Publications by authors named "Joseph Carroll"

226 Publications

Pathognomonic macular ripples are revealed by polarized infrared retinal imaging.

Exp Biol Med (Maywood) 2021 Jul 7:15353702211021089. Epub 2021 Jul 7.

Department of Ophthalmology, University of Illinois at Chicago College of Medicine, Chicago, IL 60612, USA.

A pathognomonic macular ripple sign has been reported with scanning laser ophthalmoscopy images in patients with foveal hypoplasia, though the optical basis of this sign is presently unknown. Here we present a case series of seven individuals with foveal hypoplasia (based on spectral domain optical coherence tomography). Each patient underwent infrared scanning laser ophthalmoscopy retinal imaging in both eyes, acquired with and without a polarization filter and assessment for a ripple-like effect in the fovea. On imaging, macular ripples were present in all eyes with foveal hypoplasia when using a polarization filter, but not when imaged without the filter. We conclude that the macular ripple sign is an imaging artifact attributable to the unique pattern of phase retardation of the Henle fiber layer in the setting of foveal hypoplasia. By utilizing a polarization filter with retinal photography, this feature can be exploited to promptly identify foveal hypoplasia in settings where OCT is not possible due to nystagmus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/15353702211021089DOI Listing
July 2021

Optical Coherence Tomography Angiography in the Thirteen-Lined Ground Squirrel.

Transl Vis Sci Technol 2021 07;10(8)

Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.

Purpose: To assess the performance of two spectral-domain optical coherence tomography-angiography systems in a natural model of hypoperfusion: the hibernating thirteen-lined ground squirrel (13-LGS).

Methods: Using a high-speed (130 kHz) OCT-A system (HS-OCT-A) and a commercial OCT (36 kHz; Bioptigen Envisu; BE-OCT-A), we imaged the 13-LGS retina throughout its hibernation cycle. Custom software was used to extract the superior, middle, and deep capillary plexus (SCP, MCP, and DCP, respectively). The retinal vasculature was also imaged with adaptive optics scanning light ophthalmoscopy (AOSLO) during torpor to visualize individual blood cells. Finally, correlative histology with immunolabeled or DiI-stained vasculature was performed.

Results: During euthermia, vessel density was similar between devices for the SCP and MCP (P = 0.88, 0.72, respectively), with a small difference in the DCP (-1.63 ± 1.54%, P = 0.036). Apparent capillary dropout was observed during torpor, but recovered after forced arousal, and this effect was exaggerated in high-speed OCT-A imaging. Based on cell flux measurements with AOSLO, increasing OCT-A scan duration by ∼1000× would avoid the apparent capillary dropout artifact. High correspondence between OCT-A (during euthermia) and histology enabled lateral scale calibration.

Conclusions: While the HS-OCT-A system provides a more efficient workflow, the shorter interscan interval may render it more susceptible to the apparent capillary dropout artifact. Disambiguation between capillary dropout and transient ischemia can have important implications in the management of retinal disease and warrants additional diagnostics.

Translational Relevance: The 13-LGS provides a natural model of hypoperfusion that may prove valuable in modeling the utility of OCT-A in human pathologies associated with altered blood flow.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.10.8.5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8267221PMC
July 2021

Automated image processing pipeline for adaptive optics scanning light ophthalmoscopy.

Biomed Opt Express 2021 Jun 7;12(6):3142-3168. Epub 2021 May 7.

Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA.

To mitigate the substantial post-processing burden associated with adaptive optics scanning light ophthalmoscopy (AOSLO), we have developed an open-source, automated AOSLO image processing pipeline with both "live" and "full" modes. The live mode provides feedback during acquisition, while the full mode is intended to automatically integrate the copious disparate modules currently used in generating analyzable montages. The mean (±SD) lag between initiation and montage placement for the live pipeline was 54.6 ± 32.7s. The full pipeline reduced overall human operator time by 54.9 ± 28.4%, with no significant difference in resultant cone density metrics. The reduced overhead decreases both the technical burden and operating cost of AOSLO imaging, increasing overall clinical accessibility.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.418079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8221964PMC
June 2021

Retinal alterations in patients with Lafora disease.

Am J Ophthalmol Case Rep 2021 Sep 15;23:101146. Epub 2021 Jun 15.

Division of Neurology, Department of Pediatrics, University of Texas Southwestern, Dallas, TX, USA.

Purpose: Lafora disease is a genetic neurodegenerative metabolic disorder caused by insoluble polyglucosan aggregate accumulation throughout the central nervous system and body. The retina is an accessible neural tissue, which may offer alternative methods to assess neurological diseases quickly and noninvasively. In this way, noninvasive imaging may provide a means to characterize neurodegenerative disease, which enables earlier identification and diagnosis of disease and the ability to monitor disease progression. In this study, we sought to characterize the retina of individuals with Lafora disease using non-invasive retinal imaging.

Methods: One eye of three individuals with genetically confirmed Lafora disease were imaged with optical coherence tomography (OCT) and adaptive optics scanning light ophthalmoscopy (AOSLO). When possible, OCT volume and line scans were acquired to assess total retinal thickness, ganglion cell-inner plexiform layer thickness, and outer nuclear layer + Henle fiber layer thickness. OCT angiography (OCTA) scans were acquired in one subject at the macula and optic nerve head (ONH). AOSLO was used to characterize the photoreceptor mosaic and examine the retinal nerve fiber layer (RNFL).

Results: Two subjects with previous seizure activity demonstrated reduced retinal thickness, while one subject with no apparent symptoms had normal retinal thickness. All other clinical measures, as well as parafoveal cone density, were within normal range. Nummular reflectivity at the level of the RNFL was observed using AOSLO in the macula and near the ONH in all three subjects.

Conclusions: This multimodal retinal imaging approach allowed us to observe a number of retinal structural features in all three individuals. Most notably, AOSLO revealed nummular reflectivity within the inner retina of each subject. This phenotype has not been reported previously and may represent a characteristic change produced by the neurodegenerative process.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajoc.2021.101146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8239732PMC
September 2021

Electronic Cigarette-Related Injuries Presenting to Five Large Burn Centers, 2015-2019.

