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Dive into the research topics where Calvin Sze-un Fong is active.

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Featured researches published by Calvin Sze-un Fong.


Ophthalmology | 2013

Correction of Visual Impairment by Cataract Surgery and Improved Survival in Older Persons: The Blue Mountains Eye Study Cohort

Calvin Sze-un Fong; Paul Mitchell; Elena Rochtchina; Erdahl Teber; Thomas Hong; Jie Jin Wang

OBJECTIVE We assessed whether correction of visual impairment (VI) by cataract surgery was associated with improved long-term survival in an older Australian population. DESIGN Population-based cohort study. PARTICIPANTS In the Blue Mountains Eye Study, 354 participants, aged ≥ 49 years, had both cataract and VI or had undergone cataract surgery before baseline examinations. They were subsequently examined after 5- and 10-year follow-ups. METHODS Associations between the mortality risk and the surgical correction of VI (visual acuity [VA] <20/40, attributable to cataract) were assessed in Cox proportional hazard regression models, after multivariate adjustment, using time-dependent variables for the study factor. MAIN OUTCOME MEASURES All-cause mortality. RESULTS The 15-year crude mortality of participants who had undergone cataract surgery at baseline with no subsequent VI (71.8%) was relatively similar to that in participants with cataract-related VI who had not yet undergone surgery (79.4%). However, after adjusting for age and sex, participants who underwent cataract surgery before baseline or during follow-up and no longer had VI had significantly lower long-term mortality risk (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.46-0.77) than participants with VI due to cataract who had not undergone cataract surgery. This lower mortality risk in the group with surgically corrected VI (HR, 0.54; 95% CI, 0.41-0.73) persisted after further adjustment for smoking, body mass index, home ownership, qualifications, poor self-rated health, the presence of poor mobility, hypertension, diabetes, self-reported history of angina, myocardial infarction, stroke, cancer, asthma, and arthritis. This finding remained significant (HR, 0.55; 95% CI, 0.41-0.73) after additional adjustment for the number of medications taken (continuous variable) and the number (≥ 5 vs. <5) of comorbid conditions (poor mobility, hypertension, diabetes, angina, myocardial infarction, stroke, cancer, asthma, or arthritis) as indicators of frailty. CONCLUSIONS Surgical correction of VI due to cataract was associated with significantly better long-term survival of older persons after accounting for known cataract and mortality risk factors, and indicators of general health. Whether some uncontrolled factors (frailty or general health) could have influenced decisions not to perform cataract surgery in some participants is unknown. However, this finding strongly supports many previous reports linking VI with poor survival. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.


Ophthalmology | 2013

Original articleCorrection of Visual Impairment by Cataract Surgery and Improved Survival in Older Persons: The Blue Mountains Eye Study Cohort

Calvin Sze-un Fong; Paul Mitchell; Elena Rochtchina; Erdahl Teber; Thomas Hong; Jie Jin Wang

OBJECTIVE We assessed whether correction of visual impairment (VI) by cataract surgery was associated with improved long-term survival in an older Australian population. DESIGN Population-based cohort study. PARTICIPANTS In the Blue Mountains Eye Study, 354 participants, aged ≥ 49 years, had both cataract and VI or had undergone cataract surgery before baseline examinations. They were subsequently examined after 5- and 10-year follow-ups. METHODS Associations between the mortality risk and the surgical correction of VI (visual acuity [VA] <20/40, attributable to cataract) were assessed in Cox proportional hazard regression models, after multivariate adjustment, using time-dependent variables for the study factor. MAIN OUTCOME MEASURES All-cause mortality. RESULTS The 15-year crude mortality of participants who had undergone cataract surgery at baseline with no subsequent VI (71.8%) was relatively similar to that in participants with cataract-related VI who had not yet undergone surgery (79.4%). However, after adjusting for age and sex, participants who underwent cataract surgery before baseline or during follow-up and no longer had VI had significantly lower long-term mortality risk (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.46-0.77) than participants with VI due to cataract who had not undergone cataract surgery. This lower mortality risk in the group with surgically corrected VI (HR, 0.54; 95% CI, 0.41-0.73) persisted after further adjustment for smoking, body mass index, home ownership, qualifications, poor self-rated health, the presence of poor mobility, hypertension, diabetes, self-reported history of angina, myocardial infarction, stroke, cancer, asthma, and arthritis. This finding remained significant (HR, 0.55; 95% CI, 0.41-0.73) after additional adjustment for the number of medications taken (continuous variable) and the number (≥ 5 vs. <5) of comorbid conditions (poor mobility, hypertension, diabetes, angina, myocardial infarction, stroke, cancer, asthma, or arthritis) as indicators of frailty. CONCLUSIONS Surgical correction of VI due to cataract was associated with significantly better long-term survival of older persons after accounting for known cataract and mortality risk factors, and indicators of general health. Whether some uncontrolled factors (frailty or general health) could have influenced decisions not to perform cataract surgery in some participants is unknown. However, this finding strongly supports many previous reports linking VI with poor survival. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.


