59 results on '"Hou Ang"'
Search Results
2. A deep dive into hyperbaric environments and intraocular pressure—a systematic review
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Paul Connor Lentz, Sheng Yang Lim, Bjorn Kaijun Betzler, Darby D. Miller, Syril K. Dorairaj, and Bryan Chin Hou Ang
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intraocular pressure ,glaucoma ,diving ,atmospheric pressure ,hyperbaric ,Medicine (General) ,R5-920 - Abstract
PurposeSCUBA diving exposes participants to a unique hyperbaric environment, but few studies have examined the effects of such an environment on intraocular pressure (IOP) and glaucoma. This systematic review aims to consolidate recent literature findings regarding the impact of increased atmospheric pressure on IOP and glaucoma.MethodsThree online databases were searched to identify publications encompassing the subjects of diving or increased atmospheric pressure in conjunction with IOP or glaucoma. Three reviewers independently screened the publications and identified eligible articles. Relevant data was extracted from each article. The heterogeneity of the data precluded the conduct of a meta-analysis.ResultsNine studies met the inclusion criteria. Six experimental studies employed hyperbaric chambers to measure IOP under simulated diving conditions. Among these, IOP exhibited a reduction with increased atmospheric pressures in four studies, while the findings of two studies were inconclusive. One study measured IOP pre- and post-dive and another measured IOP with and without a diving mask. Post-dive, a decrease in IOP was observed, and a statistically significant reduction was noted when subjects wore a diving mask. A retrospective study examining the incidence of acute angle closure glaucoma attack found no association with weather or atmospheric pressure.ConclusionThe majority of studies found IOP to decrease with increased atmospheric pressure and after diving. The mechanisms underlying this reduction remain incompletely understood, with potential contributors including changes in ocular blood flow, sympathetic responses, and increased oxygenation. Hyperbaric chambers may have potential in future glaucoma treatments, but more studies are required to draw reliable conclusions regarding the safety of diving for glaucoma patients.
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- 2024
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3. Remote Perimetry in a Virtual Reality Metaverse Environment for Out-of-Hospital Functional Eye Screening Compared Against the Gold Standard Humphrey Visual Fields Perimeter: Proof-of-Concept Pilot Study
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Kang-An Wong, Bryan Chin Hou Ang, Dinesh Visva Gunasekeran, Rahat Husain, Joewee Boon, Krishna Vikneson, Zyna Pei Qi Tan, Gavin Siew Wei Tan, Tien Yin Wong, and Rupesh Agrawal
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Public aspects of medicine ,RA1-1270 - Abstract
BackgroundThe growing global burden of visual impairment necessitates better population eye screening for early detection of eye diseases. However, accessibility to testing is often limited and centralized at in-hospital settings. Furthermore, many eye screening programs were disrupted by the COVID-19 pandemic, presenting an urgent need for out-of-hospital solutions. ObjectiveThis study investigates the performance of a novel remote perimetry application designed in a virtual reality metaverse environment to enable functional testing in community-based and primary care settings. MethodsThis was a prospective observational study investigating the performance of a novel remote perimetry solution in comparison with the gold standard Humphrey visual field (HVF) perimeter. Subjects received a comprehensive ophthalmologic assessment, HVF perimetry, and remote perimetry testing. The primary outcome measure was the agreement in the classification of overall perimetry result normality by the HVF (Swedish interactive threshold algorithm–fast) and testing with the novel algorithm. Secondary outcome measures included concordance of individual testing points and perimetry topographic maps. ResultsWe recruited 10 subjects with an average age of 59.6 (range 28-81) years. Of these, 7 (70%) were male and 3 (30%) were female. The agreement in the classification of overall perimetry results was high (9/10, 90%). The pointwise concordance in the automated classification of individual test points was 83.3% (8.2%; range 75%-100%). In addition, there was good perimetry topographic concordance with the HVF in all subjects. ConclusionsRemote perimetry in a metaverse environment had good concordance with gold standard perimetry using the HVF and could potentially avail functional eye screening in out-of-hospital settings.
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- 2023
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4. Prospective 12-month outcomes of combined iStent inject implantation and phacoemulsification in Asian eyes with normal tension glaucoma
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Bryan Chin Hou Ang, Wenqi Chiew, Vivien Cherng Hui Yip, Chun Hau Chua, Wei Shan Han, Ivan O’Neill C. Tecson, Jeanne Joyce Ogle, Boon Ang Lim, Owen Kim Hee, Elton Lik Yong Tay, Vernon Khet Yau Yong, Hon Tym Wong, and Leonard Wei Leon Yip
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iStent inject ,Normal tension glaucoma ,Minimally invasive glaucoma surgery ,Asian ,Ophthalmology ,RE1-994 - Abstract
Abstract Background Glaucoma is the leading cause of irreversible blindness. Normal tension glaucoma (NTG) is a subset of open-angle glaucoma, demonstrating glaucomatous optic nerve damage in the absence of raised intraocular pressure (IOP). NTG is more prevalent in Asian populations. While generally slow-progressing, NTG may be associated with significant central visual field loss. In recent years, minimally invasive glaucoma surgery has been added to the armamentarium of glaucoma surgery. This prospective study aims to evaluate 12-month surgical outcomes of combined iStent inject (Glaukos Corporation, Laguna Hills, CA) implantation and phacoemulsification in Asian eyes with NTG. Methods This is a prospective, single-centre case series of 30 eyes followed up until 12 months after surgery. Outcome measures included IOP, number of glaucoma medications, best-corrected visual acuity (BCVA) and intra and postoperative complications. Results Mean age of subjects was 73.1 ± 6.3 years. Majority were ethnic Chinese (n = 27, 90%). Baseline medicated mean IOP was 13.8 ± 2.4 mmHg and mean number of glaucoma medications was 1.3 ± 0.7. Mean Humphrey visual field mean deviation was − 13.7 ± 7.6. The mean IOP reduction at all timepoints from postoperative month (POM) 3 onwards was statistically significant (all P
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- 2022
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5. Combined Phacoemulsification and Hydrus Microstent Implantation in Asian Eyes With Moderate-to-Severe Normal Tension Glaucoma--12-Month Outcomes.
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Chin Hou Ang, Bryan, Jiahui Chen, Elizabeth, Wai Kitt Chee, Betzler, Bjorn Kaijun, Chun Hau Chua, Cherng Hui Yip, Vivien, and Wei Leon Yip, Leonard
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- 2024
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6. Recent Advancements in Glaucoma Surgery—A Review
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Bryan Chin Hou Ang, Sheng Yang Lim, Bjorn Kaijun Betzler, Hon Jen Wong, Michael W. Stewart, and Syril Dorairaj
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glaucoma ,trabeculectomy ,glaucoma tube shunts ,minimally invasive glaucoma surgery ,device ,eye ,Technology ,Biology (General) ,QH301-705.5 - Abstract
Surgery has long been an important treatment for limiting optic nerve damage and minimising visual loss in patients with glaucoma. Numerous improvements, modifications, and innovations in glaucoma surgery over recent decades have improved surgical safety, and have led to earlier and more frequent surgical intervention in glaucoma patients at risk of vision loss. This review summarises the latest advancements in trabeculectomy surgery, glaucoma drainage device (GDD) implantation, and minimally invasive glaucoma surgery (MIGS). A comprehensive search of MEDLINE, EMBASE, and CENTRAL databases, alongside subsequent hand searches—limited to the past 10 years for trabeculectomy and GDDs, and the past 5 years for MIGS—yielded 2283 results, 58 of which were included in the final review (8 trabeculectomy, 27 GDD, and 23 MIGS). Advancements in trabeculectomy are described in terms of adjunctive incisions, Tenon’s layer management, and novel suturing techniques. Advancements in GDD implantation pertain to modifications of surgical techniques and devices, novel methods to deal with postoperative complications and surgical failure, and the invention of new GDDs. Finally, the popularity of MIGS has recently promoted modifications to current surgical techniques and the development of novel MIGS devices.
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- 2023
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7. Clinical Care and the COVID-19 Outbreak
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Vasoo, Shawn, primary, Thong, Bernard, additional, Soon, Margaret, additional, Hou, Ang, additional, Tan, Albert, additional, Tan, Hui Ling, additional, and Ho, Benjamin, additional
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- 2022
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8. Premium Intraocular Lenses in Glaucoma—A Systematic Review
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Ashley Shuen Ying Hong, Bryan Chin Hou Ang, Emily Dorairaj, and Syril Dorairaj
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premium intraocular lens ,glaucoma ,multifocal intraocular lens ,extended depth of focus intraocular lens ,toric intraocular lens ,Technology ,Biology (General) ,QH301-705.5 - Abstract
The incidence of both cataract and glaucoma is increasing globally. With increasing patient expectation and improved technology, premium intraocular lenses (IOLs), including presbyopia-correcting and toric IOLs, are being increasingly implanted today. However, concerns remain regarding the use of premium IOLs, particularly presbyopia-correcting IOLs, in eyes with glaucoma. This systematic review evaluates the use of premium IOLs in glaucoma. A comprehensive search of the MEDLINE database was performed from inception until 1 June 2023. Initial search yielded 1404 records, of which 12 were included in the final review of post-operative outcomes. Studies demonstrated high spectacle independence for distance and good patient satisfaction in glaucomatous eyes, with positive outcomes also in post-operative visual acuity, residual astigmatism, and contrast sensitivity. Considerations in patient selection include anatomical and functional factors, such as the type and severity of glaucomatous visual field defects, glaucoma subtype, presence of ocular surface disease, ocular changes after glaucoma surgery, and the reliability of disease monitoring, all of which may be affected by, or influence, the outcomes of premium IOL implantation in glaucoma patients. Regular reviews on this topic are needed in order to keep up with the rapid advancements in IOL technology and glaucoma surgical treatments.
