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2.
Nat Commun ; 15(1): 4481, 2024 May 27.
Article En | MEDLINE | ID: mdl-38802397

Retinal degeneration, a leading cause of irreversible low vision and blindness globally, can be partially addressed by retina prostheses which stimulate remaining neurons in the retina. However, existing electrode-based treatments are invasive, posing substantial risks to patients and healthcare providers. Here, we introduce a completely noninvasive ultrasonic retina prosthesis, featuring a customized ultrasound two-dimensional array which allows for simultaneous imaging and stimulation. With synchronous three-dimensional imaging guidance and auto-alignment technology, ultrasonic retina prosthesis can generate programmed ultrasound waves to dynamically and precisely form arbitrary wave patterns on the retina. Neuron responses in the brain's visual center mirrored these patterns, evidencing successful artificial vision creation, which was further corroborated in behavior experiments. Quantitative analysis of the spatial-temporal resolution and field of view demonstrated advanced performance of ultrasonic retina prosthesis and elucidated the biophysical mechanism of retinal stimulation. As a noninvasive blindness prosthesis, ultrasonic retina prosthesis could lead to a more effective, widely acceptable treatment for blind patients. Its real-time imaging-guided stimulation strategy with a single ultrasound array, could also benefit ultrasound neurostimulation in other diseases.


Blindness , Retina , Visual Prosthesis , Retina/diagnostic imaging , Retina/physiology , Animals , Blindness/therapy , Blindness/physiopathology , Retinal Degeneration/therapy , Retinal Degeneration/diagnostic imaging , Ultrasonic Waves , Humans , Neurons/physiology , Ultrasonography/methods , Vision, Ocular/physiology
3.
PeerJ ; 12: e17454, 2024.
Article En | MEDLINE | ID: mdl-38818459

Background: Activation of the trigeminal vascular system in migraine releases vasoactive neurotransmitters, causing abnormal vasoconstriction, which may affect the ocular system, leading to retinal damage. The purpose of our study was to determine whether there are differences in each retinal layer between migraine patients and healthy subjects. Methods: A case-control study recruited 38 migraine patients and 38 age- and sex-matched controls. Optical coherence tomography was used to measure the thickness of the peripapillary and macular retinal nerve fiber layer (pRNFL and mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer (INL). Results: The mean ages of the migraine patients and controls were 36.29 ± 9.45 and 36.45 ± 9.27 years, respectively. Thirty-four patients (89.48%) in both groups were female. The mean disability score was 19.63 ± 20.44 (indicating severe disability). The superior-outer INL of migraine patients were thicker than controls. Thickness of the GCL at temporal-outer sector and mRNFL at the superior-outer sector of the headache-side eyes was reduced. However, the INL of the headache-side-eye showed negative correlation with the disability score. This is the first study having found thinning of the GCL and mRNFL of the headache-side eyes. The INL was also thickened in migraines but showed negative correlation with the disability score. Conclusions: Increased INL thickness in migraine patients may result from inflammation. The more severe cases with a high disability score might suffered progressive retinal neuronal loss, resulting in thinner INL than less severe cases.


Migraine Disorders , Retina , Tomography, Optical Coherence , Humans , Female , Migraine Disorders/pathology , Migraine Disorders/diagnostic imaging , Migraine Disorders/physiopathology , Male , Adult , Case-Control Studies , Retina/pathology , Retina/diagnostic imaging , Middle Aged , Retinal Ganglion Cells/pathology
4.
BMJ Case Rep ; 17(5)2024 May 08.
Article En | MEDLINE | ID: mdl-38719246

Cutis marmorata telangiectatica congenita is a rare congenital vascular malformation characterised by cutaneous vascular abnormalities, typically diagnosed at birth or in the early postnatal period. Although typically benign, this disease is associated with other systemic abnormalities, including rare ocular alterations, such as congenital glaucoma, cataracts and retinopathy.This manuscript describes a female infant, who presented with generalised livedo reticularis, a band of alopecia and cutaneous atrophy in the temporal region above the coronal suture. The patient was diagnosed with cutis marmorata telangiectatica congenita by a paediatrician, and an ophthalmological evaluation was requested. A funduscopy examination in both eyes showed temporal and superior retina with avascular areas with new vessels, venous dilations and shunts, and no retinal detachments. Given these findings, we performed retinal photocoagulation laser treatment with excellent results.This case report highlights the importance of early ophthalmological evaluation of children with this disease to prevent secondary complications, such as vitreous haemorrhage and tractional retinal detachment.