Ophthalmology | 2012

Risk of Age-related Macular Degeneration 3 Years after Cataract Surgery: Paired Eye Comparisons

Jie Jin Wang; Calvin Sze-un Fong; Elena Rochtchina; Sudha Cugati; Tania de Loryn; Shweta Kaushik; Jennifer S. L. Tan; Jennifer J. Arnold; Wayne Smith; Paul Mitchell

OBJECTIVE To clarify possible associations between cataract surgery and progression of age-related macular degeneration (AMD). DESIGN Clinic-based cohort. PARTICIPANTS We followed cataract surgical patients aged 65+ years in the Australian Cataract Surgery and Age-related Macular Degeneration (CSAMD) study. Patients who remained unilaterally phakic for at least 24 months after recruitment were included. METHODS We performed annual examinations with retinal photography. We assessed AMD using side-by-side grading of images from all visits. Paired comparisons between operated and nonoperated fellow eyes (defined as nonoperated or operated <12 months previously) were made using generalized estimating equation models. MAIN OUTCOME MEASURES Incident early AMD was defined as the new appearance of soft indistinct/reticular drusen or coexisting retinal pigmentary abnormality and soft distinct drusen in eyes at risk of early AMD. Incident late AMD was defined as the new appearance of neovascular AMD or geographic atrophy (GA) in eyes at risk of late AMD. RESULTS Among 2029 recruited, eligible participants, 1851 had cataract surgery performed at Westmead Hospital, Sydney, and 1244 (70.7%) had 36-month postoperative visits. Of these participants, 1178 had gradable photographs at baseline and at least 1 follow-up visit. Of 308 unilaterally operated participants at risk of late AMD, this developed in 4 (1.3%) operated and 7 (2.3%) nonoperated fellow eyes (odds ratio [OR], 0.74; 95% confidence interval [CI], 0.23-2.36) after adjusting for the presence of early AMD at baseline. Of 217 unilaterally operated participants at risk of early AMD, this developed in 23 (10.6%) operated and 21 (9.7%) nonoperated fellow eyes (OR, 1.07; 95% CI, 0.74-1.65). Incident retinal pigment abnormalities were more frequent in operated than nonoperated fellow eyes (15.3% vs. 9.9%; OR, 1.64; 95% CI, 1.07-2.52). There was no difference in the 3-year incidence of large soft indistinct or reticular drusen between the 2 eyes (8.8% vs. 7.9%; OR, 1.12; 95% CI, 0.79-1.60). CONCLUSIONS Prospective follow-up data and paired eye comparisons of this older surgical cohort showed no increased risk of developing late AMD, early AMD, or soft/reticular drusen over 3 years. There was a 60% increased detection of retinal pigmentary changes in surgical eyes.


Ophthalmology | 2013

Long-term Changes in Visual Acuity in an Older Population over a 15-Year Period: The Blue Mountains Eye Study

Thomas Hong; Paul Mitchell; Elena Rochtchina; Calvin Sze-un Fong; Ee-Munn Chia; Jie Jin Wang

PURPOSE To describe the change in visual acuity (VA) and incidence of visual impairment (VI) in an older population over a 15-year period. DESIGN Population-based cohort. PARTICIPANTS Of the 3654 participants of the Blue Mountains Eye Study (BMES) baseline examination from 1992 through 1994, 1149 were re-examined during the 15-year follow-up between 2007 and 2010. METHODS Best-corrected VA by means of subjective refraction was measured with a logarithm of the minimum angle of resolution chart using Early Treatment Diabetic Retinopathy Study methods at each examination. MAIN OUTCOME MEASURES Unilateral VI was defined as VA worse than 20/40 and blindness was defined as VA worse than 20/200 in the worse eye. Incident bilateral VI and blindness were determined according to VA in the better eye at the 15-year visit. Doubling of the visual angle was defined as a loss of 15 letters or more from baseline to the 15-year visit. Halving of the visual angle was defined as a VA improvement of 15 letters or more over the same period. Causes of VI were determined at examination, by photographic grading, and from medical records. RESULTS Cumulative 15-year incidence of unilateral and bilateral VI was 12.3% (95% confidence interval [CI], 11.0-13.6) and 5.2% (95% CI, 4.3-6.1), respectively, and for unilateral and bilateral blindness, the cumulative incidence was 3.7% (95% CI, 3.0-4.4) and 0.9% (95% CI, 0.5-1.3), respectively. These incidence rates increased significantly with increasing age (P<0.01 for trend). Doubling and halving of the visual angle occurred in 6.9% (95% CI, 5.9-7.9) and 1.6% (95% CI, 1.0-2.2) of participants, respectively. Cataract accounted for 48.5% of unilateral and bilateral incident VI, followed by age-related macular degeneration (26.9%). Age-related macular degeneration accounted for 56.9% of unilateral and bilateral incident blindness cases, followed by cataract (20.7%). CONCLUSIONS These data provide population-based estimates of long-term incidence of visual impairment among older persons. Our estimate for cumulative incidence of blindness, accounting for competing risk of death, was similar to that of the Beaver Dam Eye Study (BDES) after age standardization. However, our estimate for cumulative incidence of VI was lower compared with that observed in the BDES population. This difference may be explained in part by a higher mortality rate among our population. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.


