1.To Determine the Risk-Based Screening Interval for Diabetic Retinopathy: Development and Validation of Risk Algorithm from a Retrospective Cohort Study
Jinxiao LIAN ; Ching SO ; Sarah Morag MCGHEE ; Thuan-quoc THACH ; Cindy Lo Kuen LAM ; Colman Siu Cheung FUNG ; Alfred Siu Kei KWONG ; Jonathan Cheuk Hung CHAN
Diabetes & Metabolism Journal 2025;49(2):286-297
Background:
The optimal screening interval for diabetic retinopathy (DR) remains controversial. This study aimed to develop a risk algorithm to predict the individual risk of referable sight-threatening diabetic retinopathy (STDR) in a mainly Chinese population and to provide evidence for risk-based screening intervals.
Methods:
The retrospective cohort data from 117,418 subjects who received systematic DR screening in Hong Kong between 2010 and 2016 were included to develop and validate the risk algorithm using a parametric survival model. The risk algorithm can be used to predict the individual risk of STDR within a specific time interval, or the time to reach a specific risk margin and thus to allocate a screening interval. The calibration performance was assessed by comparing the cumulative STDR events versus predicted risk over 2 years, and discrimination by using receiver operative characteristics (ROC) curve.
Results:
Duration of diabetes, glycosylated hemoglobin, systolic blood pressure, presence of chronic kidney disease, diabetes medication, and age were included in the risk algorithm. The validation of prediction performance showed that there was no significant difference between predicted and observed STDR risks in males (5.6% vs. 5.1%, P=0.724) or females (4.8% vs. 4.6%, P=0.099). The area under the receiver operating characteristic curve was 0.80 (95% confidence interval [CI], 0.78 to 0.81) for males and 0.81 (95% CI, 0.79 to 0.83) for females.
Conclusion
The risk algorithm has good prediction performance for referable STDR. Using a risk-based screening interval allows us to allocate screening visits disproportionally more to those at higher risk, while reducing the frequency of screening of lower risk people.
2.To Determine the Risk-Based Screening Interval for Diabetic Retinopathy: Development and Validation of Risk Algorithm from a Retrospective Cohort Study
Jinxiao LIAN ; Ching SO ; Sarah Morag MCGHEE ; Thuan-quoc THACH ; Cindy Lo Kuen LAM ; Colman Siu Cheung FUNG ; Alfred Siu Kei KWONG ; Jonathan Cheuk Hung CHAN
Diabetes & Metabolism Journal 2025;49(2):286-297
Background:
The optimal screening interval for diabetic retinopathy (DR) remains controversial. This study aimed to develop a risk algorithm to predict the individual risk of referable sight-threatening diabetic retinopathy (STDR) in a mainly Chinese population and to provide evidence for risk-based screening intervals.
Methods:
The retrospective cohort data from 117,418 subjects who received systematic DR screening in Hong Kong between 2010 and 2016 were included to develop and validate the risk algorithm using a parametric survival model. The risk algorithm can be used to predict the individual risk of STDR within a specific time interval, or the time to reach a specific risk margin and thus to allocate a screening interval. The calibration performance was assessed by comparing the cumulative STDR events versus predicted risk over 2 years, and discrimination by using receiver operative characteristics (ROC) curve.
Results:
Duration of diabetes, glycosylated hemoglobin, systolic blood pressure, presence of chronic kidney disease, diabetes medication, and age were included in the risk algorithm. The validation of prediction performance showed that there was no significant difference between predicted and observed STDR risks in males (5.6% vs. 5.1%, P=0.724) or females (4.8% vs. 4.6%, P=0.099). The area under the receiver operating characteristic curve was 0.80 (95% confidence interval [CI], 0.78 to 0.81) for males and 0.81 (95% CI, 0.79 to 0.83) for females.
Conclusion
The risk algorithm has good prediction performance for referable STDR. Using a risk-based screening interval allows us to allocate screening visits disproportionally more to those at higher risk, while reducing the frequency of screening of lower risk people.