Livedo Reticularis , Skin Diseases, Vascular , Telangiectasis , Humans , Female , Telangiectasis/congenital , Telangiectasis/complications , Telangiectasis/diagnosis , Skin Diseases, Vascular/diagnosis , Skin Diseases, Vascular/complications , Infant , Laser Coagulation/methods , Retinal Vessels/abnormalities , Retinal Vessels/diagnostic imaging , Retina/abnormalities , Retina/diagnostic imaging
5.
Sci Rep ; 14(1): 11465, 2024 05 20.
Article En | MEDLINE | ID: mdl-38769421

Childhood maltreatment is reportedly associated with atypical gray matter structures in the primary visual cortex (V1). This study explores the hypothesis that retinal structures, the sensory organs of vision, are associated with brain atypicality and child maltreatment and examines their interrelation. General ophthalmologic examinations, visual cognitive tasks, retinal imaging, and structural magnetic resonance imaging (MRI) were conducted in children and adolescents aged 9-18 years with maltreatment experiences (CM) and typically developing (TD) children. The retinal nerve fiber layer (RNFL), the most superficial of the ten distinct retinal layers, was found to be significantly thinner in both eyes in CM. While whole-brain analysis using Voxel-based morphometry revealed a significantly larger gray matter volume (GMV) in the thalamus in CM, no significant correlation with RNFL thickness was observed. However, based on region-of-interest analysis, a thinner RNFL was associated with a larger GMV in the right V1. Although it cannot be ruled out that this outcome resulted from maltreatment alone, CM demonstrated subclinical structural atypicality in the retina, which may also correlate with the immaturity of V1 development. Examination of retinal thickness offers a novel clinical approach to capturing characteristics associated with childhood maltreatment.


Child Abuse , Gray Matter , Magnetic Resonance Imaging , Retina , Visual Cortex , Humans , Child , Gray Matter/diagnostic imaging , Gray Matter/pathology , Male , Adolescent , Female , Retina/pathology , Retina/diagnostic imaging , Magnetic Resonance Imaging/methods , Visual Cortex/diagnostic imaging , Visual Cortex/pathology
6.
Cereb Cortex ; 34(5)2024 May 02.
Article En | MEDLINE | ID: mdl-38752980

The effects of hypoxia on brain function remain largely unknown. This study aimed to clarify this issue by visual-stimulated functional magnetic resonance imaging design. Twenty-three college students with a 30-d high-altitude exposure were tested before, 1 week and 3 months after returning to sea level. Brain functional magnetic resonance imaging and retinal electroretinogram were acquired. One week after returning to sea level, decreased blood oxygenation level dependent in the right lingual gyrus accompanied with increased blood oxygenation level dependent in the frontal cortex and insular cortex, and decreased amplitude of electroretinogram a-wave in right eye; moreover, the bilateral lingual gyri showed increased functional connectivity within the dorsal visual stream pathway, and the blood oxygenation level dependent signals in the right lingual gyrus showed positive correlation with right retinal electroretinogram a-wave. Three months after returning to sea level, the blood oxygenation level dependent signals recovered to normal level, while intensively increased blood oxygenation level dependent signals in a broad of brain regions and decreased retinal electroretinogram were also existed. In conclusion, hypoxic exposure has long-term effects on visual cortex, and the impaired retinal electroretinogram may contribute to it. The increased functional connectivity of dorsal stream may compensate for the decreased function of retinal photoreceptor cells to maintain normal visual function.


Electroretinography , Magnetic Resonance Imaging , Neuronal Plasticity , Visual Pathways , Humans , Male , Young Adult , Female , Neuronal Plasticity/physiology , Visual Pathways/physiology , Visual Pathways/diagnostic imaging , Hypoxia/physiopathology , Adult , Oxygen/blood , Visual Cortex/diagnostic imaging , Visual Cortex/physiology , Brain/physiology , Brain/diagnostic imaging , Photic Stimulation/methods , Retina/physiology , Retina/diagnostic imaging , Brain Mapping/methods
7.
Opt Lett ; 49(10): 2817-2820, 2024 May 15.
Article En | MEDLINE | ID: mdl-38748169