J Burn Care Res 2021 Jun 18. Epub 2021 Jun 18.

University of California, San Diego Health, San Diego, California.

Electronic cigarettes are advertised as safer alternatives to traditional cigarettes yet cause serious injury. US burn centers have witnessed a rise in both inpatient and outpatient visits to treat thermal injuries related to their use. A multicenter retrospective chart review of American Burn Association burn registry data from 5 large burn centers was performed from January 2015 to July 2019 to identify patients with electronic cigarette-related injuries. A total of 127 patients were identified. Most sustained less than 10% total body surface area burns (mean 3.8%). Sixty-six percent sustained 2nd degree burns. Most patients (78%) were injured while using their device. Eighteen percent of patients reported spontaneous device combustion. Two patients were injured while changing their device battery, and two were injured modifying their device. Three percent were injured by second-hand mechanism. Burn injury was the most common injury pattern (100%), followed by blast injury (3.93%). Flame burns were the most common (70%) type of thermal injury; however, most patients sustained a combination-type injury secondary to multiple burn mechanisms. The most injured body region was the extremities. Silver sulfadiazine was the most common agent used in initial management of thermal injuries. Sixty-three percent of patients did not require surgery. Of the 36% requiring surgery, 43.4% required skin grafting. Multiple surgeries were uncommon. Our data recognizes electronic cigarette use as a public health problem with potential to cause thermal injury and secondary trauma. Most patients are treated on an inpatient basis although most patients treated on outpatient basis have good outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/jbcr/irab114DOI Listing
June 2021

Examining Whether AOSLO-Based Foveal Cone Metrics in Achromatopsia and Albinism Are Representative of Foveal Cone Structure.

Transl Vis Sci Technol 2021 05;10(6):22

Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.

Purpose: Adaptive optics scanning light ophthalmoscopy (AOSLO) imaging in patients with achromatopsia (ACHM) and albinism is not always successful. Here, we tested whether optical coherence tomography (OCT) measures of foveal structure differed between patients for whom AOSLO images were either quantifiable or unquantifiable.

Methods: The study included 166 subjects (84 with ACHM; 82 with albinism) with previously acquired OCT scans, AOSLO images, and best-corrected visual acuity (BCVA, if available). Foveal OCT scans were assessed for outer retinal structure, outer nuclear layer thickness, and hypoplasia. AOSLO images were graded as quantifiable if a peak cone density could be measured and/or usable if the location of peak density could be identified and the parafoveal mosaic was quantifiable.

Results: Forty-nine percent of subjects with ACHM and 57% of subjects with albinism had quantifiable AOSLO images. Older age and better BCVA were found in subjects with quantifiable AOSLO images for both ACHM (P = 0.0214 and P = 0.0276, respectively) and albinism (P = 0.0073 and P < 0.0004, respectively). There was a significant trend between ellipsoid zone appearance and ability to quantify AOSLO (P = 0.0028). In albinism, OCT metrics of cone structure did not differ between groups.

Conclusions: Previously reported AOSLO-based cone density measures in ACHM may not necessarily reflect the degree of remnant cone structure in these patients.

Translational Relevance: Until AOSLO is successful in all patients with ACHM and albinism, the possibility of the reported data from a particular cohort not being representative of the entire population remains an important issue to consider when interpreting results from AOSLO studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.10.6.22DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8132001PMC
May 2021

Management of Pediatric Pavement Burns.

J Burn Care Res 2021 May 20. Epub 2021 May 20.

UNLV School of Medicine, Charleston Blvd, Las Vegas, NV.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/jbcr/irab084DOI Listing
May 2021

Aberrant visual population receptive fields in human albinism.

J Vis 2021 May;21(5):19

Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, USA.

Retinotopic organization is a fundamental feature of visual cortex thought to play a vital role in encoding spatial information. One important aspect of normal retinotopy is the representation of the right and left hemifields in contralateral visual cortex. However, in human albinism, many temporal retinal afferents decussate aberrantly at the optic chiasm resulting in partially superimposed representations of opposite hemifields in each hemisphere of visual cortex. Previous functional magnetic resonance imaging (fMRI) studies in human albinism suggest that the right and left hemifield representations are superimposed in a mirror-symmetric manner. This should produce imaging voxels which respond to two separate locations mirrored across the vertical meridian. However, it is not yet clear how retino-cortical miswiring in albinism manifests at the level of single voxel population receptive fields (pRFs). Here, we used pRF modeling to fit both single and dual pRF models to the visual responses of voxels in visual areas V1 to V3 of five subjects with albinism. We found that subjects with albinism (but not controls) have sizable clusters of voxels with unequivocal dual pRFs consistently corresponding to, but not fully coextensive with, regions of hemifield overlap. These dual pRFs were typically positioned at locations roughly mirrored across the vertical meridian and were uniquely clustered within a portion of the visual field for each subject.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/jov.21.5.19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8142699PMC
May 2021

Color vision.

Handb Clin Neurol 2021 ;178:131-153

Laboratory of Sensorimotor Research, National Eye Institute, National Institute of Mental Health, Bethesda, MD, United States. Electronic address:

Color is a fundamental aspect of normal visual experience. This chapter provides an overview of the role of color in human behavior, a survey of current knowledge regarding the genetic, retinal, and neural mechanisms that enable color vision, and a review of inherited and acquired defects of color vision including a discussion of diagnostic tests.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/B978-0-12-821377-3.00005-2DOI Listing
July 2021

Comparison of confocal and non-confocal split-detection cone photoreceptor imaging.

Biomed Opt Express 2021 Feb 8;12(2):737-755. Epub 2021 Jan 8.

Department of Ophthalmology, Stanford University, Palo Alto, CA 94303, USA.

