Precision and agreement of axial length in paediatric population measured with MYAH and AL-Scan biometers

CLINICAL RELEVANCE

Measuring axial length is key in the field of myopia development and control. Hence, the precision and agreement of commercially available biometers is of vital interest to understand their variability and interchangeability in the paediatric population.

BACKGROUND

Different biometers are available to measure axial length and monitor myopia progression in clinical practice. The purpose of this study was to assess the precision (repeatability and reproducibility) and agreement of the MYAH and AL-Scan biometers in a paediatric population.

METHODS

Three consecutive measurements were performed using MYAH and AL-Scan biometers in each subject by the same operator to test for repeatability. To test for reproducibility, two measurements were performed for each subject by two different observers with a 5-min interval between measurements. To test the agreement, each subject was measured once with each instrument.

RESULTS

A total of 187 subjects, with a mean age of 8.5 ± 0.3 years and mean spherical equivalent refractive error of +0.22 ± 0.77 D participated in the study. For the repeatability study, the within-subject standard deviation was 0.01 mm, and the repeatability limit was 0.04 mm for both instruments, with no statistically significant differences among repeated measures (p = 0.162 for MYAH and p = 0.774 for AL-Scan). For the reproducibility study, the within-subject standard deviation was 0.01 mm and the repeatability limit was 0.04 mm. There were statistically significant differences for the repeated measures for the AL-Scan (p = 0.002) but not for the MYAH (p = 0.643). Regarding the agreement between both instruments, the 95% limit of agreement ranged from -0.04 to 0.05 mm, and the differences were statistically significant (p = 0.021).

CONCLUSIONS

The repeatability, reproducibility, and agreement of the MYAH and AL-Scan biometers seem optimal for following children with myopia.

Children's visual impairment and visual care related to socioeconomic status in Catalonia (Spain)

BACKGROUND

The objective of this study is to assess the prevalence of visual impairment and visual care practices and its association with socioeconomic conditions in the infant population in Catalonia.

METHODS

The Catalan Institute of Statistics provided a random sample of 0 to 14-year-old non-institutionalized children whose parents were interviewed in a continuous health survey from 2011 to 2015 in Catalonia. A multistage stratified and random sampling procedure considering age, sex, county and town was followed. All results have been weighted according to the sample design and are presented as the proportion of the condition with its 95% confidence limits. Chi-square tests were performed to evaluate the association between categorical variables. To study the association of visual care with independent variables, a multiple logistic regression model was used.

RESULTS

In 0 to 14-year-old children, a 12.9% (95% confidence interval [CI] [11.8-13.9]) prevalence of correctable visual impairment was observed. The prevalence of non-correctable visual impairment was 0.9% (95% CI [0.6-1.2]). Non-correctable visual impairment was more prevalent in families with lower education levels, manual professions or unemployed. Of children without visual impairment, 13,5% (95% CI:12.3-14.6) visited a visual care professional in the last 12 months while this proportion was 67.4% (95% CI [63.3-71.5]) among those with correctable visual impairment. When parents have a university degree or non-manual professions, a higher level of visual care was observed. In children with correctable visual impairment, visual reviews were more frequent when parents are employed in a non-manual profession.

CONCLUSIONS

For the first time, indicators related to visual impairment in children in Catalonia have been recorded. There is an association between lower socioeconomic status and having non-correctable visual impairment, and conversely, having correctable visual impairment was significantly associated with employed parents. More visual care is associated with higher socioeconomic status.

Why are there gender inequalities in visual impairment?

BACKGROUND

In high-income countries, the prevalence of blindness and visual impairment is higher among women, regardless of age although the mechanisms that produce these gender inequalities are not well understood. The objectives of this study were to analyse gender inequalities in the prevalence of blindness and visual impairment, age of onset, diagnosed and undiagnosed status and related eye diseases among visually impaired individuals.

METHODS

Data were obtained from the 2008 Spanish Survey on 'Disability, Personal Autonomy and Dependency Situations' (n = 213 626) participants 360 blind (160 men and 200 women), and 5560 with some visual impairment (2025 men and 3535 women). The prevalence of blindness and visual impairment, age of onset of visual impairment and diagnosed and undiagnosed eye diseases was calculated. Hierarchical multiple logistic regression models were fit to test gender differences.

