8 results on '"Ngo, Wei Kiong"'
Search Results
2. Treatment of massive subretinal hemorrhage from polypoidal choroidal vasculopathy and age-related macular degeneration.
- Author
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Tan CS, Lim LW, and Ngo WK
- Subjects
- Hematoma, Humans, Retinal Hemorrhage, Macular Degeneration, Vitrectomy
- Published
- 2017
- Full Text
- View/download PDF
3. EVEREST study report 3: diagnostic challenges of polypoidal choroidal vasculopathy. Lessons learnt from screening failures in the EVEREST study.
- Author
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Tan CS, Ngo WK, Lim LW, Tan NW, and Lim TH
- Subjects
- Adolescent, Aged, Aged, 80 and over, Angiogenesis Inhibitors therapeutic use, Choroidal Neovascularization drug therapy, Coloring Agents administration & dosage, Double-Blind Method, Female, Humans, Indocyanine Green administration & dosage, Macular Degeneration drug therapy, Male, Middle Aged, Photochemotherapy, Polyps drug therapy, Porphyrins therapeutic use, Ranibizumab therapeutic use, Vascular Endothelial Growth Factor A antagonists & inhibitors, Verteporfin, Choroidal Neovascularization diagnosis, Diagnostic Errors, Fluorescein Angiography, Macular Degeneration diagnosis, Polyps diagnosis
- Abstract
Purpose: To describe screening failures in the EVEREST study by examining the imaging characteristics that enabled differentiation of polypoidal choroidal vasculopathy (PCV) from cases that were subsequently diagnosed not to be PCV., Methods: Post-hoc analysis of 34 patients with PCV reported as screening failures from EVEREST study. Standardised confocal scanning laser indocyanine green angiography (ICGA) images were graded by the Central Reading Centre to confirm PCV diagnosis based on the presence of early focal sub-retinal hyperfluorescence on ICGA and at least one of the following six diagnostic criteria: (1) nodular appearance of polyp(s) on stereoscopic examination, (2) hypofluorescent halo around nodule(s), (3) presence of a branching vascular network, (4) pulsation of polyp(s) on dynamic ICGA, (5) orange sub-retinal nodules on colour fundus photography, or (6) massive sub-macular haemorrhage (≥4 disc areas in size). Additional detailed image grading was performed with stereo-imaging and dynamic early-phase ICGA., Results: Of the 95 screened PCV cases, 34 were excluded: (1) cases not suitable for recruitment as per the study protocol (n = 14), (2) equivocal lesions on ICGA characterised by small hyperfluorescent dots (n = 9), and (3) cases that were definitely not PCV (non-PCV, n = 11), identified by definitive diagnoses which included one case each of micro-aneurysm, retinal angiomatous proliferation, retino-choroidal anastomosis, small type-2 choroidal neovascularisation, retinal pigment epithelial (RPE) window defect and disciform scar; two cases of lesions where the choroidal vessel changed its course; and three cases of late-onset RPE staining., Conclusions: Standardised image grading techniques used in EVEREST study enabled effective differentiation of non-PCV from actual PCV., Competing Interests: Colin S. Tan receives travel support from Bayer, Heidelberg Engineering and Novartis; Wei Kiong Ngo and Louis W. Lim have nothing to disclose; Nikolle W. Tan is on the medical advisory boards of Allergan, Bayer and Novartis. Tock Han Lim receives travel support from Heidelberg engineering and Novartis. The EVEREST study was sponsored by Novartis Pharma AG, Basel, Switzerland. Funding The EVEREST study was funded by Novartis Pharma AG, Basel, Switzerland. Grant number NCT00674323 (clinicaltrials.gov). The sponsor had no role in the design or conduct of this research. Ethics approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent Informed consent was obtained from all individual participants included in the study.
- Published
- 2016
- Full Text
- View/download PDF
4. Polypoidal choroidal vasculopathy in Caucasian patients with presumed age-related macular degeneration.
- Author
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Tan CS, Ngo WK, Cheong KX, and Lim TH
- Subjects
- Female, Humans, Male, Antibodies, Monoclonal, Humanized administration & dosage, Choroid blood supply, Choroid Diseases ethnology, Macular Degeneration complications, White People
- Published
- 2014
- Full Text
- View/download PDF
5. Polypoidal choroidal vasculopathy in patients diagnosed with age-related macular degeneration.
- Author
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Tan CS, Lim LW, Ngo WK, and Lim TH
- Subjects
- Choroidal Neovascularization epidemiology, Coloring Agents, Denmark epidemiology, Fluorescein Angiography, Humans, Indocyanine Green, Polyps epidemiology, Choroid blood supply, Choroidal Neovascularization diagnosis, Macular Degeneration diagnosis, Polyps diagnosis
- Published
- 2013
- Full Text
- View/download PDF
6. Effects of medications on hypoxia‐inducible factor in the retina: A review.
- Author
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Kim, Angela H., Kolesnikova, Masha, Ngo, Wei Kiong, and Tsang, Stephen H.
