Prevalence of essential tremor in Singapore: a study on three races in an Asian country

To investigate the prevalence of Essential Tremor (ET) in Singapore and compare the rates between Singaporean Chinese, Malays, and Indians, a community-based survey among a disproportionate random sample of 15,000 individuals (9000 Chinese, 3000 Malays, 3000 Indians) aged 50 years and above was conducted. In phase 1, trained interviewers conducted a door-to-door survey using a screening questionnaire for Parkinson's disease. In phase 2, medical specialists examined participants who screened positive to evaluate for the presence of postural or kinetic tremor of the upper limbs, or head tremor. Participants with suspected ET had their diagnosis confirmed in phase 3 by a movement disorders specialist and fellow based on the latest core diagnostic criteria. Forty participants with classic ET were identified. The prevalence rate (PR) of ET was 2.37 per 1000 (95% CI: 1.65-3.32), age-adjusted to UICC world standard population. The PR was significantly higher in males (p=0.01) and increased significantly with age (p<0.001). Indians (PR=4.94 per 1000, 95% CI: 2.63-9.04) were 1.8 times more likely to have ET than Chinese (PR=2.77 per 1000, 95% CI: 1.78-4.17) (p=0.08). No Malays with ET were identified. The data suggest that the prevalence of ET increases with age, is higher in males and may be higher amongst Indians.     

Coronary artery disease in chronic kidney disease patients: assessing the evidence for diagnosis, screening and revascularization

The prevalence of chronic kidney disease (CKD) is increasing in North America, with an attendant increase in cardiovascular complications. The bulk of the mortality and morbidity in CKD patients can be attributed to coronary artery disease (CAD), especially in the presence of diabetes mellitus. Thus, screening and diagnosis of CAD is particularly important in the management of these patients, especially during evaluation for renal transplantation. However, numerous limitations exist with noninvasive tests that cloud the ideal strategy for diagnosis. In addition, the optimal revascularization strategy (surgery versus percutaneous intervention) for CAD is controversial for these patients. Randomized trials are clearly needed; unfortunately, major cardiovascular trials usually exclude patients with significant renal dysfunction. The current diagnostic and revascularization strategy for CAD in CKD patients is discussed, highlighting current controversies that warrant further investigation.     

IQ and the association with myopia in children

PURPOSE: To evaluate the association between intelligence and myopia in children. METHODS: Cycloplegic refraction and ocular biometry parameters, including axial length, vitreous chamber depth, lens thickness, anterior chamber depth, and corneal curvature were obtained in 1204 Chinese school children aged 10 to 12 years from three schools who were participants in the Singapore Cohort Study Of the Risk Factors for Myopia (SCORM). Intelligence quotient (IQ) was assessed using the nonverbal Raven Standard Progressive Matrix test. RESULTS: After controlling for age, gender, school, parental myopia, father's education, and books read per week, myopia (spherical equivalent [SE]) of at least -0.5 D was associated with high nonverbal IQ (highest quartile) versus low IQ (lowest quartile) (odds ratio = 2.4; 95% confidence interval, 1.7-3.4). Controlling for the same factors, children with higher nonverbal IQ scores had significantly more myopic refractions (-1.86 D for children with nonverbal IQ in the highest quartile compared with -1.24 D for children with nonverbal IQ in the lowest quartile; P = 0.002) and longer axial lengths (24.06 mm versus 23.80 mm; P = 0.022). Nonverbal IQ accounted for a greater proportion of the variance in refraction compared with books read per week. CONCLUSIONS: Nonverbal IQ may be an independent risk factor of myopia, and this relationship may not be explained merely by increased reading (books per week) among myopes. An interesting observation is that nonverbal IQ may be a stronger risk factor for myopia compared with books read per week. The complexity of the relationships between nonverbal IQ, reading, and myopia warrant additional studies to clarify any cause-effect relationship.     

Incidence and progression of astigmatism in Singaporean children

PURPOSE: This study investigated the incidence and progression, as well as factors associated with changes in astigmatism in school children. METHODS: This was a prospective cohort study. Children 7 to 9 years of age, of Chinese, Malay, and Asian Indian ethnicity, were examined annually over a 4-year period. Cycloplegic autorefraction was performed. A questionnaire was used to evaluate risk factors for incidence and progression of astigmatism. RESULTS: The cumulative 3-year incidence rate of astigmatism was 33.6% (cylinder power of 0.5 D or worse) or 11.5% (cylinder power of 1.0 D or worse). Myopic children had a higher incidence rate of astigmatism than nonmyopes (P <0.001). The mean J0 change per year was 0.012 D (95% CI: 0.007-0.018), whereas J45 did not show a significant change each year (mean, 0.001 D per year). Chinese children had greater worsening of J0 per year (P <0.001). Girls also had significantly greater progression of J0 than did boys (P <0.001). Similarly, myopia at baseline (P <0.001) and the hours of computer use (P=0.049) were associated with a greater progression rate of J0. J0 tended to improve in children with compound hyperopic astigmatism, worsen in children with compound myopic astigmatism, and remain stable in mixed astigmatics. CONCLUSIONS: Although there was minimal progression of astigmatism in school age children (0.44-0.53 D) over this period of follow-up, incident cases of astigmatism (>1.0 D) were not uncommon. The progression rate of astigmatism was affected by the ethnicity, presence of myopia, axis, and subtype of astigmatism.     

Interventions for angle-closure glaucoma: an evidence-based update

PURPOSE: To assess the interventions to treat acute angle closure (AAC) and primary angle closure (PAC) with or without glaucomatous optic neuropathy. CLINICAL RELEVANCE: Primary angle closure is one of the leading causes of blindness in East Asia. At present, there are few clinical guidelines on the optimal treatment of AAC or PAC in the affected or contralateral eye. METHODS: All randomized clinical trials, prospective controlled clinical trials, nonprospective controlled clinical trials, and retrospective case series with >50 cases that evaluated treatments for AAC or PAC were included. Studies published in the English language were identified from MEDLINE, PubMed, EMBASE, and the Cochrane Collaborations, as well as by a hand search of the reference lists of important articles. RESULTS: Nine randomized clinical trials and 24 nonrandomized clinical trials and large case series were evaluated. Laser peripheral iridotomy (LPI) has been found to be as effective as surgical peripheral iridectomy in randomized clinical trials of the affected and contralateral eyes of AAC or PAC patients with or without evidence of glaucoma. In another randomized clinical trial, latanoprost was found to decrease intraocular pressure (IOP) more than timolol for PAC in patients for whom LPI alone failed. CONCLUSIONS: This review suggests that LPI should be recommended for the treatment of affected and contralateral eyes of AAC patients. In patients with PAC and insufficient treatment with LPI, latanoprost eye drops may decrease IOP more than timolol. There is still insufficient evidence about other interventions for the treatment of AAC and PAC.     

Evaluation of three commercial rapid tests for detecting antibodies to human immunodeficiency virus

Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest are simple/rapid tests for the detection of antibodies to HIV-1 and HIV-2 in human whole blood, serum and plasma samples. The assay is one step and the result is read visually within 15 minutes. Using 92 known HIV-1 reactive sera and 108 known HIV-1 negative sera, the 3 HIV tests correctly identified all the known HIV-1 reactive and negative samples. The results indicated that Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest HIV are as sensitive and specific (100% concordance) as Microparticle Enzyme Immunoassay. The data indicated that these 3 HIV tests are effective testing systems for diagnosis of HIV infection in a situation when the conventional Enzyme Immunoassay is not suitable.