The Experts below are selected from a list of 996 Experts worldwide ranked by ideXlab platform
Tien Yin Wong - One of the best experts on this subject based on the ideXlab platform.
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ethnic variation in central corneal refractive power and steep cornea in asians
Ophthalmic Epidemiology, 2014Co-Authors: Chenwei Pan, Chingyu Cheng, Charumathi Sabanayagam, Merwyn Chew, Janice Lam, Marcus Ang, Tien Yin WongAbstract:AbstractPurpose: To describe ethnic differences in the distribution of central corneal refractive power and steep cornea in a multiethnic Asian population.Methods: A total of 2968 Chinese, 2957 Indian and 2928 Malay participants aged over 40 years were included in this study. Each subject underwent standardized systematic and ocular examinations, interviewer-administered questionnaires, and blood investigations for risk factor assessment. Central corneal refractive power was measured using an Autorefractor. Steep cornea was defined as central corneal refractive power exceeding 48 diopters (D) measured by keratometry.Results: Mean keratometry readings were 43.9 ± 1.5 D in Malays, 44.2 ± 1.5 D in Indians and 43.9 ± 1.5 D in Chinese. The prevalence of steep cornea was 0.6% (95% confidence interval, CI, 0.3–0.9%) in Malays, 1.0% (95% CI 0.7–1.4%) in Indians and 0.5% (95% CI 0.3–0.8%) in Chinese. In multivariate analysis, increasing central corneal refractive power was associated with Indian race, shorter body...
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testability of vision and refraction in preschoolers the strabismus amblyopia and refractive error study in singaporean children
American Journal of Ophthalmology, 2009Co-Authors: Tien Yin Wong, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Michelle J Trager, Prabakaran Selvaraj, Terri L Young, Rohit VarmaAbstract:Purpose To determine the testability of several vision and refraction tests in preschool-aged children. Design Population-based study of Chinese preschool-aged children in Singapore. Methods One thousand five hundred and forty-two Singaporean Chinese children aged 6 to 72 months were recruited through door-to-door screening of government-subsidized apartments in Singapore. Trained eye professionals administered all tests, including monocular logarithm of the minimum angle of resolution visual acuity with the Sheridan Gardiner chart, monocular Ishihara color testing (Richmond Products Inc, Albuquerque, New Mexico, USA), biometric measurements using IOLMaster (Carl Zeiss, Jena, Germany), and Randot stereoacuity (Stereo Optical Co, Chicago, Illinois, USA) for children 30 to younger than 72 months. Cycloplegic refraction and keratometry measurements also were determined using a table-mounted Autorefractor (Canon Autorefractor RK-F1; Canon, Tokyo, Japan) in children 24 to younger than 72 months. Results Testabilities were 84.8% for visual acuity (40.7% for age 30 to P P = .036 and .008, respectively). Conclusions The vision and refraction tests were testable in a high proportion of preschool-aged Chinese Singaporeans. Preschool children in older age groups are likely to complete these tests successfully, with important implications for determining age limits for screening in the community and clinic.
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cycloplegic refraction in preschool children comparisons between the hand held Autorefractor table mounted Autorefractor and retinoscopy
Ophthalmic and Physiological Optics, 2009Co-Authors: S Prabakaran, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Seowei Leo, Yvonne Ling, K Au G Eong, Tien Yin WongAbstract:Aims: It is common for refraction to be measured using different testing methods in children, with much debate still ongoing on the preferred method. Therefore, we compared cycloplegic refraction measurements using three objective methods in a large cohort of children. Methods: We present the findings from a total of 51 children who were recruited and examined as part of the Strabismus, Amblyopia and Refractive error in Singapore preschool children (STARS) study. Each child underwent a comprehensive eye examination, which included cycloplegic refraction using a hand-held Autorefractor (Retinomax), a table mounted Autorefractor (Canon FK-1) and streak retinoscopy. Spherical equivalent (SE) was calculated as (sphere + half of minus cylinder) and astigmatism was determined using the negative cylindrical component. Results: The current study sample consisted of 29 boys and 22 girls aged between 24 and 72 months (mean age 52.3 months). The mean spherical equivalent (SE) using the table-mounted Autorefractor (1.03 ± 1.64 D) was not significantly different from the streak retinoscopy (1.09 ± 1.58 D, p = 0.66). However, the mean SE using the hand-held Retinomax (0.80 ± 1.43 D) was significantly different (more ‘minus’p = 0.0004) to streak retinoscopy. The astigmatism measured using the hand held (−0.89 ± 0.51 D) and table-mounted Autorefractor (−0.83 ± 0.61 D) were significantly greater than that obtained with streak retinoscopy (−0.58 ± 0.56, p = 0.0003). Conclusions: The table-mounted Autorefractor provided a reading more similar to that of streak retinoscopy than to that of the hand-held Autorefractor. However, there were only small differences in mean SE (<0.32 D) between the hand-held Retinomax and the other methods, which will have implications in research investigations of refractive error.
