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Wong TY, Chee SP. Risk factors of acute endophthalmitis after cataract extraction: a case-control study in Asian eyes. Br J Ophthalmol 2004; 88:29-31. [PMID: 14693767 PMCID: PMC1771942 DOI: 10.1136/bjo.88.1.29] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To describe risk factors of acute endophthalmitis after cataract extraction in an Asian population. METHODS A retrospective, case-control study. Cases (n = 34) were patients with acute endophthalmitis presenting within 6 weeks after cataract surgery. Three controls per case (n = 102) were randomly selected from the cataract surgery list matched on the date of operation of cases. RESULTS Few risk factors were identified. In multivariable analysis, endophthalmitis was associated with silicone intraocular lens (odds ratio 5.1, 95% confidence intervals, 1.2 to 21.6, compared to poly(methylmethacrylate) lens) and posterior capsular rupture during surgery (odds ratio 20.9, 95% confidence intervals 2.3 to 187.9). CONCLUSION Silicone intraocular lens and rupture of the posterior capsule are risk factors of acute endophthalmitis after cataract surgery.
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Knudtson MD, Klein BEK, Klein R, Wong TY, Hubbard LD, Lee KE, Meuer SM, Bulla CP. Variation associated with measurement of retinal vessel diameters at different points in the pulse cycle. Br J Ophthalmol 2004; 88:57-61. [PMID: 14693774 PMCID: PMC1771926 DOI: 10.1136/bjo.88.1.57] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIMS To assess the variability in retinal vessel measurements at different points in the pulse cycle. METHODS A healthy white male aged 19 years had 30 digitised images taken at three distinct points in the pulse cycle over a one hour period. A pulse synchronised ear clip trigger device was used to capture images at the desired point in the pulse cycle. Two trained graders measured the retinal vessel diameter of one large arteriole, one large venule, one small arteriole, and one small venule 10 times in each of these 30 images. RESULTS Within an image, variability was similar between graders, pulse point, and vessel type. Across images taken at the same point in the pulse period, the change from the minimum to maximum measurement was between 6% and 17% for arterioles and between 2% and 11% for venules. In addition, measurements of small vessels had greater changes than large vessels and no point in the pulse period was more variable than another. Ignoring pulse cycle increased variability across images in the large venule, but not in the other vessel types. Mixed effect models were fit for each of the vessel types to determine the greatest source of variability. Controlling for pulse point and grader, the largest source of variability for all four vessels measured was across images, accounting for more than 50% of the total variability. CONCLUSION Measurements of large retinal venules is generally less variable than measurements of other retinal vessels. After controlling for pulse point and grader, the largest source of variation is across images. Understanding the components of variability in measuring retinal vessels is important as these techniques are applied in epidemiological studies.
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Wong TY, Mosley TH, Klein R, Klein BEK, Sharrett AR, Couper DJ, Hubbard LD. Retinal microvascular changes and MRI signs of cerebral atrophy in healthy, middle-aged people. Am J Ophthalmol 2004. [DOI: 10.1016/j.ajo.2003.11.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Saw SM, Wong TY. Is it possible to slow the progression of myopia? ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2004; 33:4-6. [PMID: 15008554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
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Wong TY, Saw SM. Issues and challenges for myopia research. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2004; 33:1-3. [PMID: 15008553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
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Wong TY, Mosley TH, Klein R, Klein BEK, Sharrett AR, Couper DJ, Hubbard LD. Retinal microvascular changes and MRI signs of cerebral atrophy in healthy, middle-aged people. Neurology 2003; 61:806-11. [PMID: 14504325 DOI: 10.1212/01.wnl.0000086372.05488.8d] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To examine the relation of retinal microvascular abnormalities and MRI signs of cerebral atrophy in healthy middle-aged people. METHODS A population-based, cross-sectional study involved 1,684 persons aged 51 to 72 years who had cerebral MRI and retinal photography in 1993 to 1995. Sulcal and ventricular size were quantified from the MRI scans and coded as grades 0 to 9, with sulcal widening (SW) and ventricular enlargement (VE) defined as grades 3 or higher. The presence or absence of retinopathy, microaneurysms, hemorrhages, and other characteristics were defined from retinal photographs using a standardized protocol. Generalized arteriolar narrowing was defined from a computer-assisted measurement of arteriolar diameters from digitized photographs. RESULTS Persons with retinopathy had higher sulcal (p = 0.001) and ventricular (p = 0.03) grades than persons without retinopathy. After adjusting for age, gender, race, mean arterial blood pressure, diabetes, cigarette smoking, common carotid artery intima-media thickness, and other vascular risk factors, retinopathy was significantly associated with SW (odds ratio [OR], 1.9; 95% CI, 1.2, 3.0) and VE (OR, 1.5; 95% CI, 1.0, 2.3). These associations persisted even in people without diabetes or hypertension (OR 1.9, 95% CI, 0.8, 4.4 for SW; OR 2.7, 95% CI, 1.2, 6.5 for VE). Other retinal arteriolar characteristics (arteriovenous nicking, focal and generalized arteriolar narrowing) were not related to sulcal or ventricular grade. CONCLUSIONS In healthy, middle-aged people, retinopathy is independently associated with sulcal and ventricular enlargement on MRI. This finding is compatible with the hypothesis that microvascular characteristics may influence the development of cerebral atrophic changes.
