43 results on '"Simon T. C. Ko"'
Search Results
2. Radiological Determinants of Complicated Immunoglobulin G4–Related Ophthalmic Disease: A Territory-Wide Cohort Study
- Author
-
Kenneth K H, Lai, Winnie C W, Chu, Emmy Y M, Li, Regine Y C, Chan, Yingying, Wei, Ruofan, Jia, Andy C O, Cheng, Karen K W, Chan, Joyce K Y, Chin, Jeremy S W, Kwok, Ida Y F, Io, Nelson K F, Yip, Kenneth K W, Li, Wai Ho, Chan, Nai Man, Lam, Wilson W K, Yip, Alvin L, Young, Edwin, Chan, Callie K L, Ko, Simon T C, Ko, Hunter K L, Yuen, Clement C Y, Tham, Chi Pui, Pang, and Kelvin K L, Chong
- Subjects
Cohort Studies ,Ophthalmology ,Lacrimal Apparatus Diseases ,Immunoglobulin G ,Orbital Diseases ,Humans ,Hypertrophy ,Immunoglobulin G4-Related Disease ,General Medicine ,Retrospective Studies - Abstract
To evaluate the presenting radiological features of immunoglobulin G4-related ophthalmic disease (IgG4-ROD) and their associations with IgG4-related optic neuropathy (IgG4-RON), and IgG4-related ocular adnexal lymphoma (IgG4-ROL).A territory-wide, biopsy-proven, Chinese cohort. Masked review of orbital images, medical records, and histopathology reports.A total of 115 (94%) of the 122 patients in our cohort had preoperative orbital images (computed tomography=105, magnetic resonance imaging=40). Among them, 103/115 (90%) showed enlarged lacrimal glands, and 91 (88%) were bilateral. Nerve enlargement was observed: infraorbital in 31/115 (27%) patients and frontal in 17/115 (15%), 10 and 9 being bilateral, respectively. At least 1 or more extraocular muscle (EOM) enlargement was found in 41/115 (37%) patients, bilaterally in 20. Lateral rectus occurred in 30 (73%) of these 41 EOM patients and inferior rectus in 28 (68%). Two adjacent EOMs (inferior and lateral recti in 11 patients, inferior and medial recti in 7 patients) or multiple EOMs (at least 3) were enlarged in 23/41 (56%) and 13/41 (32%) of the patients, respectively. Intraconal lesions (67% vs 11%, P0.05), infraorbital (83% vs 23%, P0.005), or frontal (50% vs 15%, P0.05) nerve enlargement was significantly associated with IgG4-RON (6 patients) by univariate analyses. Asymmetric lacrimal gland enlargement and discrete orbital mass (both P0.05) were associated with IgG4-ROL (9 patients) by multivariate analyses.In this IgG4-ROD cohort, most patients had bilateral enlarged lacrimal glands, and the lateral rectus is the most frequently involved EOM. For the first time, unique radiological patterns associated with the development of IgG4-RON and IgG4-ROL are found.
- Published
- 2022
- Full Text
- View/download PDF
3. Surgical outcomes of orbital evisceration with primary orbital implant placement in patients with endophthalmitis
- Author
-
Kenneth Ka Hei Lai, Alvin K. H. Au, Andrew K. T. Kuk, Alan Tsang, Jacqueline Hiu Ching Tai, Ting Wang, Simon T. C. Ko, Edwin Chan, and Callie K. L. Ko
- Subjects
Ophthalmology - Published
- 2022
- Full Text
- View/download PDF
4. Three-Year Clinical Trial of Low-Concentration Atropine for Myopia Progression (LAMP) Study: Continued Versus Washout
- Author
-
Li Jia Chen, Clement C Y Tham, Ka Wai Kam, Jason C. S. Yam, Xiu Juan Zhang, Yuzhou Zhang, Fen Fen Li, Chi Pui Pang, Alvin L. Young, Yu Meng Wang, Simon T. C. Ko, Benjamin Hon Kei Yip, and Shu Min Tang
- Subjects
business.industry ,Outcome measures ,Washout ,Axial length ,Clinical trial ,Ophthalmology ,Regimen ,Atropine ,Anesthesia ,Medicine ,business ,Dioptre ,Volume concentration ,medicine.drug - Abstract
Purpose (1) To compare the efficacy of continued and stopping treatment for 0.05%, 0.025%, and 0.01% atropine during the third year. (2) To evaluate the efficacy of continued treatment over 3 years. (3) To investigate the rebound phenomenon and its determinants after cessation of treatment. Design A randomized, double-masked extended trial. Participants A total of 350 of 438 children aged 4 to 12 years originally recruited into the Low-Concentration Atropine for Myopia Progression (LAMP) study. Methods At the beginning of the third year, children in each group were randomized at a 1:1 ratio to continued treatment and washout subgroups. Cycloplegic spherical equivalent (SE) refraction and axial length (AL) were measured at 4-month intervals. Main Outcome Measures Changes in SE and AL between groups. Results A total of 326 children completed 3 years of follow-up. During the third year, SE progression and AL elongation were faster in the washout subgroups than in the continued treatment groups across all concentrations: –0.68 ± 0.49 diopters (D) versus –0.28 ± 0.42 D (P Conclusions During the third year, continued atropine treatment achieved a better effect across all concentrations compared with the washout regimen. 0.05% atropine remained the optimal concentration over 3 years in Chinese children. The differences in rebound effects were clinically small across all 3 studied atropine concentrations. Stopping treatment at an older age and lower concentration are associated with a smaller rebound.
- Published
- 2022
- Full Text
- View/download PDF
5. Eight years experience with botulinum toxin A and eyelid surgery in the treatment of hemifacial spasm
- Author
-
Edwin H.W. Chan, Simon T. C. Ko, and Kenneth K.H. Lai
- Subjects
body regions ,medicine.medical_specialty ,Eyelid surgery ,business.industry ,Medicine ,business ,medicine.disease ,Botulinum toxin ,Hemifacial spasm ,Surgery ,medicine.drug ,Botulinum toxin a - Abstract
AIM: To report the therapeutic outcomes of botulinum toxin A (Botox) and eyelid surgery in patients with hemifacial spasm (HFS). METHODS: Patients’ images and medical notes were retrospectively reviewed with subsequent analysis of both the therapeutic outcomes and complications of Botox injections. RESULTS: The information of 76 patients (female=58) with HFS who received a minimum of 4 Botox injections were included. The mean follow-up interval was 83±50 (20-112)mo with an average of 16±10 (4-34) injections. The peak incidence was between 55 and 64 years and the average age of onset was 66±11 (32-85)y. Up to 23% of patients with HFS had aberrant vascular structures (right=8, left=7) in close relationship to the facial nerve (MRI=14, CT=1), where the vertebral artery (n=6) was the most involved vessel followed by the anterior inferior cerebellum artery (n=5). Patients with primary HFS had a shorter effective duration (2.5 vs 3.1mo, P
- Published
- 2021
- Full Text
- View/download PDF
6. A Review of Tolerance and Safety Profiles of Long-Term Botulinum Neurotoxin Type A in Asian Patients with Hemifacial Spasm and Benign Essential Blepharospasm
- Author
-
Edwin H.W. Chan, Simon T. C. Ko, Kenneth K.H. Lai, Callie K. L. Ko, Andrew K. T. Kuk, and Alan Tsang
- Subjects
medicine.medical_specialty ,integumentary system ,business.industry ,Botulinum Neurotoxin Type A ,Essential Blepharospasm ,Original Articles ,medicine.disease ,Dermatology ,eye diseases ,Botulinum neurotoxin ,body regions ,03 medical and health sciences ,Ophthalmology ,0302 clinical medicine ,030221 ophthalmology & optometry ,medicine ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,Hemifacial spasm - Abstract
This article reports the tolerance and long-term safety profiles of botulinum neurotoxin type A among Asian patients with benign essential blepharospasm (BEB) and hemifacial spasm (HFS). We performed a retrospective review of clinical documents and procedure records of consecutive BEB and HFS patients receiving onabotulinum toxin A (Botox) treatment in our clinic over the past 20 years. We reviewed the information of 105 patients diagnosed with BEB (n = 31) and HFS (n = 74). All of the patients were Asian. The mean age of disease onset was 59 (range 37–80) years old for BEB and 61 (range 31–83) for HFS. The mean follow up was 84 (range 12–240) months and the mean number of sessions per patient was 19 (range 1–61). The botulinum toxin dose per session increased significantly in both BEB (16.5 versus 21.6 units, p
- Published
- 2021
- Full Text
- View/download PDF
7. Single or double? A comparison of evisceration techniques
- Author
-
Kenneth Ka Hei, Lai, Andrew K T, Kuk, Alvin K H, Au, Kenneth K H, Wong, Ting, Wang, Alan, Tsang, Jacqueline H T, Tai, Tiffany H L, Ong, Simon T C, Ko, Edwin, Chan, and Callie K L, Ko
- Abstract
We compared the rates of implant exposure and extrusion after evisceration with single and double scleral closure techniques.This retrospective cohort study included all patients who underwent evisceration with an implant insertion over the past 18 years at Tung Wah Eastern Hospital and Pamela Youde Nethersole Eastern Hospital. Clinical documents and operation records were reviewed.A total of 81 ethnic Chinese patients (44 male) who underwent evisceration with primary implant insertion were reviewed. 39 (48%) patients underwent the double scleral closure technique with an implant placed posterior to the posterior sclera, and 42 (52%) patients underwent the single scleral closure technique with an implant inserted in the intra-scleral cavity. The follow-up interval was 70 months. The surgical indications were endophthalmitis (35%), painful blind eye (23%), traumatic disfigured globe (22%) and phthisis bulbi (20%). Silicone was the most used implant material (69%). The patients who underwent double scleral closure had a larger size of the implant (19.7 vs 17.9 mm, p 0.05). Both implant exposure (26% vs 3%, p 0.05) and implant extrusion (26% vs 0%, p 0.05) were more common in patients who underwent single scleral.Double scleral closure technique allows a larger implant, and it is associated with a lower rate of implant exposure and extrusion. The double scleral closure technique is a superior technique of choice in these patients with primary implant placement.