Quadrant reflectance confocal and non-confocal scanning light ophthalmoscope images of the photoreceptor mosaic were recorded in a subject with congenital achromatopsia (ACHM) and a normal control. These images, captured with various circular and annular apertures, were used to calculate split-detection images, revealing two cone photoreceptor contrast mechanisms. The first contrast mechanism, maximal in the non-confocal 5.5-10 Airy disk diameter annular region, is unrelated to the cone reflectivity in confocal or flood illumination imaging. The second mechanism, maximal for confocal split-detection, is related to the cone reflectivity in confocal or flood illumination imaging that originates from the ellipsoid zone and/or inner-outer segment junction. Seeking to maximize image contrast, split-detection images were generated using various quadrant detector combinations, with opposite (diagonal) quadrant detectors producing the highest contrast. Split-detection generated with the addition of adjacent quadrant detector pairs, shows lower contrast, while azimuthal split-detection images, calculated from adjacent quadrant detectors, showed the lowest contrast. Finally, the integration of image pairs with orthogonal split directions was used to produce images in which the photoreceptor contrast does not change with direction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.403907DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901313PMC
February 2021

A Prospective Observational Study Comparing Effects of Call Schedules on Surgical Resident Sleep and Physical Activity Using the Fitbit.

J Grad Med Educ 2021 Feb 31;13(1):113-118. Epub 2020 Dec 31.

Background: Surgical residency training has an extended tradition of long hours. Residency programs use a variety of call schedules to combat resident fatigue and sleep deprivation while maintaining adherence to duty hour restrictions. Nonetheless, there is a paucity of data regarding objective measurements of sleep during the different call schedules included in general surgery training.

Objective: The primary objective of this study was to compare the quantity of sleep in 24-hour time frames across all types of shifts worked by general surgery residents at our institution. The secondary objective was to measure activity level in total steps during various time frames.

Methods: This prospective observational study was performed between April 4 and August 26, 2018, with general surgery residents. Each resident was assigned a Fitbit Charge 2 to wear during all rotations, including general surgery and subspecialty services.

Results: Twenty-six out of 31 residents voluntarily participated in the study (84%). In-house call (IHC) had significantly less sleep in a 24-hour time frame than home call and night float (144 vs 283 vs 246 minutes, < .001 and < .028). IHC had significantly more steps than home call (11 245 vs 8756 steps, = .039). The smallest number of steps was obtained when residents were not working (7904 steps).

Conclusions: Our data demonstrate that surgical residents on IHC have significantly less sleep compared to all other types of on-call time frames. Residents on IHC have the most steps across all time frames.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4300/JGME-D-20-00304.1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901626PMC
February 2021

Optical Coherence Tomography Artifacts Are Associated With Adaptive Optics Scanning Light Ophthalmoscopy Success in Achromatopsia.

Transl Vis Sci Technol 2021 01 7;10(1):11. Epub 2021 Jan 7.

Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.

Purpose: To determine whether artifacts in optical coherence tomography (OCT) images are associated with the success or failure of adaptive optics scanning light ophthalmoscopy (AOSLO) imaging in subjects with achromatopsia (ACHM).

Methods: Previously acquired OCT and non-confocal, split-detector AOSLO images from one eye of 66 subjects with genetically confirmed achromatopsia (15 and 51 ) were reviewed along with best-corrected visual acuity (BCVA) and axial length. OCT artifacts in interpolated vertical volumes from CIRRUS macular cubes were divided into four categories: (1) none or minimal, (2) clear and low frequency, (3) low amplitude and high frequency, and (4) high amplitude and high frequency. Each vertical volume was assessed once by two observers. AOSLO success was defined as sufficient image quality in split-detector images at the fovea to assess cone quantity.

Results: There was excellent agreement between the two observers for assessing OCT artifact severity category (weighted kappa = 0.88). Overall, AOSLO success was 47%. For subjects with OCT artifact severity category 1, AOSLO success was 65%; for category 2, 47%; for category 3, 11%; and for category 4, 0%. There was a significant association between OCT artifact severity category and AOSLO success ( = 0.0002). Neither BCVA nor axial length was associated with AOSLO success ( = 0.07 and = 0.75, respectively).

Conclusions: Artifacts in OCT volumes are associated with AOSLO success in ACHM. Subjects with less severe OCT artifacts are more likely to be good candidates for AOSLO imaging, whereas AOSLO was successful in only 7% of subjects with category 3 or 4 OCT artifacts. These results may be useful in guiding patient selection for AOSLO imaging.

Translational Relevance: Using OCT to prescreen patients could be a valuable tool for clinical trials that utilize AOSLO to reduce costs and decrease patient testing burden.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.10.1.11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7804582PMC
January 2021

Assessing Interocular Symmetry of the Foveal Cone Mosaic.

Invest Ophthalmol Vis Sci 2020 12;61(14):23

Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.

Purpose: To test the hypothesis that foveal cone topography is symmetrical between contralateral eyes.

Methods: We used adaptive optics scanning light ophthalmoscopy to acquire images of the foveal cone mosaic in each eye of 58 subjects with normal vision (35 female, 23 male). Cones were semiautomatically identified over a 300 × 300-µm foveal area. From these cone coordinates, maps of cone density were derived, and we extracted estimates of peak cone density from each map. Mosaic regularity was assessed using Voronoi cell area regularity (VCAR). Average roundness and average area of the 70%, 75%, 80%, 85%, and 90% of peak density isodensity contours were evaluated.

Results: The average peak cone density for right eyes was 180,286 cones/mm2 (n = 49) and for left eyes was 182,397 cones/mm2 (n = 45), with a mean absolute difference of 6363 cones/mm2 (n = 43). Peak density, cone spacing, VCAR, and average area within the isodensity contours of fellow eyes were not significantly different (P = 0.60, P = 0.83, P = 0.30, and P = 0.39, respectively). However, the average roundness of the isodensity contours was 2% more circular in the right eyes than in the left eyes (P = 0.02).