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Wong TY, Ho HK, Lim C, Tan BY, Lim FS, Emmanuel SC. Comparative study of a two-year disease management programme for patients with diabetes in a primary healthcare setting. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2003; 32:S73-5. [PMID: 14968746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
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Foster PJ, Wong TY, Machin D, Johnson GJ, Seah SKL. Risk factors for nuclear, cortical and posterior subcapsular cataracts in the Chinese population of Singapore: the Tanjong Pagar Survey. Br J Ophthalmol 2003; 87:1112-20. [PMID: 12928278 PMCID: PMC1771847 DOI: 10.1136/bjo.87.9.1112] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
AIM To describe risk factors for nuclear, cortical, and posterior subcapsular (PSC) cataracts in Chinese Singaporeans. METHODS A population based cross sectional study was carried out on ethnic Chinese men and women aged 40-81 years. A stratified, clustered, disproportionate (more weights to older people), random sampling procedure was used to initially select 2000 Chinese names of those aged 40-79 years from the 1996 electoral register in the Tanjong Pagar district in Singapore. Eligible subjects (n = 1717) were invited for a standardised ocular examination and interview at a centralised clinic, following which an abbreviated examination was conducted for non-respondents in their homes. Cataract was graded clinically using to the Lens Opacity Classification System (LOCS) III system. The main outcome measures were adjusted odds ratio for risk factors for specific cataract types (nuclear, cortical and PSC), any cataract and cataract surgery, examined in multiple logistic regression models. RESULTS Out of the 1232 (71.8%) examined, 1206 (70.2%) provided lens data for this analysis. Increasing age was associated with all cataract types, any cataract, and cataract surgery. There was no significant sex difference in presence of any cataract, specific cataract types or cataract surgery. After controlling for age, sex, and other factors, diabetes was associated with cortical cataract (3.1; 95% CI: 1.6 to 6.1), PSC cataract (2.2; 95% CI 1.2 to 4.1), any cataract (2.0; 95% CI: 0.9 to 4.5), and cataract surgery (2.3; 95% CI: 1.3 to 4.1). Lower body mass index was associated with cortical cataract (1.8; 95% CI: 1.1 to 2.9; lowest versus highest quintile) and any cataract (2.3; 95% CI: 1.3 to 4.0). Current cigarette smoking was associated with nuclear cataract (1.7, 95% CI: 1.0 to 2.9; more than 10 cigarettes per day versus none). A non-professional occupation was associated with nuclear cataract (2.9; 95% CI: 1.5 to 5.8; for production or machine operators and 2.6; 95% CI: 1.2 to 5.5; for labourers or agricultural workers, both versus professionals). Lower education was associated with nuclear cataract (2.3; 95% CI: 1.0 to 5.2, none versus tertiary), while lower household income was associated with PSC cataract (4.7, 95% CI: 1.1 to 20.0; income <S$2000 versus >S$4000). CONCLUSIONS Age related cataracts are associated with a variety of risk factors among Chinese people in Singapore, similar to those reported in European, Indian, and African derived populations. These data support common aetiological mechanisms for age related cataracts, irrespective of ethnic origin.
