNA expression levels of neuromodulatory receptors (e.g., sex-steroids; gonadotropins) in the eye than non-ovulated females. Here, we add to this body of work by testing the hypothesis that cone opsin expression changes with female reproductive state. Ovulated females had higher expression of short wavelength sensitive opsins (sws1, sws2a, sws2b) compared with mouthbrooding females. Further, expression of sws2a, the most abundant opsin in the A. burtoni eye, positively correlated with levels of circulating 11-ketotestosterone and estradiol and estrogen, androgen, and gonadotropin system receptor expression in the eye in females. These data indicate that reproductive state-dependent plasticity also occurs at the level of photoreceptors, not just through modulation of visual signals at downstream retinal layers. Collectively, these data provide crucial evidence linking endocrine modulation of visual plasticity to mate choice behaviors in females.
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Affiliation(s)
- Julie M Butler
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg, Baton Rouge, LA 70803, USA.,Department of Biology, Stanford University, 304 Gilbert, 371 Jane Stanford Way, Stanford, CA 94305, USA
| | - Karen P Maruska
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg, Baton Rouge, LA 70803, USA
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Baraas RC, Horjen Å, Gilson SJ, Pedersen HR. The Relationship Between Perifoveal L-Cone Isolating Visual Acuity and Cone Photoreceptor Spacing-Understanding the Transition Between Healthy Aging and Early AMD. Front Aging Neurosci 2021; 13:732287. [PMID: 34566629 PMCID: PMC8458634 DOI: 10.3389/fnagi.2021.732287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/11/2021] [Indexed: 11/20/2022] Open
Abstract
Background: Age-related macular degeneration (AMD) is a multifactorial degenerative disorder that can lead to irreversible loss of visual function, with aging being the prime risk factor. However, knowledge about the transition between healthy aging and early AMD is limited. We aimed to examine the relationship between psychophysical measures of perifoveal L-cone acuity and cone photoreceptor structure in healthy aging and early AMD. Methods and Results: Thirty-nine healthy participants, 10 with early AMD and 29 healthy controls were included in the study. Multimodal high-resolution retinal images were obtained with adaptive-optics scanning-light ophthalmoscopy (AOSLO), optical-coherence tomography (OCT), and color fundus photographs. At 5 degrees retinal eccentricity, perifoveal L-cone isolating letter acuity was measured with psychophysics, cone inner segment and outer segment lengths were measured using OCT, while cone density, spacing, and mosaic regularity were measured using AOSLO. The Nyquist sampling limit of cone mosaic (Nc) was calculated for each participant. Both L-cone acuity and photoreceptor inner segment length declined with age, but there was no association between cone density nor outer segment length and age. A multiple regression showed that 56% of the variation in log L-cone acuity was accounted for by Nc when age was taken into account. Six AMD participants with low risk of progression were well within confidence limits, while two with medium-to-severe risk of progression were outliers. The observable difference in cone structure between healthy aging and early AMD was a significant shortening of cone outer segments. Conclusion: The results underscore the resilience of cone structure with age, with perifoveal functional changes preceding detectable changes in the cone photoreceptor mosaic. L-cone acuity is a sensitive measure for assessing age-related decline in this region. The transition between healthy aging of cone structures and changes in cone structures secondary to early AMD relates to outer segment shortening.
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Affiliation(s)
- Rigmor C Baraas
- Faculty of Health and Social Sciences, National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, Kongsberg, Norway
| | - Åshild Horjen
- Faculty of Health and Social Sciences, National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, Kongsberg, Norway
| | - Stuart J Gilson
- Faculty of Health and Social Sciences, National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, Kongsberg, Norway
| | - Hilde R Pedersen
- Faculty of Health and Social Sciences, National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, Kongsberg, Norway
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Lal T, Yu ZX, Guan B, Bender C, Chan CC, Cukras CA, Hufnagel RB. Clinical and Histopathologic Correlates of Asymmetric Retinitis Pigmentosa. JAMA Ophthalmol 2021; 139:1029-1032. [PMID: 34351381 DOI: 10.1001/jamaophthalmol.2021.2688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Asymmetric retinitis pigmentosa (RP) is a rare presentation of a normally symmetric condition. Histopathologic evidence should be examined to see if this asymmetry extends to the tissue and cellular levels. Objective To determine whether additional information can be obtained about asymmetric RP from studying clinical imaging and pathology correlates, including pathology samples from autopsied eyes. Design, Setting, and Participants In this case report, clinical and postmortem histopathological characteristics were compared in 2 eyes of a patient in her 50s with asymmetric RP. Individuals with rare mendelian diseases, such as RP, were studied using data from the curated National Eye Institute Eye Pathology collection. Main Outcome and Measures Results of clinical evaluation, multimodal retinal imaging, histopathology, and molecular genetic testing in a case of nonsyndromic asymmetric RP using resources from the ocular pathology collection. Results Eyes from a deceased patient in her 50s with nonsyndromic asymmetric RP found within the ocular pathology collection were studied. The patient was diagnosed with RP as an adolescent and presented in her 50s to the eye clinic with advanced RP, with the left eye affected much more severely than the right. The patient's phenotype was studied using in vivo imaging and postmortem histopathology to identify interocular differences in tissue degeneration. Extraction of blood-derived DNA and formalin-fixed paraffin-embedded DNA from autopsied eyes analyzed using next-generation sequencing did not yield a definitive molecular diagnosis nor significant tissue differences. Conclusions and Relevance This study demonstrates newly reported histopathological and molecular correlates in asymmetric RP. This report also highlights the relevance of studying previously seen patients and reevaluating their conditions using resources within the ocular pathology collection to gain further insight on their disease.
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Affiliation(s)
- Trisha Lal
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Zu-Xi Yu
- Pathology Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Bin Guan
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Chelsea Bender
- Ophthalmic Genetics Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Chi-Chao Chan
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Catherine A Cukras
- Unit on Clinical Investigation of Retinal Diseases, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
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The effect of retinal scaffold modulus on performance during surgical handling. Exp Eye Res 2021; 207:108566. [PMID: 33838142 DOI: 10.1016/j.exer.2021.108566] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/19/2021] [Accepted: 03/30/2021] [Indexed: 02/02/2023]
Abstract
Emerging treatment strategies for retinal degeneration involve replacing lost photoreceptors using supportive scaffolds to ensure cells survive the implantation process. While many design aspects of these scaffolds, including material chemistry and microstructural cues, have been studied in depth, a full set of design constraints has yet to be established. For example, while known to be important in other tissues and systems, the influence of mechanical properties on surgical handling has not been quantified. In this study, photocrosslinked poly(ethylene glycol) dimethacrylate (PEGDMA) was used as a model polymer to study the effects of scaffold modulus (stiffness) on surgical handling, independent of material chemistry. This was achieved by modulating the molecular weight and concentrations of the PEGDMA in various prepolymer solutions. Scaffold modulus of each formulation was measured using photo-rheology, which enabled the collection of real-time polymerization data. In addition to measuring scaffold mechanical properties, this approach gave insight on polymerization kinetics, which were used to determine the polymerization time required for each sample. Scaffold handling characteristics were qualitatively evaluated using both in vitro and ex vivo trials that mimicked the surgical procedure. In these trials, scaffolds with shear moduli above 35 kPa performed satisfactorily, while those below this limit performed poorly. In other words, scaffolds below this modulus were too fragile for reliable transplantation. To better compare these results with literature values, the compressive modulus was measured for select samples, with the lower shear modulus limit corresponding to roughly 115 kPa compressive modulus. While an upper mechanical property limit was not readily apparent from these results, there was increased variability in surgical handling performance in samples with shear moduli above 800 kPa. Overall, the knowledge presented here provides important groundwork for future studies designed to examine additional retinal scaffold considerations, including the effect of scaffold mechanical properties on retinal progenitor cell fate.
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Ruiz-Alonso S, Villate-Beitia I, Gallego I, Lafuente-Merchan M, Puras G, Saenz-del-Burgo L, Pedraz JL. Current Insights Into 3D Bioprinting: An Advanced Approach for Eye Tissue Regeneration. Pharmaceutics 2021; 13:pharmaceutics13030308. [PMID: 33653003 PMCID: PMC7996883 DOI: 10.3390/pharmaceutics13030308] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 12/19/2022] Open
Abstract
Three-dimensional (3D) printing is a game changer technology that holds great promise for a wide variety of biomedical applications, including ophthalmology. Through this emerging technique, specific eye tissues can be custom-fabricated in a flexible and automated way, incorporating different cell types and biomaterials in precise anatomical 3D geometries. However, and despite the great progress and possibilities generated in recent years, there are still challenges to overcome that jeopardize its clinical application in regular practice. The main goal of this review is to provide an in-depth understanding of the current status and implementation of 3D bioprinting technology in the ophthalmology field in order to manufacture relevant tissues such as cornea, retina and conjunctiva. Special attention is paid to the description of the most commonly employed bioprinting methods, and the most relevant eye tissue engineering studies performed by 3D bioprinting technology at preclinical level. In addition, other relevant issues related to use of 3D bioprinting for ocular drug delivery, as well as both ethical and regulatory aspects, are analyzed. Through this review, we aim to raise awareness among the research community and report recent advances and future directions in order to apply this advanced therapy in the eye tissue regeneration field.
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Affiliation(s)
- Sandra Ruiz-Alonso
- NanoBioCel Research Group, Laboratory of Pharmacy and Pharmaceutical Technology, Department of Pharmacy and Food Science, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain; (S.R.-A.); (I.V.-B.); (I.G.); (M.L.-M.); (G.P.)
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Institute of Health Carlos III, 28029 Madrid, Spain
- Bioaraba, NanoBioCel Research Group, 01009 Vitoria-Gasteiz, Spain
| | - Ilia Villate-Beitia
- NanoBioCel Research Group, Laboratory of Pharmacy and Pharmaceutical Technology, Department of Pharmacy and Food Science, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain; (S.R.-A.); (I.V.-B.); (I.G.); (M.L.-M.); (G.P.)
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Institute of Health Carlos III, 28029 Madrid, Spain
- Bioaraba, NanoBioCel Research Group, 01009 Vitoria-Gasteiz, Spain
| | - Idoia Gallego
- NanoBioCel Research Group, Laboratory of Pharmacy and Pharmaceutical Technology, Department of Pharmacy and Food Science, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain; (S.R.-A.); (I.V.-B.); (I.G.); (M.L.-M.); (G.P.)