3.To Determine the Risk-Based Screening Interval for Diabetic Retinopathy: Development and Validation of Risk Algorithm from a Retrospective Cohort Study
Jinxiao LIAN ; Ching SO ; Sarah Morag MCGHEE ; Thuan-quoc THACH ; Cindy Lo Kuen LAM ; Colman Siu Cheung FUNG ; Alfred Siu Kei KWONG ; Jonathan Cheuk Hung CHAN
Diabetes & Metabolism Journal 2025;49(2):286-297
Background:
The optimal screening interval for diabetic retinopathy (DR) remains controversial. This study aimed to develop a risk algorithm to predict the individual risk of referable sight-threatening diabetic retinopathy (STDR) in a mainly Chinese population and to provide evidence for risk-based screening intervals.
Methods:
The retrospective cohort data from 117,418 subjects who received systematic DR screening in Hong Kong between 2010 and 2016 were included to develop and validate the risk algorithm using a parametric survival model. The risk algorithm can be used to predict the individual risk of STDR within a specific time interval, or the time to reach a specific risk margin and thus to allocate a screening interval. The calibration performance was assessed by comparing the cumulative STDR events versus predicted risk over 2 years, and discrimination by using receiver operative characteristics (ROC) curve.
Results:
Duration of diabetes, glycosylated hemoglobin, systolic blood pressure, presence of chronic kidney disease, diabetes medication, and age were included in the risk algorithm. The validation of prediction performance showed that there was no significant difference between predicted and observed STDR risks in males (5.6% vs. 5.1%, P=0.724) or females (4.8% vs. 4.6%, P=0.099). The area under the receiver operating characteristic curve was 0.80 (95% confidence interval [CI], 0.78 to 0.81) for males and 0.81 (95% CI, 0.79 to 0.83) for females.
Conclusion
The risk algorithm has good prediction performance for referable STDR. Using a risk-based screening interval allows us to allocate screening visits disproportionally more to those at higher risk, while reducing the frequency of screening of lower risk people.
4.To Determine the Risk-Based Screening Interval for Diabetic Retinopathy: Development and Validation of Risk Algorithm from a Retrospective Cohort Study
Jinxiao LIAN ; Ching SO ; Sarah Morag MCGHEE ; Thuan-quoc THACH ; Cindy Lo Kuen LAM ; Colman Siu Cheung FUNG ; Alfred Siu Kei KWONG ; Jonathan Cheuk Hung CHAN
Diabetes & Metabolism Journal 2025;49(2):286-297
Background:
The optimal screening interval for diabetic retinopathy (DR) remains controversial. This study aimed to develop a risk algorithm to predict the individual risk of referable sight-threatening diabetic retinopathy (STDR) in a mainly Chinese population and to provide evidence for risk-based screening intervals.
Methods:
The retrospective cohort data from 117,418 subjects who received systematic DR screening in Hong Kong between 2010 and 2016 were included to develop and validate the risk algorithm using a parametric survival model. The risk algorithm can be used to predict the individual risk of STDR within a specific time interval, or the time to reach a specific risk margin and thus to allocate a screening interval. The calibration performance was assessed by comparing the cumulative STDR events versus predicted risk over 2 years, and discrimination by using receiver operative characteristics (ROC) curve.
Results:
Duration of diabetes, glycosylated hemoglobin, systolic blood pressure, presence of chronic kidney disease, diabetes medication, and age were included in the risk algorithm. The validation of prediction performance showed that there was no significant difference between predicted and observed STDR risks in males (5.6% vs. 5.1%, P=0.724) or females (4.8% vs. 4.6%, P=0.099). The area under the receiver operating characteristic curve was 0.80 (95% confidence interval [CI], 0.78 to 0.81) for males and 0.81 (95% CI, 0.79 to 0.83) for females.
Conclusion
The risk algorithm has good prediction performance for referable STDR. Using a risk-based screening interval allows us to allocate screening visits disproportionally more to those at higher risk, while reducing the frequency of screening of lower risk people.
5.Molecular basis of von Hippel-Lindau syndrome in Chinese patients.
Wai-Kwan SIU ; Ronald Ching-Wan MA ; Ching-Wan LAM ; Chloe Miu MAK ; Yuet-Ping YUEN ; Fai-Man Ivan LO ; Kin-Wah CHAN ; Siu-Fung LAM ; Siu-Cheung LING ; Sui-Fan TONG ; Wing-Yee SO ; Chun-Chung CHOW ; Mary Hoi-Yin TANG ; Wing-Hung TAM ; Albert Yan-Wo CHAN
Chinese Medical Journal 2011;124(2):237-241
BACKGROUNDVon Hippel-Lindau (VHL) syndrome is an autosomal dominant familial cancer syndrome predisposing the affected individuals to multiple tumours in various organs. The genetic basis of VHL in Southern Chinese is largely unknown. In this study, we characterized the mutation spectrum of VHL in nine unrelated Southern Chinese families.