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hypermetropia axial length and hypertension the tanjong pagar survey
American Journal of Ophthalmology, 2006Co-Authors: Athena W P Foong, Tien Yin Wong, Seangmei Saw, Paul J FosterAbstract:Purpose To examine the relationship among hypermetropia, axial length, and hypertension in a Chinese population. Design Population-based cross-sectional study. Methods This study included 1213 Chinese individuals aged 40 to 81 years. Hypertension was defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or self-report history of antihypertension treatment. Refraction was determined with an Autorefractor and refined subjectively. A-mode ultrasound scanning was used to measure axial length. Results The crude odds ratio of hypertension was 2.5 (95% CI, 1.4–4.6) for moderate hypermetropia (≥+2.00 spheric equivalent diopters) vs high myopia (≤–6.00 diopters), and 1.4 (95% CI, 0.9–2.1) for highest vs lowest axial length quintile. These associations were no longer significant after adjustment for age, gender, education, housing type, and income. Conclusions These data provide no evidence that hypermetropia or shorter axial length is associated independently with hypertension in Chinese individuals.
Mohamed Dirani - One of the best experts on this subject based on the ideXlab platform.
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mirror image congenital esotropia and concordant hypermetropia in identical twins
European Journal of Ophthalmology, 2009Co-Authors: Mohamed Dirani, Maria Schache, Paul N BairdAbstract:Purpose To report the occurrence of mirror image congenital esotropia and concordant hypermetropia in a pair of monozygotic twins. Methods A pair of twins was recruited through the Australian Twin Registry. Zygosity was determined by questionnaire, physical appearance, and standard genotyping. Visual acuity was measured using the logMAR chart at 3 m followed by cycloplegic refraction using the Topcon Autorefractor. Results Twin 1 developed right eye esotropia at 2 years of age with bilateral hypermetropia (right = +5.75 D, left = +5.75 D). Twin 2 developed left eye esotropia at age 2 years with bilateral hypermetropia (right = +6.75, left = +7.50). Conclusions We describe the first reported case of mirror image congenital esotropia with concordant hypermetropia in monozygotic twins.
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testability of vision and refraction in preschoolers the strabismus amblyopia and refractive error study in singaporean children
American Journal of Ophthalmology, 2009Co-Authors: Tien Yin Wong, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Michelle J Trager, Prabakaran Selvaraj, Terri L Young, Rohit VarmaAbstract:Purpose To determine the testability of several vision and refraction tests in preschool-aged children. Design Population-based study of Chinese preschool-aged children in Singapore. Methods One thousand five hundred and forty-two Singaporean Chinese children aged 6 to 72 months were recruited through door-to-door screening of government-subsidized apartments in Singapore. Trained eye professionals administered all tests, including monocular logarithm of the minimum angle of resolution visual acuity with the Sheridan Gardiner chart, monocular Ishihara color testing (Richmond Products Inc, Albuquerque, New Mexico, USA), biometric measurements using IOLMaster (Carl Zeiss, Jena, Germany), and Randot stereoacuity (Stereo Optical Co, Chicago, Illinois, USA) for children 30 to younger than 72 months. Cycloplegic refraction and keratometry measurements also were determined using a table-mounted Autorefractor (Canon Autorefractor RK-F1; Canon, Tokyo, Japan) in children 24 to younger than 72 months. Results Testabilities were 84.8% for visual acuity (40.7% for age 30 to P P = .036 and .008, respectively). Conclusions The vision and refraction tests were testable in a high proportion of preschool-aged Chinese Singaporeans. Preschool children in older age groups are likely to complete these tests successfully, with important implications for determining age limits for screening in the community and clinic.