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Wong TY, Tan DT. The SERI-ARVO Meeting and future challenges of ophthalmic research in Asia. Br J Ophthalmol 2003; 87:379-80. [PMID: 12642290 PMCID: PMC1771613 DOI: 10.1136/bjo.87.4.379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Rosman M, Wong TY, Ong SG, Ang CL. Retinal detachment in Chinese, Malay and Indian residents in Singapore: a comparative study on risk factors, clinical presentation and surgical outcomes. Int Ophthalmol 2002; 24:101-6. [PMID: 12201344 DOI: 10.1023/a:1016306609978] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To evaluate the risk factors, clinical presentation and surgical outcomes of retinal detachment (RD) among Chinese, Malay and Indian residents in Singapore. METHODS A retrospective descriptive study from January 1995 to December 1998. All RD operations performed at a tertiary ophthalmic center in Singapore were initially identified from a computerized audit database. Case records data of all Malay and Indian patients as well as a 10% randomized sample of Chinese patients were retrieved and analyzed. Tractional and exudative RD's were excluded. RESULTS Of the Singapore residents who had a RD operation over the 4-year period, 597 (89.6%) were Chinese, 47 (7.1%) were Malays and 22 (3.3%) were Indians. The age (mean: 46.1 +/- 15.5 years), gender distribution (70.5% males) and presenting visual acuities were similar in the 3 races. The most common site of the retinal break(s) was the superotemporal retina (44.9%), followed by the inferotemporal retina (15.3%). Chinese patients were more likely to have multiple or indeterminate breaks (p = 0.09) and macula-on RD (p = 0.04), compared to Malays and Indians. The distribution of known risk factors (myopia, lattice degeneration, prior cataract surgery and prior ocular trauma) was similar between the three races. The majority of patients required a scleral buckling operation either in isolation (71.3%), or in combination with vitrectomy (19.4%), and only 10 (7.8%) had vitrectomies without buckles. At 6 months postoperatively, anatomical success (defined as an attached retina on ocular examination) and functional success (defined as visual acuities of 6/60 or better) were achieved in 108 (94.7%) and 62 patients (54.4%), respectively, with no significant racial variation seen. The overall rate of redetachment after the initial operation was low (9.3%). CONCLUSION Variation in risk factors, clinical presentations and postoperative outcomes of retinal detachment appears to be minimal among Chinese, Malays and Indians in Singapore.
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Wong TY, Hubbard LD, Klein R, Marino EK, Kronmal R, Sharrett AR, Siscovick DS, Burke G, Tielsch JM. Retinal microvascular abnormalities and blood pressure in older people: the Cardiovascular Health Study. Br J Ophthalmol 2002; 86:1007-13. [PMID: 12185128 PMCID: PMC1771256 DOI: 10.1136/bjo.86.9.1007] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To examine the relation between blood pressure and retinal microvascular abnormalities in older people. METHODS The Cardiovascular Health Study is a prospective cohort study conducted in four US communities initiated in 1989 to 1990. Blood pressure was measured according to standardised protocols at each examination. During the 1997-8 examination, retinal photographs were taken of 2405 people aged 69-97 years (2056 without diabetes and 349 with diabetes). Signs of focal microvascular abnormalities (focal arteriolar narrowing, arteriovenous nicking, and retinopathy) were evaluated from photographs according to standardised methods. To quantify generalised arteriolar narrowing, the photographs were digitised and diameters of individual arterioles were measured and summarised. RESULTS In non-diabetic people, elevated concurrent blood pressure taken at the time of retinal photography was strongly associated with presence of all retinal microvascular lesions. The multivariable adjusted odds ratios, comparing the highest to lowest quintile of concurrent systolic blood pressure, were 4.0 (95% confidence intervals (CI): 2.4 to 6.9, p test of trend<0.001) for focal arteriolar narrowing, 2.9 (95% CI: 1.6 to 5.3, p<0.001) for arteriovenous nicking, 2.8 (95% CI: 1.5 to 5.2, p<0.001) for retinopathy, and 2.1 (95% CI: 1.4 to 3.1, p<0.001) for generalised arteriolar narrowing. Generalised arteriolar narrowing and possibly arteriovenous nicking were also significantly associated with past blood pressure measured up to 8 years before retinal photography, even after adjustment for concurrent blood pressure. These associations were somewhat weaker in people with diabetes. CONCLUSIONS Retinal microvascular abnormalities are related to elevated concurrent blood pressure in older people. Additionally, generalised retinal arteriolar narrowing and possibly arteriovenous nicking are related to previously elevated blood pressure, independent of concurrent blood pressure. These data suggest that retinal microvascular changes reflect severity and duration of hypertension.
