Barbara E. Robinson

Factors associated with the prevalence of myopia in 6-year-olds.

PURPOSE To describe the frequency of and risk factors associated with myopia in grade one children. METHODS Refractive error was measured by static retinoscopy, without cycloplegia, for 10,616 children in the first year of a province-wide vision-screening program. Information on factors that might be associated with myopia was collected from parents or guardians by self-administered questionnaires distributed before the vision screening. These factors were evaluated by a case-control method. RESULTS The prevalence of myopia, greater than -0.25 D, was 6%. The estimated relative risk of myopia was increased significantly among children whose birth weight was <2500 g and whose mothers had a history of early spectacle use. CONCLUSIONS Results suggest that the prevalence of myopia in 6-year-old children is associated with both hereditary and nonhereditary factors. In accord with prior work, the results argue that low birth weight has a permanent influence upon eye development.

Prevalence of Visual Impairment and Uncorrected Refractive Error – Report from a Canadian Urban Population-based Study

Abstract Purpose: The prevalence of visual impairment due to uncorrected refractive error has not been previously studied in Canada. A population-based study was conducted in Brantford, Ontario. Methods: The target population included all people 40 years of age and older. Study participants were selected using a randomized sampling strategy based on postal codes. Presenting distance and near visual acuities were measured with habitual spectacle correction, if any, in place. Best corrected visual acuities were determined for all participants who had a presenting distance visual acuity of less than 20/25. Results: Population weighted prevalence of distance visual impairment (visual acuity <20/40 in the better eye) was 2.7% (n = 768, 95% confidence interval (CI) 1.8–4.0%) with 71.8% correctable by refraction. Population weighted prevalence of near visual impairment (visual acuity <20/40 with both eyes) was 2.2% (95% CI 1.4–3.6) with 69.1% correctable by refraction. Multivariable adjusted analysis showed that the odds of having distance visual impairment was independently associated with increased age (odds ratio, OR, 3.56, 95% CI 1.22–10.35; ≥65 years compared to those 39–64 years), and time since last eye examination (OR 4.93, 95% CI 1.19–20.32; ≥5 years compared to ≤2 years). The same factors appear to be associated with increased prevalence of near visual impairment but were not statistically significant. Conclusions: The majority of visual impairment found in Brantford was due to uncorrected refractive error. Factors that increased the prevalence of visual impairment were the same for distance and near visual acuity measurements.

Does government assistance improve utilization of eye care services by low-income individuals?

OBJECTIVE To examine whether government-funded, low-income vision care programs improve use of eye care services by low-income individuals in Canada. DESIGN Cross-sectional survey. PARTICIPANTS 27,375 white respondents to the Canadian Community Health Survey (CCHS) Healthy Aging 2008/2009. METHODS Government-funded, low-income vision care programs were reviewed. The amount of assistance provided was compared with professional fee schedules for general/routine eye examinations and market prices for eyeglasses. The utilization of eye care providers was derived from the CCHS. RESULTS To receive low-income vision care assistance, individuals must be in receipt of social assistance. Criteria for receiving social assistance are stringent. The Canadian Financial Capability Survey revealed that 7.9% of Canadians aged 45 to 64 years and 5.5% aged ≥65 years received social assistance in 2009. The CCHS found in 2008/2009 that 12.5% of citizens aged 45 to 64 years and 13.2% of those aged ≥65 years had difficulty paying for basic expenses such as food. In 5 provinces, low-income vision care assistance fully covers a general/routine eye examination. In the remainder, the assistance provided is insufficient for a general/routine eye examination. The assistance for eyeglasses is inadequate in 5 provinces, requiring out-of-pocket copayments. Among middle-aged whites who self-reported not having glaucoma, cataracts, diabetes, or vision problems not corrected by lenses, utilization of eye care providers was 28.1% among those with financial difficulty versus 41.9% among those without (p < 0.05), giving a prevalence ratio 0.68 (95% CI 0.57-0.80) adjusted for age, sex and education. CONCLUSIONS Despite government assistance, low-income individuals use vision care services less often than wealthy individuals.

Value of Routine Eye Examinations in Asymptomatic Patients.

Purpose To determine if routine eye examinations in asymptomatic patients result in spectacle prescription change, new critical diagnosis, or new management of existing conditions. We also investigate whether age and time between assessments (assessment interval) impact detection rates. Methods The Waterloo Eye Study (WatES) database was created from a retrospective file review of 6397 patients seen at the University of Waterloo Optometry Clinic. Significant changes since the previous assessment (significant change) were defined as a change in spectacle prescription, presence of a new critical diagnosis, or a new management. Significant change, assessment interval, and age were extracted from the database for all asymptomatic patients presenting for a routine eye examination. The frequency of patients with significant change and the median assessment interval were determined for different age groups. Results Of 2656 asymptomatic patients, 1078 (41%) patients had spectacle prescription changes, 434 (16%) patients had new critical diagnoses, 809 (31%) patients had new managements, and 1535 (58%) patients had at least one of these (significant change). Median assessment intervals were 2.9 and 2.8 years for age groups 40 to <65 years and 20 to <40 years, respectively, approximately 1.5 years for patients 7 to <20, and between 1 and 1.5 years for patients <7 or >64. Controlling for assessment interval and sex, increasing age was associated with having a significant change (OR = 1.03, 95% CI 1.029–1.037). Similarly, controlling for age and sex, increased assessment interval was associated with having a significant change (OR = 1.06, 95% CI 1.02–1.11). Conclusions In asymptomatic patients, comprehensive routine optometric eye examinations detect a significant number of new eye conditions and/or result in management changes. The number detected increases with age and assessment interval.