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Institute of Health Carlos III, 28029 Madrid, Spain
- Bioaraba, NanoBioCel Research Group, 01009 Vitoria-Gasteiz, Spain
| | - Markel Lafuente-Merchan
- NanoBioCel Research Group, Laboratory of Pharmacy and Pharmaceutical Technology, Department of Pharmacy and Food Science, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain; (S.R.-A.); (I.V.-B.); (I.G.); (M.L.-M.); (G.P.)
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Institute of Health Carlos III, 28029 Madrid, Spain
- Bioaraba, NanoBioCel Research Group, 01009 Vitoria-Gasteiz, Spain
| | - Gustavo Puras
- NanoBioCel Research Group, Laboratory of Pharmacy and Pharmaceutical Technology, Department of Pharmacy and Food Science, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain; (S.R.-A.); (I.V.-B.); (I.G.); (M.L.-M.); (G.P.)
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Institute of Health Carlos III, 28029 Madrid, Spain
- Bioaraba, NanoBioCel Research Group, 01009 Vitoria-Gasteiz, Spain
| | - Laura Saenz-del-Burgo
- NanoBioCel Research Group, Laboratory of Pharmacy and Pharmaceutical Technology, Department of Pharmacy and Food Science, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain; (S.R.-A.); (I.V.-B.); (I.G.); (M.L.-M.); (G.P.)
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Institute of Health Carlos III, 28029 Madrid, Spain
- Bioaraba, NanoBioCel Research Group, 01009 Vitoria-Gasteiz, Spain
- Correspondence: (L.S.-d.-B.); (J.L.P.); Tel.: +(34)-945014542 (L.S.-d.-B.); +(34)-945013091 (J.L.P.)
| | - José Luis Pedraz
- NanoBioCel Research Group, Laboratory of Pharmacy and Pharmaceutical Technology, Department of Pharmacy and Food Science, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain; (S.R.-A.); (I.V.-B.); (I.G.); (M.L.-M.); (G.P.)
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Institute of Health Carlos III, 28029 Madrid, Spain
- Bioaraba, NanoBioCel Research Group, 01009 Vitoria-Gasteiz, Spain
- Correspondence: (L.S.-d.-B.); (J.L.P.); Tel.: +(34)-945014542 (L.S.-d.-B.); +(34)-945013091 (J.L.P.)
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Mucciolo DP, Lippera M, Giorgio D, Sodi A, Passerini I, Cipollini F, Virgili G, Giansanti F, Murro V. Outer nuclear layer relevance in visual function correlated to quantitative enface OCT parameters in Stargardt disease. Eur J Ophthalmol 2021; 31:3248-3258. [PMID: 33508977 DOI: 10.1177/1120672121990579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To evaluate the correlation between Best Corrected Visual Acuity (BCVA) and the following parameters in Stargardt Disease (STGD): Central Retinal Thickness (CR-T), Central Outer Nuclear Layer Thickness (C-ONL-T), Areas of macular Photoreceptor loss (PHRa), and Retinal Pigment Epithelium (RPE) loss (RPEa). METHODS A total of 64 eyes of 32 STGD patients were included in the study. All patients received a comprehensive ophthalmological examination, color fundus photographs, fundus auto-fluorescence imaging, and Optical Coherence Tomography (OCT). The CR-T and C-ONL-T were evaluated from standard SD-OCT scans. The PHRa and RPEa were calculated from enface OCT scans (sub RPE slab and photoreceptor slab). The collected OCT parameters were evaluated for possible association with BCVA. RESULTS The mean macular PHRa and RPEa was 16.16 ± 13.36 and 12.05 ± 12.57 mm2 respectively. The mean CR-T measured 120.78 ± 41.49 μm while the mean C-ONL-T was assessed at 4.60 ± 13.73 μm. BCVA showed the highest correlation with the C-ONL-T (r = -0.72; p < 0.001) while there was no correlation with the CR-T (r = -0.17; p = 1.00). CONCLUSIONS Enface OCT permits a rapid and precise quantitative evaluation of the macular PHR and RPE atrophy area in STGD. Nonetheless, the OCT parameter that showed the highest correlation with visual acuity in STGD was the ONL thickness.
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Affiliation(s)
- Dario Pasquale Mucciolo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Myrta Lippera
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Dario Giorgio
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Andrea Sodi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Francesca Cipollini
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Gianni Virgili
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Fabrizio Giansanti
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
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14
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Elsner AE, Papay JA, Johnston KD, Sawides L, de Castro A, King BJ, Jones DW, Clark CA, Gast TJ, Burns SA. Cones in ageing and harsh environments: the neural economy hypothesis. Ophthalmic Physiol Opt 2020; 40:88-116. [PMID: 32017191 PMCID: PMC7155023 DOI: 10.1111/opo.12670] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/31/2019] [Indexed: 01/22/2023]
Abstract
PURPOSE Cones are at great risk in a wide variety of retinal diseases, especially when there is a harsh microenvironment and retinal pigment epithelium is damaged. We provide established and new methods for assessing cones and retinal pigment epithelium, together with new results. We investigated conditions under which cones can be imaged and could guide light, despite the proximity of less than ideal retinal pigment epithelium. RECENT FINDINGS We used a variety of imaging methods to detect and localise damage to the retinal pigment epithelium. As age-related macular degeneration is a particularly widespread disease, we imaged clinical hallmarks: drusen and hyperpigmentation. Using near infrared light provided improved imaging of the deeper fundus layers. We compared confocal and multiply scattered light images, using both the variation of detection apertures and polarisation analysis. We used optical coherence tomography to examine distances between structures and thickness of retinal layers, as well as identifying damage to the retinal pigment epithelium. We counted cones using adaptive optics scanning laser ophthalmoscopy. We compared the results of five subjects with geographic atrophy to data from a previous normative ageing study. Using near infrared imaging and layer analysis of optical coherence tomography, the widespread aspect of drusen became evident. Both multiply scattered light imaging and analysis of the volume in the retinal pigment epithelial layer from the optical coherence tomography were effective in localising drusen and hyperpigmentation beneath the photoreceptors. Cone photoreceptors in normal older eyes were shorter than in younger eyes. Cone photoreceptors survived in regions of atrophy, but with greatly reduced and highly variable density. Regular arrays of cones were found in some locations, despite abnormal retinal pigment epithelium. For some subjects, the cone density was significantly greater than normative values in some retinal locations outside the atrophy. SUMMARY The survival of cones within atrophy is remarkable. The unusually dense packing of cones at some retinal locations outside the atrophy indicates more fluidity in cone distribution than typically thought. Together these findings suggest strategies for therapy that includes preserving cones.
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15
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Abstract
SIGNIFICANCE The pathological changes in clinically significant diabetic macular edema lead to greater retinal thickening in men than in women. Therefore, male sex should be considered a potential risk factor for identifying individuals with the most severe pathological changes. Understanding this excessive retinal thickening in men may help preserve vision. PURPOSE The purpose of this study was to investigate the sex differences in retinal thickness in diabetic patients. We tested whether men with clinically significant macular edema had even greater central macular thickness than expected from sex differences without significant pathological changes. This study also aimed to determine which retinal layers contribute to abnormal retinal thickness. METHODS From 2047 underserved adult diabetic patients from Alameda County, CA, 142 patients with clinically significant macular edema were identified by EyePACS-certified graders using color fundus images (Canon CR6-45NM). First, central macular thickness from spectral domain optical coherence tomography (iVue; Optovue Inc.) was compared in 21 men versus 21 women without clinically significant macular edema. Then, a planned comparison contrasted the greater values of central macular thickness in men versus women with clinically significant macular edema as compared with those without. Mean retinal thickness and variability of central macular layers were compared in men versus women. RESULTS Men without clinically significant macular edema had a 12-μm greater central macular thickness than did women (245 ± 21.3 and 233 ± 13.4 μm, respectively; t40 = -2.18, P = .04). Men with clinically significant macular edema had a 67-μm greater central macular thickness than did women (383 ± 48.7 and 316 ± 60.4 μm, P < .001); that is, men had 55 μm or more than five times more (t20 = 2.35, P = .02). In men, the outer-nuclear-layer thickness was more variable, F10,10 = 9.34. CONCLUSIONS Underserved diabetic men had thicker retinas than did women, exacerbated by clinically significant macular edema.
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16
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Minami S, Nagai N, Suzuki M, Kurihara T, Sonobe H, Watanabe K, Shinoda H, Takagi H, Tsubota K, Ozawa Y. Spatial-sweep steady-state pattern electroretinography can detect subtle differences in visual function among healthy adults. Sci Rep 2019; 9:18119. [PMID: 31792280 PMCID: PMC6889279 DOI: 10.1038/s41598-019-54606-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/18/2019] [Indexed: 11/29/2022] Open
Abstract
We aimed to establish a highly sensitive method for measuring visual function using spatial-sweep steady-state pattern electroretinography (swpPERG). Overall, 35 eyes of 35 healthy adults (18 men; mean age, 32.3 years) were examined using swpPERG, and the data were recorded using spatial-patterned and contrast-reversed stimuli of size 1 (thickest) to 6. Data were converted into frequency-domain using a Fourier transform and expressed by signal-to-noise ratio (SNR). The number of participants who showed SNR ≥ 1 was significantly lesser at stimulus sizes 5 and 6 compared with those at greater stimulus sizes. Among the data with SNR ≥ 1, SNRs were negatively correlated with age at stimulus size 5 (r = −0.500, P = 0.029), and positively correlated with macular volume evaluated by optical coherence tomography (OCT) within a 6-mm circle diameter from the fovea of the retinal nerve fibre layer at size 4 (r = 0.409, P = 0.025) and of the ganglion cell layer at size 5 (r = 0.567, P = 0.011). We found that SNRs of swpPERG, recorded using the EvokeDx system, were correlated with age and macular morphology in participants without diagnosed eye diseases. The system detected subtle differences in retinal function, which may help in early disease diagnosis and visual evaluation in neuroprotective interventions in the future.
