Publications by authors named "Carol Y L Cheung"
Purpose: To investigate the topographic characters of inter-individual variations of the macular choroidal thickness (CT).
Methods: This was a retrospective study. Macular CT data for 900 0.
Recent Advances in Clinical Applications of Imaging in Retinal Diseases.
Asia Pac J Ophthalmol (Phila)
March 2023
Many diseases that cause visual impairment, as well as systemic conditions, manifest in the posterior segment of the eye. With the advent of high-speed, high-resolution, reliable, and noninvasive imaging techniques, ophthalmologists are becoming more dependent on ocular imaging for disease diagnosis, classification, and management in clinical practice. There are rapid advances on the indications of multimodal retinal imaging techniques, including the application of ultra-widefield fundus angiography, fundus autofluorescence, optical coherence tomography, as well as optical coherence tomography angiography.
View Article and Find Full Text PDFThe clinical diagnostic evaluation of optic neuropathies relies on the analysis of the thickness of the retinal nerve fibre layer (RNFL) by optical coherence tomography (OCT). However, false positives and false negatives in the detection of RNFL abnormalities are common. Here we show that an algorithm integrating measurements of RNFL thickness and reflectance from standard wide-field OCT scans can be used to uncover the trajectories and optical texture of individual axonal fibre bundles in the retina and to discern distinctive patterns of loss of axonal fibre bundles in glaucoma, compressive optic neuropathy, optic neuritis and non-arteritic anterior ischaemic optic neuropathy.
View Article and Find Full Text PDFTo provide clinical evidence of the associations between retinal neuronal degeneration and microvasculopathy in diabetic retinopathy (DR). This case-control study included 76 patients (76 eyes) with type 2 diabetes mellitus (DM), and refraction error between -3.0 and +3.
View Article and Find Full Text PDFPurpose: To determine the myopia prevalence in Hong Kong Chinese children and their parents.
Methods: It was a population-based cross-sectional study. A total of 4257 children aged 6-8 years, and 5880 parents were recruited in the Hong Kong Children Eye Study.
We evaluated automated OCT-derived drusen volume measures in a population-based study (n = 4,512) aged ≥40 years, and its correlation with conventional color fundus photographs (CFP)-derived early AMD features. Participants had protocol-based assessment to capture medical and ocular history, genotyping for SNPs in CFH, ARMS2, and CETP, CFP-based AMD grading and automated drusen volume based on SD-OCT using built-in software (Cirrus OCT advanced RPE analysis software). Significantly fewer eyes with early AMD features (drusen, hyperpigmentation, soft or reticular drusen) had drusen volume = 0 mm (p < 0.
View Article and Find Full Text PDFPurpose: To investigate the agreement of vertical cup-to-disc ratio (VCDR) measured from Heidelberg Retina Tomograph 3 (HRT-3), high-definition optical coherence tomography (HD-OCT), and clinical grading.
Methods: A total of 933 consecutive subjects underwent optic nerve head imaging with HRT-3 and HD-OCT during a single visit. The vertical dimensions of the disc and cup were measured by slit-lamp examination using an eyepiece graticule.
Objective: To study the prevalence of and associated factors for cognitive impairment and dementia in community dwelling Chinese from Singapore.
Methods: This study includes Chinese subjects from the Epidemiology of Dementia in Singapore (EDIS) study, aged ≥60 years, who underwent comprehensive examinations, including cognitive screening with the locally validated Abbreviated Mental Test and Progressive Forgetfulness Questionnaire. Screen positive participants subsequently underwent extensive neuropsychological testing and cerebral MRI.
Objective: To evaluate the performance of progression detection and the rate of change of retinal nerve fiber layer (RNFL), neuroretinal rim, and visual field measurements in glaucoma.
Design: Prospective study.
Participants: One hundred eight eyes of 70 glaucoma patients.
Influence of height, weight, and body mass index on optic disc parameters.
Invest Ophthalmol Vis Sci
June 2010
Purpose: To examine the influence of body height, body weight, and body mass index (BMI) on optic disc parameters in a population-based study.
Methods: The Singapore Malay Eye Study examined 3280 persons of Malay ethnicity, aged 40 to 80 years, of whom 2329 (71.0%) had reliable retinal scanning confocal laser tomography images for analyses.
Objective: To evaluate and compare the diagnostic agreement and performance for glaucoma detection between a confocal scanning laser ophthalmoscope and a spectral-domain optical coherence tomograph (OCT).
Design: Prospective, cross-sectional study.
Participants: One hundred fifty-five subjects (79 glaucoma and 76 normal subjects).