Alteration in the elastic properties of biological tissues may indicate changes in the structure and components. Acoustic radiation force optical coherence elastography (ARF-OCE) can assess the elastic properties of the ocular tissues non-invasively. However, coupling the ultrasound beam and the optical beam remains challenging. In this Letter, we proposed an OCE method incorporating homolateral parallel ARF excitation for measuring the elasticity of the ocular tissues. An acoustic-optic coupling unit was established to reflect the ultrasound beam while transmitting the light beam. The ARF excited the ocular tissue in the direction parallel to the light beam from the same side of the light beam. We demonstrated the method on the agar phantoms, the porcine cornea, and the porcine retina. The results show that the ARF-OCE method can measure the elasticity of the cornea and the retina, resulting in higher detection sensitivity and a more extensive scanning range.


Cornea , Elasticity Imaging Techniques , Phantoms, Imaging , Tomography, Optical Coherence , Elasticity Imaging Techniques/methods , Animals , Swine , Cornea/diagnostic imaging , Cornea/physiology , Tomography, Optical Coherence/methods , Elasticity , Retina/diagnostic imaging , Retina/physiology
8.
Invest Ophthalmol Vis Sci ; 65(5): 16, 2024 May 01.
Article En | MEDLINE | ID: mdl-38717425

Purpose: Research on Alzheimer's disease (AD) and precursor states demonstrates a thinner retinal nerve fiber layer (NFL) compared to age-similar controls. Because AD and age-related macular degeneration (AMD) both impact older adults and share risk factors, we asked if retinal layer thicknesses, including NFL, are associated with cognition in AMD. Methods: Adults ≥ 70 years with normal retinal aging, early AMD, or intermediate AMD per Age-Related Eye Disease Study (AREDS) nine-step grading of color fundus photography were enrolled in a cross-sectional study. Optical coherence tomography (OCT) volumes underwent 11-line segmentation and adjustments by a trained operator. Evaluated thicknesses reflect the vertical organization of retinal neurons and two vascular watersheds: NFL, ganglion cell layer-inner plexiform layer complex (GCL-IPL), inner retina, outer retina (including retinal pigment epithelium-Bruch's membrane), and total retina. Thicknesses were area weighted to achieve mean thickness across the 6-mm-diameter Early Treatment of Diabetic Retinopathy Study (ETDRS) grid. Cognitive status was assessed by the National Institutes of Health Toolbox cognitive battery for fluid and crystallized cognition. Correlations estimated associations between cognition and thicknesses, adjusting for age. Results: Based on 63 subjects (21 per group), thinning of the outer retina was significantly correlated with lower cognition scores (P < 0.05). No other retinal thickness variables were associated with cognition. Conclusions: Only the outer retina (photoreceptors, supporting glia, retinal pigment epithelium, Bruch's membrane) is associated with cognition in aging to intermediate AMD; NFL was not associated with cognition, contrary to AD-associated condition reports. Early and intermediate AMD constitute a retinal disease whose earliest, primary impact is in the outer retina. Our findings hint at a unique impact on the brain from the outer retina in persons with AMD.


Aging , Cognition , Macular Degeneration , Retina , Tomography, Optical Coherence , Humans , Tomography, Optical Coherence/methods , Male , Aged , Female , Cross-Sectional Studies , Aging/physiology , Aged, 80 and over , Macular Degeneration/physiopathology , Cognition/physiology , Retina/diagnostic imaging , Retina/pathology , Retina/physiopathology , Nerve Fibers/pathology , Retinal Ganglion Cells/pathology
9.
J Biomed Opt ; 29(6): 066002, 2024 Jun.
Article En | MEDLINE | ID: mdl-38745984