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Affiliation(s)
- Sakiko Minami
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.,Department of Ophthalmology, Inagi Municipal Hospital, Tokyo, Japan.,Department of Ophthalmology, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Norihiro Nagai
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.,Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University, School of Medicine, Tokyo, Japan
| | - Misa Suzuki
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.,Department of Ophthalmology, Yokohama City University, Yokohama, Japan
| | - Toshihide Kurihara
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Hideki Sonobe
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Kazuhiro Watanabe
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Hajime Shinoda
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Hitoshi Takagi
- Department of Ophthalmology, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Yoko Ozawa
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. .,Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University, School of Medicine, Tokyo, Japan.
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17
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Mastey RR, Gaffney M, Litts KM, Langlo CS, Patterson EJ, Strampe MR, Kalitzeos A, Michaelides M, Carroll J. Assessing the Interocular Symmetry of Foveal Outer Nuclear Layer Thickness in Achromatopsia. Transl Vis Sci Technol 2019; 8:21. [PMID: 31602346 PMCID: PMC6779097 DOI: 10.1167/tvst.8.5.21] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/12/2019] [Indexed: 02/02/2023] Open
Abstract
Purpose We examine the interocular symmetry of foveal outer nuclear layer (ONL) thickness measurements in subjects with achromatopsia (ACHM). Methods Images from 76 subjects with CNGA3- or CNGB3-associated ACHM and 42 control subjects were included in the study. Line or volume scans through the fovea of each eye were acquired using optical coherence tomography (OCT). Image quality was assessed for each image included in the analysis using a previously-described maximum tissue contrast index (mTCI) metric. Three foveal ONL thickness measurements were made by a single observer and interocular symmetry was assessed using the average of the three measurements for each eye. Results Mean (± standard deviation) foveal ONL thickness for subjects with ACHM was 79.7 ± 18.3 μm (right eye) and 79.2 ± 18.7 μm (left eye) compared to 112.9 ± 15.2 (right eye) and 112.1 ± 13.9 μm (left eye) for controls. Foveal ONL thickness did not differ between eyes for ACHM (P = 0.636) or control subjects (P = 0.434). No significant relationship between mTCI and observer repeatability was observed for either control (P = 0.140) or ACHM (P = 0.351) images. Conclusions While foveal ONL thickness is reduced in ACHM compared to controls, the high interocular symmetry indicates that contralateral ONL measurements could be used as a negative control in early-phase monocular treatment trials. Translational Relevance Foveal ONL thickness can be measured using OCT images over a wide range of image quality. The interocular symmetry of foveal ONL thickness in ACHM and control populations supports the use of the non-study eye as a control for clinical trial purposes.
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Affiliation(s)
- Rebecca R Mastey
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mina Gaffney
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Katie M Litts
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christopher S Langlo
- Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Emily J Patterson
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Margaret R Strampe
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,University of Minnesota Medical School, Minneapolis, MN, USA
| | - Angelos Kalitzeos
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.,Moorfields Eye Hospital, London, EC1V 2PD, UK
| | - Michel Michaelides
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.,Moorfields Eye Hospital, London, EC1V 2PD, UK
| | - Joseph Carroll
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
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18
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Foote KG, De la Huerta I, Gustafson K, Baldwin A, Zayit-Soudry S, Rinella N, Porco TC, Roorda A, Duncan JL. Cone Spacing Correlates With Retinal Thickness and Microperimetry in Patients With Inherited Retinal Degenerations. Invest Ophthalmol Vis Sci 2019; 60:1234-1243. [PMID: 30924848 PMCID: PMC6440525 DOI: 10.1167/iovs.18-25688] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine whether high-resolution retinal imaging measures of macular structure correlate with visual function over 36 months in retinal degeneration (RD) patients and normal subjects. Methods Twenty-six eyes of 16 RD patients and 16 eyes of 8 normal subjects were studied at baseline; 15 eyes (14 RD) and 11 eyes (6 normal) were studied 36 months later. Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) was used to identify regions of interest (ROIs) with unambiguous cones at baseline to measure cone spacing. AOSLO images were aligned with spectral-domain optical coherence tomography (SD-OCT) and fundus-guided microperimetry results to correlate structure and function at the ROIs. SD-OCT images were segmented to measure inner segment (IS) and outer segment (OS) thickness. Correlations between cone spacing, IS and OS thickness and sensitivity were assessed using Spearman correlation coefficient ρ with bootstrap analyses clustered by person. Results Cone spacing (ρ = 0.57, P < 0.001) and macular sensitivity (ρ = 0.19, P = 0.14) were significantly correlated with eccentricity in patients. Controlling for eccentricity, cone spacing Z-scores were inversely correlated with IS (ρ = −0.29, P = 0.002) and OS thickness (ρ = −0.39, P < 0.001) in RD patients only, and with sensitivity in normal subjects (ρ = −0.22, P < 0.001) and RD patients (ρ = −0.38, P < 0.001). After 36 months, cone spacing increased (P < 0.001) and macular sensitivity decreased (P = 0.007) compared to baseline in RD patients. Conclusions Cone spacing increased and macular sensitivity declined significantly in RD patients over 36 months. High resolution images of cone structure correlated with retinal sensitivity, and may be appropriate outcome measures for clinical trials in RD.
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Affiliation(s)
- Katharina G Foote
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States.,Ophthalmology, University of California, San Francisco, California, United States
| | - Irina De la Huerta
- Ophthalmology, University of California, San Francisco, California, United States
| | - Kevin Gustafson
- Ophthalmology, University of California, San Francisco, California, United States
| | - Angela Baldwin
- Ophthalmology, University of California, San Francisco, California, United States
| | - Shiri Zayit-Soudry
- Ophthalmology, University of California, San Francisco, California, United States
| | - Nicholas Rinella
- Ophthalmology, University of California, San Francisco, California, United States
| | - Travis C Porco
- Ophthalmology, University of California, San Francisco, California, United States.,Francis I. Proctor Foundation, University of California, San Francisco, California, United States
| | - Austin Roorda
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States
| | - Jacque L Duncan
- Ophthalmology, University of California, San Francisco, California, United States
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19
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Thompson JR, Worthington KS, Green BJ, Mullin NK, Jiao C, Kaalberg EE, Wiley LA, Han IC, Russell SR, Sohn EH, Guymon CA, Mullins RF, Stone EM, Tucker BA. Two-photon polymerized poly(caprolactone) retinal cell delivery scaffolds and their systemic and retinal biocompatibility. Acta Biomater 2019; 94:204-218. [PMID: 31055121 DOI: 10.1016/j.actbio.2019.04.057] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/23/2019] [Accepted: 04/26/2019] [Indexed: 01/01/2023]
Abstract
Cell replacement therapies are often enhanced by utilizing polymer scaffolds to improve retention or direct cell orientation and migration. Obstacles to refinement of such polymer scaffolds often include challenges in controlling the microstructure of biocompatible molecules in three dimensions at cellular scales. Two-photon polymerization of acrylated poly(caprolactone) (PCL) could offer a means of achieving precise microstructural control of a material in a biocompatible platform. In this work, we studied the effect of various formulation and two-photon polymerization parameters on minimum laser power needed to achieve polymerization, resolution, and fidelity to a target 3D model designed to be used for retinal cell replacement. Overall, we found that increasing the concentration of crosslink-able groups decreased polymerization threshold and the size of resolvable features while increasing fidelity of the scaffold to the 3D model. In general, this improvement was achieved by increasing the number of acrylate groups per prepolymer molecule, increasing the acrylated PCL concentration, or decreasing its molecular weight. Resulting two-photon polymerized PCL scaffolds successfully supported human iPSC derived retinal progenitor cells in vitro. Sub-retinal implantation of cell free scaffolds in a porcine model of retinitis pigmentosa did not cause inflammation, infection or local or systemic toxicity after one month. In addition, comprehensive ISO 10993 testing of photopolymerized scaffolds revealed a favorable biocompatibility profile. These results represent an important step towards understanding how two-photon polymerization can be applied to a wide range of biologically compatible chemistries for various biomedical applications. STATEMENT OF SIGNIFICANCE: Inherited retinal degenerative blindness results from the death of light sensing photoreceptor cells. To restore high-acuity vision a photoreceptor cell replacement strategy will likely be necessary. Unfortunately, single cell injection typically results in poor cell survival and integration post-transplantation. Polymeric biomaterial cell delivery scaffolds can be used to promote donor cell viability, control cellular polarity and increase packing density. A challenge faced in this endeavor has been developing methods suitable for generating scaffolds that can be used to deliver stem cell derived photoreceptors in an ordered columnar orientation (i.e., similar to that of the native retina). In this study we combined the biomaterial poly(caprolactone) with two-photon lithography to generate a biocompatible, clinically relevant scaffold suitable for retina cell delivery.
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Affiliation(s)
- Jessica R Thompson
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA; Roy J. Carver Department of Biomedical Engineering, The University of Iowa, 5601 Seamans Center, Iowa City, IA 52242, USA
| | - Kristan S Worthington
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA; Roy J. Carver Department of Biomedical Engineering, The University of Iowa, 5601 Seamans Center, Iowa City, IA 52242, USA
| | - Brian J Green
- Department of Chemical and Biochemical Engineering, The University of Iowa, 4133 Seamans Center, Iowa City, IA 52242, USA
| | - Nathaniel K Mullin
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Chunhua Jiao
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Emily E Kaalberg
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Luke A Wiley
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Ian C Han
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Stephen R Russell
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Elliott H Sohn
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - C Allan Guymon
- Department of Chemical and Biochemical Engineering, The University of Iowa, 4133 Seamans Center, Iowa City, IA 52242, USA
| | - Robert F Mullins
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Edwin M Stone
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA
| | - Budd A Tucker
- Institute for Vision Research, Department of Ophthalmology and Visual Science, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, Iowa City, IA 52242, USA.