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- 2023
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9. Harnessing the real time location system for contact tracing in the busy emergency department
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Aung, Aung Hein, primary, Li Lianjie, Anthony, additional, Mar Kyaw, Win, additional, Khanna, Rhea, additional, Lim, Wei-Yen, additional, Hou, Ang, additional, and Chow Li Ping, Angela, additional
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- 2023
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10. Save your <scp>TIRs</scp> – more to auxin than meets the eye
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Aaron Chun Hou Ang and Lars Østergaard
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Physiology ,Plant Science - Published
- 2023
11. Staff and patient surveillance in hospitals: Good sentinels for the emergence of new SARS-CoV-2 variants
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Rhea Khanna, Htet Lin Htun, Anthony Lianjie Li, Win Mar Kyaw, Hou Ang, Brenda Ang, and Angela Chow
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Microbiology (medical) ,Infectious Diseases ,SARS-CoV-2 ,Chiroptera ,Animals ,COVID-19 ,Humans ,Hospitals - Published
- 2022
12. Assessing the effects of modified ultrafiltration on open heart surgery in low-weight children
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Liang, Lijun, primary, Yang, Jinming, additional, Hou, Ang, additional, and Liu, Caixia, additional
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- 2023
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13. Sociodemographic and clinical factors, visit expectations and driving factors for emergency department attendance for uncomplicated upper respiratory tract infection
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Angela Chow, Bryan Keng, Huiling Guo, Aung Hein Aung, Zhilian Huang, Yanyi Weng, and Hou Ang
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Adult ,Male ,Motivation ,Emergency Medicine ,Humans ,Female ,General Medicine ,Patient Acceptance of Health Care ,Emergency Service, Hospital ,Critical Care and Intensive Care Medicine ,Referral and Consultation ,Respiratory Tract Infections - Abstract
BackgroundUpper respiratory tract infections (URTIs) account for substantial non-urgent ED attendances. Hence, we explored the reasons for such attendances using a mixed-methods approach.MethodsWe interviewed adult patients with URTI who visited the second busiest adult ED in Singapore from June 2016 to November 2018 on their expectations and reasons for attendance. A structured questionnaire, with one open-ended question was used. Using the Andersen’s Behavioural Model for Healthcare Utilisation, the topmost reasons for ED attendances were categorised into (1) contextual predisposing factors (referral by primary care physician, family, friends or coworkers), (2) contextual enabling factors (convenience, accessibility, employment requirements), (3) individual enablers (personal preference and trust in hospital-perceived care quality and efficiency) and (4) individual needs (perceived illness severity and non-improvement). Multivariable multinomial logistic regression was used to assess associations between sociodemographic and clinical factors, patient expectations for ED visits and the drivers for ED attendance.ResultsThere were 717 patients in the cohort. The mean age of participants was 40.5 (SD 14.7) years, 61.2% were males, 66.5% without comorbidities and 40.7% were tertiary educated. Half had sought prior medical consultation (52.4%) and expected laboratory tests (55.7%) and radiological investigations (46.9%). Individual needs (32.8%) and enablers (25.1%) were the main drivers for ED attendance. Compared with ED attendances due to contextual enabling factors, attendances due to other drivers were more likely to be aged ≥45 years, had prior medical consultation and expected radiological investigations. Having a pre-existing medical condition (adjusted OR (aOR) 1.78, 95% CI 1.05 to 3.04) and an expectation for laboratory tests (aOR 1.64, 95% CI 1.01 to 2.64) were associated with individual needs while being non-tertiary educated (aOR 2.04, 95% CI 1.22 to 3.45) and having pre-existing comorbidities (aOR 1.79, 95% CI 1.04 to 3.10) were associated with individual enablers.ConclusionsMeeting individual needs of perceived illness severity or non-improvement was the topmost driver of ED visits for URTI, while contextual enabling factors such as convenience was the lowest. Patients’ sociodemographic and clinical factors and visit expectations influence their motivations for ED attendances. Addressing these factors and expectations can alleviate the overutilisation of ED services.
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- 2021
14. 12-Month Outcomes of Combined Phacoemulsification and iStent Inject in Asian Eyes with Normal Tension Glaucoma: A Single-Centre Experience
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Leonard W. Yip, John Tsia-Chuen Kan, Bryan Chin Hou Ang, Ivan C. R. O’Neill Tecson, and Jeremy Y. W. Hu
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medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Minimally invasive glaucoma surgery ,business.industry ,medicine.medical_treatment ,Glaucoma ,Subgroup analysis ,Phacoemulsification ,medicine.disease ,eye diseases ,Ophthalmology ,Single centre ,Normal tension glaucoma ,Cohort ,medicine ,sense organs ,business - Abstract
PURPOSE To evaluate efficacy and safety of the iStent inject combined with phacoemulsification in Asian eyes with normal-tension glaucoma (NTG) up to 12 months after surgery. STUDY DESIGN Retrospective case series. METHODS Retrospective case series of eyes undergoing surgery from April 2017 to August 2019. Outcome measures included intraocular pressure (IOP), number of topical glaucoma medications and adverse outcomes. Data were retrieved from the post-operative day 1 (POD1), week 1 (POW1), month 1 (POM1), month 3 (POM3), month 6 (POM6) and month 12 (POM12) timepoints. Data were analysed at each timepoint for eyes with available clinical data at that visit. Subgroup analysis was performed for a consistent cohort which included only eyes with data at all six follow-up timepoints. RESULTS Data from 91 eyes in the collective subject group was analysed. Majority of subjects were male (53, 58.2%) and Chinese (79, 86.8%). Mean age was 73.2 ± 7.2 years. Pre-operatively, mean IOP was 14.3 ± 3.0 mmHg and mean number of medications was 1.5 ± 0.8. Significant IOP reduction was observed at all timepoints except POW1 and POM12. The number of medications was reduced at all timepoints (p
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- 2021
15. Comparison of Surgical Outcomes of Sponge Application versus Subconjunctival Injection of Mitomycin-C during Combined Phacoemulsification and Trabeculectomy Surgery in Asian Eyes
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Bryan Chin Hou Ang, Wenqi Chiew, Xiner Guo, Leonard W. Yip, and Angela Pek Hoon Lim
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Intraocular pressure ,medicine.medical_specialty ,genetic structures ,Asian ,business.industry ,medicine.medical_treatment ,Mitomycin C ,Outcome measures ,Glaucoma ,Postoperative complication ,Trabeculectomy ,Phacoemulsification ,medicine.disease ,eye diseases ,Surgery ,Ophthalmology ,medicine ,Mitomycin-C ,Original Article ,sense organs ,Subconjunctival injection ,business - Abstract
Purpose: To compare the outcomes of combined phacoemulsification–trabeculectomy surgery with intraoperative sponge-applied versus subconjunctival injection of mitomycin-C (MMC) in Asian eyes. Methods: This was a retrospective review of 95 eyes that consecutively underwent combined phacoemulsification–trabeculectomy surgery in a tertiary eye center in Singapore from January 2013 to June 2014. Data collected included intraocular pressure (IOP), best corrected visual acuity, and number of glaucoma medications. Outcome measures included postoperative IOP and complications at various timepoints up to 12 months after surgery. Results: Twenty eyes (21.1%) received 0.2 mg/ml subconjunctival MMC injection (“Group 1”) and 75 (78.9%) received 0.4 mg/ml sponge-applied MMC (“Group 2”). There was no difference between groups in demographics, IOP, and number of glaucoma medications preoperatively. There was a reduction in IOP at postoperative month (POM) 1, 6, and 12 in both the groups (POM12: Group 1, −2.8 ± 5.36 mmHg, P < 0.001; Group 2, −5.8 ± 6.29 mmHg, P = 0.054). At POM1, Group 2 showed a trend toward greater IOP reduction (−5.89 ± 7.67 mmHg vs. −1.55 ± 5.68 mmHg, P = 0.061). However, at both POM6 and POM12, there was no statistically significant difference in IOP reduction between the two groups. At POM12, complete success, defined as achieving an IOP of between 6 and 15 mmHg without the use of antiglaucoma medications, was achieved in 11 (55%) eyes in Group 1 and 48 (64%) in Group 2 (P = 0.9). There was a lower rate of postoperative hypotony in the Group 1 (0%) compared to Group 2 (8%) (P = 0.34). Conclusion: Combined phacoemulsification–trabeculectomy with subconjunctival MMC injection has comparable outcomes to that with sponge-applied MMC, with a similar reduction in IOP at 1, 6, and 12 months postoperatively and a lower postoperative complication rate.
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- 2021
16. A series of 777 pellet gun ocular injuries over a 4-month period in Kashmir
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Sundaram Natarajan, Xin Wei, BryanChin Hou Ang, Arshi Nazir, FaisalQayoom Shah, Tariq Qureshi, and Astha Jain
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Adult ,Male ,Ophthalmology ,Young Adult ,Eye Injuries ,Adolescent ,Incidence ,Visual Acuity ,Humans ,Female ,Prognosis ,Eye Injuries, Penetrating ,Retrospective Studies - Abstract
To examine the incidence, clinical findings and management of pellet gun-related ocular injuries that occurred during protests in Kashmir region.This retrospective study included records from 777 patients diagnosed with pellet gun-related ocular injuries admitted to a tertiary hospital in Srinagar, India, between July and November 2016. By reviewing the clinical records, the following data were collected: demographics, clinical information pertaining to the injury, imaging reports including computer tomography and ultrasonography B-scan, management in the emergency setting, and follow-up treatment.Mean age was 22.3 ± 7.2 years and majority patients were male (97.7%). In terms of laterality, 94.3% and 5.7% of the patients sustained monocular and binocular injuries, respectively. In terms of the nature of injury, 76.3% of the eyes had open globe injury while 23.7% of the eyes had closed eye injury. Emergency surgical exploration was performed in 67.7% of closed globe injuries while emergency primary repair was done in 91.1% of open globe injuries. The vast majority of patients (98.7%) who required surgery underwent surgical intervention on the day of admission or the next day. Final best-corrected visual acuity (BCVA) after treatment was counting fingers or worse in 82.4% of the eyes.Pellet gun-related ocular injuries resulted in significant ocular morbidity, mostly manifesting as open globe injuries. Treatment often required surgical interventions, but despite expeditious management, visual prognosis remained poor for most of the patients.