Significance: Optical coherence tomography (OCT) has emerged as the standard of care for diagnosing and monitoring the treatment of various ocular disorders due to its noninvasive nature and in vivo volumetric acquisition capability. Despite its widespread applications in ophthalmology, motion artifacts remain a challenge in OCT imaging, adversely impacting image quality. While several multivolume registration algorithms have been developed to address this issue, they are often designed to cater to one specific OCT system or acquisition protocol. Aim: We aim to generate an OCT volume free of motion artifacts using a system-agnostic registration algorithm that is independent of system specifications or protocol. Approach: We developed a B-scan registration algorithm that removes motion and corrects for both translational eye movements and rotational angle differences between volumes. Tests were carried out on various datasets obtained from two different types of custom-built OCT systems and one commercially available system to determine the reliability of the proposed algorithm. Additionally, different system specifications were used, with variations in axial resolution, lateral resolution, signal-to-noise ratio, and real-time motion tracking. The accuracy of this method has further been evaluated through mean squared error (MSE) and multiscale structural similarity index measure (MS-SSIM). Results: The results demonstrate improvements in the overall contrast of the images, facilitating detailed visualization of retinal vasculatures in both superficial and deep vasculature plexus. Finer features of the inner and outer retina, such as photoreceptors and other pathology-specific features, are discernible after multivolume registration and averaging. Quantitative analyses affirm that increasing the number of averaged registered volumes will decrease MSE and increase MS-SSIM as compared to the reference volume. Conclusions: The multivolume registered data obtained from this algorithm offers significantly improved visualization of the retinal microvascular network as well as retinal morphological features. Furthermore, we have validated that the versatility of our methodology extends beyond specific OCT modalities, thereby enhancing the clinical utility of OCT for the diagnosis and monitoring of ocular pathologies.


Algorithms , Imaging, Three-Dimensional , Retina , Tomography, Optical Coherence , Tomography, Optical Coherence/methods , Retina/diagnostic imaging , Humans , Imaging, Three-Dimensional/methods , Artifacts , Reproducibility of Results , Signal-To-Noise Ratio
10.
Opt Lett ; 49(9): 2209-2212, 2024 May 01.
Article En | MEDLINE | ID: mdl-38691681

Under spatially incoherent illumination, time-domain full-field optical coherence tomography (FFOCT) offers the possibility to achieve in vivo retinal imaging at cellular resolution over a wide field of view. Such performance is possible, albeit there is the presence of ocular aberrations even without the use of classical adaptive optics. While the effect of aberrations in FFOCT has been debated these past years, mostly on low-order and static aberrations, we present, for the first time to our knowledge, a method enabling a quantitative study of the effect of statistically representative static and dynamic ocular aberrations on FFOCT image metrics, such as SNR, resolution, and image similarity. While we show that ocular aberrations can decrease FFOCT SNR and resolution by up to 14 dB and fivefold, we take advantage of such quantification to discuss different possible compromises between performance gain and adaptive optics complexity and speed, to optimize both sensor-based and sensorless FFOCT high-resolution retinal imaging.


Retina , Tomography, Optical Coherence , Tomography, Optical Coherence/methods , Retina/diagnostic imaging , Humans , Signal-To-Noise Ratio
11.
Opt Lett ; 49(9): 2489-2492, 2024 May 01.
Article En | MEDLINE | ID: mdl-38691751

Point scanning retinal imaging modalities, including confocal scanning light ophthalmoscopy (cSLO) and optical coherence tomography, suffer from fixational motion artifacts. Fixation targets, though effective at reducing eye motion, are infeasible in some applications (e.g., handheld devices) due to their bulk and complexity. Here, we report on a cSLO device that scans the retina in a spiral pattern under pseudo-visible illumination, thus collecting image data while simultaneously projecting, into the subject's vision, the image of a bullseye, which acts as a virtual fixation target. An imaging study of 14 young adult volunteers was conducted to compare the fixational performance of this technique to that of raster scanning, with and without a discrete inline fixation target. Image registration was used to quantify subject eye motion; a strip-wise registration method was used for raster scans, and a novel, to the best of our knowledge, ring-based method was used for spiral scans. Results indicate a statistically significant reduction in eye motion by the use of spiral scanning as compared to raster scanning without a fixation target.


Fixation, Ocular , Ophthalmoscopy , Retina , Humans , Retina/diagnostic imaging , Fixation, Ocular/physiology , Ophthalmoscopy/methods , Adult , Young Adult , Eye Movements
12.
Behav Brain Funct ; 20(1): 13, 2024 May 24.
Article En | MEDLINE | ID: mdl-38789988