- Published
- 2022
8. Opacity in orbital X-ray
- Author
-
Simon T. C. Ko and Sunny Chi Lik Au
- Subjects
medicine.diagnostic_test ,Opacity ,business.industry ,030208 emergency & critical care medicine ,Computed tomography ,030204 cardiovascular system & hematology ,03 medical and health sciences ,Orbit ,0302 clinical medicine ,Emergency Medicine ,Optometry ,Medicine ,Ultrasonography ,business - Abstract
X-ray interpretation is a fundamental skill in emergency practice. Post-operative eyes with implants may sometimes pose clinical challenges on post-traumatic event diagnosis and differentiation from organ wasting. Recommended by authorities and guidelines, computed tomography is indicated for evaluation of head injury cases, yet incidental abnormal findings such as radiopacity in the eyeball might create dilemma to diagnosis. History taking and clinical examinations are essential for the interpretation of the radiopacity in orbital imaging. Subtle and uncommon radiological findings of the eye will be discussed.
- Published
- 2020
- Full Text
- View/download PDF
9. Two-Year Clinical Trial of the Low-Concentration Atropine for Myopia Progression (LAMP) Study
- Author
-
Shu Min Tang, Clement C Y Tham, Li Jia Chen, Alvin L. Young, Chi Pui Pang, Simon T. C. Ko, Benjamin Hon Kei Yip, Jason C. S. Yam, Fen Fen Li, Xiu Juan Zhang, and Ka Wai Kam
- Subjects
0303 health sciences ,Visual acuity ,business.industry ,Placebo ,law.invention ,Clinical trial ,03 medical and health sciences ,Ophthalmology ,Regimen ,Dose–response relationship ,Atropine ,0302 clinical medicine ,Randomized controlled trial ,law ,Anesthesia ,030221 ophthalmology & optometry ,medicine ,medicine.symptom ,business ,Dioptre ,030304 developmental biology ,medicine.drug - Abstract
Purpose To evaluate the efficacy and safety of 0.05%, 0.025%, and 0.01% atropine eye drops over 2 years to determine which is the optimal concentration for longer-term myopia control. Design Randomized, double-masked trial extended from the Low-Concentration Atropine for Myopia Progression (LAMP) Study. Participants Three hundred eighty-three of 438 children (87%) aged 4 to 12 years with myopia of at least –1.0 diopter (D) originally randomized to receive atropine 0.05%, 0.025%, 0.01%, or placebo once daily in both eyes in the LAMP phase 1 study were continued in this extended trial (phase 2). Methods Children in the placebo group (phase 1) were switched to receive 0.05% atropine from the beginning of the second-year follow-up, whereas those in the 0.05%, 0.025%, and 0.01% atropine groups continued with the same regimen. Cycloplegic refraction, axial length (AL), accommodation amplitude, photopic and mesopic pupil diameter, and best-corrected visual acuity were measured at 4-month intervals. Main Outcome Measures Changes in spherical equivalent (SE) and AL and their differences between groups. Results Over the 2-year period, the mean SE progression was 0.55±0.86 D, 0.85±0.73 D, and 1.12±0.85 D in the 0.05%, 0.025%, and 0.01% atropine groups, respectively (P = 0.015, P 0.1), but improved mildly in the 0.01% atropine group (P = 0.04). For the phase 1 placebo group, the myopia progression was reduced significantly after switching to 0.05% atropine (SE change, 0.18 D in second year vs. 0.82 D in first year [P Conclusions Over 2 years, the efficacy of 0.05% atropine observed was double that observed with 0.01% atropine, and it remained the optimal concentration among the studied atropine concentrations in slowing myopia progression.
- Published
- 2020
- Full Text
- View/download PDF
10. Upper Cranial Nerve Involvement and Immunoglobulin G4–Related Optic Neuropathy
- Author
-
Alvin L. Young, Simon T. C. Ko, Kenneth K. W. Li, Kenneth K.H. Lai, Hunter K.L. Yuen, Kelvin K.L. Chong, Regine Y.C. Chan, and Joyce K.Y. Chin
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,genetic structures ,Cranial nerve involvement ,Optic neuropathy ,03 medical and health sciences ,0302 clinical medicine ,Oculomotor Nerve ,Ophthalmology ,Immunoglobulin g4 ,Optic Nerve Diseases ,Humans ,Medicine ,Child ,Aged ,Retrospective Studies ,030304 developmental biology ,0303 health sciences ,business.industry ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,eye diseases ,Immunoglobulin G ,Cohort ,030221 ophthalmology & optometry ,Female ,Immunoglobulin G4-Related Disease ,sense organs ,Tomography, X-Ray Computed ,business - Abstract
5% of one of the largest biopsy-proven IgG4ROD cohort suffered from IgG4-related optic neuropathy, which was associated with upper cranial nerve(s) involvement and retrobulbar mass. Visual prognosis was related to the level of presenting vision. (35 words)
- Published
- 2020
- Full Text
- View/download PDF
11. Malignancies in Immunoglobulin G4-related ophthalmic disease
- Author
-
Kenneth K.H. Lai, Emmy Y.M. Li, Regine Y.C. Chan, Kenneth C.W. Wong, Jimmy K.S. Yu, W. Cheuk, Y.H. Hui, Andy C.O. Cheng, Joyce K.Y. Chin, S. K. Ip, W. H. Chan, Jeremy S.W. Kwok, W. C. Lam, Ida Y. F. Io, Theresa S.T. Mak, Kenneth K.W. Li, N. M. Lam, Wilson W. K. Yip, Alvin L. Young, Edwin Chan, Callie K.L. Ko, Simon T. C. Ko, Hunter K.L. Yuen, Clement C.Y. Tham, Chi Pui Pang, and Kelvin K.L. Chong
- Subjects
Ophthalmology ,General Medicine - Abstract
Purpose Clinical phenotypes in Immunoglobulin G4-related disease (IgG4-RD) according to the patterns of affecting organs have different risks of malignancies. We attempt to determine the association of malignancies with IgG4-related ophthalmic disease (IgG4-ROD). Design Retrospective cohort study. Methods Review of medical records, orbital images and histopathology reports in a territory-wide cohort of biopsy proven IgG4-ROD patients from 2005–2019. Findings Among 122 patients who had biopsies taken from adnexal lesions including lacrimal glands (n = 108), orbital mass (n = 30), infiltrated orbital fat (n = 10), conjunctiva (n = 2) or extraocular muscles (n = 3), 13% (16/122) developed malignancies over 73 ± 48months’ follow-up. There were 9 cases of ocular adnexal lymphoma (OAL) and 7 extra-orbital malignancies. Compared with the general population, the incidence of OAL was significantly higher (standardized incidence ratios, SIRs = 10.0, 95%CI = 4.5–17.6) while that of extra-orbital malignancies was similar. The SIRs was highest within the first year (SIR = 46.7, 95%CI = 18.5–87.6) when 7 OAL were concomitantly diagnosed. Patients who developed OAL or extra-orbital malignancies were older than other patients at IgG4-ROD diagnosis (64.9 ± 7.1, 68.3 ± 8.5 versus 55.2 ± 15.0 years, P Conclusion In this biopsy-proven IgG4-ROD cohort, 7% developed OAL which was 10 times higher than the general population. Patients with asymmetric lacrimal gland enlargement or without trigeminal nerves involvement radiologically were associated with OAL.
