Dennis S C Lam

The Chinese University of Hong Kong, Hong Kong, Hong Kong

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Publications (635)2102.21 Total impact

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    ABSTRACT: Abstract Aims: To identify the reasons for poor uptake of cataract surgery in a program of outreach screening and low-cost surgery in Pucheng County, a rural area in northwestern China. Methods: Detailed interviews with a semi-structured questionnaire were conducted by telephone or face-to-face for participants who had been advised to attend a low-cost cataract surgery program but did not schedule the surgery within 3 months after the initial screening. Results: Among 432 eligible subjects, 355 (82.2%) were interviewed (mean age 70.6 ± 6.6 years, 73.8% female). A total of 138 subjects (38.9%) were interviewed by phone and 217 (61.1%) were interviewed face-to-face. Lack of family support (n = 106, 29.9%) and failure to understand the need for surgery (n = 96, 27.0%) were the two main reasons for not undergoing cataract surgery. Other factors included fear of surgery (n = 62, 17.5%), lack of faith in doctors (n = 36, 10.1%), financial constraints (n = 25, 7.0%) and lack of transportation (n = 4, 1.1%). Conclusion: The principal barriers to low-cost cataract surgery uptake in rural China included lack of family support and failure to understand the need for surgery. Education targeting entire families to eliminate these barriers and development of community support systems at the family level are required to achieve greater uptake of low-cost cataract surgery programs in rural China.
    Ophthalmic epidemiology 04/2014; · 1.93 Impact Factor
  • Ophthalmology 10/2013; 120(10):e71-e72. · 5.56 Impact Factor
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    ABSTRACT: OBJECTIVE: To define the prevalence of blindness and visual impairment (VI) in people in rural Hainan using the rapid assessment of avoidable blindness (RAAB) and to report the outcomes of cataract surgery among the residents. DESIGN: Population-based, cross-sectional survey. PARTICIPANTS: A total of 6482 rural residents of the Hainan province. METHODS: A total of 136 clusters, each of which consisted of 50 people aged ≥50 years, were selected through probability-proportionate-to-size sampling. Door-to-door visits were performed by 2 outreach teams. Visual acuity (VA) was measured on site, and those with VA <6/18 in either eye were examined by an ophthalmologist. Causes of blindness and VI were determined. The causes of poor visual outcome after cataract surgery were evaluated. Information regarding barriers to receiving surgery was collected by trained interviewers. MAIN OUTCOME MEASURES: Prevalence and causes of blindness (VA <3/60), severe VI (SVI) (VA <6/60 but ≥3/60), and VI (VA <6/18 but ≥6/60) based on presenting VA (PVA) were assessed. Outcomes of cataract surgery performed in public and private hospitals and charitable organizations were compared. RESULTS: A total of 6482 subjects were examined (response rate, 95.3%). The sample prevalence of blindness was 4.4% (95% confidence interval [CI], 2.0-6.8). The prevalence of SVI and VI was 1.9% (95% CI, 0-4.3) and 9.9% (95% CI, 7.6-12.2), respectively. Age and sex were associated with increased prevalence of blindness, SVI, and VI. Overall, cataract accounted for approximately 60% of blindness and SVI. Of the 524 eyes that had received cataract surgery, 87.2% had intraocular lenses implanted, 21% had a poor visual outcome (PVA <6 /60), and 20% had a borderline visual outcome (PVA <6/18 but ≥6/60). Eyes that received surgery in charitable organizations had a higher rate of intraocular lens implantation and good visual outcome (VA ≥6/18) compared with eyes that were operated on elsewhere. CONCLUSIONS: The prevalence of blindness, SVI, and VI was high among rural residents in Hainan. Cataract remained the leading cause of avoidable blindness. Outcomes of cataract surgery performed in public hospitals were suboptimal. Quality-control initiatives should be introduced to improve cataract surgery outcomes. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 05/2013; · 5.56 Impact Factor