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- 2022
17. Standalone XEN45 Gel Stent implantation versus combined XEN45-phacoemulsification in the treatment of open angle glaucoma—a systematic review and meta-analysis
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Bryan Chin Hou Ang, Bjorn Kaijun Betzler, Syril Dorairaj, Leonard W. Yip, and Sheng Yang Lim
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medicine.medical_specialty ,genetic structures ,Open angle glaucoma ,Minimally invasive glaucoma surgery ,medicine.medical_treatment ,Glaucoma ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,medicine ,Humans ,Glaucoma Drainage Implants ,Intraocular Pressure ,Phacoemulsification ,business.industry ,Stent ,medicine.disease ,Sensory Systems ,Surgery ,Ophthalmology ,Treatment Outcome ,Meta-analysis ,Concomitant ,030221 ophthalmology & optometry ,Stents ,Observational study ,business ,Glaucoma, Open-Angle ,030217 neurology & neurosurgery - Abstract
The XEN45 Gel Stent is currently the only FDA-approved sub-conjunctival minimally invasive glaucoma surgery (MIGS) procedure. It has been used worldwide either as a standalone implantation procedure or in combination with phacoemulsification surgery. Concomitant phacoemulsification is understood to influence outcomes of traditional subconjunctival filtering surgery. However, the comparative efficacy between standalone XEN45 Gel Sent implantation (“Standalone XEN45”) and combined XEN-phacoemulsification surgery (“XEN45-Phaco”) remains unclear. This study aims to appraise current literature to compare the efficacy of Standalone XEN45 and XEN45-Phaco in open-angle glaucoma. A comprehensive search of PubMed, CINAHL, CENTRAL databases was performed with the terms “Xen surgery” followed by selective vetting. Pilot, cohort, observational studies and randomised controlled trials that included at least 10 patients undergoing either Standalone XEN45 or XEN45-Phaco surgeries for the treatment of open-angle glaucoma were deemed eligible for inclusion after independent assessment by 2 authors. The search workflow was reported according to the PRISMA guidelines. Data was pooled using random-effects model. A meta-analysis of continuous outcome and proportions was performed using the meta routine in R v3.2.1. Ten studies were included. There was a statistically significant difference in IOP reduction favouring Standalone XEN45 at post-operative day 1, week 1, months 1, 3 and 6. There was a statistically significant difference in decrease in IOP-lowering medications favouring Standalone XEN45 at post-operative week 1 and month 1. Standalone XEN45 has superior IOP-lowering outcomes compared to XEN45-Phaco in the early post-operative period, up to 6 months after surgery.
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- 2021
18. The performance of iPad-based noise-field perimeter versus Humphrey Field Analyser in detecting glaucomatous visual field loss
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Bryan Chin Hou Ang, Ivan O'Neill C Tecson, Wenqi Chiew, Leonard W. Yip, Jianbin Ding, and Chunhau Chua
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medicine.medical_specialty ,Scientific community ,genetic structures ,Vision Disorders ,Glaucoma ,Article ,Perimeter ,03 medical and health sciences ,0302 clinical medicine ,Ophthalmology ,medicine ,Humans ,Scotoma ,Public health ,business.industry ,Blind spot ,Repeatability ,medicine.disease ,eye diseases ,Visual field ,Cross-Sectional Studies ,Optic nerve diseases ,030221 ophthalmology & optometry ,Visual Field Tests ,sense organs ,Visual field loss ,Visual Fields ,business ,Noise field ,030217 neurology & neurosurgery ,Kappa - Abstract
Background To conduct a preliminary evaluation of the feasibility of visual field fast (VFF), a free iPad-based noise-field perimeter, in detecting glaucomatous scotomas versus the clinical-standard Humphrey visual field (HVF) test. VFF confronts subjects with a screen of flickering stimulus, allowing the immediate perception of scotomas. Methods This was a cross-sectional observational study of 66 glaucoma patients (66 eyes) and 30 healthy controls (30 eyes). All patients had no other visual field disorders. VFF was compared against HVF in terms of whole field and quadrants for the following: (1) correspondence in scotoma detection. (2) Agreement and correlation of the scotoma size (percentage of abnormal visual field area). (3) Test duration. Other domains tested included: (1) correlation of VFF scotoma area with the severity of visual field loss on HVF (mean deviation, MD; visual field index, VFI). (2) Repeatability of VFF. (3) Patient descriptors of scotomas. Results Using HVF pattern deviation plot as a reference, VFF detected 52/57 (91.2%) of glaucoma subjects with 1 false-positive (control) (kappa = 0.86). 146/184 (79.3%) of abnormal quadrants (visual field defect present) were localized and 23/157 (14.6%) healthy quadrants were falsely identified as abnormal (kappa = 0.61). VFF underestimated scotoma area as compared to HVF (21.0% versus 44.0%, p
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- 2021
19. Refractive outcomes, corneal haze and endothelial cell loss after myopic photorefractive keratectomy in an Asian population: The Singapore Armed Forces' experience
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Bryan Chin Hou Ang, Mellisa Tan, Paul Zhao, Marcus Chiang Lee Tan, Zhi Hong Toh, Edmund Wei Long Lim, Gerard Nah, and Sae Cheong Yap
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Male ,medicine.medical_specialty ,Haze ,genetic structures ,Mitomycin ,medicine.medical_treatment ,Population ,Visual Acuity ,Astigmatism ,Refraction, Ocular ,Photorefractive Keratectomy ,Cornea ,Refractive surgery ,Ophthalmology ,Myopia ,Humans ,Medicine ,education ,Retrospective Studies ,Singapore ,education.field_of_study ,Corneal Haze ,business.industry ,Incidence (epidemiology) ,Endothelial Cells ,medicine.disease ,eye diseases ,Photorefractive keratectomy ,Treatment Outcome ,Asian population ,Lasers, Excimer ,sense organs ,business - Abstract
Importance This study reports outcomes of myopic photorefractive keratectomy (PRK) in a mainly ethnic Chinese population in Singapore. Background To assess the incidence and associations of corneal haze and endothelial cell count (ECC) loss up to 12 months after PRK. Design This was a retrospective case series conducted in a tertiary eye centre. Participants A total of 158 patients (309 eyes) with a mean age of 22.1 ± 3.4 years were included. The majority was Chinese (97.4%) and male (97.4%). Mean preoperative spherical equivalent was -3.33 ± 1.15 D. Methods Eyes were categorized based on postoperative haze severity. A multivariate analysis adjusting for age and use of intraoperative mitomycin-C (MMC), preoperative sphere and cylinder was performed. Main outcome measures Refractive outcomes and corneal haze 3 and 12 months after PRK were assessed. ECC measurements were obtained before PRK and at variable periods postoperatively. Results At 12 months, overall efficacy index was 0.98, and safety index was 1.09. Eight (2.5%) eyes underwent enhancement surgery. An analysis was performed on 295 eyes that did not undergo enhancement and had complete clinical data, which demonstrated a decrease in the incidence of haze from 38.2% at 3 months to 9.3% at 12 months. Higher myopia was associated with increased haze severity at 3 months (OR, 1.36; P = .005). Higher astigmatism was associated with increased haze severity at 3 (OR, 1.65; P = .018) and 12 months (OR, 2.32; P = .015). Intraoperative MMC was not associated with haze severity or ECC loss. Conclusions and relevance Myopia and astigmatism were associated with increased corneal haze severity. Intraoperative MMC did not accelerate ECC loss. Overall, PRK is effective, predictable and safe in Asian eyes.
- Published
- 2020
20. Visual field progression 8 years after trabeculectomy in Asian eyes: results from The Singapore 5-Fluorouracil Study
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Hla Myint Htoon, Tin Aung, Sophia Seen, Bryan Chin Hou Ang, Steve K. L. Seah, Arjunan Kumaran, Rahat Husain, Paul J. Foster, John Mark S. de Leon, Peng T. Khaw, and Gus Gazzard
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Adult ,Male ,Intraocular pressure ,medicine.medical_specialty ,Time Factors ,genetic structures ,medicine.medical_treatment ,Glaucoma ,Trabeculectomy ,Placebo ,Tonometry, Ocular ,Cellular and Molecular Neuroscience ,Ophthalmology ,Humans ,Medicine ,Postoperative Period ,Prospective Studies ,Intraocular Pressure ,Aged ,Retrospective Studies ,Singapore ,business.industry ,Incidence ,Outcome measures ,Mean age ,Middle Aged ,medicine.disease ,eye diseases ,Sensory Systems ,Visual field ,Fluorouracil ,Disease Progression ,Female ,Visual Fields ,business ,Glaucoma, Open-Angle ,Immunosuppressive Agents ,Follow-Up Studies ,medicine.drug - Abstract
Background/AimsThis work aimed to study the effect of long-term intraocular pressure (IOP) fluctuation on visual field (VF) progression 8 years post-trabeculectomy in Asian eyes.MethodsThis was a retrospective analysis of 8-year post-trabeculectomy data from The Singapore 5-Fluorouracil (5-FU) Study. VFs were analysed using Progressor software (Medisoft, Leeds, UK). Outcome measures included mean slope for VF per year, number of progressing points and mean slope for progressing points per year. Multivariate regression analyses were performed adjusting for age, gender, ethnicity, glaucoma type, intraoperative 5-FU, diabetes mellitus, hypertension, best pre-trabeculectomy VF mean deviation, post-trabeculectomy mean IOP, IOP reduction and IOP fluctuation (SD of IOPs at 6-monthly timepoints).Results127 (52.3%) subjects completed 8-year follow-up with ≥5 reliable VFs and ≥8 6-monthly IOP measurements. Mean age was 61.8±9.6 years. Post-operatively, mean IOP was 14.2±2.8 mm Hg and mean IOP fluctuation was 2.53±1.20 mm Hg. Higher IOP fluctuation was associated with greater mean slope for field (B=−0.071; p=0.013), number of progressing points (B=0.963; p=0.014) and VF progression as defined by ≥1 progressing point (OR=1.585; p=0.029). There was also a trend towards eyes with higher IOP fluctuation having ≥3 adjacent progressing points in the same hemifield (OR=1.489; p=0.055). Greater mean IOP reduction post-trabeculectomy was associated only with a lower mean slope for progressing points per year (B=−0.026; p=0.028). There was no significant effect of intra-operative 5-FU compared with placebo for all outcome measures.ConclusionIn post-trabeculectomy Asian eyes with well-controlled IOP, higher long-term IOP fluctuation may be associated with greater VF progression.