- Published
- 2022
12. Treatment outcomes and their determinants of IgG4-related ophthalmic disease: a territory-wide cohort study
- Author
-
Kenneth K H Lai, Emmy Y M Li, Regine Y C Chan, Winnie C W Chu, Andy C O Cheng, Karen K W Chan, Joyce K Y Chin, Jeremy S W Kwok, Ida Y F Io, Nelson K F Yip, Kenneth K W Li, Wai Ho Chan, Nai Man Lam, Wilson W K Yip, Alvin L Young, Edwin Chan, Callie K L Ko, Simon T C Ko, Hunter K L Yuen, Clement C Y Tham, Chi-Pui Pang, and Kelvin K L Chong
- Subjects
Cellular and Molecular Neuroscience ,Ophthalmology ,Sensory Systems - Abstract
BackgroundOral corticosteroid remains the first-line treatment of IgG4-related ophthalmic disease, but steroid-dependence is common and serious. Factors associated with steroid dependence and relapse have to be further explored.Study populationA city-wide, biopsy-proven, Chinese cohort.MethodsRetrospective, masked review of medical records, orbital images and histopathology reports.ResultsThere were 101 patients with at least 24-month follow-up. Up to 82% (82/101) received oral corticosteroid as first-line treatments, and 7 of them received also concomitant steroid-sparing agents (SSA)/biological agents as primary treatment. There was 61% (50/82) of patients required long-term corticosteroid (alone=23, with SSA=27) after 1.9±0.7 (range 1–5) relapses. When compared with the 21% (17/82) of patients who tapered corticosteroid successfully for 24 months, steroid dependence was associated with elevated baseline serum IgG4 level (94% vs 65%, pConclusionIn this cohort, 60% of patients required long-term maintenance oral corticosteroid. Elevated pretreatment serum IgG4 level and Mikulicz syndrome were associated with steroid dependence. Debulking surgery is an alternative for a subgroup of patients with discrete orbital lesions, normal baseline IgG4 level and no Mikulicz syndrome.
- Published
- 2021
13. Giant Cell Arteritis
- Author
-
Simon T. C. Ko and Sunny Chi Lik Au
- Subjects
temporal artery biopsy ,Giant cell arteritis ,Pathology ,medicine.medical_specialty ,fundus fluorescein angiography ,business.industry ,giant cell arteritis ,lcsh:R ,Medicine ,lcsh:Medicine ,business ,medicine.disease ,central retinal artery occlusion - Abstract
A 76-year-old lady presented to emergency department for left eye sudden visual loss, and fundoscopy found cherry-red spot over the central macula with attenuated retinal vessels. Central retinal artery occlusion (CRAO) was diagnosed. She did not complain of new onset headache, but mild tenderness on palpation over left temporal area with vaguely weak pulsation detected. After the acute management of CRAO pharmacologically, rebreathing into paper bag, and ocular massage; patient underwent hyperbaric oxygen therapy hoping to salvage the ischemic retina while waiting for the erythrocyte sedimentation rate result. Result was >100 mm/hr, and high dose oral steroid was started immediately. Superficial temporal artery biopsy (TAB), performed 2 days after steroid treatment, was diagnostic of giant cell arteritis (GCA). Positron emission tomography and computerized tomography scan revealed vasculitis over thoracic aorta, left common carotid and subclavian artery. Ocular imaging of CRAO, histology of GCA on TAB are discussed with the interesting images.
- Published
- 2020
14. Corneal perforation and rare primary adenocarcinoma of the lacrimal gland: A case report
- Author
-
Sunny Chi Lik Au, Simon T. C. Ko, and Edwin H.W. Chan
- Subjects
medicine.medical_specialty ,genetic structures ,business.industry ,lcsh:Medical emergencies. Critical care. Intensive care. First aid ,Eye Enucleation ,General Medicine ,Lacrimal gland ,lcsh:RC86-88.9 ,Corneal perforation ,medicine.disease ,Lacrimal apparatus ,eye diseases ,Keratitis ,medicine.anatomical_structure ,Cornea ,medicine ,Resection margin ,Radiology ,sense organs ,business ,lacrimal apparatus ,adenocarcinoma ,orbital neoplasms ,corneal perforation ,keratitis ,eye enucleation ,Orbit (anatomy) - Abstract
Rationale: Primary adenocarcinoma of the lacrimal gland is rare, and its presentation as corneal perforation is even rarer. Corneal perforation is an ocular emergency that warrants urgent ophthalmic surgery, yet complete staging of lacrimal gland tumor pre-operatively is essential for optimal oncological management. Patient’s concerns: A 57-year-old man presented with left eye pain was found to have left eye proptosis and fleshy tissue mass around the eyeball. Uveal tissue was prolapsing over the perforated keratitis cornea, and the eye was full of discharge. Diagnosis: Bedside ultrasound B-scan confirmed vitreous haze, and emergency contrast computed tomography (CT) revealed soft tissue density mass (>40 mm) molding around the left globe and optic nerve without any rim enhancing abscess. Left exogenous endophthalmitis from exposure keratopathy secondary to proptosis caused by the bulky lacrimal tumor located in the confined orbital cone was diagnosed. Interventions: Emergency enucleation surgery of the left eyeball was done for this painful blind eye to control the infection from spreading. Orbital walls were biopsied intra-operatively, and tumor staging was completed by positron emission tomography- CT scan and magnetic resonance imaging. Without evidence of metastasis, left orbital exenteration was followed by adjuvant orbital chemoradiotherapy for the sake of close proximity of resection margin. Outcomes: Left exenterated orbit was fully epithelialized at around 2 months, and there was no recurrence of the disease up to present at the 1 year follow-up. Lessons: Thorough workup on the staging of the disease to minimize the number of operations for oncological patients is always a top priority, yet it may not always be possible as in our case presenting with corneal perforation.
- Published
- 2020
15. Prevalence of strabismus and its risk factors among school aged children: The Hong Kong Children Eye Study
- Author
-
Patrick Ip, Chi Pui Pang, Yi Han Lau, Jason C. S. Yam, Alvin L. Young, Simon T. C. Ko, Xiu Juan Zhang, Ka Wai Kam, Clement C Y Tham, Yu Meng Wang, Wilson W K Yip, and Li Jia Chen
- Subjects
Male ,Pediatrics ,medicine.medical_specialty ,Multivariate analysis ,genetic structures ,Science ,Visual Acuity ,Astigmatism ,Refraction, Ocular ,Article ,Anisometropia ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,030212 general & internal medicine ,Family history ,Child ,Strabismus ,Eye diseases ,Pregnancy ,Esotropia ,Multidisciplinary ,business.industry ,Vision Tests ,Refractive Errors ,medicine.disease ,eye diseases ,Risk factors ,030221 ophthalmology & optometry ,Medicine ,Exotropia ,Hong Kong ,Female ,business - Abstract
The study aims to determine the prevalence of strabismus and its risk factors among school children in Hong Kong. This is a cross-sectional study involving 6–8 year old children from different districts in Hong Kong. 4273 children received comprehensive ophthalmological examination, cycloplegic auto-refraction, best corrected visual acuity (BCVA), anterior segment examination, cover/uncover test, ocular motility, and fundus examination. Demographic information, pre- and post- natal background, parental smoking status, and family history of strabismus were obtained through questionnaires. Strabismus was found among 133 children (3.11%, 95% CI 2.59–3.63%), including 117 (2.74%) exotropia and 12 (0.28%) esotropia cases (exotropia-esotropia ratio: 9.75:1). There was no significant difference in prevalence across age (6–8 years) and gender. Multivariate analysis revealed associations of strabismus with myopia (≤ − 1.00D; OR 1.61; 95% CI 1.03–2.52; P = 0.037) hyperopia (≥ + 2.00D; OR 2.49; 95% CI 1.42–4.39; P = 0.002), astigmatism (≥ + 2.00D; OR 2.32; 95% CI 1.36–3.94; P = 0.002), and anisometropia (≥ 2.00D; OR 3.21; 95% CI 1.36–7.55; P = 0.008). Other risk factors for strabismus included maternal smoking during pregnancy (OR 4.21; 95% CI 1.80–9.81; P = 0.001), family history of strabismus (OR 6.36; 95% CI 2.78–14.50, P 35 years; OR 1.65; CI 1.09–2.49, P = 0.018). The prevalence of strabismus among children aged 6—8 years in Hong Kong is 3.11%. Refractive errors, family history of strabismus and maternal smoking history during pregnancy are risk factors. Early correction of refractive errors and avoidance of maternal smoking during pregnancy are potentially helpful in preventing strabismus.
- Published
- 2021
- Full Text
- View/download PDF
16. Immunoglobulin G4–related lacrimal sac dacryocystocele: A novel case report
- Author
-
Edwin H.W. Chan, Simon T. C. Ko, Kai Ching Peter Leung, and Sunny Chi Lik Au
- Subjects
Dacryocystocele ,medicine.medical_specialty ,Case Report ,Disease ,Immunoglobulin-G4 related disease ,03 medical and health sciences ,0302 clinical medicine ,lcsh:Ophthalmology ,Biopsy ,medicine ,Pathological ,Index case ,Nasolacrimal duct ,Chinese ,medicine.diagnostic_test ,business.industry ,medicine.disease ,Dermatology ,Lacrimal sac tumor ,Lacrimal sac ,Ophthalmology ,medicine.anatomical_structure ,lcsh:RE1-994 ,030221 ophthalmology & optometry ,Etiology ,business ,030217 neurology & neurosurgery - Abstract
Purpose Immunoglobulin G4-related disease is a systemic fibroinflammatory disease of unknown etiology. Immunoglobulin G4-related ophthalmic disease (IgG4-ROD) can manifest in multiple ways, but lacrimal sac involvement is rare. We present the first case in Chinese population of lacrimal sac IgG4-ROD. Observations Lacrimal sac IgG4-ROD is rare, and only 9 cases were reported in literature. Despite reported cases in Asian population, mainly in Japan, there was none from the Chinese population or South Asia. Our index case is a 67-year-old Chinese male, who presented with a left insidious nasolacrimal duct swelling mimicking dacryocystocele. Lacrimal sac IgG4-ROD was diagnosed with radiological, serological, pathological and immunohistochemical evidence. The under-reporting of this disease entity may suggest a benign course of such. Conclusions and importance This is the first reported case of biopsy proven lacrimal sac definite IgG4-ROD in Chinese patient on English literature. With the limited cases reported in literature, the pathology of Immunoglobulin G4 immune process in lacrimal sac demands further investigation.