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    ABSTRACT: PURPOSE: To measure choroidal thickness (CT) in myopic eyes using enhanced depth imaging (EDI). DESIGN: A cross-sectional study. PARTICIPANTS: Fifty-six consecutive patients with spherical equivalent refractive error of at least 6 diopters (D) were evaluated. METHODS: Enhanced depth imaging optical coherence tomography (OCT) images were obtained by positioning the spectral-domain OCT device close enough to the eye to acquire an enhanced signal of the choroidal layer. Choroidal depth was measured as the distance between the outer reflective retinal pigment epithelium (RPE) layer and the inner sclera border. Measurements were made in a horizontal fashion across the fovea at 500-μm intervals of the sections. The CT was measured at the subfoveal region in a horizontal fashion, 3 mm temporal to fovea and 3 mm nasal to fovea. MAIN OUTCOME MEASURES: Correlations among CT with age, refractive error in diopters, and visual acuity in logarithm of the minimum angle of resolution (logMAR) were analyzed with linear mixed models. RESULTS: The mean age of the 56 patients was 50.4 years (±2.03 years standard deviation; interquartile range [IQR], 42-62 years), and the mean refractive error was -8.7 D (IQR, -6.1 to -11 D). The mean subfoveal CT was 118 μm (±68 μm) and correlated negatively with age (P = 0.032) and refractive error (P = 0.011). Regression analysis suggested that subfoveal CT decreased by 11.9 μm for each decade of life and by 6.205 μm for each diopter of myopia. The subfoveal CT was inversely correlated with the logMAR visual acuity (P = 0.008), and visual acuity improved by 0.02 (logMAR) in a 10-μm increase in CT. CONCLUSIONS: Choroidal thickness decreases with age and severity of myopia. Visual acuity decreases in line with decreasing subfoveal CT. A reduction in CT is related to aging and the severity of myopia, whereas visual acuity depends on subfoveal CT. Our study supports the theory that choroidal abnormality may play a key role in the pathogenesis of myopic degeneration. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 05/2013; · 5.56 Impact Factor
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    ABSTRACT: PURPOSE: To assess the long-term cost-effectiveness of treating normal tension glaucoma (NTG). METHODS: A Markov decision-analytic health model was developed to determine the cost-effectiveness of treating NTG with intraocular pressure lowering therapy to prevent progressive visual field loss. Transitional probabilities were derived from the Collaborative Normal Tension Glaucoma Study and cost data obtained from the literature and the Medicare Fee Schedule. Incremental cost-effectiveness ratios (ICER) of treating all patients with NTG and treating selected individuals with risk factors for disease progression were determined using Monte Carlo Simulation. Sensitivity analyses were performed by varying the cost of consultations, medications, laser/surgery and adjusting utility loss from progressed states. RESULTS: The ICER of treating all patients with NTG over a 10-year period was US$34,225 per QALY. The ICER would be reduced when treatment was offered selectively to those with risk factors for disease progression. The ICER for treating NTG patients with disc haemorrhage, migraine and those who were female were US$24,350, US$25,533 and US$27,000 per QALY respectively. The cost-effectiveness of treating all NTG patients in this model was sensitive to cost fluctuation of medications, choice of utility score associated with disease progression, and insensitive to cost of consultations and laser/surgery. CONCLUSIONS: It is cost-effective, in long-term, to offer intraocular pressure lowering therapy, aiming for a 30% reduction from the baseline, to all NTG patients.