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- 2020
21. Complications and post-operative interventions in XEN45 gel stent implantation in the treatment of open angle glaucoma-a systematic review and meta-analysis
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Bjorn Kaijun Betzler, Sheng Yang Lim, Boon Ang Lim, Vivien Cherng Hui Yip, and Bryan Chin Hou Ang
- Subjects
Ophthalmology - Abstract
The XEN45 Gel Stent is a subconjunctival filtering device that has demonstrated promising efficacy. This meta-analysis quantitatively evaluates reported complications and interventions after XEN45 implantation in the treatment of open angle glaucoma (OAG).Pilot, cohort, observational studies, and randomised controlled trials that included at least ten patients undergoing ab interno or externo XEN45 surgery, with or without phacoemulsification were deemed eligible for inclusion. A meta-analysis of proportions with random-effect models was performed using the meta routine in R version 3.2.1. Outcomes included the rate of complications and post-operative interventions.One hundred and fifty-two studies were identified on initial literature search and 33 were included in final analysis. Numerical hypotony was the most common post-operative complication, involving 20% of patients (95% CI: 10-31%). Post-operative gross hyphema occurred in 14% (95% CI: 7-22%) and transient intra-ocular pressure (IOP) spikes (30 mmHg) in 13% (95% CI: 4-27%). Stent exposure occurred in 1% (95% CI: 0-2%). Stent migration occurred in 1% (95% CI: 0-3%). XEN45 revision and/or a second XEN45 implantation was performed in 5% of patients (95% CI: 3-7%). Stent relocation was performed in 3% (95% CI: 1-7%). A second glaucoma procedure was performed in 11% (95% CI: 8-15%). 26% underwent one (95% CI: 17-36%), 13% underwent two (95% CI: 5-24%) while 4% underwent three (95% CI: 2-6%) bleb needling procedures. 35% of patients (95% CI: 29-40%) required at least one needling. The average rate of needling per patient was 0.38 (95% CI: 0.20-0.59). However, there is a lack of high-quality data, with 8 of the 33 studies assessed to have a moderate to high risk of bias.While literature suggests that XEN45 Gel Stent implantation is safe in the treatment of OAG, the overall current level of evidence is low and further studies are needed. More than a third of patients require at least one post-operative bleb needling procedure.
- Published
- 2021
22. Plant Development: Regular Ovule Spacing Is Controlled by Process-Specific Receptor–Ligand Combinations
- Author
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Aaron Chun Hou Ang and Lars Østergaard
- Subjects
Ovule ,0301 basic medicine ,fungi ,food and beverages ,Biology ,Ligands ,Ligand (biochemistry) ,General Biochemistry, Genetics and Molecular Biology ,Cell biology ,03 medical and health sciences ,Plant development ,030104 developmental biology ,0302 clinical medicine ,Gene Expression Regulation, Plant ,Fruit ,Seeds ,Regular pattern ,Peptides ,General Agricultural and Biological Sciences ,Receptor ,Process (anatomy) ,030217 neurology & neurosurgery - Abstract
Ovules are initiated in a highly regular pattern along the placenta inside the gynoecia of flowering plants. New research reveals that two separate EPFL peptide-mediated pathways functioning through a set of ERECTA-family receptors coordinate ovule patterning with fruit growth.
- Published
- 2020
23. Monitoring healthcare professionals after monkeypox exposure: Experience from the first case imported to Asia
- Author
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Charmaine Malenab Manauis, Hanley Jian An Ho, Angela Li Ping Chow, Brenda Ang, Monica Chan, Hou Ang, Shawn Vasoo, Win Mar Kyaw, Partha Pratim De, and Tsin W. Yeo
- Subjects
Microbiology (medical) ,Cross Infection ,Singapore ,Asia ,Health professionals ,Epidemiology ,business.industry ,Health Personnel ,Nigeria ,Monkeypox ,medicine.disease ,Disease Outbreaks ,Infectious Diseases ,medicine ,Humans ,Medical emergency ,business ,Personal Protective Equipment - Published
- 2020
24. Intra-operative optical coherence tomography in glaucoma surgery—a systematic review
- Author
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Bryan Chin Hou Ang, Sheng Yang Lim, and Syril Dorairaj
- Subjects
Intra operative ,genetic structures ,Minimally invasive glaucoma surgery ,medicine.medical_treatment ,Glaucoma ,Review Article ,03 medical and health sciences ,0302 clinical medicine ,Optical coherence tomography ,Glaucoma surgery ,medicine ,Humans ,Trabectome ,Glaucoma Drainage Implants ,Intraocular Pressure ,medicine.diagnostic_test ,business.industry ,Stent ,medicine.disease ,eye diseases ,Ophthalmology ,Imaging quality ,030221 ophthalmology & optometry ,Optometry ,sense organs ,business ,Tomography, Optical Coherence ,030217 neurology & neurosurgery - Abstract
The application of the OCT in clinical ophthalmology has expanded significantly since its introduction more than 20 years ago. There has been recent growing interest in the application of intra-operative optical coherence tomography (iOCT). The iOCT's ability to enhance visualisation and depth appreciation has the potential to be further exploited in glaucoma surgery, especially with the emergence of Minimally Invasive Glaucoma Surgery (MIGS)-to facilitate targeted device placement and fine surgical manoeuvres in the angles, the sub-conjunctival layer and the suprachoroidal space. Hence, this study aims to appraise the current literature on the applications of iOCT in glaucoma surgery. A total of 79 studies were identified following a literature search adhering to PRISMA guidelines. After full text evaluation, 10 studies discussing iOCT use in glaucoma surgery were included. Traditional glaucoma filtering procedures reviewed included trabeculectomy surgery, goniosynechiolysis, bleb needling and glaucoma drainage device implantation. MIGS procedures reviewed included canaloplasty, trabecular aspiration, ab-interno trabectome and the XEN45 gel stent. iOCT use in ophthalmic surgery is becoming increasingly prevalent and has already been applied in various surgeries and procedures in the field of glaucoma. With the greater adoption of MIGS, iOCT may further contribute in facilitating surgical techniques and improving outcomes. While iOCT offers many advantages, there are still limitations to be overcome-iOCT technology continues to evolve to optimise imaging quality and user-experience.摘要: 自20年前OCT投入眼科临床应用至今, 其应用范围不断扩展。近期术中应用光学相干断层扫描 (iOCT) 的热度不断攀升, iOCT能够提升可视化程度和深层组织的鉴别能力, 有助于其在青光眼手术中的进一步拓展应用, 尤其在青光眼微创手术(MIGS)中——它有助于在房角、结膜下和脉络膜上腔进行有针对性的引流装置的放置与精细的手术操作。本文旨在评价目前已发表的在青光眼术中应用iOCT的文献。根据PRISMA指南的文献检索标准共选出79篇研究, 经过全文评估后, 录入10篇讨论青光眼术中应用iOCT的文献。关于传统青光眼滤过术的文献包括小梁切除术、房角粘连松解术、滤过泡穿刺术和青光眼引流装置。关于MIGS手术的文献包括Schlemm氏管成形术、小梁吸除术、小梁消融术和XEN凝胶引流支架引流装置植入术。iOCT在眼科手术中的应用越来越普遍, 并且已经在青光眼领域的各类手术中使用。iOCT在MIGS中的积极应用会改进手术技术并改善手术疗效。尽管iOCT有很多优点, 但仍有需要克服的问题——iOCT技术需要继续提升以及优化成像质量和用户的体验。.
- Published
- 2019
25. Standalone XEN45 Gel Stent implantation in the treatment of open-angle glaucoma: A systematic review and meta-analysis
- Author
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Sheng Yang Lim, Bjorn Kaijun Betzler, Leonard Wei Leon Yip, Syril Dorairaj, and Bryan Chin Hou Ang
- Subjects
Ophthalmology ,Tonometry, Ocular ,Treatment Outcome ,Humans ,Stents ,Glaucoma Drainage Implants ,Glaucoma, Open-Angle ,Intraocular Pressure - Abstract
The XEN45 Gel Stent (Allergan Inc., Irvine, CA) allows the drainage of aqueous into the sub-conjunctival space, through a minimally-invasive approach. This systematic review and meta-analysis evaluates its intraocular pressure (IOP)-lowering efficacy and complications in the treatment of open-angle glaucoma. Fourteen studies comprising 963 eyes were included. IOP decreased significantly (P0.001) across all timepoints (1 day, 1 week, 1, 3, 6, 12, 18, and 24 months) with a mean decrease of 7.44 mm Hg (95%CI:4.91-9.97) at 24 months. IOP-lowering medications decreased significantly (P0.001) across all timepoints (1 week, 1, 3, 6, 12, 18, 24 months) with a mean reduction of 1.67 medications (95%CI:1.28-2.06) at 24 months. Numerical hypotony occurred in 39% (95%CI:14%-67%) and stent exposure in 1% (95%CI:0%-2%) of eyes. 38% (95%CI:30%-46%) of eyes required at least one postoperative needling, with an average of 0.6 (95%CI:0.37-0.81) needlings per eye. Standalone XEN45 Gel Stent implantation is effective in lowering IOP in open-angle glaucoma. Transient numerical hypotony is the most common postoperative complication. Sight-threatening complications are rare. Postoperative needling may be required to maintain IOP-lowering outcomes; however, the overall quality of current evidence is low, with the need for more randomized controlled trials and outcomes measured with a clinically meaningful definition of success.