Conclusions: There is interocular symmetry of peak foveal cone density, mosaic regularity, and area encompassing the most densely packed cells in subjects with normal vision. The origin and significance of the observed interocular difference in average roundness of the isodensity contours are unclear.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/iovs.61.14.23DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7746960PMC
December 2020

Photobiomodulation preserves mitochondrial redox state and is retinoprotective in a rodent model of retinitis pigmentosa.

Sci Rep 2020 11 23;10(1):20382. Epub 2020 Nov 23.

Department of Biomedical Sciences, Photobiomodulation Laboratory, College of Health Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.

Photobiomodulation (PBM) by far-red (FR) to near-infrared (NIR) light has been demonstrated to restore the function of damaged mitochondria, increase the production of cytoprotective factors and prevent cell death. Our laboratory has shown that FR PBM improves functional and structural outcomes in animal models of retinal injury and retinal degenerative disease. The current study tested the hypothesis that a brief course of NIR (830 nm) PBM would preserve mitochondrial metabolic state and attenuate photoreceptor loss in a model of retinitis pigmentosa, the P23H transgenic rat. P23H rat pups were treated with 830 nm light (180 s; 25 mW/cm; 4.5 J/cm) using a light-emitting diode array (Quantum Devices, Barneveld, WI) from postnatal day (p) 10 to p25. Sham-treated rats were restrained, but not treated with 830 nm light. Retinal metabolic state, function and morphology were assessed at p30 by measurement of mitochondrial redox (NADH/FAD) state by 3D optical cryo-imaging, electroretinography (ERG), spectral-domain optical coherence tomography (SD-OCT), and histomorphometry. PBM preserved retinal metabolic state, retinal function, and retinal morphology in PBM-treated animals compared to the sham-treated group. PBM protected against the disruption of the oxidation state of the mitochondrial respiratory chain observed in sham-treated animals. Scotopic ERG responses over a range of flash intensities were significantly greater in PBM-treated rats compared to sham controls. SD-OCT studies and histological assessment showed that PBM preserved the structural integrity of the retina. These findings demonstrate for the first time a direct effect of NIR PBM on retinal mitochondrial redox status in a well-established model of retinal disease. They show that chronic proteotoxic stress disrupts retinal bioenergetics resulting in mitochondrial dysfunction, and retinal degeneration and that therapies normalizing mitochondrial metabolism have considerable potential for the treatment of retinal degenerative disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-77290-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684292PMC
November 2020

Promises and pitfalls of evaluating photoreceptor-based retinal disease with adaptive optics scanning light ophthalmoscopy (AOSLO).

Prog Retin Eye Res 2021 Jul 6;83:100920. Epub 2020 Nov 6.

Department of Ophthalmology, University of California, San Francisco, CA, USA. Electronic address:

Adaptive optics scanning light ophthalmoscopy (AOSLO) allows visualization of the living human retina with exquisite single-cell resolution. This technology has improved our understanding of normal retinal structure and revealed pathophysiological details of a number of retinal diseases. Despite the remarkable capabilities of AOSLO, it has not seen the widespread commercial adoption and mainstream clinical success of other modalities developed in a similar time frame. Nevertheless, continued advancements in AOSLO hardware and software have expanded use to a broader range of patients. Current devices enable imaging of a number of different retinal cell types, with recent improvements in stimulus and detection schemes enabling monitoring of retinal function, microscopic structural changes, and even subcellular activity. This has positioned AOSLO for use in clinical trials, primarily as exploratory outcome measures or biomarkers that can be used to monitor disease progression or therapeutic response. AOSLO metrics could facilitate patient selection for such trials, to refine inclusion criteria or to guide the choice of therapy, depending on the presence, absence, or functional viability of specific cell types. Here we explore the potential of AOSLO retinal imaging by reviewing clinical applications as well as some of the pitfalls and barriers to more widespread clinical adoption.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.preteyeres.2020.100920DOI Listing
July 2021

Characterizing Current Attitudes and Practices for Human Subject Safety in Studies Involving Pupil Dilation.

J Empir Res Hum Res Ethics 2021 Feb-Apr;16(1-2):54-64. Epub 2020 Nov 2.

Department of Ophthalmology & Visual Sciences, 5506Medical College of Wisconsin, Milwaukee, USA.

Standards in pupil dilation practices regarding the safety of human subjects are not present in vision research despite the potential for significant adverse effects. We developed two surveys to examine current practices around pupil dilation among vision researchers and individuals associated with oversight of human subjects research. While both groups note an absence of adverse events associated with pupil dilation, vision researcher practices differed with informed consent use and measures taken to minimize complications. For Institutional Review Boards, general risk assumption associated with dilation was not unanimous and there was a lack of specific guidance available to researchers for minimizing risk. These results uncover the need for standardized practices regarding pupil dilation in human subjects research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1556264620968989DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8035129PMC
November 2020

Assessing the Influence of OCT-A Device and Scan Size on Retinal Vascular Metrics.

Transl Vis Sci Technol 2020 10 7;9(11). Epub 2020 Oct 7.

Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.

Purpose: The purpose of this study was to investigate the effect of device and scan size on quantitative optical coherence tomography angiography (OCT-A) metrics.

Methods: The 3 × 3 mm scans from Optovue AngioVue and Zeiss AngioPlex systems were included for 18 eyes of 18 subjects without ocular pathology. The foveal avascular zone (FAZ) was segmented manually by two observers, from which estimates of FAZ area (using both the nominal image scale and the axial length corrected image scale) and acircularity were derived. Three scan sizes (3 mm, 6 mm HD, and 8 mm) from the AngioVue system were included for 15 eyes of 15 subjects without ocular pathology. For each subject, larger image sizes were resized to the same resolution as 3 × 3 mm scans, aligned, then cropped to a common area. FAZ area, FAZ acircularity, average and total parafoveal intercapillary area, vessel density, and vessel end points were computed.

Results: Between the devices used here, there were no significant differences in FAZ acircularity ( = 0.88) or FAZ area using scaled ( = 0.11) or unscaled images ( = 0.069). Although there was no significant difference in FAZ area across scan sizes ( = 0.30), vessel morphometry metrics were all significantly influenced by scan size.