    Investigative ophthalmology & visual science 04/2013; · 3.43 Impact Factor
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    ABSTRACT: OBJECTIVE: To investigate the use of swept-source optical coherence tomography (OCT) for measuring the area and degree of peripheral anterior synechia (PAS) involvement in patients with angle-closure glaucoma. DESIGN: Cross-sectional study. PARTICIPANTS: Twenty-three eyes with PAS (detected by indentation gonioscopy) from 20 patients with angle-closure glaucoma (20 eyes had primary angle-closure glaucoma and 3 eyes had angle-closure glaucoma secondary to chronic anterior uveitis [n = 2] and Axenfeld-Rieger syndrome [n = 1]). METHODS: The anterior chamber angles were evaluated with indentation gonioscopy and imaged by swept-source OCT (Casia OCT, Tomey, Nagoya, Japan) in room light and in the dark using the "angle analysis" protocol, which was composed of 128 radial B-scans each with 512 A-scans (16-mm scan length). The area and degree of PAS involvement were measured in each eye after manual detection of the scleral spur and the anterior irido-angle adhesion by 2 masked observers. The interobserver variability of the PAS measurements was calculated. MAIN OUTCOME MEASURES: The agreement of PAS assessment by gonioscopy and OCT, the area and the degree of PAS involvement, and the intraclass correlation coefficient (ICC) of interobserver PAS measurements. RESULTS: The area of PAS (mean ± standard deviation) was 20.8±16.9 mm(2) (range, 3.9-74.9 mm(2)), and the degree of PAS involvement was 186.5±79.9 degrees (range, 42-314 degrees). There was no difference in the area of PAS (P = 0.90) and the degree of PAS involvement (P = 0.95) between images obtained in room light and in the dark. The interobserver ICCs were 0.99 (95% confidence interval [CI], 0.98-1.00) for the area of PAS and 0.99 (95% CI, 0.97-1.00) for the degree of PAS involvement. There was good agreement of PAS assessment between gonioscopy and OCT images (kappa = 0.79; 95% CI, 0.67-0.91). CONCLUSIONS: Swept-source OCT allows visualization and reproducible measurements of the area and degree of PAS involvement, providing a new paradigm for evaluation of PAS progression and risk assessment for development of angle-closure glaucoma. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 03/2013; · 5.56 Impact Factor
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    ABSTRACT: OBJECTIVE:: To determine the visibility of the scleral spur (SS), Schwalbe's line (SL), and Schlemm's canal (SC) imaged by a swept-source optical coherence tomographer (OCT). METHODS:: One eye from each individual was randomly selected from 30 normal subjects and 30 patients with primary open-angle glaucoma for anterior segment imaging with a swept-source OCT. The angles were imaged with 2 protocols: (1) high-density (HD, a raster of 64 B-scans each with 512 A-scans over 8 mm) and (2) low-density scans (LD, 128 radial scans each with 512 A-scans over 16 mm). The visibility of the angle structures was determined by 2 masked observers and compared among the superior (90 degrees), nasal (0 degrees), inferior (270 degrees), and temporal (180 degrees) quadrants. RESULTS:: The interobserver agreement for assessment of visibility of the angle structures was high with agreement coefficients ranging between 0.769 and 0.987. The SS, SL, and SC were visible by both observers in 95% to 100%, 68% to 98%, and 12% to 42% of a total of 240 (4×60) quadrants in 60 HD images, respectively. The visibility was reduced in LD images (50% to 95%, 0% to 10%, and 0%, respectively). The temporal and nasal quadrants generally had superior visibility of the angle structures than the superior and inferior quadrants. CONCLUSIONS:: The SS, SL, and SC could be identified with the swept-source OCT although their visibility varied with the scan location and scan density. The SS was best visualized, followed by the SL and then the SC in the OCT images.
    Journal of glaucoma 01/2013; · 1.74 Impact Factor
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    ABSTRACT: Aims To examine the additive effect of the z-4 microsatellite polymorphism of aldose reductase gene (ALR2) and glycaemic control on risk of cataract in a prospective cohort of Chinese type 2 diabetic patients. Methods The (CA)n microsatellite polymorphism of ALR2 was determined using PCR followed by capillary gel electrophoresis. Cataract was defined by presence of lens opacity on direct ophthalmoscopy or history of cataract surgery. A non-linear curve approach was used to identify the threshold of glycated hemoglobin (HbA1c) at which the odds ratio (OR) for cataract started to increase. The association of z-4 allele with cataract, above and below this threshold, was assessed using multiple logistic regression analysis. Results Of the 5,823 patients analyzed, 28.1% had cataracts. After adjusting for conventional risk factors and using non-z-4 carriers with HbA1c < 8.0 % as referent group(n = 3173), the OR(95% confidence intervals) for cataract was highest in z-4 carriers with HbA1c≥ 8.0%[1.43(1.05-1.96), n = 244], compared to non-z-4 carriers with HbA1c≥ 8.0[1.27(1.10-1.47), n = 1836] and z-4 carriers with HbA1c < 8.0%[1.01(0.77-1.29), n = 420, Ptrend < 0.001]. This additive association remained significant after additional adjustments for drug use (Ptrend = 0.002) and renal function (Ptrend = 0.01). Conclusions In type 2 diabetic patients with suboptimal glycaemic control, the z-4 allele of ALR2 (CA)n polymorphism was independently associated with increased susceptibility to cataracts.