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Wong TY, Foster PJ, Johnson GJ, Seah SKL. Education, socioeconomic status, and ocular dimensions in Chinese adults: the Tanjong Pagar Survey. Br J Ophthalmol 2002; 86:963-8. [PMID: 12185116 PMCID: PMC1771278 DOI: 10.1136/bjo.86.9.963] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2002] [Indexed: 11/03/2022]
Abstract
AIM To relate indices of education, occupation, and socioeconomic status to ocular dimensions and refraction in an adult population. METHODS A population based, cross sectional survey of adult Chinese aged 40-81 years residing in the Tanjong Pagar district in Singapore. Ocular dimensions, including axial length, anterior chamber depth, lens thickness, and vitreous chamber depth, were measured using an A-mode ultrasound device. Corneal radius of curvature and refraction were determined with an autorefractor, with refraction further refined subjectively, and lens nuclear opacity was graded clinically using the modified Lens Opacity Classification System III score. Data on education, occupation, income, and housing type were obtained from a standardised interview. RESULTS Biometric data were available on 951 phakic subjects. After controlling for age, sex, occupation, income and housing type, higher education was associated with longer axial lengths (0.60 mm; 95% confidence interval (CI): 0.34, 0.85, for every 10 years of education), longer vitreous chambers (0.53 mm; 95% CI: 0.30, 0.77), and more myopic refractions (-1.50 dioptres, 95% CI: -2.08, -0.92). Adjustment for axial length attenuated the refractive association of education (-0.68 dioptre, 95% CI: -1.14, -0.21). Similarly, near work related occupations (managers, professionals, and office workers) and higher income were independently associated with longer axial lengths, longer vitreous chambers, and more myopic refractions, and adjustment for axial length attenuated the refractive associations. CONCLUSIONS Adults with greater education, near work related occupations, and higher income are more likely to have longer axial lengths and vitreous chambers, and more myopic refractions. The refractive associations of education, occupation, and income are largely explained by variations in axial length.
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Duncan BB, Wong TY, Tyroler HA, Davis CE, Fuchs FD. Hypertensive retinopathy and incident coronary heart disease in high risk men. Br J Ophthalmol 2002; 86:1002-6. [PMID: 12185127 PMCID: PMC1771277 DOI: 10.1136/bjo.86.9.1002] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIM Although routine ophthalmoscopy is recommended in the evaluation of people with hypertension, the prognostic significance of retinopathy is unknown. The purpose of this study is to determine if hypertensive retinopathy predicts coronary heart disease (CHD). METHODS A prospective cohort study involving 560 hypertensive, hyperlipidaemic, middle aged men enrolled in the Lipid Research Clinic's Coronary Primary Prevention Trial. Signs of hypertensive retinopathy (generalised and focal arteriolar narrowing, arteriovenous nicking, widened arteriolar light reflex, retinal haemorrhage and exudates, microaneurysms, and disc swelling) were evaluated by direct funduscopy during a baseline examination by study physicians. Incident CHD events were ascertained from hospital records, necropsy reports, and death certificates, and reviewed by a masked panel of cardiologists. RESULTS There were 51 definite CHD events (definite CHD deaths or myocardial infarctions) during a median follow up of 7.8 years. After adjusting for age, blood pressure, electrocardiographic manifestations of left ventricular hypertrophy, cholesterol levels and treatment, glucose and creatinine levels, and smoking status in proportional hazards analysis, the presence of hypertensive retinopathy predicted a doubling of the risk of definite CHD events (relative risk 2.1; 95% confidence interval (CI) 1.0 to 4.2 ). The presence of either generalised or focal arteriolar narrowing predicted almost a tripling of the risk (relative risk 2.9; 95% CI 1.3 to 6.2). Associations were similar for stage 1 hypertension (systolic and diastolic blood pressures of 140-159 and 90-99 mm Hg, respectively) and for other CHD end points. CONCLUSION Hypertensive retinopathy predicts CHD in high risk men, independent of blood pressure and CHD risk factors. The data support the concept that retinal microvascular changes are markers of blood pressure damage and may be useful in risk stratification and in the tailoring of hypertension treatment decisions.