RESULTS

Women were more likely to report visual impairment (crude OR = 1.6 [95% CI: 1.56-1.74]). Prevalence of diagnosed cataract was higher among visually impaired women (crude OR = 1.4 [95% CI: 1.25-1.67]) whereas undiagnosed eye disease (crude OR = 0.7 [95% CI: 0.64-0.81]) or diagnosed glaucoma (aORsex = 0.8 [95% CI: 0.65-0.93]) were more frequent among visually impairment men. These associations were not explained by age or educational level.

CONCLUSIONS

Strong gender inequalities were observed, with a higher prevalence of visual impairment and related cataracts among women, which could be related to gender inequalities in access to health care, and undiagnosed eye disease and related glaucoma among men, which could be related to their gender socialization resulting in less frequent and effectively use of health care services.

Prevalence of visual impairment in El Salvador: inequalities in educational level and occupational status

OBJECTIVE

To examine the prevalence of blindness, visual impairment, and related eye diseases and conditions among adults in El Salvador, and to explore socioeconomic inequalities in their prevalence by education level and occupational status, stratified by sex.

METHODS

Based upon the Rapid Assessment of Avoidable Blindness (RAAB) methodology, this nationwide sample comprised 3 800 participants (3 399 examined) ≥ 50 years old from 76 randomly selected clusters of 50 persons each. The prevalence of blindness, visual impairment and related eye diseases and conditions, including uncorrected refractive error (URE), was calculated for categories of education level and occupational status. Multiple logistic regression models were fitted to calculate odds ratios (ORs) and 95% confidence intervals (CIs) and stratified by sex.

RESULTS

Age-adjusted prevalence was 2.4% (95% CI: 2.2-2.6) for blindness (men: 2.8% (95% CI: 2.5-3.1); women: 2.2% (95% CI: 1.9-2.5)) and 11.8% (95% CI: 11.6-12.0) for moderate visual impairment (men: 10.8% (95% CI: 10.5-11.1); women: 12.6% (95% CI: 12.4-12.8)). The proportion of visual impairment due to cataract was 43.8% in men and 33.5% in women. Inverse gradients of socioeconomic inequalities were observed in the prevalence of visual impairment. For example, the age-adjusted OR (AOR) was 3.4 (95% CI: 2.0-6.4) for visual impairment and 4.3 (95% CI: 2.1-10.4) for related URE in illiterate women compared to those with secondary education, and 1.9 (95% CI: 1.1-3.1) in cataract in unemployed men.

CONCLUSIONS

Blindness and visual impairment prevalence is high in the El Salvador adult population. The main associated conditions are cataract and URE, two treatable conditions. As socioeconomic and gender inequalities in ocular health may herald discrimination and important barriers to accessing affordable, good-quality, and timely health care services, prioritization of public eye health care and disability policies should be put in place, particularly among women, the unemployed, and uneducated people.

Visual impairment and blindness in spanish adults: geographic inequalities are not explained by age or education

OBJECTIVES

The objectives of this study were to examine for the first time the prevalence of visual impairment and blindness among adults in Spain, to explore regional differences, and to assess whether they may vary as a function of sex or be explained by age and individual or regional socioeconomic position.

DESIGN

Data were obtained from the 2008 Spanish Survey on Disability, Personal Autonomy, and Dependency Situations, a cross-sectional survey based on a representative sample of the noninstitutionalized population of Spain.

PARTICIPANTS

The sample was composed of 213 626 participants aged ≥15 years (103 093 men and 110 533 women); 360 were blind (160 men and 200 women), 4048 had near visual impairment (1397 men and 2651 women), and 4034 had distance visual impairment (1445 men and 2589 women).

METHODS

The prevalence of near and distance visual impairment was calculated for each region. Multiple logistic regression models were fitted to calculate odds ratios and 95% confidence intervals. All analyses were stratified by sex.

MAIN OUTCOME MEASURES

Visual impairment was based on 3 questions aimed at identifying blindness and near and distance visual impairment.