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cycloplegic refraction in preschool children comparisons between the hand held Autorefractor table mounted Autorefractor and retinoscopy
Ophthalmic and Physiological Optics, 2009Co-Authors: S Prabakaran, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Seowei Leo, Yvonne Ling, K Au G Eong, Tien Yin WongAbstract:Aims: It is common for refraction to be measured using different testing methods in children, with much debate still ongoing on the preferred method. Therefore, we compared cycloplegic refraction measurements using three objective methods in a large cohort of children. Methods: We present the findings from a total of 51 children who were recruited and examined as part of the Strabismus, Amblyopia and Refractive error in Singapore preschool children (STARS) study. Each child underwent a comprehensive eye examination, which included cycloplegic refraction using a hand-held Autorefractor (Retinomax), a table mounted Autorefractor (Canon FK-1) and streak retinoscopy. Spherical equivalent (SE) was calculated as (sphere + half of minus cylinder) and astigmatism was determined using the negative cylindrical component. Results: The current study sample consisted of 29 boys and 22 girls aged between 24 and 72 months (mean age 52.3 months). The mean spherical equivalent (SE) using the table-mounted Autorefractor (1.03 ± 1.64 D) was not significantly different from the streak retinoscopy (1.09 ± 1.58 D, p = 0.66). However, the mean SE using the hand-held Retinomax (0.80 ± 1.43 D) was significantly different (more ‘minus’p = 0.0004) to streak retinoscopy. The astigmatism measured using the hand held (−0.89 ± 0.51 D) and table-mounted Autorefractor (−0.83 ± 0.61 D) were significantly greater than that obtained with streak retinoscopy (−0.58 ± 0.56, p = 0.0003). Conclusions: The table-mounted Autorefractor provided a reading more similar to that of streak retinoscopy than to that of the hand-held Autorefractor. However, there were only small differences in mean SE (<0.32 D) between the hand-held Retinomax and the other methods, which will have implications in research investigations of refractive error.
Rohit Varma - One of the best experts on this subject based on the ideXlab platform.
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testability of refraction stereopsis and other ocular measures in preschool children the sydney paediatric eye disease study
Journal of Aapos, 2012Co-Authors: Amy Pai, Kathryn A Rose, Chameen Samarawickrama, Reena Fotedar, George Burlutsky, Rohit Varma, Paul MitchellAbstract:Purpose To determine the testability and lower age limits for applying common eye tests to preschool children. Methods Investigators from the Sydney Paediatric Eye Disease Study examined 2,461 children aged 6 to 72 months between 2007 and 2009. Cycloplegic autorefraction was measured with Retinomax and Canon Autorefractors. Ocular biometry was measured by the use of IOLMaster in children aged >30 months. The Randot Preschool Stereoacuity test, Lang-Stereotest II, and the Stereo Smile II test were administered to assess stereoacuity. Fundus photography was performed with the subjects' pupils dilated. Testability was defined as the ability to successfully complete tests in both eyes. Results There were 2,189 children with complete data. Most were testable with the Retinomax (71.8%) and Canon (66.0%) Autorefractors. Testability improved with age ( P for trend 70% testability when a subject was 24 months of age, half the age limit (48 months) found for Canon. IOLMaster was mostly testable in children aged 48+ months. Lang-Stereotest II could be used in children aged 6 months and achieved the greatest testability (94.4%) of all stereotests. White children performed better than children of some other ethnicities on Randot ( P = 0.007), with girls performing better than boys ( P = 0.01). Bilateral photography was achieved in >70% of preschool children 48 months of age. Conclusions The testability of all measures was strongly age related, with mostly no sex or ethnicity effects found. The handheld Retinomax could be tested in >70% of children aged 24 months, younger than that found for the stationary Canon Autorefractor (48 months). Testability measures for most eye tests in this preschool sample are comparable to other preschool studies.