BACKGROUND: Macular degeneration of the eye is a common cause of blindness and affects 8% of the worldwide human population. In adult cats with bilateral lesions of the central retina, we explored the possibility that motion perception training can limit the associated degradation of the visual system. We evaluated how visual training affects behavioral performance and white matter structure. Recently, we proposed (Kozak et al. in Transl Vis Sci Technol 10:9, 2021) a new motion-acuity test for low vision patients, enabling full visual field functional assessment through simultaneous perception of shape and motion. Here, we integrated this test as the last step of a 10-week motion-perception training. RESULTS: Cats were divided into three groups: retinal-lesioned only and two trained groups, retinal-lesioned trained and control trained. The behavioral data revealed that trained cats with retinal lesions were superior in motion tasks, even when the difficulty relied only on acuity. 7 T-MRI scanning was done before and after lesioning at 5 different timepoints, followed by Fixel-Based and Fractional Anisotropy Analysis. In cats with retinal lesions, training resulted in a more localized and reduced percentage decrease in Fixel-Based Analysis metrics in the dLGN, caudate nucleus and hippocampus compared to untrained cats. In motion-sensitive area V5/PMLS, the significant decreases in fiber density were equally strong in retinal-lesioned untrained and trained cats, up to 40% in both groups. The only cortical area with Fractional Anisotropy values not affected by central retinal loss was area V5/PMLS. In other visual ROIs, the Fractional Anisotropy values increased over time in the untrained retinal lesioned group, whereas they decreased in the retinal lesioned trained group and remained at a similar level as in trained controls. CONCLUSIONS: Overall, our MRI results showed a stabilizing effect of motion training applied soon after central retinal loss induction on white matter structure. We propose that introducing early motion-acuity training for low vision patients, aimed at the intact and active retinal peripheries, may facilitate brain plasticity processes toward better vision.


Magnetic Resonance Imaging , Motion Perception , White Matter , Animals , White Matter/diagnostic imaging , White Matter/pathology , Cats , Magnetic Resonance Imaging/methods , Motion Perception/physiology , Retina/diagnostic imaging , Retina/physiopathology , Male , Female
13.
Transl Vis Sci Technol ; 13(5): 15, 2024 May 01.
Article En | MEDLINE | ID: mdl-38767904

Purpose: To highlight the utility of en face swept-source optical coherence tomography angiography (SS-OCTA) in assessing vitreoretinal interface cells (VRICs) of patients with active uveitis and their dynamics. Methods: In this prospective, single-center study, 20 eyes from patients with active uveitis were analyzed using six 6 × 6-mm macular scans at three time points: active inflammation (baseline), clinically improving (T1), and resolved inflammation (T2). VRICs were visualized using 3-µm en face OCT slabs on the inner limiting membrane. The variation of VRIC number, density, and size over time was assessed, and VRIC measurements were compared with clinical grading. Results: At baseline, the VRIC count was significantly higher (552.5 VRICs) than that of the healthy controls (478.2 VRICs), with a density of 15.3 cells/mm2. VRIC number decreased significantly to 394.8 (P = 0.007) at T1, with a density of 10.9 cells/mm2 (P = 0.007). VRIC size reduced from 6.8 µm to 6.3 µm at T1 (P = 0.009) and remained stable at T2 (P = 0.3). Correlation coefficients between inflammatory parameters (anterior chamber cells and National Eye Institute vitreous haze), and VRIC count indicated a positive correlation at baseline (r = 0.53), weakening at T1 (r = 0.36), and becoming negative at T2 (r = -0.24). Conclusions: En face SS-OCTA revealed increased VRIC number and size in active uveitis, likely due to monocyte recruitment. Post-inflammation control, VRIC number, size, and density significantly decreased, returning to normal despite residual anterior chamber cells or vitreous haze. Translational Relevance: Visualization of VRICs by in vivo OCT opens up new opportunities for therapeutic targets.


Tomography, Optical Coherence , Uveitis , Vitreous Body , Humans , Male , Prospective Studies , Female , Uveitis/drug therapy , Uveitis/pathology , Middle Aged , Adult , Vitreous Body/pathology , Vitreous Body/diagnostic imaging , Fluorescein Angiography/methods , Aged , Retina/pathology , Retina/diagnostic imaging , Young Adult , Cell Count , Anti-Inflammatory Agents/therapeutic use , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/administration & dosage
14.
PLoS Genet ; 20(5): e1011273, 2024 May.
Article En | MEDLINE | ID: mdl-38728357