- Published
- 2020
17. Low-Concentration Atropine for Myopia Progression (LAMP) Study
- Author
-
Jason C. S. Yam, Clement C Y Tham, Chi Pui Pang, Shu Min Tang, Antony Law, Joyce J. Chan, Alvin L. Young, Li Jia Chen, Yuning Jiang, Simon T. C. Ko, and Emily S. Wong
- Subjects
0303 health sciences ,medicine.medical_specialty ,Visual acuity ,genetic structures ,business.industry ,medicine.medical_treatment ,Placebo-controlled study ,Eye drop ,Astigmatism ,Placebo ,medicine.disease ,eye diseases ,03 medical and health sciences ,Ophthalmology ,Atropine ,0302 clinical medicine ,030221 ophthalmology & optometry ,medicine ,medicine.symptom ,business ,Adverse effect ,Dioptre ,030304 developmental biology ,medicine.drug - Abstract
Purpose Low-concentration atropine is an emerging therapy for myopia progression, but its efficacy and optimal concentration remain uncertain. Our study aimed to evaluate the efficacy and safety of low-concentration atropine eye drops at 0.05%, 0.025%, and 0.01% compared with placebo over a 1-year period. Design Randomized, placebo-controlled, double-masked trial. Participants A total of 438 children aged 4 to 12 years with myopia of at least −1.0 diopter (D) and astigmatism of −2.5 D or less. Methods Participants were randomly assigned in a 1:1:1:1 ratio to receive 0.05%, 0.025%, and 0.01% atropine eye drops, or placebo eye drop, respectively, once nightly to both eyes for 1 year. Cycloplegic refraction, axial length (AL), accommodation amplitude, pupil diameter, and best-corrected visual acuity were measured at baseline, 2 weeks, 4 months, 8 months, and 12 months. Visual Function Questionnaire was administered at the 1-year visit. Main Outcome Measures Changes in spherical equivalent (SE) and AL were measured, and their differences among groups were compared using generalized estimating equation. Results After 1 year, the mean SE change was −0.27±0.61 D, −0.46±0.45 D, −0.59±0.61 D, and −0.81±0.53 D in the 0.05%, 0.025%, and 0.01% atropine groups, and placebo groups, respectively (P Conclusions The 0.05%, 0.025%, and 0.01% atropine eye drops reduced myopia progression along a concentration-dependent response. All concentrations were well tolerated without an adverse effect on vision-related quality of life. Of the 3 concentrations used, 0.05% atropine was most effective in controlling SE progression and AL elongation over a period of 1 year.
- Published
- 2019
- Full Text
- View/download PDF
18. An old lady with acute headache and sudden blindness
- Author
-
Simon T. C. Ko and Sunny Chi Lik Au
- Subjects
genetic structures ,Retinal Artery Occlusion ,Nausea ,business.industry ,Eye pain ,030208 emergency & critical care medicine ,030204 cardiovascular system & hematology ,Sudden visual loss ,medicine.disease ,eye diseases ,03 medical and health sciences ,Giant cell arteritis ,0302 clinical medicine ,Traumatic injury ,Anesthesia ,Arterial Occlusive Diseases ,Sudden blindness ,Emergency Medicine ,medicine ,sense organs ,medicine.symptom ,business - Abstract
A 60-year-old hypertensive lady experienced painless sudden visual loss in the right eye when resting at home. There was no traumatic injury, no eye pain, or flashes or floaters, or nausea, but mild right-sided headache for few days. She was not lifting heavy objects, nor straining. She managed to attend the emergency department within 1 h of onset of symptoms by herself walking into the consultation room unaided. Examination showed visual acuity with pinhole of hand movement over the right eye, right relative afferent pupillary defect and normal intraocular pressure of 15 mmHg. Extraocular movement was full without diplopia or pain. Eyes were not injected, and slit lamp examination was normal with clear cornea. Acute management of vascular causes of acute blindness and the role of hyperbaric oxygen therapy in ophthalmological disease in Hong Kong will be discussed.
- Published
- 2020
- Full Text
- View/download PDF
19. Impact of virtual reality simulation on learning barriers of phacoemulsification perceived by residents
- Author
-
Danny Siu-Chun Ng, Clement C Y Tham, Shameema Sikder, Simon T. C. Ko, Alvin L. Young, Zihan Sun, Jerry Ka Hing Lok, and Timothy Y Y Lai
- Subjects
medicine.medical_specialty ,Multivariate analysis ,medicine.medical_treatment ,education ,simulation surgical education ,Virtual reality ,Simulation training ,Likert scale ,03 medical and health sciences ,0302 clinical medicine ,Surgical competency ,Ophthalmology ,medicine ,030212 general & internal medicine ,Original Research ,business.industry ,Rubric ,Clinical Ophthalmology ,cataract surgery ,Phacoemulsification ,Cataract surgery ,030221 ophthalmology & optometry ,Physical therapy ,virtual reality ,business - Abstract
Danny Siu-Chun Ng,1 Zihan Sun,1 Alvin Lerrmann Young,1,2 Simon Tak-Chuen Ko,3 Jerry Ka-Hing Lok,1 Timothy Yuk-Yau Lai,1 Shameema Sikder,4 Clement C Tham1 1Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, 2Department of Ophthalmology, Prince of Wales Hospital, 3Department of Ophthalmology, Tung Wah Eastern Hospital, Hong Kong, People’s Republic of China; 4Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA Objective: To identify residents’ perceived barriers to learning phacoemulsification surgical procedures and to evaluate whether virtual reality simulation training changed these perceptions. Design: The ophthalmology residents undertook a simulation phacoemulsification course and proficiency assessment on the Eyesi system using the previously validated training modules of intracapsular navigation, anti-tremor, capsulorrhexis, and cracking/chopping. A cross-sectional, multicenter survey on the perceived difficulties in performing phacoemulsification tasks on patients, based on the validated International Council of Ophthalmology’s Ophthalmology Surgical Competency Assessment Rubric (ICO-OSCAR), using a 5-point Likert scale (1 = least and 5 = most difficulty), was conducted among residents with or without prior simulation training. Mann–Whitney U tests were carried out to compare the mean scores, and multivariate regression analyses were performed to evaluate the association of lower scores with the following potential predictors: 1) higher level trainee, 2) can complete phacoemulsification most of the time (>90%) without supervisor’s intervention, and 3) prior simulation training. Setting: The study was conducted in ophthalmology residency training programs in five regional hospitals in Hong Kong. Results: Of the 22 residents, 19 responded (86.3%), of which 13 (68.4%) had completed simulation training. Nucleus cracking/chopping was ranked highest in difficulty by all respondents followed by capsulorrhexis completion and nucleus rotation/manipulation. Respondents with prior simulation training had significantly lower difficulty scores on these three tasks (nucleus cracking/chopping 3.85 vs 4.75, P = 0.03; capsulorrhexis completion 3.31 vs 4.40, P = 0.02; and nucleus rotation/manipulation 3.00 vs 4.75, P = 0.01). In multivariate analyses, simulation training was significantly associated with lower difficulty scores on these three tasks. Conclusion: Residents who had completed Eyesi simulation training had higher confidence in performing the most difficult tasks perceived during phacoemulsification. Keywords: virtual reality, simulation surgical education, cataract surgery
- Published
- 2018
- Full Text
- View/download PDF
20. Ocular point-of-care ultrasound: the current evidence
- Author
-
Christine Pui Sum Ho, Sunny Chi Lik Au, and Simon T. C. Ko
- Subjects
medicine.medical_specialty ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,business.industry ,RC86-88.9 ,Point of care ultrasound ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Medicine ,Medical emergencies. Critical care. Intensive care. First aid ,General Medicine ,Current (fluid) ,business ,Intensive care medicine - Published
- 2021
21. 'Contact Lens' cornea in peripheral ulcerative keratitis
- Author
-
Sunny Chi Lik Au and Simon T. C. Ko
- Subjects
Contact lens ,medicine.medical_specialty ,medicine.anatomical_structure ,business.industry ,Ophthalmology ,Cornea ,Genetics ,medicine ,Medicine ,Animal Science and Zoology ,business ,Peripheral ulcerative keratitis - Published
- 2021
22. Elderly Fall and Glaucoma: Vision Assessment in Geriatrics
- Author
-
Sunny Chi Lik Au and Simon T. C. Ko
- Subjects
Geriatrics ,medicine.medical_specialty ,business.industry ,Medicine ,Glaucoma ,Optometry ,business ,medicine.disease - Published
- 2020
- Full Text
- View/download PDF
23. Diagnose through the ophthalmoscopy: From diabetic retinopathy to endocrine emergency
- Author
-
Sunny Chi Lik Au, Christine Pui Sum Ho, and Simon T. C. Ko
- Subjects
Ophthalmoscopy ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Ophthalmology ,Emergency Medicine ,Medicine ,Endocrine system ,Diabetic retinopathy ,business ,medicine.disease - Published
- 2020
- Full Text
- View/download PDF
24. Computed Tomography revealing eye with retinal surgery
- Author
-
Sunny Chi Lik Au and Simon T. C. Ko
- Subjects
medicine.medical_specialty ,Retinal surgery ,medicine.diagnostic_test ,business.industry ,Ophthalmology ,Emergency Medicine ,medicine ,Computed tomography ,business - Published
- 2020
- Full Text
- View/download PDF
25. Retinoblastoma Genes in Chinese Studies
- Author
-
Jason C. S. Yam, Kwong Wai Choy, Simon T. C. Ko, Guy L. J. Chen, Yuning Jiang, Wai Kit Chu, Winnie W. Y. Lau, Calvin C P Pang, and Bi Ning Zhang
- Subjects
Genetics ,Retinoblastoma ,Biology ,medicine.disease ,medicine.disease_cause ,eye diseases ,Loss of heterozygosity ,Chromosome instability ,DNA methylation ,medicine ,Epigenetics ,Allele ,Carcinogenesis ,Gene - Abstract
Retinoblastoma is the commonest pediatric intraocular malignancy across most ethnic populations. Its genetic basis follows a two-hit model, in which two events are needed to inactivate both alleles of the disease-causative gene, RB1. Loss of heterozygosity (LOH) is a major driving force to inactivate the whole RB1 gene. Epigenetic modifications such as DNA methylation involving different genes and microRNA (miRNA) expressions also play important roles in retinoblastoma tumorigenesis. Functionally, as RB1 is important in maintaining chromosomal stability and cell cycle progression, loss of its function would underlie aberrations in other chromosomal regions. In addition, genes other than RB1 have been identified as direct or indirect causes of retinoblastoma tumorigenesis. In this chapter, we review the major genetic studies of retinoblastoma that have been conducted in Chinese. Contrasts with other ethnic groups will be made. These studies help us to understand the mechanisms of inactivating RB1, its functional consequences, and maintaining genome stability. Evidences have also been obtained on epigenetic contribution to retinoblastoma, especially by DNA repair genes. On the basis of the genetic and epigenetic findings, development of potential alternative therapy for retinoblastoma will be discussed, together with key issues in attempts of awareness campaign for early detection and genetic counselling.