Clinical and Experimental Ophthalmology | 2012

Long-term outcomes of phacoemulsification cataract surgery performed by trainees and consultants in an Australian cohort

Calvin Sze-un Fong; Paul Mitchell; Tania de Loryn; Elena Rochtchina; Thomas Hong; Sudha Cugati; Jie Jin Wang

Background:  It is unclear whether differences exist in surgical complication rates and long‐term visual acuity outcomes between patients whose phacoemulsification cataract surgery was performed by ophthalmological trainees and those performed by consultants.


American Journal of Ophthalmology | 2013

Visual Impairment and Subsequent Use of Support Services Among Older People: Longitudinal Findings From the Blue Mountains Eye Study

Thomas Hong; Paul Mitchell; George Burlutsky; Calvin Sze-un Fong; Elena Rochtchina; Jie Jin Wang

PURPOSE To assess the impact of visual impairment and blindness on the incident use of community support services in the Blue Mountains Eye Study. DESIGN Population-based cohort. METHODS Of 3654 baseline participants (1992-1994), 2334, 1952, and 1149 were re-examined after 5, 10, and 15 years, respectively. Incident visual impairment was defined as subsequent development of visual impairment (visual acuity <20/40) in the better eye of subjects with best-corrected visual acuity ≥20/40 at baseline. Community support service use included regular use of Meals on Wheels, Home Care, or community nurse services. Informal support included assistance from family or friends. Discrete logistic regression models with time-dependent study and outcome variables were used to assess associations between visual impairment and subsequent use of support, adjusted for potential confounders. RESULTS Among participants with bilateral visual impairment at baseline, incident use of community services over 5-15 years was 41.7% compared to 19.4% in those without visual impairment at baseline (odds ratio, 1.39; 95% confidence interval, 0.54-3.60). Persons with incident bilateral visual impairment were more likely to subsequently need community support (odds ratio, 3.32; confidence interval 1.96-5.59) in 5 years, compared to persons without visual impairment during the entire follow-up period. Baseline older age, walking disability, receiving pension, and having 2+ hospital admissions within 12 months were also significantly associated with incident use of support services. CONCLUSIONS Development of bilateral visual impairment in this cohort was associated with greater likelihood of subsequent use of community or informal support services in 5 years, independent of physical comorbidities.


American Journal of Ophthalmology | 2013

Incidence and progression of epiretinal membranes in eyes after cataract surgery.

Calvin Sze-un Fong; Paul Mitchell; Elena Rochtchina; Thomas Hong; Tania de Loryn; Jie Jin Wang

PURPOSE To assess eye-specific epiretinal membrane (ERM) incidence 3 years after phacoemulsification surgery, and ERM detection bias attributable to cataract. DESIGN Cohort study. METHODS We recruited 1932 cataract surgical patients aged ≥64 years at Westmead Hospital (2004-2007). The surgical eye of each patient was assessed for presence of cellophane reflex or preretinal fibrosis at preoperative and 1-month-postoperative visits, and annually thereafter, using retinal image grading. Agreement on ERM detection between preoperative and 1-month-postoperative visits was assessed using kappa statistics. Cumulative incidence of ERM from 1 month to 3 years postoperatively was estimated using Kaplan-Meier methods and compared to the 5-year incidence of idiopathic ERM in right eyes of age-matched Blue Mountains Eye Study (BMES) participants. RESULTS ERM prevalence was 13.9% among 1394 participants with retinal photographs taken 1 month postoperatively. Of 1040 participants with retinal photographs from both preoperative and 1-month-postoperative visits, ERM was detected in 3.1% and 14.8%, respectively, with low diagnostic agreement (kappa = 0.17). Of 1119 subjects without ERM 1 month post surgery, the 3-year cumulative incidence of ERM was 11.2% (95% confidence interval [CI], 9.4%-13.4%; cellophane reflex 6.6%; preretinal fibrosis 4.2%). The age-standardized 3-year incidence of ERM in the surgical cohort (12.1%, 95% CI 8.6%-16.9%) was higher than the 5-year incidence of the BMES subsample (4.4%, 95% CI 3.0%-6.0%). CONCLUSIONS A substantial under-detection of ERM in eyes before cataract surgery could incorrectly contribute to ERM incidence after surgery. Over 3 years, ERM developed in >10%, including preretinal fibrosis in 4%, of surgical eyes free of ERM 1 month post surgery.