- Published
- 2021
26. Effects of modified ultrafiltration on open heart surgery in low-weight children
- Author
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Liang, Lijun, Yang, Jinming, Hou, Ang, and Liu, Caixia
- Published
- 2023
- Full Text
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27. Brief Aids to Guide Clinical Frailty Scale Scoring at the Front Door of Acute Hospitals
- Author
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Justin Chew, Wee Shiong Lim, Edward Chong, Hou Ang, Mark Y. Chan, Huei Nuo Tan, and Audrey Tham
- Subjects
Gerontology ,Scale (ratio) ,Frailty ,business.industry ,Health Policy ,Frail Elderly ,MEDLINE ,Geriatric assessment ,General Medicine ,medicine.disease ,Front door ,Hospitals ,Acquired immunodeficiency syndrome (AIDS) ,Medicine ,Humans ,Frail elderly ,Geriatrics and Gerontology ,business ,Geriatric Assessment ,General Nursing ,Aged - Published
- 2020
28. Sociodemographic and clinical factors, visit expectations and driving factors for emergency department attendance for uncomplicated upper respiratory tract infection.
- Author
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Chow , Angela, Keng, Bryan, Huiling Guo, Aung Hein Aung, Zhilian Huang, Yanyi Weng, Hou Ang, Chow, Angela, Guo, Huiling, Aung, Aung Hein, Huang, Zhilian, Weng, Yanyi, and Ang, Hou
- Abstract
Background: Upper respiratory tract infections (URTIs) account for substantial non-urgent ED attendances. Hence, we explored the reasons for such attendances using a mixed-methods approach.Methods: We interviewed adult patients with URTI who visited the second busiest adult ED in Singapore from June 2016 to November 2018 on their expectations and reasons for attendance. A structured questionnaire, with one open-ended question was used. Using the Andersen's Behavioural Model for Healthcare Utilisation, the topmost reasons for ED attendances were categorised into (1) contextual predisposing factors (referral by primary care physician, family, friends or coworkers), (2) contextual enabling factors (convenience, accessibility, employment requirements), (3) individual enablers (personal preference and trust in hospital-perceived care quality and efficiency) and (4) individual needs (perceived illness severity and non-improvement). Multivariable multinomial logistic regression was used to assess associations between sociodemographic and clinical factors, patient expectations for ED visits and the drivers for ED attendance.Results: There were 717 patients in the cohort. The mean age of participants was 40.5 (SD 14.7) years, 61.2% were males, 66.5% without comorbidities and 40.7% were tertiary educated. Half had sought prior medical consultation (52.4%) and expected laboratory tests (55.7%) and radiological investigations (46.9%). Individual needs (32.8%) and enablers (25.1%) were the main drivers for ED attendance. Compared with ED attendances due to contextual enabling factors, attendances due to other drivers were more likely to be aged ≥45 years, had prior medical consultation and expected radiological investigations. Having a pre-existing medical condition (adjusted OR (aOR) 1.78, 95% CI 1.05 to 3.04) and an expectation for laboratory tests (aOR 1.64, 95% CI 1.01 to 2.64) were associated with individual needs while being non-tertiary educated (aOR 2.04, 95% CI 1.22 to 3.45) and having pre-existing comorbidities (aOR 1.79, 95% CI 1.04 to 3.10) were associated with individual enablers.Conclusions: Meeting individual needs of perceived illness severity or non-improvement was the topmost driver of ED visits for URTI, while contextual enabling factors such as convenience was the lowest. Patients' sociodemographic and clinical factors and visit expectations influence their motivations for ED attendances. Addressing these factors and expectations can alleviate the overutilisation of ED services. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
29. Anterior segment imaging in minimally invasive glaucoma surgery - A systematic review
- Author
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Bjorn Kaijun Betzler, Sheng Yang Lim, John Tsia-Chuen Kan, and Bryan Chin Hou Ang
- Subjects
medicine.medical_specialty ,Minimally invasive glaucoma surgery ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Ultrasound biomicroscopy ,Stent ,Glaucoma ,General Medicine ,medicine.disease ,Ophthalmology ,Optical coherence tomography ,Angiography ,medicine ,Trabectome ,Humans ,Minimally Invasive Surgical Procedures ,Stents ,Radiology ,Implant ,business ,Intraocular Pressure ,Tomography, Optical Coherence - Abstract
Minimally invasive glaucoma surgery (MIGS) has grown in popularity over the past decade. This systematic review explores the peri-operative and intraoperative application of anterior segment imaging to maximize the efficacy and safety of MIGS. A review of the PubMed, EMBASE and CINAHL databases was conducted, with inclusion criteria restricted to MIGS that had received United States Food and Drug Administration (FDA) premarket approval, FDA 510(K) premarket notification, or were listed as a class 1 device exempt from FDA approval or notification. 21 manuscripts from 21 unique studies were identified pertaining to MIGS devices including the XEN Gel Stent, Trabectome, iStent Inject, 1st-generation iStent and the Kahook Dual Blade (KDB). Anterior segment imaging modalities included anterior segment optical coherence tomography (AS-OCT), ultrasound biomicroscopy (UBM), aqueous angiography, OCT volumetric scans and in vivo confocal microscopy. Identification and evaluation of aqueous outflow pathways before and after MIGS have potential for improving patient preoperative patient selection and postoperative outcomes. Intraoperative imaging potentially provides the resolution needed for good visualization of angle anatomy and accurate evaluation of surgical endpoints in angle-based MIGS. Anterior segment imaging has been used to identify procedural complications, provide objective information on implant location in relation to surrounding anatomy, assess the post implantation structural impact of MIGS devices and manage bleb failure and scarring. Technical difficulties in incorporating imaging modalities into the surgical microscope, variable quality of images and optical interference from ocular structures or surgical instruments are remaining barriers, which discourage the widespread clinical use of this technology.
- Published
- 2020
30. The next wave: key adaptations to operational workflows of National Screening Centre (Singapore) and the emergency department during the COVID-19 pandemic
- Author
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James Kwan, Charmaine Malenab Manauis, Shawn Vasoo, Yee Sin Leo, Amanda Hui Jun Lim, David Kuan Peng Teng, Marvin Loh, Han Jie Teo, and Hou Ang
- Subjects
2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,lcsh:Medical emergencies. Critical care. Intensive care. First aid ,lcsh:RC86-88.9 ,Emergency department ,medicine.disease ,Workflow ,Pandemic ,Emergency Medicine ,Key (cryptography) ,Medicine ,Medical emergency ,business ,Original Research - Published
- 2020
31. Atypical COVID-19: Preventing transmission from unexpected cases
- Author
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Brenda Ang, Bernard Yu-Hor Thong, Huei Nuo Tan, Angela Chow, Glenn Wei Leong Tan, Hou Ang, Htet Lin Htun, L.W. Koh, and Win Mar Kyaw
- Subjects
Microbiology (medical) ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Epidemiology ,SARS-CoV-2 ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,COVID-19 ,Virology ,law.invention ,Transmission (mechanics) ,Infectious Diseases ,law ,Medicine ,Humans ,business ,Letter to the Editor - Published
- 2020
32. Performance of Digital Contact Tracing Tools for COVID-19 Response in Singapore: Cross-Sectional Study (Preprint)
- Author
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Zhilian Huang, Huiling Guo, Yee-Mun Lee, Eu Chin Ho, Hou Ang, and Angela Chow
- Abstract
BACKGROUND Effective contact tracing is labor intensive and time sensitive during the COVID-19 pandemic, but also essential in the absence of effective treatment and vaccines. Singapore launched the first Bluetooth-based contact tracing app—TraceTogether—in March 2020 to augment Singapore’s contact tracing capabilities. OBJECTIVE This study aims to compare the performance of the contact tracing app—TraceTogether—with that of a wearable tag-based real-time locating system (RTLS) and to validate them against the electronic medical records at the National Centre for Infectious Diseases (NCID), the national referral center for COVID-19 screening. METHODS All patients and physicians in the NCID screening center were issued RTLS tags (CADI Scientific) for contact tracing. In total, 18 physicians were deployed to the NCID screening center from May 10 to May 20, 2020. The physicians activated the TraceTogether app (version 1.6; GovTech) on their smartphones during shifts and urged their patients to use the app. We compared patient contacts identified by TraceTogether and those identified by RTLS tags within the NCID vicinity during physicians’ 10-day posting. We also validated both digital contact tracing tools by verifying the physician-patient contacts with the electronic medical records of 156 patients who attended the NCID screening center over a 24-hour time frame within the study period. RESULTS RTLS tags had a high sensitivity of 95.3% for detecting patient contacts identified either by the system or TraceTogether while TraceTogether had an overall sensitivity of 6.5% and performed significantly better on Android phones than iPhones (Android: 9.7%, iPhone: 2.7%; P CONCLUSIONS TraceTogether had a much lower sensitivity than RTLS tags for identifying patient contacts in a clinical setting. Although the tag-based RTLS performed well for contact tracing in a clinical setting, its implementation in the community would be more challenging than TraceTogether. Given the uncertainty of the adoption and capabilities of contact tracing apps, policy makers should be cautioned against overreliance on such apps for contact tracing. Nonetheless, leveraging technology to augment conventional manual contact tracing is a necessary move for returning some normalcy to life during the long haul of the COVID-19 pandemic.