- Published
- 2018
- Full Text
- View/download PDF
26. Choroidal thickness in thyroid-associated orbitopathy
- Author
-
Simon T. C. Ko, Danny Siu-Chun Ng, Alvin L. Young, Frank H. P. Lai, Kelvin K.L. Chong, Alvin Au, Joy Wy Leung, and Tiara W. U. Iao
- Subjects
Adult ,Male ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Exophthalmos ,Visual Acuity ,Four quadrants ,03 medical and health sciences ,0302 clinical medicine ,Ophthalmology ,Medicine ,Humans ,In patient ,Prospective Studies ,business.industry ,Choroid ,Significant difference ,Thyroid ,Healthy subjects ,Organ Size ,Middle Aged ,eye diseases ,Healthy Volunteers ,Graves Ophthalmopathy ,medicine.anatomical_structure ,Cross-Sectional Studies ,030221 ophthalmology & optometry ,Female ,sense organs ,medicine.symptom ,business ,030217 neurology & neurosurgery ,Tomography, Optical Coherence - Abstract
IMPORTANCE To investigate the choroidal thickness (CT) in patients with thyroid-associated orbitopathy (TAO). BACKGROUND To compare CT of TAO patients and healthy subjects. DESIGN Prospective cross-sectional study in a public hospital. PARTICIPANTS One hundred and four eyes of 52 TAO patients and 52 eyes of 26 healthy subjects. METHODS CT was measured with enhanced-depth imaging optical coherence tomography (EDI-OCT) at the subfoveal, macular and peripapillary regions. Multivariate linear regression was used to evaluate the associations of subfoveal CT with systemic and ocular variables among TAO eyes. MAIN OUTCOME MEASURES CT of both groups. RESULTS CT of eyes with TAO was significantly increased at the subfoveal region, 1 and 2 mm from the fovea nasally, temporally and superiorly, and 1 mm inferior to the fovea (all P
- Published
- 2018
27. Aging and Fall: Vision Related Signs on Head Computed Tomography
- Author
-
Simon T. C. Ko and Sunny Chi Lik Au
- Subjects
medicine.diagnostic_test ,business.industry ,medicine ,Head (vessel) ,Computed tomography ,Nuclear medicine ,business - Published
- 2019
- Full Text
- View/download PDF
28. Aesthetic assessment in periciliary 'v-incision' versus conventional external dacryocystorhinostomy in Asians
- Author
-
Edwin H.W. Chan, Derek Kim-Hun Yu, Danny Siu-Chun Ng, and Simon T. C. Ko
- Subjects
Male ,Anterior lacrimal crest ,medicine.medical_specialty ,Esthetics ,Visual analogue scale ,medicine.medical_treatment ,Dermatologic Surgical Procedures ,Dacryocystorhinostomy ,Cellular and Molecular Neuroscience ,Asian People ,External dacryocystorhinostomy ,Lacrimal Duct Obstruction ,Ophthalmology ,medicine ,Humans ,Aged ,Mucous Membrane ,business.industry ,Eyelids ,Middle Aged ,Sensory Systems ,Single surgeon ,Confidence interval ,Surgery ,Dissection ,Cross-Sectional Studies ,medicine.anatomical_structure ,Patient Satisfaction ,Female ,Eyelid ,business - Abstract
To determine the functional and aesthetic outcomes of periciliary “v-incision” external dacryocystorhinostomy (DCR) and to compare with conventional approach. Charts review of consecutive cases of “v-incision” (VDCR) or conventional DCR performed in a single institute, between January 2007 and March 2014. All procedures were performed or supervised by a single surgeon. Two periciliary incisions were made near the skin–mucosal junction at the upper and lower eyelid margins medial to the punctum joining at the medial canthal angle to form a “v” shape. Subcutaneous dissection was carried out inferomedially to reach the anterior lacrimal crest. DCR was then performed in the usual manner. Functional success was defined as no persistent or recurrent epiphora and patency on irrigation of the lacrimal drainage system at least 6 months post-surgery. A cross-sectional aesthetic survey was conducted by asking the patients to rate their scar appearance satisfaction on a visual analogue scale (VAS). External photographs were graded by two independent, masked physicians using VAS as well as the Stony Brook scar evaluation scale (SBSES). Sixty-one patients with median age of 64 years met the inclusion criteria, with median follow-up duration of 28 months. Thirty-eight eyes underwent VDCR, and 23 had conventional DCR. The functional success rate for VDCR was 83.3, 95 % confidence intervals (95%CI) [lower 0.68, upper 0.92] and for conventional DCR was 73.9 %, 95%CI [lower 0.54, upper 0.87]; without statistically significant difference (p = 0.38). VDCR patients rated higher aesthetic outcome on VAS (mean scores 95.5 ± 16.8 vs 82.9 ± 25.1, p = 0.03). On the SBSES, both observers gave higher aesthetic scores to the VDCR group (observer #1 4.6 ± 1.1 and #2 4.7 ± 1.2, p
- Published
- 2015
- Full Text
- View/download PDF
29. Association of antenatal steroid and risk of retinopathy of prematurity: a systematic review and meta-analysis
- Author
-
Shu Min Tang, Sunny Chi Lik Au, Danny Siu-Chun Ng, Hiu-Lam Chan, Wilson W K Yip, Jason C. S. Yam, Simon T. C. Ko, Shi Song Rong, Cheuk-Ling Yim, Li Jia Chen, and Matthew Ka Wing Tam
- Subjects
medicine.medical_specialty ,MEDLINE ,Global Health ,Antenatal steroid ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Pregnancy ,030225 pediatrics ,Medicine ,Humans ,Retinopathy of Prematurity ,business.industry ,Obstetrics ,Outcome measures ,Childhood blindness ,Infant, Newborn ,Retinopathy of prematurity ,Prenatal Care ,Preterm Births ,medicine.disease ,Sensory Systems ,Neonatal morbidity ,Ophthalmology ,Meta-analysis ,030221 ophthalmology & optometry ,Female ,Steroids ,Morbidity ,business - Abstract
BackgroundRetinopathy of prematurity (ROP) is one of the leading causes of childhood blindness. Use of antenatal steroid can reduce neonatal morbidity and mortality in preterm births, but its effect on ROP remained controversial. We aim to determine the association between antenatal steroid and risk of ROP by a systematic review and meta-analysis.MethodsReported studies on the association between antenatal steroid and risk of ROP or severe ROP were identified from MEDLINE and Embase databases from their inception to November 2016. Outcome measures were ORs with 95% CIs. Extracted data were pooled using a random-effect model or fixed-effect model where appropriate. Heterogeneity was assessed, and sensitivity analysis was performed.ResultsA total of 434 relevant studies were identified, and 28 studies were eligible for the meta-analysis, involving 20 731 neonates with 4202 cases of ROP. Among the 28 studies included, 13 studies provided data evaluating the association between antenatal steroid use and severe ROP, involving 4999 neonates with 792 cases of severe ROP. Antenatal steroid administration was associated with a reduced risk of ROP development (ORunadjusted=0.82, 95% CI 0.68 to 0.98; ORadjusted=0.67, 95% CI 0.47 to 0.94) and progression to severe ROP (ORunadjusted=0.58, 95% CI 0.40 to 0.86).ConclusionAntenatal steroid administration is associated with a reduced risk of ROP development and progression to severe ROP. Our results strengthened the indications of antenatal steroid therapy to high-risk mothers giving preterm births, especially in low-income and middle-income countries where antenatal steroid are not yet widely used.