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Wong TY, Klein BEK, Klein R, Tomany SC. Relation of ocular trauma to cortical, nuclear, and posterior subcapsular cataracts: the Beaver Dam Eye Study. Br J Ophthalmol 2002; 86:152-5. [PMID: 11815338 PMCID: PMC1770991 DOI: 10.1136/bjo.86.2.152] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND The consequences of minor ocular trauma in the general population are unclear. The relation of self reported ocular trauma to cortical, nuclear, and posterior subcapsular cataracts is described in a defined population. METHODS Population based, cross sectional study involving all people aged 43 to 86 years, living in Beaver Dam, Wisconsin (n=4926). Ocular trauma was ascertained by interview and cataract was graded from lens photographs. The relation of ocular trauma to cortical, nuclear, and posterior subcapsular cataracts was examined. RESULTS People with a history of ocular trauma were more likely to have cortical (odds ratio (OR): 1.5; 95% confidence interval (CI): 1.0 to 2.2) and posterior subcapsular (OR: 1.7; 95% CI: 1.0 to 3.1) cataracts, compared to people without a history of trauma. These associations were stronger for people with previous trauma caused by a blunt object (OR: 3.3; 95% CI: 1.6 to 6.9 for cortical cataract, and OR: 4.1; 95% CI: 1.5 to 10.8 for posterior subcapsular cataracts). However, in analyses comparing the frequencies of cataract between traumatised and non-traumatised eyes among people with unilateral ocular trauma, the ocular trauma association for cortical cataract was no longer present, although the association for posterior subcapsular cataract persisted (OR: 2.4; 95% CI: 0.8 to 7.8). CONCLUSION The data provide evidence of a possible association between self reported ocular trauma and posterior subcapsular cataract.
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Pannifer AD, Wong TY, Schwarzenbacher R, Renatus M, Petosa C, Bienkowska J, Lacy DB, Collier RJ, Park S, Leppla SH, Hanna P, Liddington RC. Crystal structure of the anthrax lethal factor. Nature 2001; 414:229-33. [PMID: 11700563 DOI: 10.1038/n35101998] [Citation(s) in RCA: 329] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Lethal factor (LF) is a protein (relative molecular mass 90,000) that is critical in the pathogenesis of anthrax. It is a highly specific protease that cleaves members of the mitogen-activated protein kinase kinase (MAPKK) family near to their amino termini, leading to the inhibition of one or more signalling pathways. Here we describe the crystal structure of LF and its complex with the N terminus of MAPKK-2. LF comprises four domains: domain I binds the membrane-translocating component of anthrax toxin, the protective antigen (PA); domains II, III and IV together create a long deep groove that holds the 16-residue N-terminal tail of MAPKK-2 before cleavage. Domain II resembles the ADP-ribosylating toxin from Bacillus cereus, but the active site has been mutated and recruited to augment substrate recognition. Domain III is inserted into domain II, and seems to have arisen from a repeated duplication of a structural element of domain II. Domain IV is distantly related to the zinc metalloprotease family, and contains the catalytic centre; it also resembles domain I. The structure thus reveals a protein that has evolved through a process of gene duplication, mutation and fusion, into an enzyme with high and unusual specificity.
