A5034831563- Retinal Diseases and Treatments
- Retinal Development and Disorders
- Glaucoma and retinal disorders
- Retinal Imaging and Analysis
- Ophthalmology and Visual Impairment Studies
- melanin and skin pigmentation
- Visual perception and processing mechanisms
- Genomics and Phylogenetic Studies
- Lysosomal Storage Disorders Research
- Microbial Community Ecology and Physiology
- Color Science and Applications
- Machine Learning and Data Classification
- Photoreceptor and optogenetics research
- Genetic diversity and population structure
- Neural Networks and Applications
- Corneal surgery and disorders
- Psychology of Moral and Emotional Judgment
- Machine Learning in Healthcare
- Glycogen Storage Diseases and Myoclonus
- Animal Vocal Communication and Behavior
- Color perception and design
- Optical Imaging and Spectroscopy Techniques
- Stress Responses and Cortisol
- Retinopathy of Prematurity Studies
- RNA and protein synthesis mechanisms
University College London
2019-2024
Moorfields Eye Hospital
2020-2024
Moorfields Eye Hospital NHS Foundation Trust
2021-2024
University of Leicester
2023
University of Arkansas at Fayetteville
2023
University of California, Davis
2020-2022
Medical College of Wisconsin
2015-2021
University of Colorado Boulder
2016
University of Colorado System
2016
City, University of London
2015
Purpose: Congenital achromatopsia (ACHM) is an autosomal recessive disorder in which cone function absent or severely reduced. Gene therapy animal models of ACHM have shown restoration function, though translation these results to humans relies, part, on the presence viable photoreceptors at time treatment. Here, we characterized residual structure subjects with CNGB3-associated ACHM. Methods: High-resolution imaging (optical coherence tomography [OCT] and adaptive optics scanning light...
Congenital achromatopsia is an autosomal recessive disease causing substantial reduction or complete absence of cone function. Although believed to be a relatively stationary disorder, questions remain regarding the stability structure over time. In this study, authors sought assess repeatability and examine longitudinal changes in measurements central patients with achromatopsia.Forty-one subjects CNGB3-associated were imaged period between 6 26 months using optical coherence tomography...
Purpose: Mutations in six genes have been associated with achromatopsia (ACHM): CNGA3, CNGB3, PDE6H, PDE6C, GNAT2, and ATF6. ATF6 is the most recent gene to be identified, though thorough phenotyping of this genetic subtype lacking. Here, we sought test hypothesis that ATF6-associated ACHM a structurally distinct form congenital ACHM. Methods: Seven genetically confirmed subjects from five nonconsanguineous families were recruited. Foveal hypoplasia integrity ellipsoid zone (EZ) band...
Fast and reliable quantification of cone photoreceptors is a bottleneck in the clinical utilization adaptive optics scanning light ophthalmoscope (AOSLO) systems for study, diagnosis, prognosis retinal diseases. To-date, manual grading has been sole source AOSLO quantification, as no automatic method reliably utilized detection real-world low-quality images diseased retina. We present novel deep learning based approach that combines information from both confocal non-confocal split detector...
Quantification of the human rod and cone photoreceptor mosaic in adaptive optics scanning light ophthalmoscope (AOSLO) images is useful for study various retinal pathologies. Subjective time-consuming manual grading has remained gold standard evaluating these images, with no well validated automatic methods detecting individual rods having been developed. We present a novel deep learning based method, called CNN (RAC-CNN), classifying cones multimodal AOSLO images. test our method on from...
Chronic, non-communicable diseases present a major barrier to living long and healthy life. In many cases, early diagnosis can facilitate prevention, monitoring, treatment efforts, improving patient outcomes. There is therefore critical need make screening techniques as accessible, unintimidating, cost-effective possible. The association between ocular biomarkers systemic health disease (oculomics) presents an attractive opportunity for detection of diseases, ophthalmic are often relatively...
Pathological neovascularisation within the normally avascular cornea is a serious event that can interfere with normal vision. Upregulation of vascular endothelial growth factor (VEGF) has been associated in eye, suggesting maintaining low levels VEGF important for corneal avascularity and intact This study aims to determine expression profile possible contribution sVEGFR-1 barrier.Experimental case series investigating soluble fms-like tyrosine kinase (sFlt) neovascularised human...
Purpose: Mutations in the coding sequence of L and M opsin genes are often associated with X-linked cone dysfunction (such as Bornholm Eye Disease, BED), though exact color vision phenotype these disorders is variable. We examined individuals L/M gene mutations to clarify link between deficiency dysfunction. Methods: recruited 17 males for imaging. The thickness integrity photoreceptor layers were evaluated using spectral-domain optical coherence tomography. Cone density was measured...
Purpose: To assess residual cone structure in subjects with mutations exon 2, 3, and 4 of the OPN1LW or OPN1MW opsin. Methods: Thirteen males had their OPN1LW/OPN1MW opsin genes characterized. The mosaic was imaged using both confocal nonconfocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO), retinal thickness evaluated optical coherence tomography (OCT). Six completed serial imaging over a maximum period 18 months density measured across sessions. Results: Ten an...