    Journal of diabetes and its complications 01/2013; · 2.11 Impact Factor
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    ABSTRACT: Background: Lipoprotein lipase (LPL) promotes the binding and transfer of apolipoprotein E (ApoE) lipoprotein particle components to cells. Age-related macular degeneration (AMD), characterized by drusen, containing lipids, is reportedly associated with a lower frequency of the ApoE 4 allele than are control subjects. Because of the functional association of LPL and ApoE, we sought to examine whether an LPL polymorphism affects AMD risk. The common LPL alteration Ser447Ter decreases triglyceride levels and risk of cardiovascular disease. Methods: We genotyped this LPL polymorphism in 140 unrelated Hong Kong Chinese AMD patients and 100 elderly normal controls using polymerase chain reaction followed by Mnl I restriction enzyme digestion. Results: There was no difference in frequency of the 447Ter allele between patients (11.4%) and controls (11.0%). Conclusions: Either LPL does not play a role in AMD, or its effect is not revealed by this polymorphism or in this ethnic group.
    Journal of Biochemistry and Molecular Biology in the Post-Genomic Era. 01/2013; 2(1):2156-5732.
  • Xiao Ying Liang, Mingguang He, Dennis S.C. Lam
    Asia-Pacific Journal of Ophthalmology. 01/2013; 2(3):141-142.
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    ABSTRACT: PURPOSE: To identify effective methods to increase the number of cataract surgeries in a rural setting in Pucheng County of Shaanxi Province, northwestern China. DESIGN: Community-based randomized interventional study. PARTICIPANTS: Four hundred thirty-two patients 50 years of age or older with operable cataract who had not undergone surgery 3 months after participation in a cataract outreach screening program. METHODS: Three hundred fifty-five (82.2%) patients eligible for surgery, but not scheduling it on their own, were contacted and were assigned randomly into 4 groups. Participants in group 1 (n = 86) were given informative reminders by telephone or in person by a trained facilitator about undergoing low-cost cataract surgery. Group 2 (n = 86) was offered free cataract surgery. Group 3 (n = 90) was offered free surgery and reimbursement of transportation expenses. Group 4 (n = 93) was provided with free rides from home to hospital in addition to the reminder and free surgery. MAIN OUTCOME MEASURES: Number of participants undergoing cataract surgery after interventions. RESULTS: In total, 94 patients (26.5%) underwent cataract surgery after interventions. In group 1, 13 patients (14.4%) underwent surgery, which was significantly lower than the number in group 2 (n = 25 [27.8%]; P = 0.027), group 3 (n = 28 [31.1%]; P = 0.012), and group 4 (n = 26 [28%]; P = 0.038). There were no significant differences between groups 2 and 3 (P = 0.768) or between groups 2 and 4 (P = 0.869). CONCLUSIONS: Provision of free cataract surgery was twice as effective as giving patients an informative reminder when it came to increasing the uptake of cataract surgery. However, offering reimbursement of transportation expenses or provision of free rides had minimal added impact on the response rate of participants to undergo cataract surgery. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 10/2012; · 5.56 Impact Factor
