Publications by authors named "Kendrick C Shih"

Background: Myopia, characterized by excessive axial elongation of the eyeball, increases risks of having sight-threatening diseases and impose a financial burden to healthcare system. Although myopic control interventions showed their effectiveness in slowing progression, the efficacy varies between individuals and does not completely halt progression. The study aims to investigate the efficacy of combining 0.

View Article and Find Full Text PDF

Purpose: To evaluate the influence of systemic factors on macular vessel density in quantitative Optical Coherence Tomography Angiography (OCTA) by sex.

Study Design: A cross-sectional study.

Methods: A total of 2018 adults were recruited in this study.

View Article and Find Full Text PDF

Purpose: Traditional direct ophthalmoscopy (TDO) is the oldest method of fundus examination; however, it has fallen out of use due to its technical difficulty and limitations to clinical utility, amidst the advent of potentially better options. A spectrum of new technologies may help in addressing the shortcomings of TDO: simulation mannequins with non-tracked TDO, simulation models with tracked TDO, and smartphone ophthalmoscopy (SFO).

Methodology: A systematic search of PubMed, Embase, and Cochrane databases for all studies evaluating usage of simulation mannequins/models and SFO in ophthalmology education was performed, from inception till April 2023 with no language restriction.

View Article and Find Full Text PDF

Dry eye disease is a common multifactorial condition that may be idiopathic or associated with autoimmune conditions, such as Sjogren syndrome. Commensal microorganisms modify immune responses, so it is relevant to understand how they modify such immune-mediated diseases. Microbiota in the gut regulate inflammation in the eye, and conversely, severe inflammation of the ocular surface results in alteration of gut microbiome.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigated how different types of refractive errors (like myopia and hyperopia) affect glaucoma diagnostic measurements from optical coherence tomography (OCT) and OCT angiography (OCTA).
  • It included 1,339 eyes from 791 participants, measuring parameters like nerve fiber layer thickness and capillary density, with results showing more significant effects of ametropia on specific sectors compared to overall measurements.
  • The researchers concluded that adjustments based on axial length and spherical equivalent should be tailored to each sector to help reduce false-positive rates in glaucoma diagnosis.
View Article and Find Full Text PDF

Purpose: Endothelial keratoplasty (EK) is the conventional treatment to improve visual acuity of corneal endothelium decompensation (CED) patients, with other therapies mainly for symptomatic relief. However, the shortage of corneal grafts and other limitations to EK urge the development of novel alternative treatments. In the last decade, novel options have been proposed, yet only a limited number of reviews have systematically reported on outcomes.

View Article and Find Full Text PDF

A persistent epithelial defect (PED) is a corneal epithelial defect that failed to heal after 2weeks. It is a condition that carries much morbidity, and our understanding of PED remains poor, with current treatment methods often having unsatisfactory outcomes. With PEDs becoming more prevalent, more efforts are required to establish reliable treatment modalities.

View Article and Find Full Text PDF

According to the World Health Organization, corneal blindness constitutes 5.1% of global blindness population. Surgical outcomes have been improved significantly in the treatment of corneal blindness.

View Article and Find Full Text PDF

Purpose: We aim to investigate the effect of sustained hyperglycemia on corneal epithelial wound healing, ocular surface and systemic immune response, and microbiome indices in diabetic mice compared to controls after alkaline chemical injury of the eye.

Methods: Corneal alkaline injury was induced in the right eye of Ins2 (Akita) mice and wild-type mice. The groups were observed at baseline and subsequently days 0, 3, and 7 after injury.

View Article and Find Full Text PDF

Background/aims: To assess the normative values and parameters of optical coherence tomography angiography (OCTA) influencing the best corrected visual acuity (BCVA) in adults aged 50 and above.

Methods: This was a prospective cross-sectional study from an eye screening programme in Hong Kong for 4188 citizens aged 50 and above. Images were analysed using a validated quantification software calculating vessel density and capillary perfusion density (CPD), along with other OCTA parameters, such as the foveal avascular zone area (FAZ) and circularity.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to address biases in glaucoma diagnostics caused by refractive errors using optical coherence tomography (OCT) and OCT angiography (OCTA).
  • Imaging data from 1346 eyes in the Hong Kong FAMILY cohort was analyzed, revealing that myopic eyes showed significantly higher false positive rates in certain diagnostic measures compared to emmetropic eyes.
  • Age, sex, and axial length adjustments in the analysis effectively reduced these false positives, suggesting that incorporating these adjustments into OCT systems could improve diagnosis accuracy for myopic patients.
View Article and Find Full Text PDF

This systematic review aimed to determine the comorbid dry eye (DE) and allergic conjunctivitis (AC) prevalence. We searched PubMed and EMBASE for articles published until 22 March 2022, combining the terms "(dry eye OR keratoconjunctivitis sicca) AND allergic conjunctivitis." Study-specific estimates (DE and AC incidence rates among patients with AC and DE, respectively) were combined using the one-group meta-analysis in a random-effects model.

View Article and Find Full Text PDF

Chemical injury of the cornea results in epithelial defect and subsequent stromal scarring and infection. Our study aims to evaluate the effectiveness of pre-treatment of Lycium barbarum polysaccharide (LBP) in promoting corneal re-epithelialization after alkaline burn. The corneas of C57BL/6J mice were pre-treated with topical phosphate-buffered saline or LBP (0.