Existing imaging genetics studies have been mostly limited in scope by using imaging-derived phenotypes defined by human experts. Here, leveraging new breakthroughs in self-supervised deep representation learning, we propose a new approach, image-based genome-wide association study (iGWAS), for identifying genetic factors associated with phenotypes discovered from medical images using contrastive learning. Using retinal fundus photos, our model extracts a 128-dimensional vector representing features of the retina as phenotypes. After training the model on 40,000 images from the EyePACS dataset, we generated phenotypes from 130,329 images of 65,629 British White participants in the UK Biobank. We conducted GWAS on these phenotypes and identified 14 loci with genome-wide significance (p<5×10-8 and intersection of hits from left and right eyes). We also did GWAS on the retina color, the average color of the center region of the retinal fundus photos. The GWAS of retina colors identified 34 loci, 7 are overlapping with GWAS of raw image phenotype. Our results establish the feasibility of this new framework of genomic study based on self-supervised phenotyping of medical images.


Fundus Oculi , Genome-Wide Association Study , Phenotype , Retina , Humans , Genome-Wide Association Study/methods , Retina/diagnostic imaging , Male , Polymorphism, Single Nucleotide , Female , Image Processing, Computer-Assisted/methods
15.
Vestn Oftalmol ; 140(2. Vyp. 2): 172-179, 2024.
Article Ru | MEDLINE | ID: mdl-38739148

Multifocal electroretinography is a valuable diagnostic method for the objective localization and quantitative assessment of functional disorders of the central retina in age-related macular degeneration. It is used to detect early changes, monitor the course of the disease and treatment outcomes. In many cases, multifocal electroretinography is a more sensitive method for detecting functional disorders at the early/intermediate stage of age-related macular degeneration compared to morphological (optical coherence tomography) and subjective (visual acuity, perimetry) testing methods.


Electroretinography , Macular Degeneration , Retina , Humans , Electroretinography/methods , Macular Degeneration/diagnosis , Macular Degeneration/physiopathology , Retina/diagnostic imaging , Retina/physiopathology , Tomography, Optical Coherence/methods , Visual Acuity , Early Diagnosis , Disease Progression
16.
Sci Rep ; 14(1): 12069, 2024 05 27.
Article En | MEDLINE | ID: mdl-38802443

Optical coherence tomography (OCT) displays the retinal nerve fiber layer (RNFL) or macular ganglion cell and inner plexiform layer (GCIPL) thickness below 1st percentile in red color. This finding generally indicates severe inner-retinal structural changes and suggests poor visual function. Nevertheless, some individuals show preserved visual function despite these circumstances. This study aimed to identify the correlation between best-corrected visual acuity (BCVA) and inner-retinal thickness based on OCT parameters in various optic neuropathy patients with extremely low RNFL/GCIPL thickness, and determine the limitation of OCT for predicting visual function in these patients. 131 patients were included in the study. The mean BCVA in logMAR was 0.55 ± 0.70 with a broad range from - 0.18 to 3.00. Among the OCT parameters, temporal GCIPL (r = - 0.412) and average GCIPL (r = - 0.366) exhibited the higher correlations with BCVA. Etiological comparisons of optic neuropathies revealed significantly lower BCVA in LHON (all p < 0.05). Idiopathic optic neuritis (ON) and MOGAD exhibited better and narrower BCVA distributions compared to the other optic neuropathies. OCT had limited utility in reflecting BCVA, notwithstanding significant inner-retinal thinning after optic nerve injuries. Caution is needed in interpreting OCT findings, especially as they relate to the etiology of optic neuropathy.


Optic Nerve Diseases , Tomography, Optical Coherence , Visual Acuity , Humans , Male , Female , Tomography, Optical Coherence/methods , Adult , Middle Aged , Optic Nerve Diseases/physiopathology , Visual Acuity/physiology , Retina/diagnostic imaging , Retina/physiopathology , Retina/pathology , Young Adult , Adolescent , Retinal Ganglion Cells/pathology , Aged , Nerve Fibers/pathology , Child
17.
Front Endocrinol (Lausanne) ; 15: 1373363, 2024.
Article En | MEDLINE | ID: mdl-38808107

