Biomedical subjects

Kathryn Rose

Publications and source records attributed to Kathryn Rose.

13 recordsLinked to original sources

PubMed2006

Comparison of aberrometer and autorefractor measures of refractive error in children.

PURPOSE: The purpose of this study was to evaluate and compare the Complete Ophthalmic Analysis System (COAS) G200 Aberrometer (Wavefront Sciences Inc., Albuquerque, NM) and Canon RK-F1 Autorefractor (Canon Inc., Tokyo, Japan) for measuring refractive errors in young children. METHODS: The Sydney Myopia Study is a population-based study of refractive error and eye health in young Australian children. Cycloplegic refractions were performed on 1504 school year 1 students (mostly 6 years old) and 890 school year 7 (mostly 12 years old) students using both the COAS G200 Aberrometer and Canon RK-F1 autorefractor. Refractive data were analyzed using power vectors. Mean differences and 95% limits of agreement were determined for refractive components between the two instruments. RESULTS: The mean age +/- standard deviation was 6.7 +/- 0.4 years (range, 5.5-9.1 years) and 12.6 +/- 0.5 years (range, 11.1-14.4 years) for the year 1 and year 7 students, respectively. Mean paired differences for the M component (spherical equivalent) between the COAS G200 and Canon RK-F1 were <0.25 D in both age groups and were statistically significant in the year 1 group only (p < 0.001). Small significant differences were found in the astigmatic components (J0 and J45) in both groups. A smaller coefficient of agreement for the M component was found in the older group (0.54 D), whereas the coefficients of agreement of the astigmatic components (J0 and J45) were similar for both groups. CONCLUSIONS: The COAS G200 aberrometer was an easy-to-use instrument for the measurement of refractive error in children. In addition to being able to measure higher and lower order aberrations, the COAS G200 provides refractive error measurements comparable to those of an autorefractor.

Adolescent↗

PubMed2006

Accommodative facility in eyes with and without myopia.

PURPOSE: To compare accommodative facility in eyes with myopia to that in eyes with emmetropia or hyperopia and to determine whether accommodative facility can be used to predict an association with myopia. METHODS: In the Sydney Myopia Study, year-1 school children (6.7 +/- 0.4 years) were assessed for accommodative facility at distance (3 m) and near (33 cm) with semiautomated flippers. Spherical equivalent refractive error (RE) was defined as myopia (< or = -0.50 D), emmetropia (> -0.50 D, but < +1.50 D), and hyperopia (> or = +1.50 D) based on postcycloplegia readings. Only right eye data were considered. Differences between groups were analyzed with the Brown-Forsythe F test after adjustment for age and gender. Multiple comparisons were adjusted with the by the Games-Howell METHOD RESULTS: Of the 1328 right eyes assessed, 20 (1.5%) eyes were myopic, 977 (73.6%) were emmetropic, and 331 (24.9%) were hyperopic. At distance, mean facility was less for myopic eyes at 5.5 +/- 2.0 cycles per minute (cpm) in comparison to 6.9 +/- 1.7 cpm for eyes with emmetropia or hyperopia (P = 0.005). Myopic eyes recorded greater positive and negative accommodative response times than did emmetropic or hyperopic eyes (P < 0.05). There were no differences among the groups in near facility. The area under the receiver operating characteristic (ROC) curve for distance facility was 0.692 (P = 0.003, 95% CI, 0.580-0.805). CONCLUSIONS: Myopic eyes have reduced accommodative facility at distance, and accommodative responsiveness to both positive and negative defocus is slow. However, accommodative facility as a test does not have sufficient power to discriminate eyes with myopia from other refractive errors.

Accommodation, Ocular↗

PubMed2005

Numerical confusion errors in ishihara testing: findings from a population-based study.