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Wong TY, Klein R, Couper DJ, Cooper LS, Shahar E, Hubbard LD, Wofford MR, Sharrett AR. Retinal microvascular abnormalities and incident stroke: the Atherosclerosis Risk in Communities Study. Lancet 2001; 358:1134-40. [PMID: 11597667 DOI: 10.1016/s0140-6736(01)06253-5] [Citation(s) in RCA: 556] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Retinal microvascular abnormalities reflect damage from hypertension and other vascular processes. We examined the relation of such abnormalities to incident stroke. METHODS A cohort of 10358 men and women (aged 51 to 72 years) living in four US communities underwent retinal photography and standard grading for retinal microvascular abnormalities. The calibres of all retinal arterioles and venules were measured after digital conversion of the photographs, and a summary arteriole-to-venule ratio (AVR) was calculated as an index of arteriolar narrowing (smaller AVR indicates greater narrowing). Cases of incident stroke admitted to hospital were identified and validated by case record reviews. FINDINGS Over an average of 3.5 years, 110 participants had incident strokes. After adjustment for age, sex, race, 6-year mean arterial blood pressure, diabetes, and other stroke risk factors, most retinal microvascular characteristics were predictive of incident stroke, with adjusted relative risks of 2.58 (1.59-4.20) for any retinopathy, 3.11 (1.71-5.65) for microaneurysms, 3.08 (1.42-6.68) for soft exudates, 2.55 (1.27-5.14) for blot haemorrhages, 2.26 (1.00-5.12) for flame-shaped haemorrhages, and 1.60 (1.03-2.47) for arteriovenous nicking. The relative risk of stroke increased with decreasing AVR (p=0.03). The associations were similar for ischaemic strokes specifically, and for strokes in individuals with hypertension, either with or without diabetes. INTERPRETATION Retinal microvascular abnormalities are related to incident stroke. The findings support a microvascular role in the pathogenesis of stroke. They suggest that retinal photography may be useful for cerebrovascular-risk stratification in appropriate populations.
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Abstract
Military laser weapons systems are becoming indispensable in most modern armies. These lasers have undergone many stages of development, and have outpaced research on eye protection measures, which continue to have inherent limitations. Eye injuries caused by military lasers are increasingly reported, leading to speculation that these would become an important cause of blinding in modern conflicts. As part of the effort to ban inhumane weapons, international laws have been passed to restrict the proliferation of such blinding weapons. However, there are controversies concerning the interpretation, implementation and effectiveness of these laws. The ophthalmic community can play a greater role in highlighting ocular morbidity from military lasers, and in preventing their further proliferation.
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Chuang SF, Jin YT, Tsai PF, Wong TY. Effect of various surface protections on the margin microleakage of resin-modified glass ionomer cements. J Prosthet Dent 2001; 86:309-14. [PMID: 11552169 DOI: 10.1067/mpr.2001.116133] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
STATEMENT OF PROBLEM Because conventional glass ionomer cements are moisture sensitive, a surface coating is recommended during the initial setting stage. It is unknown whether resin-modified glass ionomer cements also need surface protection. PURPOSE This study investigated the effect of various surface protections on microleakage with Class V resin-modified glass ionomer restorations. MATERIAL AND METHODS Forty extracted molars with buccal and lingual Class V cavity preparations were restored with a resin-modified glass ionomer (Fuji II LC). The occlusal margin of each restoration was on enamel and the cervical margin on dentin. After immediate finishing and polishing, the teeth were divided into 4 groups according to the following surface protection treatments: group I, unprotected; group II, Fuji varnish; group III, resin adhesive; and group IV, acid etching and resin adhesive. After these procedures, all teeth were stored in isotonic saline for 24 hours, thermocycled 1500 times at 5 degrees C to 60 degrees C, and soaked in dye solution for 24 hours. The teeth then were longitudinally sectioned and observed under a stereomicroscope. The degree of dye penetration was recorded and analyzed with the Kruskal-Wallis and Mann-Whitney tests (P<.05) RESULTS None of the 4 groups demonstrated complete margin sealing at either the occlusal or cervical margins. Groups II and III displayed the least microleakage at cervical margins; a significant difference existed between groups I and III (P=.034). Compared with the other 3 groups, group IV showed significantly greater microleakage at the cervical margins. CONCLUSION Although resin-modified glass ionomers can be finished immediately, they remain moisture sensitive. Within the limitations of this study, the results suggest that resin adhesive should be used as a surface protection to reduce margin microleakage of resin-modified glass ionomer restorations.