Conclusions: The scan devices and sizes used here do not affect FAZ area measures derived from manual segmentations. In contrast, vessel morphometry metrics are affected by scan size. As individual differences in axial length induce differences in absolute scan size, extreme care should be taken when interpreting metrics of vessel morphometry, both between and within OCT-A devices.

Translational Relevance: A better characterization of the confounds surrounding OCT-A retinal vasculature metrics can lead to improved application of these metrics as biomarkers for retinal and systemic diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.9.11.7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7545061PMC
October 2020

Early Characteristics and Progression of Blunt Traumatic Aortic Injuries at a Single Level I Trauma Center.

Vasc Endovascular Surg 2021 Feb 16;55(2):105-111. Epub 2020 Oct 16.

University of Nevada Las Vegas School of Medicine, Las Vegas, NV, USA.

Objectives: The most widely accepted grading system for blunt traumatic aortic injury (BTAI) by the Society of Vascular Surgery (SVS) recommends endovascular repair for grade 2 and greater. Non-operative management in grade 2 injuries has been shown to be reasonable in certain circumstances. The natural history of low-grade injuries (1, 2) when managed non-operatively is not well defined.

Methods: Utilizing our trauma registry, patients from 2013 to 2016 with blunt traumatic injury who underwent initial computed tomography were identified. Aortic pathology was graded and grouped by SVS classification. Clinical courses were reviewed for timing of interventions, repeat imaging, concurrent injuries, and outcomes. Analysis of variance and Chi-square tests of significance were utilized to compare between groups.

Results: Out of 10,178 patients, we identified 32 with BTAI (grade: 1 (n = 13), 2 (n = 5), 3 (n = 3), 4 (n = 11)). High-grade injuries (3, 4) resulted only from motor vehicle, motorcycle, and pedestrian mechanisms. Initially, 9 patients (28%) required intervention, 5 (16%) were treated non-operatively, and 18 (56%) underwent repeat imaging. On repeat imaging, injuries that did not resolve remained stable and no injuries were found to progress. Of these patients, 9 (50%) required delayed intervention and 9 (50%) successfully underwent non-operative management. Patients with low-grade injuries were more likely to have successful non-operative management than those with high-grade injuries (72% vs 7%; p < 0.01).

Conclusions: While low-grade injuries generally have good outcomes, some ultimately do require delayed intervention, and short-term imaging is not reliable in identifying these cases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1538574420966450DOI Listing
February 2021

Noninvasive Imaging of Cone Ablation and Regeneration in Zebrafish.

Transl Vis Sci Technol 2020 09 16;9(10):18. Epub 2020 Sep 16.

Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.

Purpose: To observe and characterize cone degeneration and regeneration in a selective metronidazole-mediated ablation model of ultraviolet-sensitive (UV) cones in zebrafish using in vivo optical coherence tomography (OCT) imaging.

Methods: Twenty-six zebrafish were imaged with OCT, treated with metronidazole to selectively kill UV cones, and imaged at 1, 3, 7, 14, 28, or 56 days after ablation. Regions 200 × 200 µm were cropped from volume OCT scans to count individual UV cones before and after ablation. Fish eyes were fixed, and immunofluorescence staining was used to corroborate cone density measured from OCT and to track monocyte response.

Results: Histology shows significant loss of UV cones after metronidazole treatment with a slight increase in observable blue cone density one day after treatment (Kruskal, Wallis, = 0.0061) and no significant change in blue cones at all other timepoints. Regenerated UV cones measured from OCT show significantly lower density than pre-cone-ablation at 14, 28, and 56 days after ablation (analysis of variance, < 0.01, < 0.0001, < 0.0001, respectively, 15.9% of expected nonablated levels). Histology shows significant changes to monocyte morphology (mixed-effects analysis, < 0.0001) and retinal position (mixed-effects analysis, < 0.0001).

Conclusions: OCT can be used to observe loss of individual cones selectively ablated by metronidazole prodrug activation and to quantify UV cone loss and regeneration in zebrafish. OCT images also show transient changes to the blue cone mosaic and inner retinal layers that occur concomitantly with selective UV cone ablation.

Translational Relevance: Profiling cone degeneration and regeneration using in vivo imaging enables experiments that may lead to a better understanding of cone regeneration in vertebrates.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.9.10.18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7500127PMC
September 2020

Long-Term Investigation of Retinal Function in Patients with Achromatopsia.

Invest Ophthalmol Vis Sci 2020 09;61(11):38

UCL Institute of Ophthalmology, University College London, London, United Kingdom.

Purpose: To investigate the long-term natural history of retinal function of achromatopsia (ACHM).

Methods: Subjects with molecularly confirmed ACHM were recruited in a prospective cohort study of mesopic microperimetry. Coefficient of repeatability and intraclass correlation coefficient (ICC) of mean sensitivity (MS) were calculated. Best-corrected visual acuity (BCVA), bivariate contour ellipse area (BCEA), contrast sensitivity (CS), MS, total volume (VTOT), and central field volume (V5°) from volumetric and topographic analyses were acquired. Correlation of functional parameters with structural findings from optical coherence tomography (OCT) was performed.

Results: Eighteen subjects were recruited. Mean follow-up was 7.2 years. The MS test-retest repeatability coefficient was 1.65 decibels (dB), and the ICC was 0.973 (95% confidence interval, 0.837-0.98). Mean MS was similar for right and left eyes (16.97dB and 17.14dB, respectively). A negative significant correlation between logMAR BCVA and the retinal sensitivity indices (MS, VTOT, V5°) was found. A significant negative correlation between logCS and MS, VTOT, and V5° was also observed. BCVA and BCEA improved during follow-up. Mean CS, MS, VTOT, and V5° at final follow-up were similar to baseline. MS was similar between CNGA3- and CNGB3-ACHM. Patients with and without the presence of a foveal ellipsoid zone on OCT had similar MS (16.64 dB and 17.17 dB, respectively).