Objectives: To explore the correlation between the vessel density (VD) of the retina and choroid vascular plexuses and the thicknesses of their respective retinal layers and choroid membranes in participants with severe non-proliferative diabetic retinopathy (NPDR). Methods: We retrospectively analyzed the data of 42 eyes of 42 participants with diabetes mellitus (DM) and severe NPDR. In addition, 41 eyes of 41 healthy controls were evaluated. Measurements were taken for both groups using optical coherence tomography angiography (OCTA), including the area and perimeter of the foveal vascular zone (FAZ) and the vascular density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choroid capillary (CC). These measurements were compared with the retinal thickness (RT) of the inner/intermediate retinal layers and choroidal thickness (CT). The study evaluated the correlation between RT or CT and VD in the respective vascular networks, namely superficial capillary plexus (SCP), deep capillary plexus (DCP), or CC. Results: The inner RT and VD in all plexuses were significantly lower in the severe NPDR group than in the healthy controls. Furthermore, the FAZ area and perimeter were larger in the severe NPDR group. Inner RT was correlated with VD in the SCP group (r=0.67 and r=0.71 in the healthy control and severe NPDR groups, respectively; p<0.05). CT negatively correlated with VD in the CC (r=-0.697 and r=-0.759 in the healthy control and severe NPDR groups, respectively; p<0.05). Intermediate RT significantly correlated with VD in the DCP of the severe NPDR group (r=-0.55, p<0.05), but not in the healthy control group. Conclusions: Retinal or choroidal thickness strongly correlated with VD. Therefore, patients with severe NPDR must consider the distinct anatomical and functional entities of the various retinal layers and the choroid.


Choroid , Diabetic Retinopathy , Retina , Retinal Vessels , Tomography, Optical Coherence , Humans , Diabetic Retinopathy/diagnostic imaging , Diabetic Retinopathy/pathology , Female , Male , Middle Aged , Retrospective Studies , Tomography, Optical Coherence/methods , Choroid/blood supply , Choroid/diagnostic imaging , Choroid/pathology , Retinal Vessels/diagnostic imaging , Retinal Vessels/pathology , Retina/pathology , Retina/diagnostic imaging , Aged , Adult , Microvascular Density , Case-Control Studies , Severity of Illness Index , Fluorescein Angiography/methods
18.
Invest Ophthalmol Vis Sci ; 65(5): 5, 2024 May 01.
Article En | MEDLINE | ID: mdl-38696189

Purpose: Neuroinflammation plays a significant role in the pathology of Alzheimer's disease (AD). Mouse models of AD and postmortem biopsy of patients with AD reveal retinal glial activation comparable to central nervous system immunoreactivity. We hypothesized that the surface area of putative retinal gliosis observed in vivo using en face optical coherence tomography (OCT) imaging will be larger in patients with preclinical AD versus controls. Methods: The Spectralis II instrument was used to acquire macular centered 20 × 20 and 30 × 25-degrees spectral domain OCT images of 76 participants (132 eyes). A cohort of 22 patients with preclinical AD (40 eyes, mean age = 69 years, range = 60-80 years) and 20 control participants (32 eyes, mean age = 66 years, range = 58-82 years, P = 0.11) were included for the assessment of difference in surface area of putative retinal gliosis and retinal nerve fiber layer (RNFL) thickness. The surface area of putative retinal gliosis and RNFL thickness for the nine sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) map were compared between groups using generalized linear mixed models. Results: The surface area of putative retinal gliosis was significantly greater in the preclinical AD group (0.97 ± 0.55 mm2) compared to controls (0.68 ± 0.40 mm2); F(1,70) = 4.41, P = 0.039; Cohen's d = 0.61. There was no significant difference between groups for RNFL thickness in the 9 ETDRS sectors, P > 0.05. Conclusions: Our analysis shows greater putative retinal gliosis in preclinical AD compared to controls. This demonstrates putative retinal gliosis as a potential biomarker for AD-related neuroinflammation.


Alzheimer Disease , Gliosis , Retinal Ganglion Cells , Tomography, Optical Coherence , Humans , Gliosis/pathology , Gliosis/diagnosis , Alzheimer Disease/diagnosis , Alzheimer Disease/pathology , Tomography, Optical Coherence/methods , Aged , Female , Male , Aged, 80 and over , Middle Aged , Retinal Ganglion Cells/pathology , Nerve Fibers/pathology , Retinal Diseases/diagnosis , Retinal Diseases/etiology , Retina/pathology , Retina/diagnostic imaging
19.
BMC Ophthalmol ; 24(1): 208, 2024 May 07.
Article En | MEDLINE | ID: mdl-38715011