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    ABSTRACT: OBJECTIVE: To compare phacoemulsification versus trabeculectomy with adjunctive mitomycin C in medically uncontrolled chronic angle-closure glaucoma (CACG) without cataract. DESIGN: Prospective, randomized clinical trial. PARTICIPANTS: Fifty medically uncontrolled CACG eyes without cataract of 50 patients. INTERVENTION: Patients were randomized into undergoing either phacoemulsification or trabeculectomy with adjunctive mitomycin C. After surgery, patients were followed up every 3 months for 2 years. MAIN OUTCOME MEASURES: Intraocular pressure (IOP) and requirement for glaucoma drugs. RESULTS: Twenty-six CACG eyes were randomized to receive phacoemulsification, and 24 eyes underwent trabeculectomy with mitomycin C. Phacoemulsification and trabeculectomy resulted in significant and comparable IOP reduction at 24 months after surgery (reduction of 8.4 mmHg or 34% for phacoemulsification vs. 8.9 mmHg or 36% for trabeculectomy; P = 0.76). Over first 24 months, trabeculectomy-treated eyes required on average 1.1 fewer drugs than phacoemulsification-treated eyes (P<0.001). However, trabeculectomy was associated with significantly more surgical complications than phacoemulsification (46% vs. 4%; P = 0.001). Eight (33%) of 24 trabeculectomy eyes demonstrated cataract during follow-up. CONCLUSIONS: Both phacoemulsification and trabeculectomy are effective in reducing IOP in medically uncontrolled CACG eyes without cataract. Trabeculectomy is more effective than phacoemulsification in reducing dependence on glaucoma drugs, but is associated with more complications. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 09/2012; · 5.56 Impact Factor
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    ABSTRACT: Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study including 1,854 PACG cases and 9,608 controls across 5 sample collections in Asia. Replication experiments were conducted in 1,917 PACG cases and 8,943 controls collected from a further 6 sample collections. We report significant associations at three new loci: rs11024102 in PLEKHA7 (per-allele odds ratio (OR) = 1.22; P = 5.33 × 10(-12)), rs3753841 in COL11A1 (per-allele OR = 1.20; P = 9.22 × 10(-10)) and rs1015213 located between PCMTD1 and ST18 on chromosome 8q (per-allele OR = 1.50; P = 3.29 × 10(-9)). Our findings, accumulated across these independent worldwide collections, suggest possible mechanisms explaining the pathogenesis of PACG.
    Nature Genetics 08/2012; 44(10):1142-6. · 29.65 Impact Factor
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    ABSTRACT: Purpose. To investigate the longitudinal profiles of microgliosis after optic nerve injury induced by optic nerve crush and acute elevation of intraocular pressure (IOP). Methods. A confocal scanning laser ophthalmoscope was used to image the retinal microglia of the CX3CR1(GFP/+) transgenic mice in vivo at baseline, 3 days and then weekly for 4 weeks after optic nerve crush (n = 3), and after elevating the IOP to 110 mm Hg for 30 (n = 3) or 60 (n = 3) minutes. Results. After optic nerve crush, the density of microglia increased by 2.43 ± 0.19-fold at week 1 and then gradually declined with 2.04 ± 0.24-, 1.69 ± 0.25-, and 1.29 ± 0.11-fold increases at week 2, 3, and 4, respectively. Microgliosis followed a similar pattern after acute IOP elevation and the increase in microglia was associated with the duration of IOP elevation. There were 1.35 ± 0.17- and 2.03 ± 0.08-fold increases in microglia at week 1, and 1.15 ± 0.11- and 1.11 ± 0.10-fold increases at week 4, after 30 and 60 minutes of acute IOP elevation, respectively. The morphology of microglia changed from ramified to ameboid form in 1 week, and then returned to ramified form in the subsequent weeks. There was a significant negative association between the number of surviving retinal ganglion cells (RGCs) and the extent of microgliosis during the follow-up period (R(2) = 0.72, P = 0.004). Conclusions. Longitudinal in vivo imaging of the retinal microglia can provide an effective approach to study microgliosis and its association with RGC degeneration.
    Investigative ophthalmology & visual science 08/2012; 53(10):6254-62. · 3.43 Impact Factor
  • Article: Reply.