- Subjects
HYPOXIA-inducible factors ,MACULAR degeneration ,RETINAL diseases ,RETINA ,DIABETIC retinopathy ,DEFEROXAMINE - Abstract
Hypoxia‐inducible factor (HIF) plays a critical role in the mechanisms that allow cells to adapt to various oxygen levels in the environment. Specifically, HIF‐1⍺ has shown to be widely involved in cellular repair, survival, and energy metabolism. HIF‐1⍺ has also been found in increased levels in cancer cells, highlighting the importance of balance in the hypoxic response. Promoting HIF‐1⍺ activity as a potential therapy for degenerative diseases and inhibiting HIF‐1⍺ as a therapy for pathologies with overactive cell proliferation are actively being explored. Digoxin and metformin, HIF‐1⍺ inhibitors, and deferoxamine and ⍺‐ketoglutarate analogues, HIF‐1⍺ activators, are being studied for application in age‐related macular degeneration, diabetic retinopathy, and retinitis pigmentosa. However, these same medications have retinal toxicities that must be assessed before implementation of therapeutic care. Herein, we highlight the duality of therapeutic and toxic potential of HIF‐1⍺ that must be carefully assessed prior to its clinical application in retinal disorders. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
7. Neovascular Age-Related Macular Degeneration (nAMD): A Review of Emerging Treatment Options.
- Author
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Tan, Colin S, Ngo, Wei Kiong, Chay, Isaac W, Ting, Dominic S, and Sadda, SriniVas R
- Subjects
- *
MACULAR degeneration , *CLINICAL trials , *ENDOTHELIAL growth factors , *LOW vision , *OFF-label use (Drugs) , *POLYPOIDAL choroidal vasculopathy , *THERAPEUTICS - Abstract
Neovascular age-related macular degeneration (nAMD) is a common world-wide cause of visual loss. Intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents are an effective means to treat nAMD and reduce its impact on vision compared to either sham treatment or photodynamic therapy. Currently, the approved anti-VEGF drugs include ranibizumab, aflibercept and brolucizumab. In addition, bevacizumab, used as an off-label drug, and has been shown to be effective in treating nAMD. While anti-VEGF agents are effective, its limitations include the requirement for frequent, often monthly injections, and the need for long-term treatment of nAMD. These present significant burdens on the healthcare system and on the patients. In addition, reviews of patients with nAMD treated with anti-VEGF have reported deterioration of vision over time with progression of geographic atrophy. These limitations are partly addressed by exploring different treatment regimens that reduce the frequency of treatments. Newer anti-VEGF drugs have been shown in Phase III clinical trials to have injection intervals as long as 12 or even 16 weeks for a proportion of patients. There is research on newer drugs that affect other pathways, such as the angiopoietin pathway, which may impact nAMD by extending the treatment interval and reducing the burden of treatment. Other measures include the use of sustained-release implants that release the drug regularly over a period of time, and can be refilled periodically, as well as hydrogel platforms that serve to release the drug. The use of biosimilars will also serve to reduce the cost of treatment for nAMD. A new frontier of gene therapy, primarily targeting genes involved in the transduction of retinal cells to produce anti-VEGF proteins intraocularly, also opens a new avenue of therapeutic approaches that can be used for treatment. This review paper will discuss both current treatment options and the newer treatments under development. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Paracentral acute middle maculopathy secondary to retinal artery macroaneurysm elucidates anatomy and physiology of retinal capillary plexus.
- Author
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Goh, Eunice and Ngo, Wei Kiong
- Subjects
- *
RETINAL artery , *SCANNING laser ophthalmoscopy , *MACULAR degeneration , *ANATOMY , *PHYSIOLOGY - Abstract
Purpose: To report a novel case of Paracentral Acute Middle Maculopathy (PAMM) Secondary to Retinal Artery Macroaneurysm. Methods: A case report. Results: A 72‐year‐old lady presented with three‐month history of sudden onset left paracentral scotoma. Her medical history include hypertension and hyperlipidemia. Visual acuity was 6/7.5 and 6/45 in the right and left eye respectively. Anterior segment examination and intraocular pressures were unremarkable. A ruptured retinal arterial macroaneurysm (RAM) was seen along the second‐order artery along the inferotemporal arcade with a small area of deep‐retinal whitening along the distal branches of the artery. Corresponding optical coherence tomography showed a round superficial retinal hyperreflective lesion consistent with RAM and hyperreflective band involving the outer plexiform layer (OPL), inner nuclear layer (INL) and inner plexiform layer (IPL) consistent with PAMM. Confocal scanning laser ophthalmoscopy video fluorescein angiogram (FA) demonstrated a ruptured and hemorrhagic RAM with significantly delayed distal filling of the artery, with resultant PAMM in an area supplied by the tributary arterioles of the affected artery. Conclusions: Oxygen consumption is highest at the metabolically active middle retinal layer. The inner and middle retinal layers are supplied by the superficial capillary plexus in the ganglion cell layer, intermediate capillary plexus (ICP) in the INL‐IPL boundary and deep capillary plexus (DCP) in the INL‐OPL boundary. Rupture and partial thrombosis of the RAM resulted in mechanical narrowing of the vessel lumen and severe flow limitation, which was further exacerbated by her history of hypertension and hyperlipidemia. This was consistent with the FA findings of delayed filling in the distal parts of the artery. Flow limitation results in decreased blood supply to the retinal capillary plexuses, further decreasing perfusion pressure, causing most disruption to the delicately balanced ICP and DCP blood supply of the middle retinal layer. Middle retinal infarction occurs most readily and presents as PAMM in our patient. In conclusion, we described a novel case of PAMM secondary to a ruptured and partially thrombosed RAM which clearly elucidates the anatomy and physiology of retinal capillary plexuses. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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