RESULTS

The prevalence (percentage) of blindness was 0.17 (men, 0.16; women, 0.18): 1.89 for near visual impairment (men, 1.36; women, 2.40), 1.89 for distance visual impairment (men, 1.40; women, 2.34), and 2.43 for any visual impairment (men, 1.81; women, 3.02). Regional inequalities in the prevalence of visual impairment were observed, correlated with regional income, and the prevalence was consistently higher among women than men. The magnitude of the inequalities remained after adjusting for age and educational level, and a north-to-south pattern of increasing prevalence was observed.

CONCLUSIONS

Regional and sex inequalities in the prevalence of visual impairment and blindness were observed in Spain, with a north-to-south gradient of increasing prevalence that was not explained by age or individual educational level but was correlated with regional level of economic development. Factors that could be prioritized for future policies and research include differential regional economic development, rural environment, quality of eye care services, diabetes, ultraviolet light exposure, or gender inequalities in diagnostic and therapeutic health care.

[Vision problems causing and not causing visual impairment in a working population of Catalonia]

OBJECTIVES

To analyze the distribution of visual problems which cause and do not cause visual impairment in a working population, and their relation to social class.

METHODS

This was a cross-sectional study of 86,831 employed workers (59,397 men, and 27,421 women) in Catalonia ages 16 to 65 years who, in 2009, underwent health surveillance exams at the Asepeyo Health Prevention. The prevalence of visual problems that cause and do not cause visual impairment was calculated by age, sex and occupational social class, and associations were analyzed using logistic regression.

RESULTS

2.2% (95% CI 2.1-2.3) of the active working population studied had vision problems that cause visual impairment, even while wearing corrective lenses. After adjusting for age, workers in Class V show a 2.4-fold greater risk of visual impairment than those in Class I.

CONCLUSIONS

Women, older workers and disadvantaged social groups showed the highest prevalence and risk of visual impairment. Conversely, problems resolved by vision correction that do not cause visual impairment are concentrated in non-manual workers.

[Prevalence and burden of visual impairment in Catalonia, Spain]

The aim of this work is to determine the prevalence of visual impairment in Catalonia and analyze inequalities in vision. Cross sectional study in the population having ≥ 15 years of age (7,881 men and 8,045 women) based on data from the Encuesta de Salud de Cataluña 2006. Logistic regression models were used to calculate the adjusted odds ratio by age, civil state, level of studies, income and working situation with a confidence interval (CI) of 95%. A 4.7% (CI 95% 4.4-5.0) of the population of Catalonia, a 5.3% of female (CI 95% 4.8-5.8), and 4.1% of men (CI 95% 3.7-4.5) state that they have poor vision. The most unfavourable situations of self-reported poor vision by the Catalan population correspond to the elderly and women with lower levels of both studies and income.

Postoperative contamination after using vancomycin and gentamicin during phacoemulsification

OBJECTIVE

To investigate if the addition of vancomycin and gentamicin to the irrigating solutions during phacoemulsification with lens implantation reduces the incidence of positive postoperative intraocular cultures.

DESIGN

Two-part double-masked, placebo-controlled, randomized clinical trial.

PATIENTS

In the preliminary study, intracameral antibiotic concentrations were measured immediately after surgery (in 10 eyes) and 2 hours after surgery (in 10 eyes) in patients treated with antibiotics. In the primary study, 120 eyes underwent uncomplicated surgery. The treatment group and the placebo group were composed of 60 eyes each.

INTERVENTION

The treatment group received vancomycin, 20 micrograms/mL, and gentamicin, 8 micrograms/mL, in the irrigating fluid. The placebo group received only irrigating fluid. All patients in the primary study underwent anterior chamber aspiration following surgery, and culturing was performed 2 hours later.

MAIN OUTCOME MEASURE

Identification and quantification of positive cultures in thioglycolate broth and chocolate agar.

RESULTS

In the preliminary study, the half-life of both intraocular antibiotics was less than 2 hours. In the primary study, intraocular aspirates yielded positive cultures in 3 specimens (5.0%) in the antibiotic-treated group and in 7 specimens (12.0%) in the placebo group.

CONCLUSIONS

Although we found a higher rate of positive postoperative cultures in the placebo group (odds ratio = 2.51), 2 hours of contact between the antibiotic solution and bacteria did not produce results that reached statistical significance (P =.18) to support adding vancomycin and gentamicin to the irrigating solutions during phacoemulsification. Further studies are needed to evaluate the clinical implications of using antibiotics in irrigating solutions.