    Vishal Jhanji, Alex H Fan, Dennis S C Lam
    American Journal of Ophthalmology 08/2012; 154(2):418. · 4.02 Impact Factor
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    ABSTRACT: To evaluate the long-term efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy as primary treatment for subfoveal myopic choroidal neovascularization (CNV). In all, 37 treatment-naïve eyes of 37 patients with subfoveal myopic CNV who received intravitreal bevacizumab (n=22) or ranibizumab (n=15) injections with at least 2 years of follow-up were reviewed. All eyes received initial three loading doses of anti-VEGF at monthly intervals and retreatment was performed in persistent or recurrent CNV. Multivariate regression analyses were performed to determine the prognostic factors for visual outcome. The mean age was 57.3 years and the mean refractive error was -11.7 D. For all eyes, the mean logMAR best-corrected visual acuity improved from 0.86 (20/145) at baseline to 0.48 (20/60) at 2 years (P<0.001). The mean visual improvement for the bevacizumab and ranibizumab groups at 2 years was 2.8 and 5.1 lines, respectively (P=0.073). There was no significant difference in the proportion of eyes having visual gain of three or more lines or visual loss of three or more lines between the two groups. The mean number of injections was 3.8 for both bevacizumab and ranibizumab groups. Multivariate analyses showed that eyes with higher myopic refractive error were less likely to have visual gain after treatment (P=0.043), while size of CNV was negatively correlated with mean change in vision (P=0.046). Intravitreal anti-VEGF therapy resulted in long-term visual improvement in myopic CNV. The treatment efficacy in terms of visual gain and number of retreatment appeared to be similar between bevacizumab and ranibizumab.
    Eye (London, England) 05/2012; 26(7):1004-11. · 1.97 Impact Factor
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    ABSTRACT: To evaluate the agreement of optic disc measurements obtained with the Cirrus high-density optical coherence tomography (HD-OCT) and the Heidelberg retina tomograph (HRT) and compare the intervisit, test-retest variability between the instruments. Prospective, cross-sectional study. Two hundred seven subjects (109 glaucoma and 98 normal subjects). One eye from each individual was selected randomly for optic disc imaging by the Cirrus HD-OCT and the HRT. Areas of the optic disc and the cup, cup volume, vertical cup-to-disc ratio and cup-to-disc area ratio were compared between the instruments. The OCT measurements were corrected for ocular magnification using the Littman's formula. The measurement agreement was evaluated with the Bland-Altman plots. The intervisit test-retest variability was examined in 17 randomly selected glaucoma patients who underwent optic disc imaging weekly for 8 consecutive weeks. The intraclass correlation coefficients (ICC) and the reproducibility coefficients of the optic disc parameters were computed. Measurement agreement, reproducibility coefficients, and ICCs of optic disc parameters. The OCT measured smaller optic disc and rim areas and greater cup volume, vertical cup-to-disc ratio and cup-to-disc area ratio than the HRT did (all with P<0.001). There were proportional biases in the Bland-Altman plots between OCT and HRT optic disc measurements except for rim area and cup-to-disc area ratio. The 95% limits of agreement of rim area ranged between -0.28 and 0.88 mm(2) before, and between -0.22 and 0.92 mm(2) after correction for ocular magnification. Both OCT and HRT showed high test-retest reproducibility with ICCs ≥ 0.921. Although the reproducibility coefficient of OCT rim area (0.093 mm(2); 95% confidence interval [CI], 0.081-0.105 mm(2)) was significantly smaller than that of the HRT (0.186 mm(2); 95% CI, 0.163-0.210 mm(2); P = .018), there were no differences in the ICCs between the instruments. Optic disc assessment by spectral-domain OCT and confocal scanning laser ophthalmoscopy demonstrates poor agreement but similarly low test-retest variability. The source of their disagreement and its effects on the detection of progression require further study.
    Ophthalmology 05/2012; 119(9):1852-7. · 5.56 Impact Factor
  • Ning Cheung, Dennis S C Lam, Tien Y Wong
    BMJ (online) 05/2012; 344:e2970. · 16.38 Impact Factor
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    ABSTRACT: We sought to determine whether corneal biomechanical parameters are predictive of reduction in axial length after anti-metabolite trabeculectomy. Chinese subjects undergoing trabeculectomy with mitomycin C by a single experienced surgeon underwent the following measurements: Corneal hysteresis (CH, Ocular Response Analyzer, Reichert Ophthalmic Instruments), Goldmann intra-ocular pressure (IOP), central corneal thickness (CCT) and axial length (AL, IOLMaster, Carl Zeiss Meditec, Dublin, CA) were measured pre-operatively, and AL, CH and IOP were measured 1 day and 1 week post-operatively. Mean age of 31 subjects was 52.0 ± 15.2 years, and 15 (48.4%) were female. The mean pre-operative IOP of 21.4 ± 9.3 mmHg was reduced to 8.2 ± 4.6 mmHg 1 day and 11.0 ± 4.4 mmHg 1 week post-operatively (p < 0.001). AL declined from 22.99 ± 0.90 to 22.76 ± 0.87 mm at 1 day and 22.74 ± 0.9 mm at 1 week; 30/31 (%) eyes had a decline in AL (p < 0.001, sign test). In multivariate linear regression models including post-operative data from 1 day and 1 week, greater decline in Goldmann IOP (p < 0.0001, greater pre-op axial length (p < 0.001) and lower pre-operative CH (p = 0.03), were all associated with greater decline in post-operative axial length. Eyes with lesser ability of the ocular coat to absorb energy (lower CH) had significantly greater decrease in axial length after trabeculectomy-induced IOP-lowering.