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20
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Bensinger E, Rinella N, Saud A, Loumou P, Ratnam K, Griffin S, Qin J, Porco TC, Roorda A, Duncan JL. Loss of Foveal Cone Structure Precedes Loss of Visual Acuity in Patients With Rod-Cone Degeneration. Invest Ophthalmol Vis Sci 2019; 60:3187-3196. [PMID: 31335944 PMCID: PMC6657704 DOI: 10.1167/iovs.18-26245] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 06/13/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To assess the relationship between cone spacing and visual acuity in eyes with rod-cone degeneration (RCD) followed longitudinally. Methods High-resolution images of the retina were obtained using adaptive optics scanning laser ophthalmoscopy from 13 eyes of nine RCD patients and 13 eyes of eight healthy subjects at two sessions separated by 10 or more months (mean 765 days, range 311-1935 days). Cone spacing Z-score measured as close as possible (average <0.25°) to the preferred retinal locus was compared with visual acuity (letters read on the Early Treatment of Diabetic Retinopathy Study [ETDRS] chart and logMAR) and foveal sensitivity. Results Cone spacing was significantly correlated with ETDRS letters read (ρ = -0.47, 95%CI -0.67 to -0.24), logMAR (ρ = 0.46, 95%CI 0.24 to 0.66), and foveal sensitivity (ρ = -0.30, 95%CI -0.52 to -0.018). There was a small but significant increase in mean cone spacing Z-score during follow-up of +0.97 (95%CI 0.57 to 1.4) in RCD patients, but not in healthy eyes, and there was no significant change in any measure of visual acuity. Conclusions Cone spacing was correlated with visual acuity and foveal sensitivity. In RCD patients, cone spacing increased during follow-up, while visual acuity did not change significantly. Cone spacing Z-score may be a more sensitive measure of cone loss at the fovea than visual acuity in patients with RCD.
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Affiliation(s)
- Ethan Bensinger
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, California, United States
| | - Nicholas Rinella
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Asma Saud
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Panagiota Loumou
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Kavitha Ratnam
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, California, United States
| | - Shane Griffin
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Jia Qin
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Travis C. Porco
- Department of Ophthalmology, University of California, San Francisco, California, United States
- Proctor Foundation, Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Austin Roorda
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, California, United States
| | - Jacque L. Duncan
- Department of Ophthalmology, University of California, San Francisco, California, United States
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Georgiou M, Litts KM, Kalitzeos A, Langlo CS, Kane T, Singh N, Kassilian M, Hirji N, Kumaran N, Dubra A, Carroll J, Michaelides M. Adaptive Optics Retinal Imaging in CNGA3-Associated Achromatopsia: Retinal Characterization, Interocular Symmetry, and Intrafamilial Variability. Invest Ophthalmol Vis Sci 2019; 60:383-396. [PMID: 30682209 PMCID: PMC6354941 DOI: 10.1167/iovs.18-25880] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/21/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate retinal structure in subjects with CNGA3-associated achromatopsia and evaluate disease symmetry and intrafamilial variability. Methods Thirty-eight molecularly confirmed subjects underwent ocular examination, optical coherence tomography (OCT), and nonconfocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). OCT scans were used for evaluating foveal hypoplasia, grading foveal ellipsoid zone (EZ) disruption, and measuring outer nuclear layer (ONL) thickness. AOSLO images were used to quantify peak foveal cone density, intercell distance (ICD), and the coefficient of variation (CV) of ICD. Results Mean (±SD) age was 25.9 (±13.1) years. Mean (± SD) best corrected visual acuity (BCVA) was 0.87 (±0.14) logarithm of the minimum angle of resolution. Examination with OCT showed variable disruption or loss of the EZ. Seven subjects were evaluated for disease symmetry, with peak foveal cone density, ICD, CV, ONL thickness, and BCVA not differing significantly between eyes. A cross-sectional evaluation of AOSLO imaging showed a mean (±SD) peak foveal cone density of 19,844 (±13,046) cones/mm2. There was a weak negative association between age and peak foveal cone density (r = -0.397, P = 0.102), as well as between EZ grade and age (P = 0.086). Conclusions The remnant cone mosaics were irregular and variably disrupted, with significantly lower peak foveal cone density than unaffected individuals. Variability was also seen among subjects with identical mutations. Therefore, subjects should be considered on an individual basis for stratification in clinical trials. Interocular symmetry suggests that both eyes have comparable therapeutic potential and the fellow eye can serve as a valid control. Longitudinal studies are needed, to further examine the weak negative association between age and foveal cone structure observed here.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Katie M. Litts
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Christopher S. Langlo
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Melissa Kassilian
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Neruban Kumaran
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, California, United States
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
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22
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Burns SA, Elsner AE, Sapoznik KA, Warner RL, Gast TJ. Adaptive optics imaging of the human retina. Prog Retin Eye Res 2019; 68:1-30. [PMID: 30165239 PMCID: PMC6347528 DOI: 10.1016/j.preteyeres.2018.08.002] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 12/18/2022]
Abstract
Adaptive Optics (AO) retinal imaging has provided revolutionary tools to scientists and clinicians for studying retinal structure and function in the living eye. From animal models to clinical patients, AO imaging is changing the way scientists are approaching the study of the retina. By providing cellular and subcellular details without the need for histology, it is now possible to perform large scale studies as well as to understand how an individual retina changes over time. Because AO retinal imaging is non-invasive and when performed with near-IR wavelengths both safe and easily tolerated by patients, it holds promise for being incorporated into clinical trials providing cell specific approaches to monitoring diseases and therapeutic interventions. AO is being used to enhance the ability of OCT, fluorescence imaging, and reflectance imaging. By incorporating imaging that is sensitive to differences in the scattering properties of retinal tissue, it is especially sensitive to disease, which can drastically impact retinal tissue properties. This review examines human AO retinal imaging with a concentration on the use of the Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO). It first covers the background and the overall approaches to human AO retinal imaging, and the technology involved, and then concentrates on using AO retinal imaging to study the structure and function of the retina.
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Affiliation(s)
- Stephen A Burns
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States.
| | - Ann E Elsner
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Kaitlyn A Sapoznik
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Raymond L Warner
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Thomas J Gast
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
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23
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Lee DJ, Woertz EN, Visotcky A, Wilk MA, Heitkotter H, Linderman RE, Tarima S, Summers CG, Brooks BP, Brilliant MH, Antony BJ, Lujan BJ, Carroll J. The Henle Fiber Layer in Albinism: Comparison to Normal and Relationship to Outer Nuclear Layer Thickness and Foveal Cone Density. Invest Ophthalmol Vis Sci 2018; 59:5336-5348. [PMID: 30398625 PMCID: PMC6219160 DOI: 10.1167/iovs.18-24145] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/24/2018] [Indexed: 12/31/2022] Open
Abstract
Purpose Directional optical coherence tomography (D-OCT) allows the visualization of the Henle fiber layer (HFL) in vivo. Here, we used D-OCT to characterize the HFL and outer nuclear layer (ONL) in albinism and examine the relationship between true foveal ONL and peak cone density. Methods Horizontal D-OCT B-scans were acquired, registered, and averaged for 12 subjects with oculocutaneous albinism and 26 control subjects. Averaged images were manually segmented to extract HFL and ONL thickness. Adaptive optics scanning light ophthalmoscopy was used to acquire images of the foveal cone mosaic in 10 subjects with albinism, from which peak cone density was assessed. Results Across the foveal region, the HFL topography was different between subjects with albinism and normal controls. In particular, foveal HFL thickness was thicker in albinism than in normal controls (P < 0.0001), whereas foveal ONL thickness was thinner in albinism than in normal controls (P < 0.0001). The total HFL and ONL thickness was not significantly different between albinism and controls (P = 0.3169). Foveal ONL thickness was positively correlated with peak cone density in subjects with albinism (r = 0.8061, P = 0.0072). Conclusions Foveal HFL and ONL topography are significantly altered in albinism relative to normal controls. Our data suggest that increased foveal cone packing drives the formation of Henle fibers, more so than the lateral displacement of inner retinal neurons (which is reduced in albinism). The ability to quantify foveal ONL and HFL may help further stratify grading schemes used to assess foveal hypoplasia.
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Affiliation(s)
- Daniel J. Lee
- Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Erica N. Woertz
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Alexis Visotcky
- Division of Biostatistics, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Melissa A. Wilk
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, United States
| | - Heather Heitkotter
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Rachel E. Linderman
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Sergey Tarima
- Division of Biostatistics, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - C. Gail Summers
- Department of Ophthalmology & Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, United States
| | | | - Murray H. Brilliant
- Center for Human Genetics, Marshfield Clinic Research Institute, Marshfield, Wisconsin, United States
| | | | - Brandon J. Lujan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Joseph Carroll
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Papay JA, Elsner AE. Near-infrared polarimetric imaging and changes associated with normative aging. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2018; 35:1487-1495. [PMID: 30183002 PMCID: PMC6640646 DOI: 10.1364/josaa.35.001487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 07/10/2018] [Indexed: 05/20/2023]
Abstract
With aging, the human retina undergoes cell death and additional structural changes that can increase scattered light. We quantified the effect of normative aging on multiply scattered light returning from the human fundus. As expected, there was an increase of multiply scattered light associated with aging, and this is consistent with the histological changes that occur in the fundus of individuals before developing age-related macular degeneration. This increase in scattered light with aging cannot be attributed to retinal reflectivity, anterior segment scatter, or pupil diameter.
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Affiliation(s)
- Joel A. Papay
- School of Optometry, Indiana University, Bloomington, Indiana 47405, USA
| | - Ann E. Elsner
- School of Optometry, Indiana University, Bloomington, Indiana 47405, USA
- Corresponding author:
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25
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Tumahai P, Moureaux C, Meillat M, Debellemanière G, Flores M, Delbosc B, Saleh M. High-resolution imaging of photoreceptors in healthy human eyes using an adaptive optics retinal camera. Eye (Lond) 2018; 32:1723-1730. [PMID: 29993035 DOI: 10.1038/s41433-018-0140-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 01/21/2018] [Accepted: 02/19/2018] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To determine the effects of age on perifoveal cone density in healthy subjects using adaptive optics. METHODS Healthy subjects of various ages were imaged using an adaptive optics retinal camera (RTX-1® Imagine Eyes, Orsay, France). All patients underwent a comprehensive ophthalmologic examination and retinal imaging using spectral-domain optical coherence tomography (Spectralis®, Heidelberg Engineering, Heidelberg, Germany). Cone density together with cone spacing and cone mosaic packing were measured in the nasal and temporal area 450 µm from the fovea. A multivariate analysis was performed to determine which of the following parameters were related to a decrease in cone density: age, axial length, central macular thickness, and retrofoveal choroidal thickness. RESULTS One hundred and sixty-seven eyes of 101 subjects aged 6-78 years were studied. Perifoveal cone density significantly decreased with age (R2 = 0.17, p<0.01). Inversely, cone spacing increased with age (R2=0.18, p<0.01). There was no change in the cone packing mosaic (p>0.05). The mean coefficient of variation between fellow eyes was 3.9%. Age and axial length were related to a cone density decrease, while choroidal and retinal thicknesses did not affect cone metrics in healthy subjects. CONCLUSIONS A moderate perifoveal cone loss occurs with age. The precise consequences of these findings on visual function should be investigated. In addition to a better understanding of normal retinal anatomy, these results could act as a comparative database for further studies on normal and diseased retinas.