- Published
- 2020
33. Association of VIPR2 and ZMAT4 with high myopia
- Author
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Rita Yu Yin Yong, Mellisa Tan, Kai Xiong Cheong, Frederick Tey, and Bryan Chin Hou Ang
- Subjects
0301 basic medicine ,Adult ,Male ,Han chinese ,China ,genetic structures ,Genotype ,Single-nucleotide polymorphism ,030105 genetics & heredity ,Biology ,Polymorphism, Single Nucleotide ,Linkage Disequilibrium ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Myopia ,Humans ,Genetic Predisposition to Disease ,Gene ,Genetics (clinical) ,Genetic Association Studies ,Genetics ,Haplotype ,High myopia ,RNA-Binding Proteins ,eye diseases ,Ophthalmology ,Haplotypes ,Case-Control Studies ,Pediatrics, Perinatology and Child Health ,030221 ophthalmology & optometry ,Receptors, Vasoactive Intestinal Peptide, Type II ,Female ,VIPR2 - Abstract
Background: To investigate the associations of Single Nucleotide Polymorphisms (SNPs) in the VIPR2 and ZMAT4 genes with high myopia in a Han Chinese population. Materials and Methods: In this case-...
- Published
- 2020
34. Performance of digital contact tracing tools for COVID-19 response in Singapore : cross-sectional study
- Author
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Yee Mun Lee, Huiling Guo, Zhilian Huang, Eu Chin Ho, Angela Chow, Hou Ang, and Lee Kong Chian School of Medicine (LKCMedicine)
- Subjects
020205 medical informatics ,Coronavirus disease 2019 (COVID-19) ,Cross-sectional study ,Computer science ,infectious disease ,Pneumonia, Viral ,Wearable computer ,Real-time Locating Systems ,Health Informatics ,Infectious Disease ,02 engineering and technology ,contact tracing ,Wearable Electronic Devices ,03 medical and health sciences ,COVID-19 Testing ,0302 clinical medicine ,Time frame ,Computer Systems ,real-time locating systems ,electronic medical records ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Electronic Health Records ,Humans ,Medicine [Science] ,030212 general & internal medicine ,Android (operating system) ,Pandemics ,Original Paper ,Physician-Patient Relations ,Singapore ,Clinical Laboratory Techniques ,Medical record ,public health ,COVID-19 ,Reproducibility of Results ,medicine.disease ,Mobile Applications ,Real-time locating system ,Cross-Sectional Studies ,Medical emergency ,Coronavirus Infections ,Contact tracing - Abstract
BackgroundEffective contact tracing is labor intensive and time sensitive during the COVID-19 pandemic, but also essential in the absence of effective treatment and vaccines. Singapore launched the first Bluetooth-based contact tracing app—TraceTogether—in March 2020 to augment Singapore’s contact tracing capabilities.ObjectiveThis study aims to compare the performance of the contact tracing app—TraceTogether—with that of a wearable tag-based real-time locating system (RTLS) and to validate them against the electronic medical records at the National Centre for Infectious Diseases (NCID), the national referral center for COVID-19 screening.MethodsAll patients and physicians in the NCID screening center were issued RTLS tags (CADI Scientific) for contact tracing. In total, 18 physicians were deployed to the NCID screening center from May 10 to May 20, 2020. The physicians activated the TraceTogether app (version 1.6; GovTech) on their smartphones during shifts and urged their patients to use the app. We compared patient contacts identified by TraceTogether and those identified by RTLS tags within the NCID vicinity during physicians’ 10-day posting. We also validated both digital contact tracing tools by verifying the physician-patient contacts with the electronic medical records of 156 patients who attended the NCID screening center over a 24-hour time frame within the study period.ResultsRTLS tags had a high sensitivity of 95.3% for detecting patient contacts identified either by the system or TraceTogether while TraceTogether had an overall sensitivity of 6.5% and performed significantly better on Android phones than iPhones (Android: 9.7%, iPhone: 2.7%; PConclusionsTraceTogether had a much lower sensitivity than RTLS tags for identifying patient contacts in a clinical setting. Although the tag-based RTLS performed well for contact tracing in a clinical setting, its implementation in the community would be more challenging than TraceTogether. Given the uncertainty of the adoption and capabilities of contact tracing apps, policy makers should be cautioned against overreliance on such apps for contact tracing. Nonetheless, leveraging technology to augment conventional manual contact tracing is a necessary move for returning some normalcy to life during the long haul of the COVID-19 pandemic.
- Published
- 2020
35. Association of SNTB1 with High Myopia
- Author
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Mellisa Tan, Rita Yu Yin Yong, Bryan Chin Hou Ang, Kai Xiong Cheong, and Frederick Tey
- Subjects
Male ,China ,Han chinese ,Genotyping Techniques ,Single-nucleotide polymorphism ,Biology ,Polymorphism, Single Nucleotide ,Young Adult ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Asian People ,Gene Frequency ,Humans ,Gene ,Genetic Association Studies ,Genetics ,Haplotype ,High myopia ,Sensory Systems ,Ophthalmology ,Haplotypes ,Case-Control Studies ,Dystrophin-Associated Proteins ,Myopia, Degenerative ,030221 ophthalmology & optometry ,SNTB1 ,030217 neurology & neurosurgery - Abstract
To investigate the associations of Single Nucleotide Polymorphisms (SNPs) in the SNTB1 gene with high myopia in a Han Chinese population. Based on previous studies, four SNPs from the SNTB1 gene were chosen for genotyping. This is a case-control genetic association study comprising 193 high myopia participants and 135 normal emmetropic controls from a Han Chinese population. Allelic frequencies of the SNPs and haplotypes were compared to assess the associations of the SNPs with high myopia and axial length (AL). The SNPs rs7839488 (effect allele: A; OR = 0.685), rs4395927 (effect allele: T; OR = 0.692), and rs6469937 (effect allele: A; OR = 0.683) displayed significant associations with high myopia initially (P = .044, 0.049, and 0.035, respectively), but did not withstand permutation testing (all Ppermutation>0.05). rs6469937 displayed associations with high myopia in the dominant model (AG+AA: OR = 0.609) against GG (reference). rs6469937 was also associated with AL in the dominant model (AG+AA: Beta = −0.58) against GG (reference). The haplotype analysis demonstrated ATGA as the protective haplotype against high myopia, which remained statistically significant in permutation testing (Ppermutation = 0.045). Our findings are suggestive that SNTB1 is associated with high myopia in a Han Chinese population.
- Published
- 2020
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- View/download PDF
36. Non-Occlusive Retinal Vascular Inflammation and Role of Red Blood Cell Deformability in Birdshot Chorioretinopathy
- Author
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Rupesh Agrawal, Praveen Kumar Balne, Philip H. Jones, Carlos Pavesio, David T. Shima, Joao Cardoso, Thomas J. Smart, CD Richards, and Bryan Chin Hou Ang
- Subjects
Adult ,Male ,medicine.medical_specialty ,Erythrocytes ,Optical Tweezers ,Retinal Artery Occlusion ,Vascular occlusion ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Erythrocyte Deformability ,Ophthalmology ,Retinal Vein Occlusion ,Humans ,Immunology and Allergy ,Medicine ,Prospective Studies ,Aged ,Retinal Vasculitis ,030203 arthritis & rheumatology ,Vascular inflammation ,business.industry ,Birdshot Chorioretinopathy ,breakpoint cluster region ,Retinal ,Middle Aged ,medicine.disease ,Birdshot chorioretinopathy ,Red blood cell ,medicine.anatomical_structure ,chemistry ,030221 ophthalmology & optometry ,Female ,medicine.symptom ,business - Abstract
Purpose: To investigate differences in red blood cell (RBC) deformability between birdshot chorioretinopathy (BCR) subjects and matched controls, and to postulate its relationship with lack...