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Wong TY, Chiu SI, So MK, Tsang MK, Lai ST, Tse KK, Io IY. Septic metastatic endophthalmitis complicating Klebsiella pneumoniae liver abscess in a non-diabetic Chinese man. Hong Kong Med J 2001; 7:303-6. [PMID: 11590274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Septic metastatic endophthalmitis is a rare but serious disease. Endophthalmitis arising from Klebsiella pneumoniae liver abscess has been reported with diabetes mellitus as a major associated condition, but is rarely seen in patients without diabetes. A non-diabetic patient with liver abscess complained of right eye discomfort and floaters 3 days after admission. Both blood and liver aspirate cultured Klebsiella pneumoniae. The patient was treated initially with systemic and subconjunctival antibiotics followed by intravitreal antibiotics with successful visual salvation. Previous reports from the literature showed poor visual outcome despite treatment and delayed recognition was often the cause. Clinicians should be alert to endophthalmitis whenever a patient with Klebsiella pneumoniae liver abscess complains of ocular symptoms. Urgent ophthalmological assessment should be sought.
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Chow KM, Wang AY, Hui AC, Wong TY, Szeto CC, Li PK. Nonconvulsive status epilepticus in peritoneal dialysis patients. Am J Kidney Dis 2001; 38:400-5. [PMID: 11479169 DOI: 10.1053/ajkd.2001.26105] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This report describes nonconvulsive status epilepticus (NCSE) in four patients with end-stage renal disease (ESRD) on peritoneal dialysis therapy. All patients presented with acute confusion or stuporous state without clinical motor seizures. Three patients had active systemic infections and were being administered antibiotics. Diagnoses were confirmed in all cases by electroencephalogram (EEG), which showed characteristic diffuse sharp waves and spikes. The EEG appearance improved after anticonvulsant therapy. All patients had satisfactory control of their electrical seizure activity and made varying degrees of mental recovery. To our knowledge, this is the first reported series of NCSE in patients with ESRD on peritoneal dialysis therapy. It shows NCSE as a differential diagnosis for acute confusion. We emphasize the need for nephrologists to consider NCSE as a differential diagnosis for uremic encephalopathy.
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Wong TY, Moss SE, Klein R, Klein BE. Is the pulse rate useful in assessing risk of diabetic retinopathy and macular oedema? The Wisconsin Epidemiological Study of Diabetic Retinopathy. Br J Ophthalmol 2001; 85:925-7. [PMID: 11466246 PMCID: PMC1724060 DOI: 10.1136/bjo.85.8.925] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To describe the relation between pulse rate and incident diabetic retinopathy. METHODS Population based cohort study of people with diabetes. Resting pulse rate was measured in 30 second intervals. Diabetic retinopathy was evaluated from masked gradings of fundus photographs. RESULTS People with higher pulse rates were more likely to have 4 year progression of retinopathy, progression to proliferative retinopathy, and incident macular oedema than those with lower pulse rates. However, these associations were attenuated after controlling for blood pressure, glycosylated haemoglobin, and other risk factors. CONCLUSION Pulse rate may be a clinical indicator of overall risk of diabetic retinopathy, but is not independently associated with the condition.
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Szeto CC, Wong TY, Leung CB, Leung TW, Wang AY, Lui SF, Li PK. Selective internal radiation therapy by yttrium-90 microspheres for hepatocellular carcinoma after renal transplantation. Clin Transplant 2001; 15:284-8. [PMID: 11683824 DOI: 10.1034/j.1399-0012.2001.150411.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We report a HBsAg-positive patient who developed hepatocellular carcinoma (HCC) 7 years after cadaveric kidney transplantation. The tumor was unresectable because of coexisting cirrhosis. Selective internal radiation (SIR) therapy, a novel therapy with the technique recently perfected, was used. Yttrium-90 microspheres were given via an angiographic catheter under fluoroscopy guidance. Serum alpha-fetal protein (AFP) was normalized within 2 wk. A follow-up abdominal CT scan revealed significant necrosis of the tumor and compensatory hypertrophy of non-diseased liver. The treatment was well tolerated except for transient liver function deterioration. The patient enjoyed 15 months of symptom-free survival before she died of liver failure. Practical aspects and potential applications of SIR therapy in this group of patients are discussed.