Purpose: To evaluate optical coherence tomography (OCT) retinal nerve fiber layer thickness (RNFLT) measurement for glaucoma progression analysis.
Methods: One hundred sixteen eyes of 64 patients with glaucoma who were observed within a period of 5 years were included. All eyes had at least four serial RNFL measurements obtained with the Stratus OCT (Carl Zeiss Meditec, Dublin, CA) and with the first and last measurements separated by at least 3 years.
Purpose: To develop a grading system to evaluate the scleral spur visibility and to investigate the association between this and the angle width.
Methods: Sixty healthy normal subjects (33 with open angles and 27 with narrow angles on dark room gonioscopy) underwent anterior segment imaging with the Visante OCT (Carl Zeiss Meditec, Dublin, CA). The anterior chamber angles at 12-o' clock hour positions were imaged and analyzed.
Purpose: To evaluate and compare the longitudinal variability of optical coherence tomography (OCT) and confocal scanning laser ophthalmoscopy (CSLO) optic disc measurements.
Methods: A total of 25 normal and 50 glaucomatous eyes from 75 subjects were included in the analysis. The optic disc was measured by OCT and CSLO.
Purpose: To compare anterior chamber angle measurements obtained from two anterior segment optical coherence tomography (OCT) instruments and to evaluate their agreements and interobserver reproducibility.
Methods: Forty-nine eyes from 49 healthy normal subjects were studied. The anterior chamber angle was imaged with the Visante anterior segment OCT (Carl Zeiss Meditec, Dublin, CA) and the slit lamp OCT (SLOCT, Heidelberg Engineering, GmbH, Dossenheim, Germany) on one randomly selected eye in each subject and measured by two independent observers.
Purpose: To determine the changes in corneal optical performance after posterior lamellar corneal transplantation.
Design: Retrospective case series.
Methods: The anterior segment in four eyes of four patients who underwent Descemet stripping endothelial keratoplasty (DSEK) with cataract extraction and intraocular lens (IOL) implantation were imaged with the Visante anterior segment optical coherence tomography [OCT] (Carl Zeiss Meditec, Dublin, California, USA).
Purpose: To examine the relationship between signal strength and retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT).
Design: Observational cross-sectional study.
Participants: Forty normal subjects were recruited.
Purpose: To evaluate the repeatability and reproducibility of central corneal thickness (CCT) measurements obtained by 2 anterior segment optical coherence tomography (OCT) imaging systems and to examine their agreements with ultrasound pachymetry.
Design: Observational cross-sectional study.
Participants: Fifty eyes from 50 healthy normal subjects were recruited.
Purpose: To describe the use of anterior segment optical coherence tomography (OCT) in studying the dynamic dark-light changes of the anterior chamber angle.
Methods: Thirty-seven normal subjects with open angles on dark-room gonioscopy and 18 subjects with narrow angles were analyzed. The dynamic dark-light changes of the anterior-chamber angle were captured with real-time video recording.
Purpose: To evaluate the relationships between optic disc measurements, obtained by an optical coherence tomograph and a confocal scanning laser ophthalmoscope, and myopia.
Methods: One hundred thirty-three eyes from 133 healthy subjects with mean spherical equivalent -6.0 +/- 4.
Purpose: To compare the relationships between optic nerve structural measures and visual function, as well as the diagnostic sensitivity for glaucoma detection between the retinal nerve fiber layer (RNFL) and neuroretinal rim measurements.
Methods: A total of 101 normal and 156 glaucomatous eyes of 257 enrolled subjects were examined. RNFL thickness was measured by optical coherence tomography, and the neuroretinal rim (rim area, rim/disc area, and rim volume) was measured with a confocal scanning laser ophthalmoscope.
Purpose: To assess the agreement of central and paracentral corneal thickness measurements between ultrasound pachymetry (USP), Orbscan II, and Visante anterior segment optical coherence tomography (ASOCT).
Design: Observational cross-sectional study.
Participants: Seventy eyes of 70 subjects.
Aim: To evaluate the repeatability and reproducibility of anterior chamber angle measurement obtained by anterior segment optical coherence tomography.
Methods: Twenty-five normal subjects were invited for anterior chamber angle imaging with an anterior segment optical coherence tomography (OCT) on one randomly selected eye in three separate visits within a week. Each eye was imaged three times under room light (light intensity = 368 lux) and three times in the dark during the first visit.
Purpose: To investigate the relationship between myopia and macular thickness, as measured by optical coherence tomography.
Methods: A total of 143 normal subjects comprising 80 eyes with high myopia (spherical equivalent [SE] < -6.0 D), 37 eyes with low to moderate myopia (SE between -6.