- Published
- 2017
30. Endoscopic-assisted retrieval of retained lacrimal stent material in congenital nasolacrimal duct obstruction without dacryocystorhinostomy
- Author
-
Edwin H.W. Chan, Fu Man Tong, Danny Siu-Chun Ng, Shun Kit Chow, and Simon T. C. Ko
- Subjects
Male ,medicine.medical_specialty ,medicine.medical_treatment ,Dacryocystorhinostomy ,Ophthalmologic Surgical Procedures ,03 medical and health sciences ,0302 clinical medicine ,Lacrimal Duct Obstruction ,medicine ,Humans ,Intubation ,030223 otorhinolaryngology ,Nasolacrimal duct ,medicine.diagnostic_test ,business.industry ,Stent ,Endoscopy ,medicine.disease ,Lacrimal sac ,Surgery ,Ophthalmology ,medicine.anatomical_structure ,Nasolacrimal duct obstruction ,Eye Foreign Bodies ,Child, Preschool ,030221 ophthalmology & optometry ,Stents ,business ,Nasolacrimal Duct ,Ophthalmologic Surgical Procedure - Abstract
We report a 3-year-old child with history of congenital nasolacrimal duct obstruction who failed lacrimal probing and underwent bicanalicular intubation. Removal of stent from the superior punctum was unsuccessful and it was trapped in the lacrimal sac. We performed endonasal endoscopic-assisted retrieval of retained stent material without necessitating dacryocystorhinostomy (DCR). There was no recurrence of infection and nasolacrimal duct obstruction symptoms during 6 months of follow-up.
- Published
- 2016
- Full Text
- View/download PDF
31. A prospective study of fusional convergence parameters in Chinese patients with intermittent exotropia
- Author
-
Jason C. S. Yam, Simon T. C. Ko, Clement W N Chan, Ursula S. F. Wong, Patrick K W Wu, and Gabriela S. L. Chong
- Subjects
Male ,medicine.medical_specialty ,Adolescent ,Visual Acuity ,Good control ,Correlation ,Internal medicine ,medicine ,Humans ,In patient ,Prospective Studies ,Child ,Prospective cohort study ,business.industry ,Convergence, Ocular ,medicine.disease ,Ophthalmology ,Poor control ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Cardiology ,Exotropia ,Hong Kong ,Female ,Minimum deviation ,business ,Intermittent exotropia - Abstract
Purpose To evaluate the correlation between different fusional convergence parameters and the Newcastle Control Score (NCS) in children with intermittent exotropia. Methods In this consecutive prospective observational series, 101 Chinese children with intermittent exotropia were examined by a single observer, who assessed the level of control using the revised NCS and measured the angle of deviation and fusional convergence. Levels of control were defined according to the NCS as good (0-3), moderate (4-6), or poor (7-9). The correlation between the different fusional convergence parameters and the NCS was evaluated. Results The total convergence amplitude was similar among the different control groups ( P = 0.288 and P = 0.628 at near and at distance, respectively). The convergence reserve was higher in the good control group compared with the moderate and poor control groups, both at near ( P = 0.001) and at distance ( P = 0.001). Among all fusional convergence parameters, we determined that the fusional reserve ratio had strongest correlation with control (near ratio: r = −0.66, P = 0.001; distant ratio: r = −0.59, P = 0.001). Among patients with a fusional reserve ratio ≥2 at distance, 100% (5 of 5 patients) of these patients demonstrated good control (NCS ≤ 3). Conclusions In children with intermittent exotropia, the total convergence amplitude was similar among different levels of control. The convergence reserve was lower in the poor control group. Fusional reserve ratio ≥2 was an indicator of good control in patients.
- Published
- 2013
- Full Text
- View/download PDF
32. Preoperative Factors Predicting the Surgical Response of Bilateral Lateral Rectus Recession Surgery in Patients With Infantile Exotropia
- Author
-
Ursula S. F. Wong, Jason C. S. Yam, Gabriela S. L. Chong, Clement W N Chan, Patrick K W Wu, and Simon T. C. Ko
- Subjects
Male ,medicine.medical_specialty ,Refractive error ,genetic structures ,Ophthalmologic Surgical Procedures ,Risk Factors ,medicine ,Prism diopters ,Humans ,In patient ,Age of Onset ,Retrospective Studies ,Anisometropia ,business.industry ,Infant ,Retrospective cohort study ,General Medicine ,Infantile exotropia ,medicine.disease ,eye diseases ,Surgery ,Ophthalmology ,Treatment Outcome ,Oculomotor Muscles ,Child, Preschool ,Preoperative Period ,Pediatrics, Perinatology and Child Health ,Bilateral lateral rectus recession ,Exotropia ,Female ,sense organs ,business ,Follow-Up Studies - Abstract
Purpose: To determine the preoperative factors affecting the efficacy in bilateral lateral rectus recession surgery for infantile exotropia. Methods: This was a retrospective study of 50 patients with infantile exotropia who had bilateral lateral rectus recession surgery correction with more than 1 year of follow-up. Preoperative parameters influencing the response of the surgery were obtained and evaluated using multiple regression analysis including age at onset, age at surgery, interval between onset and surgery, preoperative deviation, refractive error, anisometropia, amount of surgery performed, presence of A- or V-pattern, and preoperative phase of exotropia. The response to surgery was defined as the change in deviation divided by the amount of the surgery. Results: Thirty-two (64%) and 24 (48%) patients had successful outcome at 6 weeks and 1 year postoperatively, respectively. The mean response to surgery was 1.79 ± 0.63 prism diopters (PD)/mm recession at 6 weeks and 1.58 ± 0.75 PD/mm recession at 1 year postoperatively. Exotropic drift was 5.12 ± 7.27 PD at 6 weeks and 8.02 ± 6.81 PD at 1 year postoperatively. Pre-operative deviation was correlated with the response of surgery at 6 weeks (β = 0.342, P = .020) and 1 year (β = 0.391, P = .007) postoperatively. Conclusions: Surgical response decreases over time due to the exotropic drift. Larger preoperative distance deviation was associated with larger surgical response. Both the exotropic drift and the preoperative deviation should be considered in applying the surgical dose in infantile exotropia. [J Pediatr Ophthalmol Strabismus 2013;50(4):245–250.]
- Published
- 2013
- Full Text
- View/download PDF
33. Molecular and Clinical Genetics of Retinoblastoma
- Author
-
Simon T. C. Ko, Kwong Wai Choy, Calvin C P Pang, Winnie W. Y. Lau, Wai Kit Chu, Li Jia Chen, and Jason C. S. Yam
- Subjects
Mutation ,DNA repair ,Retinoblastoma ,Microsatellite instability ,Biology ,medicine.disease_cause ,MLH1 ,medicine.disease ,eye diseases ,Loss of heterozygosity ,medicine ,Cancer research ,Carcinogenesis ,Gene - Abstract
Retinoblastoma (RB) is the most common intraocular cancer in children affecting all populations. Prognosis is highly dependent on the timing of diagnosis. Late presentation with extraocular spread is often fatal. In contrast, early-staged diseases are mostly curable using systemic plus focal therapy. Therefore, early presymptomatic diagnosis and even prenatal diagnosis are crucial to improve the clinical outcome. In recent years extensive studies on the RB1 gene and other RB-related genes have contributed to the better understanding of the disease mechanism. Inactivation of both copies of the RB1 gene on chromosome 13q14, due to loss-of-function mutations, is a prerequisite for tumorigenesis in RB. Secondary genetic alterations, such as lesions in another gene, are necessary to precipitate tumour development. We have found in Hong Kong Chinese about 19% of RB patients carry a germ-line RB1 mutation with no methylation at the RB1 promoter. We detected inactivation of the RB1 gene by loss-of-function mutations and loss of heterozygosity (LOH), but rarely by promoter hypermethylation, in Chinese sporadic RB. Promoter hypermethylation that silences gene expressions in the tumour suppressor gene RASSF1A and the DNA repair genes MGMT and MLH1 is a causative factor of retinoblastoma. We have also revealed the presence of microsatellite instability and recurrent loss of heterozygosity at multiple chromosomal regions in the retinoblastoma genome, showing genes other than RB1 as primary or secondary cause of retinoblastoma. Recently, we are working on extraocular regulation of RB development. Our studies on Chinese RB samples have led to useful information in the RB genome and cell biology for novel design of therapeutic modalities for RB.