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Affiliation(s)
- P Tumahai
- Ophthalmology Department, University Hospital of Besançon, Besançon, Franche-Comté, France.
| | - C Moureaux
- Ophthalmology Department, University Hospital of Besançon, Besançon, Franche-Comté, France
| | - M Meillat
- Ophthalmology Department, University Hospital of Besançon, Besançon, Franche-Comté, France
| | - G Debellemanière
- Ophthalmology Department, University Hospital of Besançon, Besançon, Franche-Comté, France
| | - M Flores
- Ophthalmology Department, University Hospital of Besançon, Besançon, Franche-Comté, France
| | - B Delbosc
- Ophthalmology Department, University Hospital of Besançon, Besançon, Franche-Comté, France
| | - M Saleh
- Ophthalmology Department, University Hospital of Besançon, Besançon, Franche-Comté, France
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26
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McKendrick AM, Chan YM, Nguyen BN. Spatial vision in older adults: perceptual changes and neural bases. Ophthalmic Physiol Opt 2018; 38:363-375. [PMID: 29774576 DOI: 10.1111/opo.12565] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/27/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE The number of older adults is rapidly increasing internationally, leading to a significant increase in research on how healthy ageing impacts vision. Most clinical assessments of spatial vision involve simple detection (letter acuity, grating contrast sensitivity, perimetry). However, most natural visual environments are more spatially complicated, requiring contrast discrimination, and the delineation of object boundaries and contours, which are typically present on non-uniform backgrounds. In this review we discuss recent research that reports on the effects of normal ageing on these more complex visual functions, specifically in the context of recent neurophysiological studies. RECENT FINDINGS Recent research has concentrated on understanding the effects of healthy ageing on neural responses within the visual pathway in animal models. Such neurophysiological research has led to numerous, subsequently tested, hypotheses regarding the likely impact of healthy human ageing on specific aspects of spatial vision. SUMMARY Healthy normal ageing impacts significantly on spatial visual information processing from the retina through to visual cortex. Some human data validates that obtained from studies of animal physiology, however some findings indicate that rethinking of presumed neural substrates is required. Notably, not all spatial visual processes are altered by age. Healthy normal ageing impacts significantly on some spatial visual processes (in particular centre-surround tasks), but leaves contrast discrimination, contrast adaptation, and orientation discrimination relatively intact. The study of older adult vision contributes to knowledge of the brain mechanisms altered by the ageing process, can provide practical information regarding visual environments that older adults may find challenging, and may lead to new methods of assessing visual performance in clinical environments.
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Affiliation(s)
- Allison M McKendrick
- Department of Optometry & Vision Sciences, The University of Melbourne, Parkville, Australia
| | - Yu Man Chan
- Department of Optometry & Vision Sciences, The University of Melbourne, Parkville, Australia
| | - Bao N Nguyen
- Department of Optometry & Vision Sciences, The University of Melbourne, Parkville, Australia
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27
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Sajdak BS, Bell BA, Lewis TR, Luna G, Cornwell GS, Fisher SK, Merriman DK, Carroll J. Assessment of Outer Retinal Remodeling in the Hibernating 13-Lined Ground Squirrel. Invest Ophthalmol Vis Sci 2018; 59:2538-2547. [PMID: 29847661 PMCID: PMC5967598 DOI: 10.1167/iovs.17-23120] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 04/20/2018] [Indexed: 12/25/2022] Open
Abstract
Purpose We examined outer retinal remodeling of the euthermic and torpid cone-dominant 13-lined ground squirrel (13-LGS) retina using optical coherence tomography (OCT) imaging and histology. Methods Retinas and corneas of living 13-LGSs were imaged during euthermic and torpid physiological states using OCT. Retinal layer thickness was measured at the visual streak from registered and averaged vertical B-scans. Following OCT, some retinas were collected immediately for postmortem histologic comparison using light microscopy, immunofluorescence, or transmission electron microscopy. Results Compared to OCT images from euthermic retinae, OCT images of torpid retinae revealed significantly thicker inner and outer nuclear layers, as well as increases in the distances between outer retinal reflectivity bands 1 and 2, and bands 3 and 4. A significant decrease in the distance between bands 2 and 3 also was seen, alongside significant thinning of the choriocapillaris and choroid. OCT image quality was reduced in torpid eyes, partly due to significant thickening of the corneal stroma during this state. Conclusions The torpid retina of the hibernating 13-LGS undergoes structural changes that can be detected by OCT imaging. Comparisons between in vivo OCT and ex vivo histomorphometry may offer insight to the origin of hyperreflective OCT bands within the outer retina of the cone-dominant 13-LGS.
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Affiliation(s)
- Benjamin S. Sajdak
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Brent A. Bell
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States
| | - Tylor R. Lewis
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Gabriel Luna
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States
| | - Grayson S. Cornwell
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States
| | - Steven K. Fisher
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States
| | - Dana K. Merriman
- Biology & Microbiology, University of Wisconsin Oshkosh, Oshkosh, Wisconsin, United States
| | - Joseph Carroll
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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28
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Langlo CS, Erker LR, Parker M, Patterson EJ, Higgins BP, Summerfelt P, Razeen MM, Collison FT, Fishman GA, Kay CN, Zhang J, Weleber RG, Yang P, Pennesi ME, Lam BL, Chulay JD, Dubra A, Hauswirth WW, Wilson DJ, Carroll J. REPEATABILITY AND LONGITUDINAL ASSESSMENT OF FOVEAL CONE STRUCTURE IN CNGB3-ASSOCIATED ACHROMATOPSIA. Retina 2017; 37:1956-1966. [PMID: 28145975 PMCID: PMC5537050 DOI: 10.1097/iae.0000000000001434] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Congenital achromatopsia is an autosomal recessive disease causing substantial reduction or complete absence of cone function. Although believed to be a relatively stationary disorder, questions remain regarding the stability of cone structure over time. In this study, the authors sought to assess the repeatability of and examine longitudinal changes in measurements of central cone structure in patients with achromatopsia. METHODS Forty-one subjects with CNGB3-associated achromatopsia were imaged over a period of between 6 and 26 months using optical coherence tomography and adaptive optics scanning light ophthalmoscopy. Outer nuclear layer (ONL) thickness, ellipsoid zone (EZ) disruption, and peak foveal cone density were assessed. RESULTS ONL thickness increased slightly compared with baseline (0.184 μm/month, P = 0.02). The EZ grade remained unchanged for 34/41 subjects. Peak foveal cone density did not significantly change over time (mean change 1% per 6 months, P = 0.126). CONCLUSION Foveal cone structure showed little or no change in this group of subjects with CNGB3-associated achromatopsia. Over the time scales investigated (6-26 months), achromatopsia seems to be a structurally stable condition, although longer-term follow-up is needed. These data will be useful in assessing foveal cone structure after therapeutic intervention.
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Affiliation(s)
- Christopher S. Langlo
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Laura R. Erker
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Maria Parker
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Emily J. Patterson
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Brian P. Higgins
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Phyllis Summerfelt
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Moataz M. Razeen
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Alexandria Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Frederick T. Collison
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois
| | - Gerald A. Fishman
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois
| | | | - Jing Zhang
- Vitreo Retinal Associates, Gainesville, Florida
| | - Richard G. Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Paul Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida
| | | | - Alfredo Dubra
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | | | - David J. Wilson
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin; and
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Sawides L, Sapoznik KA, de Castro A, Walker BR, Gast TJ, Elsner AE, Burns SA. Alterations to the Foveal Cone Mosaic of Diabetic Patients. Invest Ophthalmol Vis Sci 2017; 58:3395-3403. [PMID: 28687853 PMCID: PMC5501497 DOI: 10.1167/iovs.17-21793] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Purpose We measured localized changes occurring in the foveal cone photoreceptors and related defects in the cone mosaic to alterations in the nearby retinal vasculature. Methods The central 4° of the retina of 54 diabetic (53.7 ± 12.5 years) and 85 control (35.8 ± 15.2 years) participants were imaged with the Indiana adaptive optics scanning laser ophthalmoscope. Foveal cones and overlying retinal capillaries were imaged and infrared scanning laser ophthalmoscopy (IR SLO) images and optical coherence tomography (OCT) B-scans were obtained. Follow-up imaging sessions were performed with intervals from 4 to 50 months for 22 of the 54 diabetic participants. Results The foveal cone mosaics of 49 of 54 diabetic participants were of sufficient quality to assess the absence or presence of small localized defects in the cone mosaic. In 13 of these 49 diabetic participants we found localized defects, visualized as sharp-edged areas of cones with diminished reflectivity. These small, localized areas ranged in size from 10 × 10 μm to 75 × 30 μm. Of these 13 participants with cone defects, 11 were imaged over periods from 4 to 50 months and the defects remained relatively stable. These dark regions were not shadows of overlying retinal vessels, but all participants with these localized defects had alterations in the juxtafoveal capillary network. Conclusions The foveal cone mosaic can show localized areas of dark cones that persist over time, that apparently correspond to either missing or nonreflecting cones, and may be related to local retinal ischemia.