Conclusions: We demonstrate a highly reproducible assessment of MS. Retinal function including MS, volumetric indices, and CS are stable in ACHM. Improvement of fixation stability and small changes of BCVA over time may be part of the natural history of the disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/iovs.61.11.38DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7509756PMC
September 2020

Seeking clarity on retinal findings in patients with COVID-19.

Lancet 2020 09;396(10254):e38

Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226-0509, USA; Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226-0509, USA. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S0140-6736(20)31917-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7498232PMC
September 2020

Preservation of the Foveal Avascular Zone in Achromatopsia Despite the Absence of a Fully Formed Pit.

Invest Ophthalmol Vis Sci 2020 08;61(10):52

Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.

Purpose: To examine the foveal avascular zone (FAZ) in patients with congenital achromatopsia (ACHM).

Methods: Forty-two patients with genetically confirmed ACHM were imaged either with Optovue's AngioVue system or Zeiss's Plex Elite 9000, and the presence or absence of a FAZ was determined. For images where a FAZ was present and could be confidently segmented, FAZ area, circularity index, and roundness were measured and compared with previously published normative values. Structural optical coherence tomography images were acquired to assess the degree of foveal hypoplasia (number and thickness of inner retinal layers present at the fovea).

Results: A FAZ was present in 31 of 42 patients imaged (74%), although no determination could be made for 11 patients due to poor image quality (26%). The mean ± SD FAZ area for the ACHM retina was 0.281 ± 0.112 mm2, which was not significantly different from the previously published normative values (P = 0.94). However, their FAZs had decreased circularity (P < 0.0001) and decreased roundness (P < 0.0001) compared to the normative cohort. In the patients with ACHM examined here, the FAZ area decreased as the number and thickness of the retained inner retinal layers increased.

Conclusions: Our data demonstrate that despite the presence of foveal hypoplasia, patients with ACHM can have a FAZ. This is distinct from other conditions associated with foveal hypoplasia, which generally show an absence of the FAZ. In ACHM, FAZ formation does not appear to be sufficient for complete pit formation, contrary to some models of foveal development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/iovs.61.10.52DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7463179PMC
August 2020

Intraobserver Repeatability and Interobserver Reproducibility of Foveal Cone Density Measurements in and -Associated Achromatopsia.

Transl Vis Sci Technol 2020 06 26;9(7):37. Epub 2020 Jun 26.

Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.

Purpose: To examine repeatability and reproducibility of foveal cone density measurements in patients with and -associated achromatopsia (ACHM) using split-detection adaptive optics scanning light ophthalmoscopy (AOSLO).

Methods: Thirty foveae from molecularly confirmed subjects with ACHM, half of whom harbored disease-causing variants in and half in underwent nonconfocal split-detection AOSLO imaging. Cone photoreceptors within the manually delineated rod-free zone were manually identified twice by two independent observers. The coordinates of the marked cones were used for quantifying foveal cone density. Cone density and difference maps were generated to compare cone topography between trials.

Results: We observed excellent intraobserver repeatability in foveal cone density estimates, with intraclass correlation coefficients (ICCs) ranging from 0.963 to 0.991 for and subjects. Interobserver reproducibility was also excellent for both (ICC = 0.952; 95% confidence interval [CI], 0.903-1.0) and (ICC = 0.968; 95% CI, 0.935-1.0). However, Bland-Altman analysis revealed bias between observers.

Conclusions: Foveal cone density can be measured using the described method with good repeatability and reproducibility both for - and -associated ACHM. Any degree of bias observed among the observers is of uncertain clinical significance but should be evaluated on a study-specific basis.

Translational Relevance: This approach could be used to explore disease natural history, as well as to facilitate stratification of patients and monitor efficacy of interventions for ongoing and upcoming ACHM gene therapy trials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.9.7.37DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414701PMC
June 2020

Comparison of the Morphology of the Foveal Pit Between African and Caucasian Populations.

Transl Vis Sci Technol 2020 04 28;9(5):24. Epub 2020 Apr 28.

Steele Center for Translational Medicine, John A. Moran Eye Center, Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, UT, USA.

Purpose: The purpose of this study was to characterize foveal pit morphology in an African (Ghanaian) population, to compare it to that of a Caucasian group and to determine if it varied with age in the two populations.

Methods: The depth, diameter, slope, and volume of the foveal pit were interpolated from optical coherence tomography volume scans recorded in 84 Ghanaian and 37 Caucasian individuals. Their association with age, sex, and ethnicity was investigated using multilevel regression models.

Results: The foveal pit differed significantly in width, slope, and volume between Ghanaian men and women ( < 0.001), but only in width and volume between Caucasian men and women ( < 0.01). In Ghanaians, age was associated with a narrowing of the foveal depression and a reduction of its volume. Overall, these changes were more pronounced in women as compared to men and were largely absent from the Caucasian group. When controlled for age, the foveal pit of Ghanaians was significantly wider and larger in volume as compared to the Caucasian group ( < 0.001).

Conclusions: The morphology of the foveal pit differs between African and Caucasian individuals. These anatomic differences should be considered when examining differences in prevalence and clinical features of vitreoretinal disorders involving the fovea between the two populations.

Translational Relevance: Differences in retinal anatomy may partly explain variations in the prevalence and clinical features of retinal diseases between Africans and Caucasians. Such differences should be adequately considered in diagnoses and monitoring of ocular diseases in patients with African ancestry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.9.5.24DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7401974PMC
April 2020

Longitudinal Assessment of Remnant Foveal Cone Structure in a Case Series of Early Macular Telangiectasia Type 2.

Transl Vis Sci Technol 2020 03 30;9(4):27. Epub 2020 Mar 30.

Moorfields Eye Hospital NHS Foundation Trust, London, UK.

Purpose: To determine the extent of remnant cone structure within early foveal ellipsoid zone (EZ) lesions in macular telangiectasia type 2 longitudinally using both confocal and split detector adaptive optics scanning light ophthalmoscopy (AOSLO).