ABSTRACT Purpose: To determine the interocular symmetry of foveal cone topography in achromatopsia (ACHM) using non-confocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). Methods: Split-detector AOSLO images mosaic were acquired from both eyes 26 subjects (mean age 24.3 years; range 8–44 years, 14 females) with genetically confirmed CNGA3- or CNGB3-associated ACHM. Cones identified within a manually delineated rod-free zone. Peak density (PCD) was determined an 80 ×...
The presence of a bright light in the visual field has two main effects on retinal image: reduced contrast and increased illuminance because scattered light; latter can, under some conditions, lead to an improvement sensitivity. combined effect remains poorly understood, particularly at low levels. A psychophysical flicker-cancellation test was used measure amount angular distribution eye for 40 observers. Contrast thresholds were measured using functional sensitivity test. Pupil-plane...
We examine the interocular symmetry of foveal outer nuclear layer (ONL) thickness measurements in subjects with achromatopsia (ACHM).Images from 76 CNGA3- or CNGB3-associated ACHM and 42 control were included study. Line volume scans through fovea each eye acquired using optical coherence tomography (OCT). Image quality was assessed for image analysis a previously-described maximum tissue contrast index (mTCI) metric. Three ONL made by single observer average three eye.Mean (± standard...
Purpose: Blue cone monochromacy (BCM) is a rare inherited disorder in which both long- (L-) and middle- (M-) wavelength sensitive classes are either impaired or nonfunctional. Assessing genotype-phenotype relationships BCM can improve our understanding of retinal development the absence functional L- M-cones. Here we examined foveal structure patients with genetically-confirmed BCM, using adaptive optics scanning light ophthalmoscopy (AOSLO). Methods: Twenty-three male (aged 6–75 years) were...
Abstract In light of ongoing environmental change, understanding the complex impact interacting stressors on species, communities, and ecosystems is an important challenge. Many studies to date examine effects potential a single species concern. Yet these often resonate throughout community may produce changes in ecosystem dynamics that are equally critical resilience. The aim this study was develop mechanistic how rapidly changing stressor, water temperature, will alter trophic interactions...
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 subjects achromatopsia (ACHM). Methods: Previously acquired OCT and non-confocal, split-detector AOSLO from one eye 66 genetically confirmed (15 CNGA3 51 CNGB3) were reviewed along best-corrected visual acuity (BCVA) axial length. interpolated vertical volumes CIRRUS macular cubes divided into four...
As commercially available glasses for color vision deficiency (CVD) are classified as low risk, they not subject to stringent marketing regulations. We investigate how EnChroma and VINO affect performance on the Colour Assessment Diagnosis (CAD) test in individuals with CVD. Data were obtained from 51 red-green Blood or saliva samples collected examine structure of OPN1LW/OPN1MW array. Individuals completed CAD twice without once each pair glasses. Although there was a statistically...
To examine repeatability and reproducibility of foveal cone density measurements in patients with CNGA3- CNGB3-associated achromatopsia (ACHM) using split-detection adaptive optics scanning light ophthalmoscopy (AOSLO).Thirty foveae from molecularly confirmed subjects ACHM, half whom harbored disease-causing variants CNGA3 CNGB3, underwent nonconfocal AOSLO imaging. Cone photoreceptors within the manually delineated rod-free zone were identified twice by two independent observers. The...
Quantification of the rod photoreceptor mosaic using adaptive optics scanning light ophthalmoscopy (AOSLO) remains challenging. Here we demonstrate a method for deriving estimates density and rod:cone ratio based on measures spacing, cone numerosity, inner segment area. Twenty-two AOSLO images with complete visualization were used to validate this spacing-derived estimating density. The was then estimate metrics in an additional 105 without visualization. comparable published data from...
To compare foveal hypoplasia and the appearance of ellipsoid zone (EZ) at fovea in patients with genetically confirmed achromatopsia (ACHM) blue cone monochromacy (BCM).
Lafora disease is a genetic neurodegenerative metabolic disorder caused by insoluble polyglucosan aggregate accumulation throughout the central nervous system and body. The retina an accessible neural tissue, which may offer alternative methods to assess neurological diseases quickly noninvasively. In this way, noninvasive imaging provide means characterize disease, enables earlier identification diagnosis of ability monitor progression. study, we sought individuals with using non-invasive...
Aims/Purpose: There is increasing evidence of impaired visual function prior to the presence diabetic retinopathy (DR), yet current diagnostic criteria and treatment onset rely mostly on retinal vascular changes. In this study we measured changes in chromatic rapid flicker sensitivity subjects with prediabetes diabetes establish value such tests as a potential biomarker detecting early diabetes. Methods: Three groups were recruited: 1) normal controls, 2) (HbA1c between 42‐47 mmol/mol), 3)...