PURPOSE: To describe the prevalence of numerical confusion errors in Ishihara testing in a representative sample of Australian children. DESIGN: Cross-sectional, population-based study. METHODS: The Sydney Myopia Study examined a representative stratified random cluster sample of 1,741 children (aged 6 years) attending 34 schools in Sydney, Australia (response rate, 78.9%), including color vision tests in 1,735 children. Those with any color vision defects (n = 33; 1.9%; 97% boys) were excluded. Responses for each Ishihara plate were recorded. RESULTS: Numerical confusion errors were made by 75.8% of children with normal color vision; there was no gender difference. Plates 3 and 7 were particularly prone to numerical confusion errors; 48.4% and 40.8%, respectively, of children misread these plates. CONCLUSION: Numerical confusion errors in the Ishihara test were relatively common in children with normal color vision. The frequency of such errors could indicate an inherent deficiency in this commonly used test.

Child↗

PubMed2005

Accuracy of the Lang II stereotest in screening for binocular disorders in 6-year-old children.

PURPOSE: To assess the accuracy of the Lang II stereotest in screening for strabismus, amblyopia, and anisometropia in 6-year-old children. DESIGN: Cross-sectional population-based study. METHODS: The Sydney Myopia Study examined 1765 6-year-old children (78.9% of eligible) who were identified by random cluster sampling of 34 schools in Sydney, Australia. Sensitivity and specificity of the Lang II stereotest was determined by best stereoacuity. Cycloplegic autorefraction, assessment of visual acuity, and ocular motility were conducted. RESULTS: Test sensitivity ranged from 21.4% for anisometropia (> or =1.0 diopter) to 31.3% for amblyopia. The detection rate for new cases of amblyopia ranged from 20% to 40%; the detection rate for new cases of strabismus was 30%. Specificity was >98% in all three conditions. Children with false-negative results included newly diagnosed cases of strabismus (14 of 25 children) or amblyopia (5 of 12 children). CONCLUSION: The Lang II stereotest, when used alone, has very limited value as a screening test of binocular dysfunction.

Amblyopia↗

PubMed2005

Patterns of spectacle use in young Australian school children: findings from a population-based study.

PURPOSE: To describe the patterns of spectacle use in a population-based sample of Australian Year 1 school children (mostly aged 6 years). METHODS: Logarithm of the minimum angle of resolution (logMAR) visual acuity was measured in both eyes before and after pinhole correction, and using spectacles if worn. Cycloplegic autorefraction (cyclopentolate) and detailed dilated fundus examination were performed. Visual impairment was defined as visual acuity <40 logMAR letters (ie, <20/40 Snellen equivalent). Myopia was defined as spherical equivalent (SE) refraction < or = -0.50 diopters (D), and hyperopia as SE refraction > or = +2.0D, deemed significant when > or = +3.0D. Astigmatism was defined as cylinder > or =1.0D and anisometropia as SE refraction difference between the two eyes at least 1.0D. RESULTS: One thousand seven hundred forty predominantly 6-year-old school children were examined during 2003 to 2004. Spectacle use was documented in 77 children (4.4% of sample). Uncorrected visual impairment was found in the worse eye of 71 children (4.1%) and refractive error accounted for the majority (69.0%). Astigmatism was the most common refractive error causing visual impairment, accounting for 46.5%. Hyperopia, with or without astigmatism, was the most frequent reason for spectacle use, documented in 40.3%. Spectacle use in the absence of significant refractive error, amblyogenic risk factors, or visual impairment was noted in 26 children (33.8% of spectacle wearers). The prescription of spectacles could have benefited a further 26 children (1.5% of sample), mostly for correction of astigmatism. CONCLUSION: This study documents a significant disparity between spectacle use and need. Astigmatism was the most common cause of visual impairment due to refractive error.

Child↗

PubMed2005

Visual acuity and the causes of visual loss in a population-based sample of 6-year-old Australian children.