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Affiliation(s)
- Lucie Sawides
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Kaitlyn A Sapoznik
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Alberto de Castro
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Brittany R Walker
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Thomas J Gast
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Ann E Elsner
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Stephen A Burns
- School of Optometry, Indiana University, Bloomington, Indiana, United States
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30
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Litts KM, Ach T, Hammack KM, Sloan KR, Zhang Y, Freund KB, Curcio CA. Quantitative Analysis of Outer Retinal Tubulation in Age-Related Macular Degeneration From Spectral-Domain Optical Coherence Tomography and Histology. Invest Ophthalmol Vis Sci 2017; 57:2647-56. [PMID: 27177321 PMCID: PMC4868096 DOI: 10.1167/iovs.16-19262] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose To assess outer retinal tubulation (ORT) morphology from spectral-domain optical coherence tomography (SD-OCT) volumes and donor eye histology, analyze ORT reflectivity, and estimate the number of cones surviving in ORT. Methods In SD-OCT volumes from nine patients with advanced AMD, ORT was analyzed en face and in B-scans. The hyperreflective ORT border in cross-section was delineated and surface area calculated. Reflectivity was compared between ORT types (Closed, Open, Forming, and Branching). A flatmount retina from a donor with neovascular AMD was labeled to visualize the external limiting membrane that delimits ORT and allow measurements of cross-sectional cone area, center-to-center cone spacing, and cone density. The number of cones surviving in ORT was estimated. Results By en face SD-OCT, ORT varies in complexity and shape. Outer retinal tubulation networks almost always contain Closed cross-sections. Spectral-domain OCT volumes containing almost exclusively Closed ORTs showed no significant direction-dependent differences in hyperreflective ORT border intensity. The surface areas of partial ORT assessed by SD-OCT volumes ranged from 0.16 to 1.76 mm2. From the flatmount retina, the average cross-sectional area of cone inner segments was 49.1 ± 7.9 μm2. The average cone spacing was 7.5 ± 0.6 μm. Outer retinal tubulation cone density was 20,351 cones/mm2. The estimated number of cones in ORT in a macula ranged from 26,399 to 186,833 cones, which is 6% to 44% of the cones present in a healthy macula. Conclusions These first estimates for cone density and number of cones surviving in ORT suggest that ORT formation considerably distorts the photoreceptor mosaic. Results provide additional insight into the reflectivity characteristics and number of ORT cones observable in living patients by SD-OCT, as cones persist and disease progresses.
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Affiliation(s)
- Katie M Litts
- Department of Ophthalmology University of Alabama School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States 2Vision Science Graduate Program, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Thomas Ach
- Department of Ophthalmology University of Alabama School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States 3Department of Ophthalmology, University Hospital Würzburg, Würzburg, Germany
| | - Kristen M Hammack
- Department of Ophthalmology University of Alabama School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States 4Department of Computer and Information Sciences, University of Alabama at Birmingham, Birmingham, Alabama, Unite
| | - Kenneth R Sloan
- Department of Ophthalmology University of Alabama School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States 4Department of Computer and Information Sciences, University of Alabama at Birmingham, Birmingham, Alabama, Unite
| | - Yuhua Zhang
- Department of Ophthalmology University of Alabama School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - K Bailey Freund
- Vitreous Retina Macula Consultants of New York, New York, New York, United States 6Department of Ophthalmology, New York University School of Medicine, New York, New York, United States
| | - Christine A Curcio
- Department of Ophthalmology University of Alabama School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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Worthington KS, Wiley LA, Kaalberg EE, Collins MM, Mullins RF, Stone EM, Tucker BA. Two-photon polymerization for production of human iPSC-derived retinal cell grafts. Acta Biomater 2017; 55:385-395. [PMID: 28351682 DOI: 10.1016/j.actbio.2017.03.039] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/15/2017] [Accepted: 03/24/2017] [Indexed: 11/16/2022]
Abstract
Recent advances in induced pluripotent stem cell (iPSC) technology have paved the way for the production of patient-specific neurons that are ideal for autologous cell replacement for treatment of neurodegenerative diseases. In the case of retinal degeneration and associated photoreceptor cell therapy, polymer scaffolds are critical for cellular survival and integration; however, prior attempts to materialize this concept have been unsuccessful in part due to the materials' inability to guide cell alignment. In this work, we used two-photon polymerization to create 180μm wide non-degradable prototype photoreceptor scaffolds with varying pore sizes, slicing distances, hatching distances and hatching types. Hatching distance and hatching type were significant factors for the error of vertical pore diameter, while slicing distance and hatching type most affected the integrity and geometry of horizontal pores. We optimized printing parameters in terms of structural integrity and printing time in order to create 1mm wide scaffolds for cell loading studies. We fabricated these larger structures directly on a porous membrane with 3µm diameter pores and seeded them with human iPSC-derived retinal progenitor cells. After two days in culture, cells nested in and extended neuronal processes parallel to the vertical pores of the scaffolds, with maximum cell loading occurring in 25μm diameter pores. These results highlight the feasibility of using this technique as part of an autologous stem cell strategy for restoring vision to patients affected with retinal degenerative diseases. STATEMENT OF SIGNIFICANCE Cell replacement therapy is an important goal for investigators aiming to restore neural function to those suffering from neurodegenerative disease. Cell delivery scaffolds are frequently necessary for the success of such treatments, but traditional biomaterials often fail to facilitate the neuronal orientation and close packing needed to recapitulate the in vivo environment. Here, we use two-photon polymerization to create prototype cell scaffolds with densely packed vertical pores for photoreceptor cell loading and small, interconnected horizontal pores for nutrient diffusion. This study offers a thorough characterization of how two-photon polymerization parameters affect final structural outcomes and printing time. Our findings demonstrate the feasibility of using two-photon polymerization to create scaffolds that can align neuronal cells in 3D and are large enough to be used for transplantation. In future work, these scaffolds could comprise biodegradable materials with tunable microstructure, elastic modulus and degradation time; a significant step towards a promising treatment option for those suffering from late-stage neurodegeneration, including retinal degenerative blindness.
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Affiliation(s)
- Kristan S Worthington
- Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, 375 Newton Road, Iowa City, IA 52242, USA.
| | - Luke A Wiley
- Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, 375 Newton Road, Iowa City, IA 52242, USA.
| | - Emily E Kaalberg
- Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, 375 Newton Road, Iowa City, IA 52242, USA.
| | - Malia M Collins
- Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, 375 Newton Road, Iowa City, IA 52242, USA.
| | - Robert F Mullins
- Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, 375 Newton Road, Iowa City, IA 52242, USA.
| | - Edwin M Stone
- Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, 375 Newton Road, Iowa City, IA 52242, USA.
| | - Budd A Tucker
- Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, 4111 Medical Education and Research Facility, 375 Newton Road, Iowa City, IA 52242, USA.
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Marcos S, Werner JS, Burns SA, Merigan WH, Artal P, Atchison DA, Hampson KM, Legras R, Lundstrom L, Yoon G, Carroll J, Choi SS, Doble N, Dubis AM, Dubra A, Elsner A, Jonnal R, Miller DT, Paques M, Smithson HE, Young LK, Zhang Y, Campbell M, Hunter J, Metha A, Palczewska G, Schallek J, Sincich LC. Vision science and adaptive optics, the state of the field. Vision Res 2017; 132:3-33. [PMID: 28212982 PMCID: PMC5437977 DOI: 10.1016/j.visres.2017.01.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 12/27/2022]
Abstract
Adaptive optics is a relatively new field, yet it is spreading rapidly and allows new questions to be asked about how the visual system is organized. The editors of this feature issue have posed a series of question to scientists involved in using adaptive optics in vision science. The questions are focused on three main areas. In the first we investigate the use of adaptive optics for psychophysical measurements of visual system function and for improving the optics of the eye. In the second, we look at the applications and impact of adaptive optics on retinal imaging and its promise for basic and applied research. In the third, we explore how adaptive optics is being used to improve our understanding of the neurophysiology of the visual system.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Yuhua Zhang
- University of Alabama at Birmingham, Birmingham, USA
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Distribution differences of macular cones measured by AOSLO: Variation in slope from fovea to periphery more pronounced than differences in total cones. Vision Res 2016; 132:62-68. [PMID: 27793592 DOI: 10.1016/j.visres.2016.06.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/22/2016] [Accepted: 06/28/2016] [Indexed: 11/23/2022]
Abstract
Large individual differences in cone densities occur even in healthy, young adults with low refractive error. We investigated whether cone density follows a simple model that some individuals have more cones, or whether individuals differ in both number and distribution of cones. We quantified cones in the eyes of 36 healthy young adults with low refractive error using a custom adaptive optics scanning laser ophthalmoscope. The average cone density in the temporal meridian was, for the mean±SD, 43,216±6039, 27,466±3496, 14,996±1563, and 12,207±1278cones/mm2 for 270, 630, 1480, and 2070μm from the foveal center. Cone densities at 630μm retinal eccentricity were uncorrelated to those at 2070μm, ruling out models with a constant or proportional relation of cone density to eccentricity. Subjects with high central macula cone densities had low peripheral cone densities. The cone density ratio (2070:630μm) was negatively correlated with cone density at 630μm, consistent with variations in the proportion of peripheral cones migrating towards the center. We modelled the total cones within a central radius of 7deg, using the temporal data and our published cone densities for temporal, nasal, superior, and inferior meridians. We computed an average of 221,000 cones. The coefficient of variation was 0.0767 for total cones, but higher for samples near the fovea. Individual differences occur both in total cones and other developmental factors related to cone distribution.
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Langlo CS, Patterson EJ, Higgins BP, Summerfelt P, Razeen MM, Erker LR, Parker M, Collison FT, Fishman GA, Kay CN, Zhang J, Weleber RG, Yang P, Wilson DJ, Pennesi ME, Lam BL, Chiang J, Chulay JD, Dubra A, Hauswirth WW, Carroll J. Residual Foveal Cone Structure in CNGB3-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2016; 57:3984-95. [PMID: 27479814 PMCID: PMC4978151 DOI: 10.1167/iovs.16-19313] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 06/13/2016] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Congenital achromatopsia (ACHM) is an autosomal recessive disorder in which cone function is absent or severely reduced. Gene therapy in animal models of ACHM have shown restoration of cone function, though translation of these results to humans relies, in part, on the presence of viable cone photoreceptors at the time of treatment. Here, we characterized residual cone structure in subjects with CNGB3-associated ACHM. METHODS High-resolution imaging (optical coherence tomography [OCT] and adaptive optics scanning light ophthalmoscopy [AOSLO]) was performed in 51 subjects with CNGB3-associated ACHM. Peak cone density and inter-cone spacing at the fovea was measured using split-detection AOSLO. Foveal outer nuclear layer thickness was measured in OCT images, and the integrity of the photoreceptor layer was assessed using a previously published OCT grading scheme. RESULTS Analyzable images of the foveal cones were obtained in 26 of 51 subjects, with nystagmus representing the major obstacle to obtaining high-quality images. Peak foveal cone density ranged from 7,273 to 53,554 cones/mm2, significantly lower than normal (range, 84,733-234,391 cones/mm2), with the remnant cones being either contiguously or sparsely arranged. Peak cone density was correlated with OCT integrity grade; however, there was overlap of the density ranges between OCT grades. CONCLUSIONS The degree of residual foveal cone structure varies greatly among subjects with CNGB3-associated ACHM. Such measurements may be useful in estimating the therapeutic potential of a given retina, providing affected individuals and physicians with valuable information to more accurately assess the risk-benefit ratio as they consider enrolling in experimental gene therapy trials. (www.clinicaltrials.gov, NCT01846052.).