Methods: Spectral domain optical coherence tomography (SDOCT), confocal and split detector AOSLO were acquired from seven patients (10 eyes) with small (early) EZ lesions on SDOCT secondary to macular telangiectasia type 2 at baseline, 6 months, and 12 months. The presence of cone structure on AOSLO in areas of EZ loss as well as cones at 1° eccentricity, and their change over time were quantified.

Results: By split detector AOSLO, remnant cone structure was identified within and on the borders of all foveal EZ lesions. Within the extent of these lesions, cone spacing ranged from 4.97 to 9.95 µm at baseline, 5.30 to 6.10 µm at 6 months, and 4.99 to 7.12 µm at 12 months. Four eyes with significantly smaller EZ lesions showed evidence of recovery of EZ reflectivity on SDOCT B-scans. Remnant cone structure was identified in some areas where EZ reflectivity recovered at the following time point. Eyes that showed recovery of EZ reflectivity had a continuous external limiting membrane.

Conclusions: Remnant cone structure can persist within small SDOCT-defined EZ lesions, which can wax and wane in appearance over time. AOSLO can help to inform the interpretation of SDOCT imaging.

Translational Relevance: The absence of EZ in early macular telangiectasia type 2 and other retinal conditions needs careful interpretation because it does not always indicate an absence of underlying cone structure. The integrity of the external limiting membrane may better predict the presence of remnant cone structure and recovery of EZ reflectivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/tvst.9.4.27DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7396184PMC
March 2020

Contemporary management of traumatic cervical and thoracic esophageal perforation: The results of an Eastern Association for the Surgery of Trauma multi-institutional study.

J Trauma Acute Care Surg 2020 10;89(4):691-697

From the Division of Acute Care Surgery, Department of Surgery (L.A.R.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Ascension St. John Medical Center Trauma Services (E.A.S.), Tulsa, Oklahoma; Department of Surgery (R.G.M., B.R.H.R.), Harborview Medical Center, University of Washington School of Medicine, Seattle, Washington; Division of Acute Care Surgery, Department of Surgery (J.J.), University of Alabama at Birmingham, Birmingham, Alabama; Department of Surgery (M.R.N., Z.S.), Allegheny General Hospital, Pittsburgh, Pennsylvania; Department of General Surgery (E.C., J.C.), Denver Health Medical Center, Denver, Colorado; University of Nevada at Las Vegas School of Medicine (S.S., J.T.C.), Las Vegas, Nevada; Department of Trauma (L.E.J., J.W.), St. Vincent Indianapolis Hospital, Indianapolis, Indiana; Department of Surgery (A.J.Y., J.P.), University of Pennsylvania, Philadelphia, Pennsylvania; Department of Surgery (S.B., D.G.), Loma Linda Medical Center, Loma Linda, California; Division of Trauma, Burns, and Surgical Critical Care, Department of Surgery (J.N.), University of California at Irvine, Orange, California; Department of Surgery (M.E.K.), University of Mississippi Medical Center, Jackson, Mississippi; Division of Trauma and Acute Care Surgery, Department of Surgery (N.B., K.J.), Tufts Medical Center, Boston, Massachusetts; and Division of Acute Care Surgery, Department of Surgery (P.B.), Banner University Medical Center, University of Arizona College of Medicine, Phoenix, Arizona.

Background: Traumatic esophageal perforation is rare and associated with significant morbidity and mortality. There is substantial variability in diagnosis and treatment. Esophageal stents have been increasingly used for nontraumatic perforation; however, stenting for traumatic perforation is not yet standard of care. The purpose of this study was to evaluate current management of traumatic esophageal perforation to assess the frequency of and complications associated with esophageal stenting.

Methods: This was an Eastern Association for the Surgery of Trauma multi-institutional retrospective study from 2011 to 2016 of patients with traumatic cervical or thoracic esophageal injury admitted to one of 11 participating trauma centers. Data were collected and sent to a single institution where it was analyzed. Patient demographics, injury characteristics, initial management, complications, and patient mortality were collected. Primary outcome was mortality; secondary outcomes were initial treatment, esophageal leak, and associated complications.

Results: Fifty-one patients were analyzed. Esophageal injuries were cervical in 69% and thoracic in 31%. Most patients were initially managed with operative primary repair (61%), followed by no intervention (19%), esophageal stenting (10%), and wide local drainage (10%). Compared with patients who underwent operative primary repair, patients managed with esophageal stenting had an increased rate of esophageal leak (22.6% vs. 80.0%, p = 0.02). Complication rates were higher in blunt compared with penetrating mechanisms (100% vs. 31.8%, p = 0.03) despite similar Injury Severity Score and neck/chest/abdomen Abbreviated Injury Scale. Overall mortality was 9.8% and did not vary based on location of injury, mechanism of injury, or initial management.

Conclusion: Most patients with traumatic esophageal injuries still undergo operative primary repair; this is associated with lower rates of postoperative leaks as compared with esophageal stenting. Patients who have traumatic esophageal injury may be best managed by direct repair and not esophageal stenting, although further study is needed.

Level Of Evidence: Therapeutic, level IV.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/TA.0000000000002841DOI Listing
October 2020

Imaging of Macrophage-Like Cells in Living Human Retina Using Clinical OCT.

Invest Ophthalmol Vis Sci 2020 06;61(6):48

,.

Purpose: To image retinal macrophages at the vitreoretinal interface in the living human retina using a clinical optical coherence tomography (OCT) device.

Methods: Eighteen healthy controls and three patients with retinopathies were imaged using a clinical spectral-domain OCT. In controls, 10 sequential scans were collected at three different locations: (1) ∼9 degrees temporal to the fovea, (2) the macula, and (3) the optic nerve head (ONH). Intervisit repeatability was evaluated by imaging the temporal retina twice on the same day and 3 days later. Only 10 scans at the temporal retina were obtained from each patient. A 3-µm OCT reflectance (OCT-R) slab located above the inner limiting membrane (ILM) surface was averaged.