PURPOSE: To describe the distribution of visual acuity and causes of visual loss in a representative sample of Australian schoolchildren. DESIGN: Population-based cross-sectional study. PARTICIPANTS: One thousand seven hundred thirty-eight predominantly 6-year old children examined during 2003 to 2004. METHODS: Logarithm of the minimum angle of resolution (logMAR) visual acuity was measured in both eyes before and after pinhole correction and with spectacles if worn. Cycloplegic autorefraction (cyclopentolate) and detailed dilated fundus examination were performed. MAIN OUTCOME MEASURES: Visual impairment was defined as any (visual acuity <20/40; <40 letters) or severe (visual acuity < or =20/200; 0-5 letters) for both better and worse eyes. Myopia was defined as spherical equivalent (SE) refraction < or =-0.50 diopters (D), and hyperopia as SE refraction > or =+2.0 D, deemed significant when > or =+3.0 D. Astigmatism was defined as cylinder > or =1.0 D and anisometropia as SE refraction difference between eyes at least 1.0 D. Amblyopia was defined as corrected visual acuity <0.3 logMAR units (<20/40; <40 letters) in the affected eye not attributable to any underlying structural abnormality of the eye or visual pathway, together with a 2-logMAR line difference between the eyes and presence of an amblyogenic risk factor. RESULTS: The mean visual acuity of this sample was 20/25 (49.3 letters). Uncorrected visual impairment was found in the better eye of 23 children (1.3%) and in the worse eye of 71 children (4.1%). The prevalence was higher in girls than boys and among children of lower socioeconomic status. Refractive error was the most frequent cause, accounting for 69.0%, followed by amblyopia (22.5%). Astigmatism was the principle refractive error causing visual impairment and was frequently uncorrected. Presenting visual impairment (using current glasses if worn) was found in the better and worse eyes of 15 children (0.9%) and 54 children (2.8%), respectively. This was mainly due to under corrected or uncorrected refractive error. CONCLUSIONS: This study has documented a relatively low prevalence of visual impairment in a population of Australian children. Uncorrected astigmatism and amblyopia were the most frequent causes.

Child↗

PubMed2005

How genetic is school myopia?

Myopia is of diverse aetiology. A small proportion of myopia is clearly familial, generally early in onset and of high level, with defined chromosomal localisations and in some cases, causal genetic mutations. However, in economically developed societies, most myopia appears during childhood, particularly during the school years. The chromosomal localisations characterised so far for high familial myopia do not seem to be relevant to school myopia. Family correlations in refractive error and axial length are consistent with a genetic contribution to variations in school myopia, but potentially confound shared genes and shared environments. High heritability values are obtained from twin studies, but rest on contestable assumptions, and require further critical analysis, particularly in view of the low heritability values obtained from parent-offspring correlations where there has been rapid environmental change between generations. Since heritability is a population-specific parameter, the values obtained on twins cannot be extrapolated to define the genetic contribution to variation in the general population. In addition, high heritability sets no limit to the potential for environmentally induced change. There is in fact strong evidence for rapid, environmentally induced change in the prevalence of myopia, associated with increased education and urbanisation. These environmental impacts have been found in all major branches of the human family, defined in modern molecular terms, with the exception of the Pacific Islanders, where the evidence is too limited to draw conclusions. The idea that populations of East Asian origin have an intrinsically higher prevalence of myopia is not supported by the very low prevalence reported for them in rural areas, and by the high prevalence of myopia reported for Indians in Singapore. A propensity to develop myopia in "myopigenic" environments thus appears to be a common human characteristic. Overall, while there may be a small genetic contribution to school myopia, detectable under conditions of low environmental variation, environmental change appears to be the major factor increasing the prevalence of myopia around the world. There is, moreover, little evidence to support the idea that individuals or populations differ in their susceptibility to environmental risk factors.

Adolescent↗

PubMed2004

Incorporating vision and hearing tests into aged care assessment: methods and the pilot study.