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Affiliation(s)
- Christopher S. Langlo
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Emily J. Patterson
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Brian P. Higgins
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Phyllis Summerfelt
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Moataz M. Razeen
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Alexandria Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Laura R. Erker
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Maria Parker
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Frederick T. Collison
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois, United States
| | - Gerald A. Fishman
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois, United States
| | | | - Jing Zhang
- Vitreoretinal Associates, Gainesville, Florida, United States
| | - Richard G. Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Paul Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - David J. Wilson
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - John Chiang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Jeffrey D. Chulay
- Applied Genetics Technologies Corporation (AGTC), Alachua, Florida, United States
| | - Alfredo Dubra
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | | | - Joseph Carroll
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - for the ACHM-001 Study Group
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Alexandria Faculty of Medicine, University of Alexandria, Alexandria, Egypt
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois, United States
- Vitreoretinal Associates, Gainesville, Florida, United States
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
- Applied Genetics Technologies Corporation (AGTC), Alachua, Florida, United States
- Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Ophthalmology, University of Florida, Gainesville, Florida, United States
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Subhi Y, Forshaw T, Sørensen TL. Macular thickness and volume in the elderly: A systematic review. Ageing Res Rev 2016; 29:42-9. [PMID: 27262495 DOI: 10.1016/j.arr.2016.05.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/30/2016] [Accepted: 05/31/2016] [Indexed: 12/22/2022]
Abstract
Ageing leads to a number of changes in the body including the macula. Detailed imaging using optical coherence tomography have enabled in vivo studies of how macula changes with age. Here we systematically review 49 studies (9115 participants and 11,577 eyes) to provide an overview of how ageing manifests in the macula of the elderly focusing on clinical relevant measures that are thicknesses and volumes of different macular areas. Ageing seems to increase center point foveal thickness. Ageing does not seem to change the center subfield thickness significantly. Ageing decreases the inner and outer macular thickness, and the overall macular thickness and volume. Studies find that specific retinal layers at specific locations seem to be the contributor to these changes. These findings confirm that age-related changes suggested in histological studies are measurable in vivo on thickness and volume and differ depending on location. Studies are needed to explore reasons for the large variance in measurements and how ageing by itself contributes to development of macular disease.
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Chui TYP, Mo S, Krawitz B, Menon NR, Choudhury N, Gan A, Razeen M, Shah N, Pinhas A, Rosen RB. Human retinal microvascular imaging using adaptive optics scanning light ophthalmoscopy. Int J Retina Vitreous 2016; 2:11. [PMID: 27847629 PMCID: PMC5088465 DOI: 10.1186/s40942-016-0037-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/21/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Retinal microvascular imaging is an especially promising application of high resolution imaging since there are increasing options for therapeutic intervention and need for better structural and functional biomarkers to characterize ocular and systemic vascular diseases. MAIN BODY Adaptive optics scanning light ophthalmoscopy (AOSLO) is an emerging technology for improving in vivo imaging of the human retinal microvasculature, allowing unprecedented visualization of retinal microvascular structure, measurements of blood flow velocity, and microvascular network mapping. This high resolution imaging technique shows significant potential for studying physiological and pathological conditions of the retinal microvasculature noninvasively. CONCLUSION This review will briefly summarize the abilities of in vivo human retinal microvasculature imaging in healthy controls, as well as patients with diabetic retinopathy, retinal vein occlusion, and sickle cell retinopathy using AOSLO and discuss its potential contribution to scientific research and clinical applications.
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Affiliation(s)
- Toco Y P Chui
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Shelley Mo
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Brian Krawitz
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Nikhil R Menon
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Nadim Choudhury
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Alexander Gan
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA
| | - Moataz Razeen
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Alexandria Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Nishit Shah
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA
| | - Alexander Pinhas
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Richard B Rosen
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY USA.,Icahn School of Medicine at Mount Sinai, New York, NY USA
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DIRECTIONAL OPTICAL COHERENCE TOMOGRAPHY PROVIDES ACCURATE OUTER NUCLEAR LAYER AND HENLE FIBER LAYER MEASUREMENTS. Retina 2016; 35:1511-20. [PMID: 25829348 DOI: 10.1097/iae.0000000000000527] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE The outer nuclear layer (ONL) contains photoreceptor nuclei, and its thickness is an important biomarker for retinal degenerations. Accurate ONL thickness measurements are obscured in standard optical coherence tomography (OCT) images because of Henle fiber layer (HFL). Improved differentiation of the ONL and HFL boundary is made possible by using directional OCT, a method that purposefully varies the pupil entrance position of the OCT beam. METHODS Fifty-seven normal eyes were imaged using multiple pupil entry positions with a commercial spectral domain OCT system. Cross-sectional image sets were registered to each other and segmented at the top of HFL, the border of HFL and the ONL and at the external limiting membrane. Thicknesses of the ONL and HFL were measured and analyzed. RESULTS The true ONL and HFL thicknesses varied substantially by eccentricity and between individuals. The true macular ONL thickness comprised an average of 54.6% of measurements that also included HFL. The ONL and HFL thicknesses at specific retinal eccentricities were poorly correlated. CONCLUSION Accurate ONL and HFL thickness measurements are made possible by the optical contrast of directional OCT. Distinguishing these individual layers can improve clinical trial endpoints and assessment of disease progression.
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Sharma R, Williams DR, Palczewska G, Palczewski K, Hunter JJ. Two-Photon Autofluorescence Imaging Reveals Cellular Structures Throughout the Retina of the Living Primate Eye. Invest Ophthalmol Vis Sci 2016; 57:632-46. [PMID: 26903224 PMCID: PMC4771181 DOI: 10.1167/iovs.15-17961] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 12/30/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Although extrinsic fluorophores can be introduced to label specific cell types in the retina, endogenous fluorophores, such as NAD(P)H, FAD, collagen, and others, are present in all retinal layers. These molecules are a potential source of optical contrast and can enable noninvasive visualization of all cellular layers. We used a two-photon fluorescence adaptive optics scanning light ophthalmoscope (TPF-AOSLO) to explore the native autofluorescence of various cell classes spanning several layers in the unlabeled retina of a living primate eye. METHODS Three macaques were imaged on separate occasions using a custom TPF-AOSLO. Two-photon fluorescence was evoked by pulsed light at 730 and 920 nm excitation wavelengths, while fluorescence emission was collected in the visible range from several retinal layers and different locations. Backscattered light was recorded simultaneously in confocal modality and images were postprocessed to remove eye motion. RESULTS All retinal layers yielded two-photon signals and the heterogeneous distribution of fluorophores provided optical contrast. Several structural features were observed, such as autofluorescence from vessel walls, Müller cell processes in the nerve fibers, mosaics of cells in the ganglion cell and other nuclear layers of the inner retina, as well as photoreceptor and RPE layers in the outer retina. CONCLUSIONS This in vivo survey of two-photon autofluorescence throughout the primate retina demonstrates a wider variety of structural detail in the living eye than is available through conventional imaging methods, and broadens the use of two-photon imaging of normal and diseased eyes.
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Affiliation(s)
- Robin Sharma
- The Institute of Optics, University of Rochester, Rochester, New York, United States
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - David R. Williams
- The Institute of Optics, University of Rochester, Rochester, New York, United States
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
| | | | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jennifer J. Hunter
- Center for Visual Science, University of Rochester, Rochester, New York, United States
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
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Towards an Analytical Age-Dependent Model of Contrast Sensitivity Functions for an Ageing Society. ScientificWorldJournal 2015; 2015:625034. [PMID: 26078994 PMCID: PMC4453283 DOI: 10.1155/2015/625034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/27/2015] [Indexed: 11/19/2022] Open
Abstract
The Contrast Sensitivity Function (CSF) describes how the visibility of a grating depends on the stimulus spatial frequency. Many published CSF data have demonstrated that contrast sensitivity declines with age. However, an age-dependent analytical model of the CSF is not available to date. In this paper, we propose such an analytical CSF model based on visual mechanisms, taking into account the age factor. To this end, we have extended an existing model from Barten (1999), taking into account the dependencies of this model's optical and physiological parameters on age. Age-dependent models of the cones and ganglion cells densities, the optical and neural MTF, and optical and neural noise are proposed, based on published data. The proposed age-dependent CSF is finally tested against available experimental data, with fair results. Such an age-dependent model may be beneficial when designing real-time age-dependent image coding and display applications.
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Marquioni-Ramella MD, Suburo AM. Photo-damage, photo-protection and age-related macular degeneration. Photochem Photobiol Sci 2015. [DOI: 10.1039/c5pp00188a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The course of Age-related Macular Degeneration (AMD) is described as the effect of light (400–580 nm) on various molecular targets in photoreceptors and the retinal pigment epithelium (RPE). Photo-damage is followed by inflammation, increasing oxidative stress and, probably, unveiling new photosensitive molecules.