METHODSNine probands with clinical features of VHL, two symptomatic and eight asymptomatic family members were included in this study. Prenatal diagnosis was performed twice for one proband. Two probands had only isolated bilateral phaeochromocytoma. The VHL gene was screened for mutations by polymerase chain reaction, direct sequencing and multiplex ligation-dependent probe amplification (MLPA).
RESULTSThe nine probands and the two symptomatic family members carried heterozygous germline mutations. Eight different VHL mutations were identified in the nine probands. One splicing mutation, NM_000551.2: c.463+1G > T, was novel. The other seven VHL mutations, c.233A > G [p.Asn78Ser], c.239G > T [p.Ser80Ile], c.319C > G [p.Arg107Gly], c.481C > T [p.Arg161X], c.482G > A [p.Arg161Gln], c.499C > T [p.Arg167Trp] and an exon 2 deletion, had been previously reported. Three asymptomatic family members were positive for the mutation and the other five tested negative. In prenatal diagnosis, the fetuses were positive for the mutation.
CONCLUSIONSGenetic analysis could accurately confirm VHL syndrome in patients with isolated tumours such as sporadic phaeochromocytoma or epididymal papillary cystadenoma. Mutation detection in asymptomatic family members allows regular tumour surveillance and early intervention to improve their prognosis. DNA-based diagnosis can have an important impact on clinical management for VHL families.
Asian Continental Ancestry Group ; DNA Mutational Analysis ; Humans ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Von Hippel-Lindau Tumor Suppressor Protein ; genetics ; von Hippel-Lindau Disease ; genetics
7.Safe Excision of a Large Overhanging Cystic Bleb Following Autologous Blood Injection and Compression Suture.
Danny Siu Chun NG ; Ruby Hok Ying CHING ; Jason Cheuk Sing YAM ; Clement Wai Nang CHAN
Korean Journal of Ophthalmology 2013;27(2):145-148
Here, we report a large, overhanging cystic bleb that compromised vision and induced a foreign body sensation in a patient who underwent a trabeculectomy surgery with anti-metabolite therapy 4 years prior. Ultrasound biomicroscopy revealed multiple loculations with thin septa inside the bleb and a high risk of damage to the bleb was anticipated with a straight forward surgical excision. We injected autologous blood and placed a compression suture 6 weeks prior to surgical excision of the overhanging portion of the bleb. The operation was successful in preserving excellent bleb function, restoring visual acuity, and alleviating symptoms in our patient with up to 9 months of follow-up.
Blister/pathology/*surgery
;
Blood Transfusion, Autologous/*methods
;
Conjunctiva/pathology/surgery
;
Glaucoma/*surgery
;
Humans
;
Male
;
Middle Aged
;
Postoperative Complications/*surgery
;
*Suture Techniques
;
Trabeculectomy/*adverse effects
8.Safe Excision of a Large Overhanging Cystic Bleb Following Autologous Blood Injection and Compression Suture.
Danny Siu Chun NG ; Ruby Hok Ying CHING ; Jason Cheuk Sing YAM ; Clement Wai Nang CHAN
Korean Journal of Ophthalmology 2013;27(2):145-148
Here, we report a large, overhanging cystic bleb that compromised vision and induced a foreign body sensation in a patient who underwent a trabeculectomy surgery with anti-metabolite therapy 4 years prior. Ultrasound biomicroscopy revealed multiple loculations with thin septa inside the bleb and a high risk of damage to the bleb was anticipated with a straight forward surgical excision. We injected autologous blood and placed a compression suture 6 weeks prior to surgical excision of the overhanging portion of the bleb. The operation was successful in preserving excellent bleb function, restoring visual acuity, and alleviating symptoms in our patient with up to 9 months of follow-up.