- Published
- 2018
37. Plant Development: Regular Ovule Spacing Is Controlled by Process-Specific Receptor–Ligand Combinations
- Author
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Hou Ang, Aaron Chun, primary and Østergaard, Lars, additional
- Published
- 2020
- Full Text
- View/download PDF
38. Bracing for impact: operational upshots from the National Centre for Infectious Diseases Screening Centre (Singapore) during the COVID‐19 outbreak
- Author
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Manauis, Charmaine Malenab, primary, Loh, Marvin, additional, Kwan, James, additional, Chua Mingzhou, John, additional, Teo, Han Jie, additional, Teng Kuan Peng, David, additional, Vasoo Sushilan, Shawn, additional, Leo, Yee Sin, additional, and Hou, Ang, additional
- Published
- 2020
- Full Text
- View/download PDF
39. Efficacy of the XEN gel stent on intraocular pressure lowering in East Asian eyes
- Author
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Jeremy Y. W. Hu, Bryan Chin Hou Ang, and Leonard W. Yip
- Subjects
Male ,Intraocular pressure ,medicine.medical_specialty ,genetic structures ,medicine.medical_treatment ,Visual Acuity ,Glaucoma ,Prosthesis Design ,03 medical and health sciences ,Tonometry, Ocular ,0302 clinical medicine ,Interquartile range ,Medicine ,Humans ,Adverse effect ,Glaucoma Drainage Implants ,Intraocular Pressure ,Aged ,Retrospective Studies ,Singapore ,business.industry ,Incidence ,Stent ,Retrospective cohort study ,Cataract surgery ,medicine.disease ,eye diseases ,Surgery ,Ophthalmology ,Treatment Outcome ,030221 ophthalmology & optometry ,Female ,Stents ,sense organs ,Implant ,business ,Gels ,030217 neurology & neurosurgery ,Glaucoma, Open-Angle - Abstract
This study aims to evaluate the efficacy and safety of XEN45 gel stent (Allergan plc, Dublin, Ireland) in East Asian patients with glaucoma. A retrospective study of consecutive XEN45 gel stent implantation surgeries with or without concurrent cataract surgery from May 2017 to August 2018 was performed in a single institution. The clinical charts of all cases were reviewed to examine the safety and efficacy of the implant. Primary outcome measures were intraocular pressure (IOP), number of topical glaucoma medications required, additional procedures done and adverse outcomes. All patients included were required to fulfil a minimum of three follow-up visits by post-operative month 1. Sixty-three eyes were included in the study. The median duration of follow-up was 6 months [interquartile range (IQR) 2–9]. Median IOP was significantly lowered from 19 mmHg (IQR 16–24) pre-operatively to 15 mmHg (IQR 11–18) at the end-of-follow-up (p
- Published
- 2019
40. Noncanonical Auxin Signaling
- Author
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Heather M McLaughlin, Aaron Chun Hou Ang, and Lars Østergaard
- Subjects
0106 biological sciences ,0301 basic medicine ,Plant Development ,Repressor ,Biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Auxin ,Gene ,Derepression ,Regulation of gene expression ,chemistry.chemical_classification ,Indoleacetic Acids ,Arabidopsis Proteins ,Mechanism (biology) ,fungi ,food and beverages ,Plants ,Cell biology ,DNA-Binding Proteins ,030104 developmental biology ,PERSPECTIVES ,chemistry ,Signal transduction ,Protein Kinases ,Function (biology) ,Signal Transduction ,010606 plant biology & botany - Abstract
Auxin influences all aspects of plant growth and development and exerts its function at scales ranging from the subcellular to the whole-organism level. A canonical mechanism for auxin signaling has been elucidated, which is based on derepression of downstream genes via ubiquitin-mediated degradation of transcriptional repressors. While the combinatorial nature of this canonical pathway provides great potential for specificity in the auxin response, alternative noncanonical signaling pathways required to mediate certain processes have been identified. One such pathway affects gene regulation in a manner that is reminiscent of mechanisms employed in animal hormone signaling, while another triggers transcriptional changes through auxin perception at the plasma membrane and the stabilization of transcriptional repressors. In some cases, the exact perception mechanisms and the nature of the receptors involved are yet to be revealed. In this review, we describe and discuss current knowledge on noncanonical auxin signaling and highlight unresolved questions surrounding auxin biology.
- Published
- 2021
41. Herpes Simplex Acute Retinal Necrosis Presenting as Unilateral Disc Swelling in Young Immunocompetent Patients
- Author
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Bryan Chin Hou Ang, Su Ling Ho, Yan Tong Koh, Rupesh Agrawal, and Stephen C. Teoh
- Subjects
Adult ,Male ,Pathology ,medicine.medical_specialty ,Optic Neuritis ,Herpesvirus 2, Human ,Eye Infections, Viral ,Retinitis ,Herpesvirus 1, Human ,Fundus (eye) ,Antiviral Agents ,Immunocompromised Host ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Immunology and Allergy ,Optic neuritis ,Medical history ,Fluorescein Angiography ,Papilledema ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Herpes Simplex ,Retinal Necrosis Syndrome, Acute ,medicine.disease ,Fluorescein angiography ,Vitreous Body ,Ophthalmology ,030221 ophthalmology & optometry ,Acute retinal necrosis ,medicine.symptom ,Vasculitis ,business ,Immunocompetence ,030217 neurology & neurosurgery - Abstract
To report two cases of young immunocompetent males with herpes simplex acute retinal necrosis (HSV ARN) with initial diagnosis of unilateral disc swelling.Retrospective case series.Two young immunocompetent males who were diagnosed to have unilateral disc swelling were treated as presumed optic neuritis and started on systemic steroids. On dilated fundal examination, unilateral retinitis and vasculitis was found after 2-3 days of systemic steroids and the diagnosis of ARN was made. Tetraplex vitreous tap subsequently returned as HSV-2 and HSV for the first and second patient, respectively. Both patients had no significant systemic medical history and tested negative for human immunodeficiency virus (HIV). Despite aggressive treatment, both patients developed profound visual morbidity.Close monitoring of patients with unilateral disc swelling and dilated fundus evaluation is critical, particularly upon initiation of systemic steroid therapy, even if immunocompetent, as misdiagnoses can result in potentially devastating consequences.
- Published
- 2016
42. Controversies in the pathophysiology and management of hyphema
- Author
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Paul M. Sullivan, Dinesh Visva Gunasekeran, Rupesh Agrawal, Bryan Chin Hou Ang, Rekha Khandelwal, Svati Bansal, and Jiaying Lee
- Subjects
medicine.medical_specialty ,business.industry ,General surgery ,medicine.disease ,eye diseases ,Traumatic hyphema ,Eye injuries ,Surgery ,03 medical and health sciences ,Ophthalmology ,0302 clinical medicine ,Intraocular lenses ,030225 pediatrics ,Antifibrinolytic agent ,030221 ophthalmology & optometry ,medicine ,Traumatic glaucoma ,business ,Hyphema ,Mydriatics ,Ophthalmologic Surgical Procedure - Abstract
Traumatic hyphemas present dilemmas to physicians. There are numerous controversies pertaining to the optimal approach to traumatic hyphema and no standardized guidelines for its management. We address some of these controversies and present a pragmatic approach. We discuss various medical agents and surgical techniques available for treatment, along with the indications for their use. We address the complications associated with hyphema and how to diagnose and manage them and consider the management of hyphema in special situations such as in children and sickle-cell anemia and in rare clinical syndromes such as recurrent hyphema after placement of anterior chamber intraocular lenses.
- Published
- 2016
43. Changes in Japanese eyes after laser peripheral iridotomy: an anterior segment optical coherence tomography study
- Author
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Bryan Chin Hou Ang, Tin Aung, Takanori Mizoguchi, Monisha E. Nongpiur, and Mineo Ozaki
- Subjects
Intraocular pressure ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Anterior Eye Segment ,03 medical and health sciences ,Ophthalmology ,0302 clinical medicine ,medicine.anatomical_structure ,Optical coherence tomography ,Laser peripheral iridotomy ,Iridectomy ,030221 ophthalmology & optometry ,medicine ,Gonioscopy ,Iris (anatomy) ,business ,Laser coagulation ,030217 neurology & neurosurgery - Abstract
BACKGROUND The aim was to investigate the changes in anterior segment parameters, as assessed by anterior segment optical coherence tomography in Japanese subjects after laser peripheral iridotomy (LPI). DESIGN This was a prospective observational study. PARTICIPANTS The participants include 72 subjects with angle closure including primary angle closure suspect (PACS), primary angle closure (PAC), and primary angle closure glaucoma (PACG). METHODS Anterior segment optical coherence tomography parameters was measured by customized software. Complete data of 51 subjects were available for final analysis. MAIN OUTCOME MEASURES These were the following parameters: angle opening distance, trabecular-iris space area, anterior chamber depth, width, area and volume (iris thickness, curvature, and area, and lens vault (LV). RESULTS A total of 25 PACS, 17 PAC and 9 PACG were included. Mean age was 74.7 ± 6.7 years, and majority were women (80.4%). Following LPI, there was a significant increase in mean gonioscopic angle width (1.16 vs. 1.93, P
- Published
- 2016
44. Proteomic analysis of aqueous humor from primary open angle glaucoma patients on drug treatment revealed altered complement activation cascade
- Author
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Yap Terence, Leonard W. Yip, Siu Kwan Sze, Jin Wei, Sunil S. Adav, Bryan Chin Hou Ang, and School of Biological Sciences
- Subjects
Male ,Proteomics ,0301 basic medicine ,genetic structures ,Open angle glaucoma ,Glaucoma ,Biochemistry ,Mass Spectrometry ,Pathogenesis ,Aqueous Humor ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,medicine ,Humans ,Eye Proteins ,Complement Activation ,Aged ,biology ,business.industry ,Biological sciences [Science] ,General Chemistry ,Prognosis ,medicine.disease ,eye diseases ,Pathophysiology ,Complement system ,030104 developmental biology ,Case-Control Studies ,Immunology ,Disease Progression ,030221 ophthalmology & optometry ,biology.protein ,Female ,sense organs ,Antibody ,business ,Protein Processing, Post-Translational ,Glaucoma, Open-Angle - Abstract
Primary open angle glaucoma (POAG) is a complex disease and a leading cause of irreversible blindness, and its underlying pathophysiology remains poorly understood. Proteomic characterization of the protein composition of aqueous humor (AH) may identify prognostic candidate proteins involved in pathogenesis and progression of the disease. To delineate the possible mechanisms that lead to POAG, this study adopted state-of-art mass spectrometric technique and analyzed AH of POAG and their respective controls. In total, more than 1000 proteins were identified with false discovery rate of less than 1%. Numerous proteins of complement cascade, immunoglobulin, neuronal and amyloidogenic proteins, which were part of processes like acute-phase and inflammatory response, humoral immune and acute inflammatory response, regulation of complement activation and protein processing were identified. Proteins of complement system underwent significant changes, which correlate to pathogenic events characterizing POAG, including altered complement cascade, astrocyte activation, neural degeneration, and apoptosis. Further, protein modification such as deamidation of complement subcomponent was noted, particularly in POAG. Proteomic analysis of AH allows a better understanding of the mechanism involved in the pathogenesis of POAG. MOE (Min. of Education, S’pore) NMRC (Natl Medical Research Council, S’pore) Accepted version
- Published
- 2018
45. Evaluation of Various Cooling Systems After Exercise-Induced Hyperthermia
- Author
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Iswady Iskandar, Jason Kai Wei Lee, Bryan Chin Hou Ang, Eunice Y. N. Teo, Noreffendy B. Ali, Lydia Yu Li Law, and Pearl M. S. Tan
- Subjects
Hyperthermia ,Male ,medicine.medical_specialty ,Heat Stroke ,Physical Exertion ,Physical Therapy, Sports Therapy and Rehabilitation ,Context (language use) ,030204 cardiovascular system & hematology ,Core temperature ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Heart Rate ,medicine ,Humans ,Orthopedics and Sports Medicine ,Thermosensing ,Stroke ,Exercise ,Original Research ,Cross-Over Studies ,business.industry ,030229 sport sciences ,General Medicine ,medicine.disease ,Cryotherapy ,Physical therapy ,Exercise Test ,Perception ,business - Abstract
Context: Rapid diagnosis and expeditious cooling of individuals with exertional heat stroke is paramount for survival. Objective: To evaluate the efficacy of various cooling systems after exercise-induced hyperthermia. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty-two men (age = 24 ± 2 years, height = 1.76 ± 0.07 m, mass = 70.7 ± 9.5 kg) participated. Intervention(s): Each participant completed a treadmill walk until body core temperature reached 39.50°C. The treadmill walk was performed at 5.3 km/h on an 8.5% incline for 50 minutes and then at 5.0 km/h until the end of exercise. Each participant experienced 4 cooling phases in a randomized, repeated-crossover design: (1) no cooling (CON), (2) body-cooling unit (BCU), (3) EMCOOLS Flex.Pad (EC), and (4) ThermoSuit (TS). Cooling continued for 30 minutes or until body core temperature reached 38.00°C, whichever occurred earlier. Main Outcome Measure(s): Body core temperature (obtained via an ingestible telemetric temperature sensor) and heart rate were measured continuously during the exercise and cooling phases. Rating of perceived exertion was monitored every 5 minutes during the exercise phase and thermal sensation every minute during the cooling phase. Results: The absolute cooling rate was greatest with TS (0.16°C/min ± 0.06°C/min) followed by EC (0.12°C/min ± 0.04°C/min), BCU (0.09°C/min ± 0.06°C/min), and CON (0.06°C/min ± 0.02°C/min; P < .001). The TS offered a greater cooling rate than all other cooling modalities in this study, whereas EC offered a greater cooling rate than both CON and BCU (P < .0083 for all). Effect-size calculations, however, showed that EC and BCU were not clinically different. Conclusion: These findings provide objective evidence for selecting the most effective cooling system of those we evaluated for cooling individuals with exercise-induced hyperthermia. Nevertheless, factors other than cooling efficacy need to be considered when selecting an appropriate cooling system.