- Published
- 2017
- Full Text
- View/download PDF
34. The Natural Course of Intermittent Exotropia over a 3-year Period and the Factors Predicting the Control Deterioration
- Author
-
Jason C. S. Yam, Simon T. C. Ko, Jeremy J. S. W. Kwok, and Gabriela S. L. Chong
- Subjects
medicine.medical_specialty ,Natural course ,Multidisciplinary ,High prevalence ,business.industry ,Control (management) ,medicine.disease ,Article ,Surgery ,Natural history ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Sample size determination ,030221 ophthalmology & optometry ,medicine ,Prospective cohort study ,business ,Exotropia ,Intermittent exotropia ,030217 neurology & neurosurgery - Abstract
Intermittent exotropia (IXT) is a common entity among Chinese children1. Despite its high prevalence in daily practice, the natural history of IXT is still unclear. This may be because previous studies have a limited sample size or are retrospective in nature2,3,4. Older studies seem to have no standardized method in assessing the control of IXT. Some considered the angle of deviation during a manifested exotropia to be less significant compared to the frequency with which it is manifested5. Others defined the control as the observed frequency with which the exo-deviation is manifested and along with the speed and ability to regain realignment after dissociation6. More recently, the assessment of the control has become more and more objective and standardized with the emergence of different point based systems7,8. Other parameters apart from these conventional ones may be helpful in understanding the natural history of IXT. Recent studies demonstrated that fusional convergence parameters are associated with the control of IXT9,10. Conducting a prospective study with the Newcastle Control Score would be helpful to understand the factors predicting the natural development of IXT. The purpose of this study is to determine the natural course of IXT and to identify fusional convergence parameters that may have predictive value in the change in the Newcastle Control Score in a 3-year period.
- Published
- 2016
- Full Text
- View/download PDF
35. Ophthalmological signet ring sign by a glaucoma implant
- Author
-
Sunny Chi Lik Au and Simon T. C. Ko
- Subjects
Male ,medicine.medical_specialty ,business.industry ,Ophthalmic Images ,Glaucoma ,Middle Aged ,Prosthesis Design ,medicine.disease ,Ophthalmology ,Imaging, Three-Dimensional ,lcsh:Ophthalmology ,lcsh:RE1-994 ,Humans ,Medicine ,Implant ,Glaucoma Drainage Implants ,Tomography, X-Ray Computed ,business ,Intraocular Pressure ,Sign (mathematics) ,Signet ring - Published
- 2019
- Full Text
- View/download PDF
36. Exotropic Drift and Ocular Alignment After Surgical Correction for Intermittent Exotropia
- Author
-
Patrick K W Wu, Po Lin Leow, Simon T. C. Ko, and Clement W N Chan
- Subjects
Male ,Reoperation ,medicine.medical_specialty ,Time Factors ,Future studies ,Eye Movements ,genetic structures ,Ophthalmologic Surgical Procedures ,Ophthalmology ,medicine ,Humans ,Child ,Retrospective Studies ,Depth Perception ,business.industry ,Infant ,Retrospective cohort study ,General Medicine ,Surgical correction ,medicine.disease ,eye diseases ,Ocular alignment ,Surgery ,Treatment Outcome ,Oculomotor Muscles ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Exotropia ,Female ,Minimum deviation ,sense organs ,business ,Esotropia ,Intermittent exotropia ,Follow-Up Studies - Abstract
Purpose: To evaluate changes in the angle of deviation over time and compare the motor success rate with different initial postoperative deviation in patients undergoing surgical correction for intermittent exotropia. Methods: Forty-eight patients aged between 1 and 10 years who underwent bilateral lateral rectus recession for intermittent exotropia were retrospectively evaluated. Preoperative and postoperative ocular deviations at 1 week, 1 month, and 6 months were analyzed. Full surgical correction was attempted in all patients. Motor success was defined as ocular deviation within 10 prism diopters of orthophoria at 6 months postoperatively. Results: The follow-up period ranged from 6 months to 3 years. Although most patients had exotropic drift, this drift was greater in patients with initial esotropia (86.7%) and orthophoria (70.0%) compared to patients with exotropia (26.1%). Motor success was achieved in 29 (60.4%) patients. There was no statistical difference between ocular alignment at 1 week postoperatively and final motor success ( P = .782). There was good correlation between ocular alignment at 1 week and 6 months postoperatively (ρ = 0.585, P < .001). Age and preoperative deviation were not found to be associated with motor success. Conclusions: The success rate appears to be unaffected by initial ocular alignment, suggesting that deliberate initial overcorrection may be unnecessary. Future studies are warranted to evaluate the long-term stability of this alignment. [J Pediatr Ophthalmol Strabismus 2010;47:12–16.]
- Published
- 2010
- Full Text
- View/download PDF
37. Association of Gestational Hypertensive Disorders with Retinopathy of prematurity: A Systematic Review and Meta-analysis
- Author
-
Shi Song Rong, Priscilla Y. L. Chan, Shu Min Tang, Sunny Chi Lik Au, Danny Siu-Chun Ng, Jason C. S. Yam, Li Jia Chen, Henry H. W. Lau, and Simon T. C. Ko
- Subjects
Gestational hypertension ,Pediatrics ,medicine.medical_specialty ,MEDLINE ,Infant, Newborn, Diseases ,Article ,03 medical and health sciences ,0302 clinical medicine ,Pregnancy ,medicine ,Humans ,Retinopathy of Prematurity ,030212 general & internal medicine ,Prospective Studies ,Prospective cohort study ,Multidisciplinary ,business.industry ,Infant, Newborn ,Infant ,Retinopathy of prematurity ,Hypertension, Pregnancy-Induced ,medicine.disease ,Infant newborn ,Meta-analysis ,030221 ophthalmology & optometry ,Gestation ,Female ,business - Abstract
The role of gestational hypertensive disorders, which includes both pre-eclampsia and gestational hypertension, in the development of retinopathy of prematurity (ROP) has been controversial. Therefore, this systematic review and meta-analysis is to evaluate the association between gestational hypertensive disoders and ROP. Eligible studies published up to June 5, 2016 were identified from MEDLINE and EMBASE that evaluated the association between the two conditions. Totally 1142 published records were retrieved for screening, 925 of them eligible for detailed evaluation. Finally 19 studies involving 45281 infants with 5388 cases of ROP met our criteria for meta-analysis. Gestational hypertensive disorders were not associated with ROP (unadjusted OR: 0.89; P = 0.38; adjusted OR: 1.35; P = 0.18). Subgroup analyses also revealed no significant association between ROP with pre-eclampsia (unadjusted OR: 0.85; P = 0.29; adjusted OR:1.29; P = 0.28) or with gestational hypertension (unadjusted OR: 1.10; P = 0.39; adjusted OR: 1.25; P = 0.60) separately. Sensitivity analysis indicated our results were robust. We concluded no significant association between gestational hypertensive disorders and ROP. More large scale well-conducted prospective cohorts on the topic are needed.
- Published
- 2016
38. Predictive Factors Affecting the Short Term and Long Term Exodrift in Patients with Intermittent Exotropia after Bilateral Rectus Muscle Recession and Its Effect on Surgical Outcome
- Author
-
Jason C. S. Yam, Clement W N Chan, Simon T. C. Ko, Gabriela S. L. Chong, Ursula S. F. Wong, and Patrick K W Wu
- Subjects
Male ,medicine.medical_specialty ,Article Subject ,Adolescent ,Rectus Abdominis ,Visual Acuity ,lcsh:Medicine ,General Biochemistry, Genetics and Molecular Biology ,medicine ,Humans ,In patient ,Postoperative Period ,Retrospective review ,General Immunology and Microbiology ,business.industry ,lcsh:R ,Rectus muscle ,General Medicine ,Term (time) ,Surgery ,Treatment Outcome ,Oculomotor Muscles ,Anesthesia ,Child, Preschool ,Correlation analysis ,Bilateral lateral rectus recession ,Exotropia ,Female ,business ,Intermittent exotropia ,Research Article ,Follow-Up Studies - Abstract
Purpose. To determine the predictive factors that affect short term and long term postoperative drift in intermittent exotropia after bilateral lateral rectus recession and to evaluate its effect on surgical outcome.Methods. Retrospective review of 203 patients with diagnosis of intermittent exotropia, who had surgical corrections with more than 3 years of followup. Different preoperative parameters were obtained and evaluated using Pearson’s correlation analysis.Results. The proportion of exodrift increased from 62% at 6 weeks to 84% at 3 years postoperatively. The postoperative drift was4.3±8.1 PD at 6 weeks,5.8±8.4 PD at 6 months,7.2 ± 8.3 PD at 1 year,7.4 ± 8.4 PD at 2 years, and7.7 ± 8.5 PD at 3 years. Preoperative deviation and initial overcorrection were significant factors affecting the postoperative drift at 3 years (r=0.177,P=0.011,r=-0.349, andP<0.001, resp.).Conclusions. Postoperative exodrift along three years occurs in a majority of patients after bilateral lateral rectus recession for intermittent exotropia. The long term surgical success is significantly affected by this postoperative exodrift. A larger preoperative deviation and a larger initial overcorrection are associated with a larger early and late postoperative exodrift.