BACKGROUND: To find the relationship between the changes of retinal and choriodal structure/ vascular densities (VD) and the myopia progress. METHODS: 126 eyes of 126 age-matched young participants were divided into three groups: Emmetropia and Low Myopia (EaLM) (33 eyes), Moderate Myopia (MM) (39 eyes), and High Myopia (HM) (54 eyes). Fundus images measuring 12 × 12 mm were captured using ultra-widefield swept-source optical coherence tomography angiography (SS-OCTA). Each image was uniformly divided into nine regions: supra-temporal (ST), temporal (T), infra-temporal (IT), superior (S), central macular area (C), inferior (I), supra-nasal (SN), nasal (N), and infra-nasal (IN). Various structural parameters, including inner retina thickness (IRT), outer retina thickness (ORT), and choroid thickness (CT), were assessed, and the VD of the superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaries (CC), and choroid vessels (ChdV) were quantified. RESULTS: CT in upper fundus exhibited a significant reduction from EaLM to MM. Additionally, ORT (ST, S. SN, C, N, IT, I, IN), CT (ST, S, SN, T, C, N, IT, I, IN) and VDs of SCP (ST, S, C, I, IN), DCP (ST, S, T, C, I) and ChdV (T, N, I, IN) were statistically diminished in EaLM compared to HM. Furthermore, IRT (N), ORT (N, IN), CT (S, SN, T, C, IT, I) and VDs of SCP (I, IN) and DCP (I) exhibited significant decreases as MM progressed towards HM. Intriguingly, there was a notable increase in the VD of CC (ST, S, T, C, N) as myopia progressed from MM to HM. CONCLUSION: Significant changes in retinal and choroid structure and vascular density occur as moderate myopia advances to high myopia. Efforts to curb myopia progression to this stage are essential, as the failure to do so may lead to the development of corresponding retinopathy.


Choroid , Fluorescein Angiography , Myopia , Retinal Vessels , Tomography, Optical Coherence , Humans , Tomography, Optical Coherence/methods , Choroid/blood supply , Choroid/diagnostic imaging , Choroid/pathology , Male , Female , Young Adult , Myopia/physiopathology , Adult , Retinal Vessels/diagnostic imaging , Retinal Vessels/pathology , Fluorescein Angiography/methods , Retina/diagnostic imaging , Retina/pathology , Disease Progression , Adolescent , Fundus Oculi
20.
Sensors (Basel) ; 24(9)2024 Apr 23.
Article En | MEDLINE | ID: mdl-38732784

Artificial retinas have revolutionized the lives of many blind people by enabling their ability to perceive vision via an implanted chip. Despite significant advancements, there are some limitations that cannot be ignored. Presenting all objects captured in a scene makes their identification difficult. Addressing this limitation is necessary because the artificial retina can utilize a very limited number of pixels to represent vision information. This problem in a multi-object scenario can be mitigated by enhancing images such that only the major objects are considered to be shown in vision. Although simple techniques like edge detection are used, they fall short in representing identifiable objects in complex scenarios, suggesting the idea of integrating primary object edges. To support this idea, the proposed classification model aims at identifying the primary objects based on a suggested set of selective features. The proposed classification model can then be equipped into the artificial retina system for filtering multiple primary objects to enhance vision. The suitability of handling multi-objects enables the system to cope with real-world complex scenarios. The proposed classification model is based on a multi-label deep neural network, specifically designed to leverage from the selective feature set. Initially, the enhanced images proposed in this research are compared with the ones that utilize an edge detection technique for single, dual, and multi-object images. These enhancements are also verified through an intensity profile analysis. Subsequently, the proposed classification model's performance is evaluated to show the significance of utilizing the suggested features. This includes evaluating the model's ability to correctly classify the top five, four, three, two, and one object(s), with respective accuracies of up to 84.8%, 85.2%, 86.8%, 91.8%, and 96.4%. Several comparisons such as training/validation loss and accuracies, precision, recall, specificity, and area under a curve indicate reliable results. Based on the overall evaluation of this study, it is concluded that using the suggested set of selective features not only improves the classification model's performance, but aligns with the specific problem to address the challenge of correctly identifying objects in multi-object scenarios. Therefore, the proposed classification model designed on the basis of selective features is considered to be a very useful tool in supporting the idea of optimizing image enhancement.


Artificial Intelligence , Neural Networks, Computer , Retina , Retina/diagnostic imaging , Humans , Image Enhancement/methods , Algorithms , Image Processing, Computer-Assisted/methods , Visual Prosthesis
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