- Published
- 2017
46. The Singapore 5-Fluorouracil Trial
- Author
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Melissa H. Y. Wong, Bryan Chin Hou Ang, Rahat Husain, Tina T. Wong, Francis T.S. Oen, Hla Myint Htoon, Gus Gazzard, Tin Aung, Steve K. L. Seah, Paul J. Foster, and Peng T. Khaw
- Subjects
Intraocular pressure ,medicine.medical_specialty ,genetic structures ,business.industry ,Proportional hazards model ,medicine.medical_treatment ,Glaucoma ,Retrospective cohort study ,medicine.disease ,Placebo ,Surgery ,law.invention ,Ophthalmology ,Randomized controlled trial ,law ,Anesthesia ,Medicine ,Trabeculectomy ,business ,Prospective cohort study - Abstract
Objective To report the 8-year outcomes of Asian subjects who underwent trabeculectomy augmented by intraoperative 5-fluorouracil (5-FU) or placebo. Design Retrospective review of a randomized controlled trial. Participants Subjects with primary open-angle or angle-closure glaucoma. Methods Study subjects were prospectively followed up for 3 years. After the last subject recruited had completed 8 years of follow-up, the charts of all subjects were reviewed to capture data from the year 3 visit onward. Kaplan–Meier survival function with Cox regression was performed to identify risk factors associated with trabeculectomy failure at 8 years. Main Outcome Measures The primary outcome was trabeculectomy failure defined as intraocular pressure (IOP) >21 or 17 and >14 mmHg. Secondary outcomes included IOP at 8 years and number of glaucoma medications. Complete success was defined using IOP end points ≤21, ≤17, or ≤14 mmHg at 8 years without medications. Results Of the 243 enrolled subjects, 170 (70.0%) completed 8 years follow-up, 86 in the 5-FU and 84 in the placebo group. There was no significant difference in failure rates at 8 years for the failure definitions of IOP >21 mmHg (11.6% of the 5-FU group vs. 16.7% of the placebo group; P = 1.00), IOP >17 mmHg (23.3% of the 5-FU group vs. 31% of the placebo group; P = 0.78), and IOP >14 mmHg (46.5% of the 5-FU group vs. 58.3% of the placebo group; P = 0.37). Mean IOP at 8 years was 13.7 mmHg in the 5-FU versus 14.4 mmHg in the placebo group ( P = 0.24). Mean number of medications was 0.65 drops in the 5-FU versus 0.93 drops in the placebo group ( P = 0.06). Complete success with IOP ≤21 mmHg at 8 years was achieved in 48 subjects (55.8%) in the 5-FU and 33 subjects (39.3%) in the placebo group ( P = 0.09). Absence of bleb microcysts at 1 year, preoperative IOP, and number of bleb needlings performed within the first year were significantly associated with failure. Conclusions There was no significant difference in IOP between the 5-FU and the placebo group at 8 years. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
- Published
- 2013
47. Correlating myopia severity with visual performance in a young Asian male population
- Author
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E.W.L. Lim, M.C.L. Tan, Colin S. Tan, A.H. Yang, Bryan Chin Hou Ang, Mellisa Tan, Kai Xiong Cheong, and Frederick Tey
- Subjects
Ophthalmology ,business.industry ,Medicine ,Optometry ,Male population ,General Medicine ,business - Published
- 2016
48. Risk factors for early-onset corneal haze after photorefractive keratectomy in an Asian population: Outcomes from the Singapore Armed Forces Corneal Refractive Surgery Programme 2006 to 2013
- Author
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Lennard See Yin Thean, Clement Woon Teck Tan, Bryan Chin Hou Ang, Mellisa Mei Hui Tan, Gerard Nah, Edmund Wei Long Lim, Reuben Chao Ming Foo, and Paul Song Bo Zhao
- Subjects
0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Visual acuity ,Haze ,genetic structures ,Adolescent ,medicine.medical_treatment ,Visual Acuity ,Astigmatism ,Photorefractive Keratectomy ,Cornea ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Risk Factors ,Refractive surgery ,Ophthalmology ,Keratectomy ,medicine ,Myopia ,Humans ,Dioptre ,Retrospective Studies ,Corneal Haze ,business.industry ,Odds ratio ,medicine.disease ,eye diseases ,Sensory Systems ,Photorefractive keratectomy ,030104 developmental biology ,Treatment Outcome ,030221 ophthalmology & optometry ,Surgery ,Female ,Lasers, Excimer ,sense organs ,medicine.symptom ,business - Abstract
Purpose To assess the incidence and risk factors for early corneal haze after myopic photorefractive keratectomy (PRK). Setting Tertiary eye center, Singapore. Design Retrospective case series. Methods The refractive results and corneal haze severity 3 months after PRK were analyzed. Eyes were categorized into 4 groups based on haze severity. Multivariate ordinal logistic regression analysis adjusting for age, ethnicity, sex, use of intraoperative mitomycin-C (MMC), preoperative sphere, and preoperative cylinder was performed. Results The study reviewed data from 177 patients (347 eyes) with a mean age of 22.6 years ± 4.1 (SD). The majority of the patients were Chinese (98.3%) and men (98.3%). The mean preoperative spherical equivalent (SE) was −3.34 ± 1.19 diopters (D). One hundred thirty-five eyes (38.9%) had PRK with MMC. Ten eyes (2.9%) had enhancement surgery. The overall efficacy index was 0.88 and the safety index was 1.07. At 3 months, 187 eyes (53.9%) had no haze, 76 eyes (21.9%) had a haze grade of more than 0 and less than 1, 76 eyes (21.9%) had a haze grade of 1 or more and less than 2, and 8 eyes (2.3%) had grade 2 haze. Higher degrees of myopia (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.13-1.63; P = .001) and astigmatism (OR, 1.56; 95% CI, 1.09-2.24; P = .014) were associated with increased severity of corneal haze, whereas older age (OR, 0.94; 95% CI, 0.88-0.99; P = .023) had a protective effect. Conclusion Myopia and astigmatism were associated with increased severity of haze, and older age was protective against early corneal haze development after PRK in an Asian population. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.
- Published
- 2015
49. Case report of cytomegalovirus retinitis in an HIV-positive patient with a CD4-count nadir of 254 cells per μl
- Author
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Stephen C. Teoh and Bryan Chin Hou Ang
- Subjects
medicine.medical_specialty ,business.industry ,Congenital cytomegalovirus infection ,Human immunodeficiency virus (HIV) ,virus diseases ,Aqueous humor ,medicine.disease ,Positive patient ,medicine.disease_cause ,Gastroenterology ,Ophthalmology ,Internal medicine ,mental disorders ,Immunology ,Correspondence ,Medicine ,Cytomegalovirus retinitis ,business ,Nadir (topography) - Abstract
Case report of cytomegalovirus retinitis in an HIV-positive patient with a CD4-count nadir of 254 cells per μ l
- Published
- 2012
50. Mycotic Aneurysm of Infrarenal Aorta: A Case Report and Review of Literature
- Author
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Beltran-Ordonez, Irene S., primary, Yian, Tay Seow, additional, Hou, Ang, additional, and Hai, Eric Wong Ming, additional
- Published
- 2015
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