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Wong TY, Klein R, Klein BE, Tielsch JM, Hubbard L, Nieto FJ. Retinal microvascular abnormalities and their relationship with hypertension, cardiovascular disease, and mortality. Surv Ophthalmol 2001; 46:59-80. [PMID: 11525792 DOI: 10.1016/s0039-6257(01)00234-x] [Citation(s) in RCA: 363] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Retinal microvascular abnormalities, such as generalized and focal arteriolar narrowing, arteriovenous nicking and retinopathy, reflect cumulative vascular damage from hypertension, aging, and other processes. Epidemiological studies indicate that these abnormalities can be observed in 2-15% of the nondiabetic general population and are strongly and consistently associated with elevated blood pressure. Generalized arteriolar narrowing and arteriovenous nicking also appear to be irreversible long-term markers of hypertension, related not only to current but past blood pressure levels as well. There are data supporting an association between retinal microvascular abnormalities and stroke, but there is no convincing evidence of an independent or direct association with atherosclerosis, ischemic heart disease, or cardiovascular mortality. New computer-related imaging methods are currently being developed to detect the presence and severity of retinal arteriolar narrowing and other microvascular characteristics. When reliably quantified, retinal microvascular abnormalities may be useful as risk indicators for cerebrovascular diseases.
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Saw SM, Wu HM, Seet B, Wong TY, Yap E, Chia KS, Stone RA, Lee L. Academic achievement, close up work parameters, and myopia in Singapore military conscripts. Br J Ophthalmol 2001; 85:855-60. [PMID: 11423462 PMCID: PMC1724036 DOI: 10.1136/bjo.85.7.855] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To determine the relation of refractive error to environmental factors, including close up work, in Singapore military conscripts. METHODS A cross sectional study was conducted on 429 Singapore military conscripts. Non-cycloplegic refraction and A-scan biometry were performed in both eyes. A detailed questionnaire was administered by in-person interview to obtain information about current and past near work activity, extra tuition lessons, educational experiences, and family demographics. RESULTS Myopia associated with the conscript having been educated in the (gifted, special, or express) educational streams (adjusted odds ratio (OR) = 3.8, 95% confidence interval CI 2.0-7.3), and having completed pre-university education (OR=4.1, 95% CI 1.9-8.8). The reported close up work activity at age 7 years did correlate with age of onset of myopia (p<0.001). In parallel, supplemental tuition lessons in primary school has (OR=2.6, 95% CI 1.4-4.9) associated with conscript myopia. Parental myopia was positively associated with myopia (p<0.001), but this relation disappeared when adjusted for environmental factors. Current (p=0.83) and past close up work activity at age 7 years (p=0.13) did not correlate with myopia. CONCLUSION Educational level and educational stream positively related to myopia. A relation was observed with reported close up work activity in early childhood and with tuition classes during elementary school, but not with current close up work activity. These results underscore the strong influence of environment in myopia pathogenesis but a role for close up work activity remains indeterminate.
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Chow KM, Wang AY, Mac-Moune Lai F, Wong TY, Li PK. Rapid recurrence of ANCA-negative pauci-immune vasculitis after cadaveric renal transplantation. Am J Kidney Dis 2001; 38:E3. [PMID: 11431216 DOI: 10.1053/ajkd.2001.25217] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We report a patient with renal failure secondary to antineutrophil cytoplasmic autoantibody (ANCA)-negative pauci-immune systemic vasculitis who developed rapid recurrence of vasculitis involving skin, eye, and kidney allograft 1 month after cadaveric renal transplant while being maintained on cyclosporine, mycophenolate mofetil, and prednisolone. Despite early institution of aggressive treatment with plasma exchange, the disease remained uncontrolled and resulted in substantial morbidity and subsequent graft failure within 1 year post-transplantation. This case confirms that ANCA-negative vasculitides may recur in transplanted patients taking mycophenolate mofetil. Transplantation is contraindicated when active disease is evident.
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