View Article and Find Full Text PDF

Diabetes Mellitus (DM) is a chronic metabolic disorder characterized by sustained hyperglycemia, potentially leading to life-threatening health problems. While the complication of diabetic retinopathy has been extensively studied, less attention has been given to the impact of diabetes on ocular surface health. In fact diabetic keratopathy is potentially sight-threatening and may also provide diagnostic and management cues for other diabetic systemic complications.

View Article and Find Full Text PDF
Article Synopsis
  • This study evaluates the effectiveness of store-and-forward tele-ophthalmology for diagnosing cataracts, glaucoma, and age-related macular degeneration in patients over 40 with vision impairment lasting three months or more.
  • The research involved comparing tele-ophthalmology results with traditional face-to-face assessments and used statistical measures to determine agreement and accuracy between the two methods.
  • Findings indicated that tele-ophthalmology matched in accuracy, particularly excelling in diagnosing AMD with over 99% sensitivity and specificity, while also showing solid performance with cataracts and glaucoma, and both modalities incurred similar costs.
View Article and Find Full Text PDF

Forming thin tissue constructs with minimal extracellular matrix surrounding them is important for tissue engineering applications. Here, we explore and optimize a strategy that enables rapid fabrication of scaffold-free corneal tissue constructs using the liquid-liquid interface of an aqueous two-phase system (ATPS) that is based on biocompatible polymers, dextran and polyethylene glycol. Intact tissue-like constructs, made of corneal epithelial or endothelial cells, can be formed on the interface between the two liquid phases of ATPS within hours and subsequently collected simply by removing the liquid phases.

View Article and Find Full Text PDF

In health care, virtual reality (VR) and augmented reality (AR) have been applied extensively for many purposes. Similar to other technologies such as telemedicine and artificial intelligence, VR and AR may improve clinical diagnosis and screening services in ophthalmology by alleviating current problems, including workforce shortage, diagnostic error, and underdiagnosis. In the past decade a number of studies and products have used VR and AR concepts to build clinical tests for ophthalmology, but comprehensive reviews on these studies are limited.

View Article and Find Full Text PDF

Different pathophysiologic mechanisms are involved in the initiation, development, and outcome of dry eye disease (DED). Animal models have proven valuable and efficient in establishing ocular surface microenvironments that mimic humans, thus enabling better understanding of the pathogenesis. Several dry eye animal models, including lacrimal secretion insufficiency, evaporation, neuronal dysfunction, and environmental stress models, are related to different etiological factors.

View Article and Find Full Text PDF

Thyroid Eye Disease (TED) is an autoimmune disease that affects the extraocular muscles and periorbital fat. It most commonly occurs with Graves' Disease (GD) as an extrathyroidal manifestation, hence, it is also sometimes used interchangeably with Graves' Ophthalmopathy (GO). Well-known autoimmune markers for GD include thyroid stimulating hormone (TSH) receptor antibodies (TSH-R-Ab) which contribute to hyperthyroidism and ocular signs.

View Article and Find Full Text PDF

We systematically reviewed published research on dry eye disease and its association with higher order aberrations (HOAs). The purpose of this review was to first determine if an association between tear film metrics and HOAs exists and second to determine if the treatment of dry eyes can improve tear film metrics and HOAs together. A search was conducted in Entrez PubMed on 25 April 2021 using the keywords "higher order aberrations" and "dry eye".

View Article and Find Full Text PDF

Recent studies have highlighted the association between ocular diseases and microbiota profiles of the host intestinal tract and oral cavity. There is mounting evidence supporting the existence of a 'gut-eye axis', whereby changes in gut microbiome alter host immunity, with consequential implications for ocular health and disease. In this review, we examined recent published findings on the association between gut microbiome and ocular morbidity, based on 25 original articles published between 2011 to 2020.

View Article and Find Full Text PDF

The public specialty ophthalmic clinics in Hong Kong, under the Hospital Authority, receive tens of thousands of referrals each year. Triaging these referrals incurs a significant workload for practitioners and the other clinical duties. It is well-established that Hong Kong is currently facing a shortage of healthcare workers.

View Article and Find Full Text PDF

Purpose: Cornea epithelial-stromal scarring is related to the differentiation of fibroblasts into opaque myofibroblasts. Our study aims to assess the effectiveness of Lycium barbarum polysaccharide (LBP) solution as a pre-treatment in minimizing corneal scarring.

Methods: Human corneal fibroblasts were cultured in a three-dimensional collagen type I-based hydrogel in an eye-on-a-chip model.

View Article and Find Full Text PDF

The cytoprotective versus cytotoxic role of macroautophagy in ocular ischemia/reperfusion injuries remains controversial and its effects under hyperglycemia are unclear. We investigated the involvement of autophagy in in vitro and in vivo normoglycemic and hyperglycemic models of retinal ischemia/reperfusion injury. Retinal ischemia (2 h) and reperfusion (2 or 22 h) was induced in wild-type and type I diabetic Ins2 mice using a middle cerebral artery occlusion model.

View Article and Find Full Text PDF