Acta Ophthalmologica | 2012

Visual outcomes 12 months after phacoemulsification cataract surgery in patients with diabetes

Calvin Sze-un Fong; Paul Mitchell; Elena Rochtchina; Tania de Loryn; Thomas Hong; Jie Jin Wang

Purpose:  To assess cataract surgery visual outcomes 12 months postoperatively in patients with diabetes, with or without diabetic retinopathy (DR), compared to patients without diabetes.


Asia-Pacific journal of ophthalmology | 2014

Patients' Short-term Satisfaction With Cataract Surgery and Long-Term Sustainability of Improved Visual-Related Quality of Life Over 3 Postoperative Years.

Thomas Hong; Paul Mitchell; Calvin Sze-un Fong; Elena Rochtchina; de Loryn T; Jie Jin Wang

PurposeThis study aimed to assess self-reported satisfaction following cataract surgery, and the sustainability of improved visual function and health-related quality of life in a cataract surgical cohort over 3 years post–phacoemulsification surgery. DesignA clinic-based cohort study. MethodsCataract surgical patients were recruited and followed up annually after surgery. Logarithm of the minimum angle of resolution (LogMAR) visual acuity, visual function (using the VF-14 questionnaire), and health-related quality of life (using the Short-Form Health Survey [SF-36] questionnaire) were assessed preoperatively and at 1, 2, and 3 years postoperatively. ResultsOf the 2029 patients recruited, 1924 (94.8%) had at least 1 postoperative visit, and 1229 (63.9%) had the 3-year follow-up examination performed. The mean age was 75.1 ± 6 years, and 54.1% were female. Of the 1229, 439 (35.7%) and 286 (23.3%) had completed the VF-14 and SF-36 questionnaires, respectively, at all 3 follow-up visits. The majority (92.1%) of patients reported being satisfied with the outcome of the surgery 6 months postoperatively. The overall VF-14 scores were significantly improved at the 12-month postoperative visits compared with preoperative scores (P < 0.01), independent of age and sex. The improved VF-14 mean scores were sustained for up to 3 years postoperatively. Health-related quality of life (SF-36 scores) showed no significant changes between preoperative and 1-, 2-, and 3-year postoperative examinations. ConclusionsWe documented the sustainability of improvement in visual function-related quality of life associated with cataract surgery over 3 postoperative years. Cataract surgery was not associated with improvement in health-related quality-of-life scores.


British Journal of Ophthalmology | 2011

Sustainability of visual acuity in the first 2 years after cataract surgery

Calvin Sze-un Fong; Paul Mitchell; Elena Rochtchina; Tania de Loryn; Thomas Hong; Jie Jin Wang

Purpose To assess whether improved visual acuity (VA) is sustained 2 years after the cataract surgery. Methods The Cataract Surgery and Age-Related Macular Degeneration (CSAMD) study followed 1936 patients aged ≥65 years undergoing phacoemulsification cataract surgery at Westmead Hospital (Sydney, Australia) between 2004 and 2007. Presenting and pinhole VA were assessed and retinal photography was performed annually. VA improvement or reduction was defined if VA differed by ≥2 lines between 1 and 24 months. Results VA data were available for 1809 patients at 1 month and 1294 at both postoperative visits (71.5% of 1809). At the 2-year visit, 930 patients (71.9%) maintained the same pinhole VA levels that they had at 1 month postoperatively, 199 (15.4%) had an improvement and 165 (12.7%) a reduction in pinhole VA. After adjusting for age and gender, pre-existing macular conditions (early AMD, macular hole or previous laser treatment) were associated with pinhole VA reduction (p=0.02). At the 24-month visit, 58.1% of those with presenting VA improvement wore distance spectacles. Conclusions One in eight cataract surgical patients lost at least two lines in pinhole VA over the 2-year postoperative period. Regular eye examinations of patients after cataract surgery may help to maximise the surgical benefits over the long term.

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Jie Jin Wang

National University of Singapore

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Wayne Smith

University of Newcastle

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