PURPOSE: Vision and hearing impairments are frequent in older people and may contribute to their reliance on aged care services. This study aims to assess whether incorporating vision and hearing screening into routine aged care assessments and provision of appropriate health care services will influence health outcomes of older individuals. METHODS: The proposed project is a 2 x 2 factorial design randomized controlled trial. The pilot study recruited 208 participants aged 65+ years attending an aged care assessment center at Westmead Hospital, Sydney, who were randomly allocated to one of four groups: vision and hearing tests, vision tests only, hearing tests only, or neither. Face-to-face interviews with all participants were conducted. Questionnaires included Activity of Daily Living (ADL), 36-item Short-Form health survey (SF-36), Mini-Mental State Exam (MMSE) and questions about use of health care and community support services. Participants will be re-examined after 12 months to assess changes over time in quality-of-life, physical and cognitive function, incident falls and use of health and community aged care services.

Aged↗

PubMed2004

Neighbourhood characteristics and mortality in the Atherosclerosis Risk in Communities Study.

BACKGROUND: This study investigates the relationship between neighbourhood characteristics and mortality (all-cause, cardiovascular disease [CVD], and cancer) in the Atherosclerosis Risk in Communities Study (ARIC). METHODS: Analysis was limited to African-American and white participants 45-64 years of age at baseline whose records were linked to census data. Deaths ascertained through 31 December 1999 were included in the analysis. Individual-level characteristics were obtained from the baseline interview. A composite index was used to characterize the neighbourhood socioeconomic environment. Proportional hazards regression was used to estimate the effect of neighbourhood socioeconomic status (SES) index and family income on the survival time. RESULTS: The rate of mortality adjusted for age and gender was highest among those who lived in disadvantaged neighbourhoods and were of lower SES. In general, all-cause and CVD mortality rates decreased with increasing neighbourhood SES advantage and family income in all race-gender groups. Although this pattern generally persisted after adjustment for individual socioeconomic factors, statistically significant associations persisted for CVD mortality in whites only (hazard ratio = 1.4, 95% CI: 1.0, 2.0) for most disadvantaged versus most advantaged tertile). When compared with the most affluent participants living in the most advantaged neighbourhoods, the increased risk of all-cause and CVD mortality associated with being poor and living in the most disadvantaged neighbourhoods was equivalent to being 11 and 13 years older at baseline for whites and African Americans, respectively. CONCLUSION: Our findings indicate that neighbourhood socioeconomic characteristics are associated with modest increases in CVD mortality in white adults. The lack of neighbourhood effects in African Americans needs to be interpreted with caution due to the limited range in the characteristics of the neighbourhood from which these participants were drawn.

Black or African American↗

PubMed2004

The relation between birth weight and intima-media thickness in middle-aged adults.

BACKGROUND: Birth weight has been found to be inversely associated with the risk of coronary heart disease and stroke, although the mechanisms for this association remain unclear. Here, we investigate the relation between reported birth weight and atherosclerosis in middle age. METHODS: We included the 9817 participants (age 44-65) in the Atherosclerosis Risk in Communities (ARIC) study who were neither a twin nor born prematurely. Carotid atherosclerosis was assessed as intima-media thickness measured by B-mode ultrasound. We studied the association with recalled exact birth weight, and for those unable to recall exact birth weight, with recalled birth weight category. RESULTS: Mean intima-media thickness (+/- standard deviation) was 0.73 +/- 0.17 mm. Mean birth weight for the 4635 participants recalling exact birth weight was 3.49 +/- 0.71 kg. A further 4946 participants recalled birth weight category, with 4730 (96%) reporting "medium" birth weight. In univariate analysis, birth weight and intima-media thickness were positively related. However, adjustment for confounding factors reduced the association to only a 0.004 mm higher intima-media thickness (95% CI = - 0.003 to 0.011) mm per 1 kg of birth weight. The same pattern of univariate positive relationship and attenuation with adjustment was seen for birth weight category and intima-media thickness. There was no evidence of interaction between adult body mass index (BMI) and birth weight, or of interaction between category of adult BMI and birth weight category. An inverse relation between birth weight category and intima-media thickness was seen only for those in the lowest category of adult BMI (BMI <25 kg/m). CONCLUSIONS: We found no evidence of a clinically significant relation between birth weight and carotid atherosclerosis.