Results: In controls, ramified macrophage-like cells with regular spatial separation were visualized in the temporal and ONH OCT-R images; however, cell structures were not resolvable at the macula. Interim changes in cell position suggestive of cell translocation were observed between images collected on the same day and those collected 3 days later. There was considerable variation in cell density and nearest-neighbor distance (NND) across controls. Mean ± SD cell densities measured at the temporal and ONH were 78 ± 23 cells/mm2 and 57 ± 16 cells/mm2, respectively. Similarly, mean ± SD NNDs measured at the temporal and ONH were 74.3 ± 13.3 µm and 93.3 ± 20.0 µm, respectively. Nonuniform spatial distribution and altered morphology of the cells were identified in patients with retinopathies.

Conclusions: Our findings showed regular spatial separation and ramified morphology of macrophage-like cells on the ILM surface with cell translocation over time in controls. Their distribution and morphology suggest an origin of macrophage-like cells such as microglia or hyalocytes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/iovs.61.6.48DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7416910PMC
June 2020

On the axial location of Gunn's dots.

Am J Ophthalmol Case Rep 2020 Sep 1;19:100757. Epub 2020 Jun 1.

Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, 419 W. Redwood Street, Baltimore, MD, 21201, USA.

Purpose: To determine the axial location of Gunn's dots in the retina.

Methods: Adaptive optics scanning laser ophthalmoscopy (AOSLO) images and adaptive optics - optical coherence tomography (AO-OCT) volumes were collected from a region where Gunn's dots were found inferior to the optic disc from a subject determined by clinical examination to be a glaucoma suspect. AO-OCT volumes were also collected along the horizontal and vertical meridians from six healthy subjects and one glaucoma subject to identify and document other occurrences of Gunn's dots. AO-OCT volumes were registered in three-dimensions and averaged. Gunn's dots were segmented, and their volume, area, and diameter were measured.

Results: All Gunn's dots imaged in this study from all subjects were confined to the inner limiting membrane, neither extending into the vitreous nor into the nerve fiber layer. The size of the dots was highly variable. The measured volume, area, and diameter (mean ± standard deviation) were 1119.9 ± 590.9 μm, 220.2 ± 105.5 μm, and 14.3 ± 3.1 μm, the latter within the range as previously published reports.

Conclusions: Based upon evidence from this study and others, Gunn's dots are not thought to be Müller cell end-feet or hyalocytes. We hypothesize that they are related to microglia, either as the by-product of their phagocytosis function, or are actual dead ameboid-shaped microglia who have fulfilled their scavenger role in retinal pathology. Further studies are needed in diseased eyes to determine if they have predictive value.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajoc.2020.100757DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7287238PMC
September 2020

The relationship between retinal cone density and cortical magnification in human albinism.

J Vis 2020 06;20(6):10

,.

The human fovea lies at the center of the retina and supports high-acuity vision. In normal visual system development, the highest acuity is correlated with both a high density of cone photoreceptors in the fovea and a magnified retinotopic representation of the fovea in the visual cortex. Both cone density and the cortical area dedicated to each degree of visual space-the latter describing cortical magnification (CM)-steadily decrease with increasing eccentricity from the fovea. In albinism, peak cone density at the fovea and visual acuity are decreased, but seem to be within normal limits in the periphery, thus providing a model to explore the correlation between retinal structure, cortical structure, and behavior. Here, we used adaptive optics scanning light ophthalmoscopy to assess retinal cone density and functional magnetic resonance imaging to measure CM in the primary visual cortex of normal controls and individuals with albinism. We find that retinotopic organization is more varied among individuals with albinism than previously appreciated. Additionally, CM outside the fovea is similar to that in controls, but also more variable. CM in albinism and controls exceeds that which might be predicted based on cone density alone, but is more accurately predicted by retinal ganglion cell density. This finding suggests that decreased foveal cone density in albinism may be partially counteracted by nonuniform connectivity between cones and their downstream signaling partners. Together, these results emphasize that central as well as retinal factors must be included to provide a complete picture of aberrant structure and function in albinism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/jov.20.6.10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7416892PMC
June 2020

Interocular asymmetry of foveal avascular zone morphology and parafoveal capillary density in sickle cell retinopathy.

PLoS One 2020 10;15(6):e0234151. Epub 2020 Jun 10.

Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States of America.

Objectives: To examine interocular asymmetry of foveal avascular zone (FAZ) and parafoveal capillary density metrics in sickle cell retinopathy (SCR) using optical coherence tomography angiography (OCT-A).

Methods: This cross-sectional, retrospective study evaluated SCR patients and unaffected controls who underwent 3x3mm macular OCT-A imaging using a spectral domain-OCT system. FAZ (area, perimeter, and acircularity index) and parafoveal capillary density metrics were computed for both eyes of each participant. In unaffected controls, interocular difference in FAZ and parafoveal capillary density metrics were evaluated using Bland-Altman plots. SCR patients with interocular difference outside the upper 97.5% and lower 2.5% limits of agreement from controls were defined as having interocular asymmetry. Area under receiver operating characteristic curve (AROC) was also performed to determine the ability of the absolute interocular difference to differentiate between subjects with SCR-including non-proliferative SCR (NP-SCR) and proliferative SCR (P-SCR)-and unaffected controls.

Results: Thirty-one patients with SCR (21 NP-SCR and 10 P-SCR) and 14 race-matched and age-matched controls were included for analysis. Interocular asymmetry was seen for all FAZ and parafoveal capillary density metrics in NP-SCR and P-SCR subjects. SCR subjects showed greater disease severity in the left-eye for FAZ and parafoveal capillary density metrics.

Conclusions: NP-SCR and P-SCR patients demonstrated quantifiable interocular asymmetry in FAZ and parafoveal capillary density metrics compared to unaffected subjects, with left-eye predominance in disease severity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0234151PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7286490PMC
August 2020