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Affiliation(s)
| | - Angela M. Suburo
- Medicina Celular y Molecular
- Facultad de Ciencias Biomédicas
- Universidad Austral
- Pilar B1629AHJ
- Argentina
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Clark CA, Elsner AE, Konynenbelt BJ. Eye shape using partial coherence interferometry, autorefraction, and SD-OCT. Optom Vis Sci 2015; 92:115-22. [PMID: 25437906 PMCID: PMC4516166 DOI: 10.1097/opx.0000000000000453] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Peripheral refraction and retinal shape may influence refractive development. Peripheral refraction has been shown to have a high degree of variability and can take considerable time to perform. Spectral domain optical coherence tomography (SD-OCT) and peripheral axial length measures may be more reliable, assuming that the retinal position is more important than the peripheral optics of the lens/cornea. METHODS Seventy-nine subjects' right eyes were imaged for this study (age range, 22 to 34 years; refractive error, -10 to +5.00). Thirty-degree SD-OCT (Spectralis, Heidelberg Engineering, Heidelberg, Germany) images were collected in a radial pattern along with peripheral refraction with an autorefractor (Shin-Nippon Autorefractor) and peripheral axial length measurements with partial coherence interferometry (IOLMaster, Zeiss). Statistics were performed using repeated-measures analysis of variance in SPSS (IBM, Armonk, NY), Bland-Altman analyses, and regression. All measures were converted to diopters to allow direct comparison. RESULTS Spectral domain OCT showed a retinal shape with an increased curvature for myopes compared with emmetropes/hyperopes. This retinal shape change became significant around 5 degrees. The SD-OCT analysis for retinal shape provides a resolution of 0.026 diopters, which is about 10 times more accurate than using autorefraction (AR) or clinical refractive techniques. Bland-Altman analyses suggest that retinal shape measured by SD-OCT and the partial coherence interferometry method were more consistent with one another than either was with AR. CONCLUSIONS With more accurate measures of retinal shape using SD-OCT, consistent differences between emmetropes/hyperopes and myopes were found nearer to the fovea than previously reported. Retinal shape may be influenced by central refractive error, and not merely peripheral optics. Partial coherence interferometry and SD-OCT appear to be more accurate than AR, which may be influenced by other factors such as fixation and accommodation. Autorefraction does measure the optics directly, which may be a strength of that method.
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Affiliation(s)
- Christopher A Clark
- *OD †PhD, FAAO ‡BS Indiana University School of Optometry, Bloomington, Indiana (all authors)
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VanNasdale DA, Elsner AE, Peabody TD, Kohne KD, Malinovsky VE, Haggerty BP, Weber A, Clark CA, Burns SA. Henle fiber layer phase retardation changes associated with age-related macular degeneration. Invest Ophthalmol Vis Sci 2014; 56:284-90. [PMID: 25525166 DOI: 10.1167/iovs.14-14459] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To quantify and compare phase retardation amplitude and regularity associated with the Henle fiber layer (HFL) between nonexudative AMD patients and age-matched controls using scanning laser polarimetry (SLP) imaging. METHODS A scanning laser polarimeter was used to collect 15 × 15° macular-centered images in 25 patients with nonexudative AMD and 25 age-matched controls. Raw image data were used to compute macular phase retardation maps associated with the HFL. Consecutive, annular regions of interest from 0.5 to 3.0° eccentricity, centered on the fovea, were used to generate intensity profiles from phase retardation data and analyzed with two complementary techniques: a normalized second harmonic frequency (2f) of the fast Fourier Transform (FFT) analysis and a curve fitting analysis using a 2f sine function. Paired t-tests were used to compare the normalized 2f FFT magnitude at each eccentricity between the two groups, the eccentricity that yielded the maximum normalized 2f FFT between paired individuals across the two groups, and curve fitting RMS error at each eccentricity between the two groups. RESULTS Normalized 2f FFT components were lower in the AMD group at each eccentricity, with no difference between the two groups in the maximum normalized 2f FFT component eccentricity. The root-mean-square (RMS) error from curve fitting was significantly higher in the AMD group. CONCLUSIONS Phase retardation changes in the central macula indicate loss and/or structural alterations to central cone photoreceptors in nonexudative AMD patients. Scanning laser polarimetry imaging is a noninvasive method for quantifying cone photoreceptor changes associated with central macular disease.
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Affiliation(s)
- Dean A VanNasdale
- The Ohio State University College of Optometry, Columbus, Ohio, United States
| | - Ann E Elsner
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | - Todd D Peabody
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | - Kimberly D Kohne
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | | | - Bryan P Haggerty
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | - Anke Weber
- Aachen University Hospital, Aachen, Germany
| | | | - Stephen A Burns
- Indiana University School of Optometry, Bloomington, Indiana, United States
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Menghini M, Lujan BJ, Zayit-Soudry S, Syed R, Porco TC, Bayabo K, Carroll J, Roorda A, Duncan JL. Correlation of outer nuclear layer thickness with cone density values in patients with retinitis pigmentosa and healthy subjects. Invest Ophthalmol Vis Sci 2014; 56:372-81. [PMID: 25515570 DOI: 10.1167/iovs.14-15521] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We studied the correlation between outer nuclear layer (ONL) thickness and cone density in normal eyes and eyes with retinitis pigmentosa (RP). METHODS Spectral-domain optical coherence tomography (SD-OCT) scans were acquired using a displaced pupil entry position of the scanning beam to distinguish Henle's fiber layer from the ONL in 20 normal eyes (10 subjects) and 12 eyes with RP (7 patients). Cone photoreceptors were imaged using adaptive optics scanning laser ophthalmoscopy. The ONL thickness and cone density were measured at 0.5° intervals along the horizontal meridian through the fovea nasally and temporally. The ONL thickness and cone density were correlated using Spearman's rank correlation coefficient r. RESULTS Cone densities averaged over the central 6° were lower in eyes with RP than normal, but showed high variability in both groups. The ONL thickness and cone density were significantly correlated when all retinal eccentricities were combined (r = 0.74); the correlation for regions within 0.5° to 1.5° eccentricity was stronger (r = 0.67) than between 1.5° and 3.0° eccentricity (r = 0.23). Although cone densities were lower between 0.5° and 1.5° in eyes with RP, ONL thickness measures at identical retinal locations were similar in the two groups (P = 0.31), and interindividual variation was high for ONL and cone density measures. Although ONL thickness and retinal eccentricity were important predictors of cone density, eccentricity was over 3 times more important. CONCLUSIONS The ONL thickness and cone density were correlated in normal eyes and eyes with RP, but both were strongly correlated with retinal eccentricity, precluding estimation of cone density from ONL thickness. (ClinicalTrials.gov number, NCT00254605.).
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Affiliation(s)
- Moreno Menghini
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Brandon J Lujan
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States West Coast Retina Medical Group, San Francisco, California, United States
| | - Shiri Zayit-Soudry
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Reema Syed
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Travis C Porco
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California, United States F.I. Proctor Foundation for Research in Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Kristine Bayabo
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States
| | - Joseph Carroll
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Austin Roorda
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
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Chui TYP, VanNasdale DA, Elsner AE, Burns SA. The association between the foveal avascular zone and retinal thickness. Invest Ophthalmol Vis Sci 2014; 55:6870-7. [PMID: 25270194 DOI: 10.1167/iovs.14-15446] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate the association between the size and shape of the foveal avascular zone and retinal thickness in healthy subjects. METHODS In vivo imaging of the foveal microvasculature was performed on 32 subjects by using an adaptive optics scanning laser ophthalmoscope (AOSLO). Motion contrast maps of the AOSLO images were used to generate a montage revealing the foveal capillary network. Foveal avascular zone (FAZ) diameters along the horizontal (FAZH) and vertical (FAZV) meridians were measured on the montages. An asymmetry index (AI) of the FAZ was then computed as the ratio of the FAZH to FAZV. Retinal thickness was investigated by using spectral-domain optical coherence tomography (SDOCT). Inner retinal layer (INLFAZ) thickness and outer nuclear layer (ONLFAZ) thickness were measured at the edges of the FAZ on the horizontal and vertical SDOCT scans on the same eye. RESULTS The foveal capillary network was readily visualized in all subjects. As expected there was individual variation in the size and shape of the FAZ. Along the horizontal and vertical meridians, the mean±SD (μm) of the FAZ diameter was 607±217 and 574±155, respectively. The INLFAZ thickness was 68±9 and 66±9, and the ONLFAZ thickness was 103±13 and 105±11, respectively. The mean±SD of the AI was 1.03±0.27. The difference between FAZH and FAZV decreases with increasing FAZ area (P=0.004). Mean ONLFAZ was negatively correlated with FAZ effective diameter (P<0.0001). No significant correlation was found between mean INLFAZ and FAZ effective diameter (P=0.16). CONCLUSIONS Despite large individual variations in size and shape of the FAZ, the INLFAZ has a relatively constant thickness at the margins of the FAZ, suggesting the presence of retinal capillaries is needed to sustain an INLFAZ thickness greater than 60 μm. A smaller FAZ area is associated with a vertically elongated FAZ.
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Affiliation(s)
- Toco Y P Chui
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Dean A VanNasdale
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Ann E Elsner
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Stephen A Burns
- School of Optometry, Indiana University, Bloomington, Indiana, United States
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Obata R, Yanagi Y. Quantitative analysis of cone photoreceptor distribution and its relationship with axial length, age, and early age-related macular degeneration. PLoS One 2014; 9:e91873. [PMID: 24632778 PMCID: PMC3954804 DOI: 10.1371/journal.pone.0091873] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 02/17/2014] [Indexed: 11/19/2022] Open
Abstract
PURPOSE It has not been clarified whether early age-related macular degeneration (AMD) is associated with cone photoreceptor distribution. We used adaptive optics fundus camera to examine cone photoreceptors in the macular area of aged patients and quantitatively analyzed its relationship between the presence of early AMD and cone distribution. METHODS Sixty cases aged 50 or older were studied. The eyes were examined with funduscopy and spectral-domain optical coherence tomography to exclude the eyes with any abnormalities at two sites of measurement, 2° superior and 5° temporal to the fovea. High-resolution retinal images with cone photoreceptor mosaic were obtained with adaptive optics fundus camera (rtx1, Imagine Eyes, France). After adjusting for axial length, cone packing density was calculated and the relationship with age, axial length, or severity of early AMD based on the age-related eye disease study (AREDS) classification was analyzed. RESULTS Patient's age ranged from 50 to 77, and axial length from 21.7 to 27.5 mm. Mean density in metric units and that in angular units were 24,900 cells/mm2, 2,170 cells/deg2 at 2° superior, and 18,500 cells/mm2, 1,570 cels/deg2 at 5° temporal, respectively. Axial length was significantly correlated with the density calculated in metric units, but not with that in angular units. Age was significantly correlated with the density both in metric and angular units at 2° superior. There was no significant difference in the density in metric and angular units between the eyes with AREDS category one and those with categories two or three. CONCLUSION Axial length and age were significantly correlated with parafoveal cone photoreceptor distribution. The results do not support that early AMD might influence cone photoreceptor density in the area without drusen or pigment abnormalities.
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Affiliation(s)
- Ryo Obata
- Department of Ophthalmology, University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan
- * E-mail:
| | - Yasuo Yanagi
- Department of Ophthalmology, University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan
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