Blister/pathology/*surgery
;
Blood Transfusion, Autologous/*methods
;
Conjunctiva/pathology/surgery
;
Glaucoma/*surgery
;
Humans
;
Male
;
Middle Aged
;
Postoperative Complications/*surgery
;
*Suture Techniques
;
Trabeculectomy/*adverse effects
9.Quantitative Anatomy of C7 Vertebra in Southern Chinese for Insertion of Lateral Mass Screws and Pedicle Screws.
Michael Siu Hei TSE ; Chi Hin CHAN ; Kam Kwong WONG ; Wing Cheung WONG
Asian Spine Journal 2016;10(4):705-710
STUDY DESIGN: Retrospective study. PURPOSE: To analyze the quantitative anatomy of C7 vertebra for insertion of lateral mass screws and pedicle screws in Southern Chinese patients. OVERVIEW OF LITERATURE: C7 lateral mass is smaller when compared to other subaxial cervical levels, which limits the length of lateral mass screws that can be used. Some studies have suggested pedicle screws for better fixation. But, this option is limited by the narrow pedicle width. METHODS: We have obtained computed tomography (CT) cervical spine data in 0.625 mm slices from our radiology department. The patients were adults. CTs were from May to August, 2015. The lateral mass screw length was measured using Margerl's technique and pedicle width and pedicle screw trajectory were determined in three-dimensional reformated images. RESULTS: CT scans of cervical spines of 94 patients were obtained and 188 lateral masses and pedicles of C7 vertebrae were measured. The mean lateral mass screw length was 13.2 mm (standard deviation [SD] 1.6 mm), mean outer pedicle width was 5.9 mm (SD 1.0 mm) and mean pedicle screw trajectory was 29.4 degrees (SD 3.6 degrees). Most (91.0%) of the pedicles had an outer diameter ≥4.5 mm. CONCLUSIONS: The mean lateral mass screw length was longer when compared with other similar studies, while the mean outer pedicle width was narrower. Nearly 10% of the pedicles were unable to accommodate 3.5 mm screws. These findings favor the use of lateral mass screws to provide a safe and stable fixation for C7 vertebrae in Southern Chinese patients, while the final choice of fixation method should only be confirmed after careful preoperative planning with CT scan.
Adult
;
Asian Continental Ancestry Group*
;
Humans
;
Methods
;
Pedicle Screws*
;
Retrospective Studies
;
Spine*
;
Tomography, X-Ray Computed
10.Identification of genes expressed during myocardial development.
Siu Yuen CHAN ; Anthony Kin Wang CHAN ; Becky Pik Ki CHEUNG ; Ying LIANG ; Maurice Ping LEUNG
Chinese Medical Journal 2003;116(9):1329-1332
OBJECTIVETo identify genes expressed in the fetal heart that are potentially important for myocardial development and cardiomyocyte proliferation.
METHODSmRNAs from fetal (29 weeks) and adult cardiomyocytes were use for suppression subtractive hybridization (SSH). Both forward (fetal as tester) and reverse (adult as driver) subtractions were performed. Clones confirmed by dot-blot analysis to be differentially expressed were sequenced and analyzed.
RESULTSDifferential expressions were detected for 39 out of 96 (41%) clones on forward subtraction and 24 out of 80 (30%) clones on reverse. For fetal dominating genes, 28 clones matched to 10 known genes (COL1A2, COL3A1, endomucin, HBG1, HBG2, PCBP2, LOC51144, TGFBI, vinculin and PND), 9 clones to 5 cDNAs of unknown functions (accession AK021715, AF085867, AB040948, AB051460 and AB051512) and 2 clones had homology to hEST sequences. For the reverse subtraction, all clones showed homology to mitochondrial transcripts.
CONCLUSIONSWe successfully applied SSH to detect those genes differentially expressed in fetal cardiac myocytes, some of which have not been shown relative to myocardial development.
Aged ; Cells, Cultured ; Collagen ; Collagen Type I ; Collagen Type III ; genetics ; DNA-Binding Proteins ; genetics ; Forkhead Transcription Factors ; Gene Expression ; physiology ; Heart ; embryology ; growth & development ; Heterogeneous-Nuclear Ribonucleoproteins ; genetics ; Humans ; Nerve Tissue Proteins ; genetics ; Nucleic Acid Hybridization ; RNA-Binding Proteins ; Transcription Factors ; Transforming Growth Factor beta ; genetics ; Transforming Growth Factor beta1 ; Vinculin ; genetics