    Current eye research 05/2012; 37(5):381-7. · 1.51 Impact Factor
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    ABSTRACT: differentiate the associations of exudative age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) with the ARMS2/HTRA1 locus. The entire ARMS2 sequence was sequenced and HTRA1 rs11200638 genotyped in 568 unrelated Chinese individuals: 156 exudative AMD patients, 164 PCV patients, and 248 controls. A meta-analysis was performed to examine the effects of rs10490924 and rs11200638 at the ARMS2/HTRA1 locus in PCV. In total, 31 polymorphisms in ARMS2 were identified. Significant associations with both exudative AMD and PCV were observed in 11 of them and HTRA1 rs11200638, with different genotypic distributions between exudative AMD and PCV (P < 0.001). After adjusting for rs11200638, ARMS2 rs10490924 remained significantly associated with exudative AMD (P = 0.011), but not with PCV (P = 0.077). Meta-analysis showed consistent allelic associations of rs10490924 and rs11200638 with PCV in different study populations. There is a strong and consistent association of the ARMS2/HTRA1 locus with both exudative AMD and PCV, suggesting the two disorders share, at least partially, similar molecular mechanisms. Different effect sizes indicate the existence of additional genetic and environmental factors affecting them to different extents.
    Investigative ophthalmology & visual science 04/2012; 53(6):3175-82. · 3.43 Impact Factor

Publication Stats

9k Citations
2,102.21 Total Impact Points


  • 1997–2014
    • The Chinese University of Hong Kong
      • • Department of Ophthalmology and Visual Sciences
      • • Prince of Wales Hospital
      Hong Kong, Hong Kong
  • 2006–2012
    • Caritas Hong Kong
      Chiu-lung, Kowloon City, Hong Kong
    • Princess Margaret Hospital, Hong Kong
      Hong Kong, Hong Kong
    • Hong Kong SAR Government
      Hong Kong, Hong Kong
    • Zhejiang University
      • School of Medicine
      Hangzhou, Zhejiang Sheng, China
    • Peking Union Medical College Hospital
      Peping, Beijing, China
    • Fudan University
      Shanghai, Shanghai Shi, China
    • Qingdao University
      • Department of Ophthalmology
      Tsingtao, Shandong Sheng, China
  • 2011
    • Wills Eye Institute
      Philadelphia, Pennsylvania, United States
  • 2008–2011
    • Sun Yat-Sen University
      • State Key Laboratory of Oncology
      Shengcheng, Guangdong, China
  • 2007–2011
    • Shantou University
      Swatow, Guangdong, China
  • 2008–2009
    • Hong Kong Sanatorium & Hospital
      Hong Kong, Hong Kong
  • 2004–2009
    • New York Eye and Ear Infirmary
      • Department of Ophthalmology
      New York City, New York, United States
  • 2002–2009
    • Prince of Wales Hospital, Hong Kong
      Chiu-lung, Kowloon City, Hong Kong
    • Hong Kong Hospital Authority
      Hong Kong, Hong Kong
    • Greater Baltimore Medical Center
      Baltimore, Maryland, United States
    • Niigata University
      • Department of Ophthalmology and Otolaryngology
      Niahi-niigata, Niigata, Japan
  • 2003–2006
    • Alice Ho Miu Ling Nethersole Hospital
      Ch’üan-wan, Tsuen Wan, Hong Kong
    • Tuen Mun Hospital
      Hong Kong, Hong Kong
  • 2002–2005
    • Christian Hospital
      Saint Louis, Michigan, United States