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testability of vision and refraction in preschoolers the strabismus amblyopia and refractive error study in singaporean children
American Journal of Ophthalmology, 2009Co-Authors: Tien Yin Wong, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Michelle J Trager, Prabakaran Selvaraj, Terri L Young, Rohit VarmaAbstract:Purpose To determine the testability of several vision and refraction tests in preschool-aged children. Design Population-based study of Chinese preschool-aged children in Singapore. Methods One thousand five hundred and forty-two Singaporean Chinese children aged 6 to 72 months were recruited through door-to-door screening of government-subsidized apartments in Singapore. Trained eye professionals administered all tests, including monocular logarithm of the minimum angle of resolution visual acuity with the Sheridan Gardiner chart, monocular Ishihara color testing (Richmond Products Inc, Albuquerque, New Mexico, USA), biometric measurements using IOLMaster (Carl Zeiss, Jena, Germany), and Randot stereoacuity (Stereo Optical Co, Chicago, Illinois, USA) for children 30 to younger than 72 months. Cycloplegic refraction and keratometry measurements also were determined using a table-mounted Autorefractor (Canon Autorefractor RK-F1; Canon, Tokyo, Japan) in children 24 to younger than 72 months. Results Testabilities were 84.8% for visual acuity (40.7% for age 30 to P P = .036 and .008, respectively). Conclusions The vision and refraction tests were testable in a high proportion of preschool-aged Chinese Singaporeans. Preschool children in older age groups are likely to complete these tests successfully, with important implications for determining age limits for screening in the community and clinic.
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testability of the retinomax Autorefractor and iolmaster in preschool children the multi ethnic pediatric eye disease study
Ophthalmology, 2008Co-Authors: Mark Borchert, Ying Wang, Kristina Tarczyhornoch, Susan A Cotter, J Deneen, Stanley P Azen, Rohit VarmaAbstract:Purpose To determine the testability of Retinomax and IOLMaster ocular biometry in preschool children. Design Population-based study of inner city preschool children in Los Angeles County. Participants Two thousand five hundred forty-five Hispanic and 2178 African American children 6 to 72 months old. Methods Subjects were identified by door-to-door screening within previously identified contiguous census tracts. Pediatric ophthalmologists or optometrists performed comprehensive eye examinations on all subjects. Refractive error and keratometry measurements were attempted on all subjects with the Retinomax Autorefractor after cycloplegia. Axial length measurements with the IOLMaster partial coherence interferometer were attempted on those subjects ages 30 to 72 months. Main Outcome Measures Ability to obtain high confidence autorefraction readings or axial length measurements on both eyes. Results Overall, 89% were testable in both eyes with the Retinomax device, and 91% of the children were testable with the IOLMaster. Testability rose sharply with age, so that by age 36 months 98% of children were testable with the Retinomax device and 90% were testable with IOLMaster. There were no consistent gender- or ethnicity-related differences in testability overall or when stratified by age for either device. Conclusions Young children can be reliably tested for ocular biometry with the Retinomax and IOLMaster devices. This may impact strategies for management of cataracts and refractive errors in preschool children.
Ningli Wang - One of the best experts on this subject based on the ideXlab platform.
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cycloplegic refraction by 1 cyclopentolate in young adults is it the gold standard the anyang university students eye study auses
British Journal of Ophthalmology, 2019Co-Authors: Shiming Li, Jialing Du, Ian G Morgan, He Li, Jianping Hu, Xiaohui Yang, Ningli WangAbstract:Aims To document the difference between non-cycloplegic and cycloplegic refraction and explore its associated factors in Chinese young adults. Methods A school-based study including 7971 undergraduates was conducted in Anyang, Henan Province, China. Cycloplegia was achieved with two drops of 1% cyclopentolate and 1 drop of Mydrin P (Tropicamide 0.5%, phenylephrine HCl 0.5%) with a 5 min interval. Non-cycloplegic and cycloplegic refractions were measured by an Autorefractor. A paired-sample t-test and Spearman correlation analysis were used for analysis with data from only the right eyes included. Results Of the 7971 students examined, 7793 (97.8%) with complete data were included, aging 20.2±1.5 years. Male students accounted for 36.8%. Overall, there was a significant difference between non-cycloplegic and cycloplegic SE (spherical equivalent) of 0.83±0.81D (p Conclusion Lack of cycloplegia will lead to significant misclassification of myopia, emmetropia and hyperopia in Chinese young adults. Cycloplegia is therefore essential for this age-group in epidemiological studies.