Adult↗

PubMed2003

Prevalence of undetected ocular conditions in a pilot sample of school children.

Parents of 134 children (age 5-18 years; 84% participation) attending a private school gave informed consent for their child's participation in a pilot study to demonstrate the feasibility and estimate sample size for a larger study of myopia prevalence, the Sydney Myopia Study. LogMAR visual acuity and other ocular assessments, including cycloplegic autorefraction (tropicamide 1%) and examination of the media and fundus, were performed. The prevalence of significant ocular conditions was 28.2%. Eleven children (8.4%) wore glasses. Five were referred for a change in their correction. Previously undetected ocular conditions (19.8%) included one child with ocular pathology and four children with strabismus. Uncorrected refractive error (16.8%) was the most common reason for referral and was more predominant in the senior students (25%), corresponding with an age-related shift in mean spherical equivalent refraction towards myopia (less than 7 years: +0.40 +/- 0.60 D; more than 15 years: -1.15 +/- 1.18 D). Three senior students were classified as having socially significant correctable vision impairment. These findings suggest that reliance on ad hoc referrals could result in delayed referral and that vision screening in both early and later school years may be desirable.

Adolescent↗

PubMed2002

Correctable visual impairment in an older population: the blue mountains eye study.

PURPOSE: To describe temporal changes in the characteristics of older persons with visual impairment in their better eye correctable by refraction. DESIGN: Study of two cross sections of a community 6 years apart. METHODS: The Blue Mountains Eye Study examined 3654 persons aged 49 to 97 during 1992 to 1994 (cross-section 1) and 3509 persons (2335 cohort survivors plus 1174 persons who moved to the area and age group) during 1997 to 2000 (cross-section 2). Logarithm of minimal angle of resolution visual acuity was measured before and after refraction. Correctable visual impairment was defined as visual impairment < 20/40 in the better eye before refraction that improved after refraction to no impairment (>/= 20/40). Factors associated with correctable visual impairment and persistent correctable impairment were determined. RESULTS: Cross-sections 1 and 2 had similar age-gender distributions. In cross-section 1, 7.5% of participants had correctable visual impairment, 3.6% had noncorrectable visual impairment, and 88.9% had no impairment. Corresponding rates in cross-section 2 were 5.6%, 2.7%, and 91.7%. In both cross sections, similar proportions (around 68%) of those visually impaired had correctable visual impairment and similar sociodemographic measures predicted correctable visual impairment. Cross-section 1 participants who were married, owned their home, had high job prestige, gained qualifications after high school, or were current drivers were less likely to have correctable visual impairment after controlling for age and gender. Adjusted odds for correctable visual impairment increased in those living alone, using community support services, dependent on others, with myopia, wearing distance glasses, or with low perceived health and heart disease. Histories of stroke, cancer, and diabetes were similar between groups with correctable and no visual impairment. CONCLUSION: Socioeconomic parameters, myopia, wearing distance glasses, reported health problems, and poor perceived health were associated with correctable visual impairment in this older population.

Aged↗

PubMed2002

Five-year outcome of correctable visual impairment: the Blue Mountains Eye Study.

This report aims to describe the outcome and socio-economic characteristics of older persons attending the Blue Mountains Eye Study (BMES) with persistent correct-able visual impairment (VI). The BMESI examined 3654 persons aged 49+ during 1992-1994 and re-examined 2335 survivors during 1997-1999 (BMES II). Visual acuity was measured before and after standardized refraction. Participants had correctable VI if their better eye was visually impaired <6/12 before refraction (with distance glasses if worn) and was unimpaired after refraction. In BMES I,274 persons (7.5%) had correctable VI, of whom 127 returned to BMES II. Of this group of 127, 34 had persistent correctable VI and 74 were no longer impaired. Fewer persons with correctable VI returned and more died prior to BMES II, compared to persons with no or non-correctable VI. This study showed that persistent correctable impairment was more frequent with increasing age, among women, in those living alone, using community support services,or with a history of heart disease.

Aged↗