Retinoscopy

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Tien Yin Wong - One of the best experts on this subject based on the ideXlab platform.

  • cycloplegic refraction in preschool children comparisons between the hand held autorefractor table mounted autorefractor and Retinoscopy
    Ophthalmic and Physiological Optics, 2009
    Co-Authors: S Prabakaran, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Seowei Leo, Yvonne Ling, K Au G Eong, Tien Yin Wong
    Abstract:

    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.

Mohamed Dirani - One of the best experts on this subject based on the ideXlab platform.

  • cycloplegic refraction in preschool children comparisons between the hand held autorefractor table mounted autorefractor and Retinoscopy
    Ophthalmic and Physiological Optics, 2009
    Co-Authors: S Prabakaran, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Seowei Leo, Yvonne Ling, K Au G Eong, Tien Yin Wong
    Abstract:

    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.

S Prabakaran - One of the best experts on this subject based on the ideXlab platform.

  • cycloplegic refraction in preschool children comparisons between the hand held autorefractor table mounted autorefractor and Retinoscopy
    Ophthalmic and Physiological Optics, 2009
    Co-Authors: S Prabakaran, Mohamed Dirani, Audrey Chia, Gus Gazzard, Qiao Fan, Seowei Leo, Yvonne Ling, K Au G Eong, Tien Yin Wong
    Abstract:

    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.

Leon B Ellwein - One of the best experts on this subject based on the ideXlab platform.

  • refractive error and visual impairment in school age children in gombak district malaysia
    Ophthalmology, 2005
    Co-Authors: Yahya Abqariyah, Gopal P Pokharel, Leon B Ellwein
    Abstract:

    Purpose To assess the prevalence of refractive error and visual impairment in school-age children in Gombak District, a suburban area near Kuala Lumpur city. Design Population-based, cross-sectional survey. Participants Four thousand six hundred thirty-four children 7 to 15 years of age living in 3004 households. Methods Random selection of geographically defined clusters was used to identify the study sample. Children in 34 clusters were enumerated through a door-to-door survey and examined in 140 schools between March and July 2003. The examination included visual acuity measurements; ocular motility evaluation; Retinoscopy and autorefraction under cycloplegia; and examination of the external eye, anterior segment, media, and fundus. Main Outcome Measures Distance visual acuity and cycloplegic refraction. Results The examined population was 70.3% Malay, 16.5% Chinese, 8.9% Indian, and 4.3% of other ethnicity. The prevalence of uncorrected (unaided), presenting, and best-corrected visual impairment (visual acuity ≤20/40 in the better eye) was 17.1%, 10.1%, and 1.4%, respectively. More than half of those in need of corrective spectacles were without them. In eyes with reduced vision, refractive error was the cause in 87.0%, amblyopia in 2.0%, other causes in 0.6%, and unexplained causes in 10.4%, mainly suspected amblyopia. Myopia (spherical equivalent of at least −0.50 diopter [D] in either eye) measured with Retinoscopy was present in 9.8% of children 7 years of age, increasing to 34.4% in 15-year-olds; and in 10.0% and 32.5%, respectively, with autorefraction. Myopia was associated with older age, female gender, higher parental education, and Chinese ethnicity. Hyperopia (≥2.00 D) with Retinoscopy varied from 3.8% in 7-year-olds, 5.0% with autorefraction, to less than 1% by age 15, with either measurement method. Hyperopia was associated with younger age and "other" ethnicity. Astigmatism (≥0.75 D) was present in 15.7% of children with Retinoscopy and in 21.3% with autorefraction. Conclusions Visual impairment in school-age children in urban Gombak District is overwhelmingly caused by myopia, with a particularly high prevalence among children of Chinese ethnicity. Eye health education and screening may help address the unmet need for refractive correction.

  • refractive error and visual impairment in urban children in southern china
    Investigative Ophthalmology & Visual Science, 2004
    Co-Authors: Mingguang He, Junwen Zeng, J Xu, Gopal P Pokharel, Leon B Ellwein
    Abstract:

    PURPOSE. To assess the prevalence of refractive error and visual impairment in school-age children in a metropolitan area of southern China. METHODS. Random selection of geographically defined clusters was used to identify children 5 to 15 years of age in Guangzhou. Children in 22 clusters were enumerated through a door-to-door survey and examined in 71 schools and 19 community facilities from October 2002 to January 2003. The examination included visual acuity measurements, ocular motility evaluation, Retinoscopy, and autorefraction under cycloplegia and examination of the external eye, anterior segment, media, and fundus. RESULTS. A total of 5053 children living in 4814 households were enumerated, and 4364 (86.4%) were examined. The prevalence of uncorrected, presenting, and best-corrected visual acuity 20/40 or worse in the better eye was 22.3%, 10.3%, and 0.62%, respectively. Refractive error was the cause in 94.9% of the 2335 eyes with reduced vision, amblyopia in 1.9%, other causes in 0.4%, and unexplained causes in the remaining 2.8%. External and anterior segment abnormalities were seen in 1496 (34.3%) children, mainly minor conjunctival abnormalities. Media and fundus abnormalities were observed in 32 (0.73%) children. Myopia (spherical equivalent of at least -0.50 D in either eye) measured with Retinoscopy affected 73.1% of children 15 years of age, 78.4% with autorefraction. The prevalence of myopia was 3.3% in 5-yearolds with Retinoscopy and 5.7% with autorefraction. Females had a significantly higher risk of myopia. Hyperopia (+2.00 D or more) measured with Retinoscopy was present in 16.7% of 5-year-olds, 17.0% with autorefraction. The prevalence of hyperopia was below 1% in 15-year-olds, with both methods. Astigmatism (cylinder of ≥0.75 D) was present in 33.6% of children with Retinoscopy and in 42.7% with autorefraction. CONCLUSIONS. The prevalence of reduced vision because of myopia is high in school-age children living in metropolitan Guangzhou, representing an important public health problem. One third of these children do not have the necessary corrective spectacles. Effective strategies are needed to eliminate this easily treated cause of significant visual impairment.

David K Coats - One of the best experts on this subject based on the ideXlab platform.

  • the effect of off the visual axis Retinoscopy on objective refractive measurement
    American Journal of Ophthalmology, 2004
    Co-Authors: David W Jackson, Evelyn A Paysse, Kirk R Wilhelmus, Mohamed A W Hussein, Gina Rosby, David K Coats
    Abstract:

    Abstract Purpose To determine the effect of off-axis Retinoscopy on objective refractive measurement. Design Prospective experimental study. Methods Eight volunteers underwent cycloplegic Retinoscopy of their right eye on-the-visual-axis, and 5, 10, 15, and 20 degrees off-the-visual-axis in adduction. A single masked examiner performed all Retinoscopy with random order of the patient and axis refracted. Results The average spherical retinoscopic value at 0, 5,10,15, and 20 degrees of off-axis alignment was −0.40, −0.90, −1.00, −1.38, and −1.80 diopters, respectively. The average spherical equivalent retinoscopic value obtained for each of the above positions of eye alignment was −0.02, −0.59, −0.45, −0.64, and −0.98 diopters, respectively. The induced cylinder power increased by an average of 3% for each degree of off-axis Retinoscopy, though the axis of the cylinder was not predictable. Conclusion Objective refractive measurement by Retinoscopy is significantly altered by off-the visual-axis Retinoscopy. The induced error may be clinically important even with small degrees of eccentricity.