Qiao Fan - One of the best experts on this subject based on the ideXlab platform.
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testability of vision and refraction in preschoolers the strabismus amblyopia and refractive error study in singaporean children
American Journal of Ophthalmology, 2009Co-Authors: Tien Yin Wong, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Michelle J Trager, Prabakaran Selvaraj, Terri L Young, Rohit VarmaAbstract:Purpose To determine the testability of several vision and refraction tests in preschool-aged children. Design Population-based study of Chinese preschool-aged children in Singapore. Methods One thousand five hundred and forty-two Singaporean Chinese children aged 6 to 72 months were recruited through door-to-door screening of government-subsidized apartments in Singapore. Trained eye professionals administered all tests, including monocular logarithm of the minimum angle of resolution visual acuity with the Sheridan Gardiner chart, monocular Ishihara color testing (Richmond Products Inc, Albuquerque, New Mexico, USA), biometric measurements using IOLMaster (Carl Zeiss, Jena, Germany), and Randot stereoacuity (Stereo Optical Co, Chicago, Illinois, USA) for children 30 to younger than 72 months. Cycloplegic refraction and keratometry measurements also were determined using a table-mounted Autorefractor (Canon Autorefractor RK-F1; Canon, Tokyo, Japan) in children 24 to younger than 72 months. Results Testabilities were 84.8% for visual acuity (40.7% for age 30 to P P = .036 and .008, respectively). Conclusions The vision and refraction tests were testable in a high proportion of preschool-aged Chinese Singaporeans. Preschool children in older age groups are likely to complete these tests successfully, with important implications for determining age limits for screening in the community and clinic.
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cycloplegic refraction in preschool children comparisons between the hand held Autorefractor table mounted Autorefractor and retinoscopy
Ophthalmic and Physiological Optics, 2009Co-Authors: S Prabakaran, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Seowei Leo, Yvonne Ling, K Au G Eong, Tien Yin WongAbstract:Aims: It is common for refraction to be measured using different testing methods in children, with much debate still ongoing on the preferred method. Therefore, we compared cycloplegic refraction measurements using three objective methods in a large cohort of children. Methods: We present the findings from a total of 51 children who were recruited and examined as part of the Strabismus, Amblyopia and Refractive error in Singapore preschool children (STARS) study. Each child underwent a comprehensive eye examination, which included cycloplegic refraction using a hand-held Autorefractor (Retinomax), a table mounted Autorefractor (Canon FK-1) and streak retinoscopy. Spherical equivalent (SE) was calculated as (sphere + half of minus cylinder) and astigmatism was determined using the negative cylindrical component. Results: The current study sample consisted of 29 boys and 22 girls aged between 24 and 72 months (mean age 52.3 months). The mean spherical equivalent (SE) using the table-mounted Autorefractor (1.03 ± 1.64 D) was not significantly different from the streak retinoscopy (1.09 ± 1.58 D, p = 0.66). However, the mean SE using the hand-held Retinomax (0.80 ± 1.43 D) was significantly different (more ‘minus’p = 0.0004) to streak retinoscopy. The astigmatism measured using the hand held (−0.89 ± 0.51 D) and table-mounted Autorefractor (−0.83 ± 0.61 D) were significantly greater than that obtained with streak retinoscopy (−0.58 ± 0.56, p = 0.0003). Conclusions: The table-mounted Autorefractor provided a reading more similar to that of streak retinoscopy than to that of the hand-held Autorefractor. However, there were only small differences in mean SE (<0.32 D) between the hand-held Retinomax and the other methods, which will have implications in research investigations of refractive error.