- Published
- 2014
39. Prognostic factors predicting the surgical outcome of bilateral lateral rectus recession surgery for patients with infantile exotropia
- Author
-
Simon T. C. Ko, Jason C. S. Yam, Patrick K W Wu, Ursula S. F. Wong, Clement W N Chan, and Gabriela S. L. Chong
- Subjects
Male ,medicine.medical_specialty ,Refractive error ,genetic structures ,Visual Acuity ,Ophthalmologic Surgical Procedures ,medicine ,Humans ,Age of Onset ,Retrospective Studies ,Vision, Binocular ,business.industry ,Follow up studies ,Infant ,Retrospective cohort study ,General Medicine ,Infantile exotropia ,medicine.disease ,Prognosis ,Surgery ,Ophthalmology ,Oculomotor Muscles ,Bilateral lateral rectus recession ,Exotropia ,Female ,Age of onset ,business ,Follow-Up Studies - Abstract
To determine the presurgery factors affecting early and long-term favorable outcomes of bilateral lateral rectus recession surgery for infantile exotropia. A retrospective study of 50 patients with infantile exotropia (both constant-type and intermittent-type exotropia with onset before 1 year of age) who had bilateral lateral rectus recession surgery correction with more than 1 year follow up. Presurgery data were obtained and evaluated by use of multiple regression analysis. Smaller presurgery distance deviation (p = 0.042), older age at surgery (p = 0.025), longer interval between onset and surgery (p = 0.020), and more myopic refractive error (p = 0.007) were associated with successful outcome at 6 weeks, but none was correlated with successful outcome at 1 year. Among all data, presurgery distance deviation was the only significant determinant (multiple regression analysis, p = 0.021) for successful outcome at 6 weeks. Presurgery distance deviation (β = 0.952, p
- Published
- 2012
40. Orbital Kaposiform Hemangioendothelioma
- Author
-
Jason C. S. Yam, Clement W N Chan, Patrick K W Wu, Ursula S. F. Wong, and Simon T. C. Ko
- Subjects
medicine.medical_specialty ,Younger age ,genetic structures ,Medical treatment ,business.industry ,medicine.medical_treatment ,Retrospective cohort study ,Intraocular lens ,General Medicine ,Phacoemulsification ,medicine.disease ,eye diseases ,Ophthalmology ,Cataracts ,Intraocular lenses ,Pediatrics, Perinatology and Child Health ,medicine ,Optometry ,sense organs ,business ,Dioptre - Abstract
Purpose To report the refractive changes after cataract surgery and intraocular lens (IOL) implantation in Hong Kong Chinese children. Methods The clinical records of all patients who had cataract extraction and IOL implantation before age 18 years and with more than 2 years of follow-up were studied retrospectively. The refractive errors of all patients determined by cycloplegic refraction at 6 weeks, 3 months, 6 months, and 1 year postoperatively and then annually thereafter were included for analysis. Patients were stratified into groups according to their age at IOL implantation for analysis. Results Twenty-six eyes (81.3%) had developmental cataracts, 3 eyes (9.4%) had traumatic cataracts, and 3 eyes (9.4%) were iatrogenic (from surgical or medical treatment). Patients demonstrated a mean myopic shift (diopters) of -5.53 (0 to 2 years old) -4.68 (3 to 5 years old), -2.60 (6 to 8 years old), -0.42 (9 to 11 years), and -0.09 (> 11 years). There was no significant difference in myopic shift between eyes that were operated on and those that were not. No statistically significant differences in refractive change were found in comparing males to females, unilateral to bilateral cases, traumatic to non-traumatic cases, amblyopic to nonamblyopic eyes, primary to secondary intraocular lenses, or polymethylmethacrylate to acrylic IOLs. Conclusion The postoperative myopic shift in pediatric patients undergoing IOL implantation is greatest in the younger age groups and persists until at least 8 years of age. The mean rate of myopic shift also decreases with age. The refractive development of the pseudophakic eyes was not significantly different from the fellow phakic eyes.
- Published
- 2012
- Full Text
- View/download PDF
41. Long-term ocular alignment after bilateral lateral rectus recession in children with infantile and intermittent exotropia
- Author
-
Patrick K W Wu, Gabriela S. L. Chong, Simon T. C. Ko, Clement W N Chan, Jason C. S. Yam, and Ursula S. F. Wong
- Subjects
medicine.medical_specialty ,genetic structures ,Ophthalmologic Surgical Procedures ,Amblyopia ,Ophthalmology ,medicine ,Humans ,In patient ,Child ,Retrospective Studies ,Depth Perception ,Vision, Binocular ,business.industry ,Retrospective cohort study ,Infantile exotropia ,medicine.disease ,eye diseases ,Ocular alignment ,Surgery ,Treatment Outcome ,Oculomotor Muscles ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Bilateral lateral rectus recession ,Exotropia ,sense organs ,business ,Intermittent exotropia ,Esotropia ,Follow-Up Studies - Abstract
Purpose To compare postoperative drift after bilateral lateral rectus recession for infantile exotropia (XT) and for intermittent XT and to compare initial postoperative alignment with long-term motor outcome. Methods Medical records of all patients with infantile exotropia or intermittent exotropia who had undergone bilateral lateral rectus muscle recession surgery with a follow-up longer than 3 years were reviewed. The pre- and postoperative angles of deviation at distance and at near and postoperative drift at distance were compared. Surgical outcome was categorized as "success" (esotropia Δ or exotropia Δ ), "recurrence" (>10 Δ exotropia), or "overcorrection" (>5 Δ of esotropia). Results The overall mean postoperative exotropic drift at 3 years was 10.4 Δ in the infantile XT group and 7.2 Δ in the intermittent XT group ( P = 0.05). Both groups had a low success rate at 3 years: 41% in the infantile XT group and 51% in the intermittent XT group ( P = 0.270). For patients with an initial esotropia of 0 Δ to 10 Δ , the success rate at 3 years was 86% in the infantile XT group (12 of 14) and 65% in the intermittent XT group (28 of 43). Conclusions Postoperative exotropic drift is clinically similar in patients with intermittent versus infantile exotropia. Esotropia of 0 Δ to 10 Δ during the early postoperative period may be associated with the best long-term ocular alignment.
- Published
- 2011
42. Refractive changes after pediatric intraocular lens implantation in Hong Kong children
- Author
-
Jason C S, Yam, Patrick K W, Wu, Simon T C, Ko, Ursula S F, Wong, and Clement W N, Chan
- Subjects
Male ,Aging ,Phacoemulsification ,Adolescent ,Infant, Newborn ,Visual Acuity ,Infant ,Refraction, Ocular ,Cornea ,Axial Length, Eye ,Postoperative Complications ,Lens Implantation, Intraocular ,Child, Preschool ,Myopia ,Hong Kong ,Humans ,Female ,Child ,Retrospective Studies - Abstract
To report the refractive changes after cataract surgery and intraocular lens (IOL) implantation in Hong Kong Chinese children.The clinical records of all patients who had cataract extraction and IOL implantation before age 18 years and with more than 2 years of follow-up were studied retrospectively. The refractive errors of all patients determined by cycloplegic refraction at 6 weeks, 3 months, 6 months, and 1 year postoperatively and then annually thereafter were included for analysis. Patients were stratified into groups according to their age at IOL implantation for analysis.Twenty-six eyes (81.3%) had developmental cataracts, 3 eyes (9.4%) had traumatic cataracts, and 3 eyes (9.4%) were iatrogenic (from surgical or medical treatment). Patients demonstrated a mean myopic shift (diopters) of -5.53 (0 to 2 years old) -4.68 (3 to 5 years old), -2.60 (6 to 8 years old), -0.42 (9 to 11 years), and -0.09 (11 years). There was no significant difference in myopic shift between eyes that were operated on and those that were not. No statistically significant differences in refractive change were found in comparing males to females, unilateral to bilateral cases, traumatic to non-traumatic cases, amblyopic to nonamblyopic eyes, primary to secondary intraocular lenses, or polymethylmethacrylate to acrylic IOLs.The postoperative myopic shift in pediatric patients undergoing IOL implantation is greatest in the younger age groups and persists until at least 8 years of age. The mean rate of myopic shift also decreases with age. The refractive development of the pseudophakic eyes was not significantly different from the fellow phakic eyes.
- Published
- 2011
43. A Rare Case of Acute Ocular Hypertensive Episode in a Patient with Chronic Infantile Neurological Cutaneous Articular Syndrome
- Author
-
Jonathan Chun-ho Ho, Irene Tak Yee Yeung, Karen Kar Wun Chan, and Simon T. C. Ko
- Subjects
Intraocular pressure ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Cryopyrin-associated periodic syndrome ,Ocular hypertension ,General Medicine ,medicine.disease ,Dermatology ,03 medical and health sciences ,0302 clinical medicine ,Chronic disease ,Correspondence ,Rare case ,030221 ophthalmology & optometry ,medicine ,Gonioscopy ,030212 general & internal medicine ,High intraocular pressure ,business - Published
- 2016
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.