An Optimal Measurement of Fixation Disparity Using Ogle’s Apparatus

ABSTRACT

Purpose: Fixation disparity (FD) is a small misalignment of the eyes within the normal alignment when viewing under binocular condition. Ogle’s apparatus measures FD. Standards of procedures vary, which may lead to different outcomes.

Methods: Students with normal ocular alignment, stereopsis ≤60 seconds of arc and visual acuity <0.1 logMAR, were included in this prospective comparative study. Four procedures (P1-P4) of measuring FD with Ogle’s apparatus were performed with divergent placement of the line (P1 and P3), or the line moving from subjective zero (P1 and P2: prisms of ascending strength; P3 and P4: prisms alternating base in base out; combined and P4). Differences in the FD curve were determined by looking at point zero, motor fusion amplitude, and the degree of FD.

Results: Twenty-six participants were examined by these 4 procedures. Point zero showed a significant difference between P1-P2 (P=0.006) and P3-P4 (P=0.001). P1 and P3 indicated the highest point zero: median of -1 and -1.5 minutes of arc exodisparity. Motor fusion amplitude showed a significant difference between P1-P2 (P=0.037), P1-P3 (P=0.004), and P2-P4 (P=0.002). P1 revealed the highest motor fusion amplitude (median of 34Δ) and P4 the lowest amplitude (median of 28Δ). No significant differences were found in esodisparity. In exodisparity there was a significant difference comparing P1-P2 (P=0.000), P3-P4 (P=0.000), and P1-P3 (P=0.021). P1 gave the highest exodisparity (median 22 minutes of arc) and P4 the lowest (median 10 minutes of arc).

Conclusion: Clinically relevant differences were found in exodisparity, mainly caused by difference in line shifting. Exodisparity was significantly lower, moving the line from subjective zero. The most accurate procedure is using prisms of ascending strength combined with divergent placement of the line (P1). These findings standardize a reliable procedure of measuring the FD curve for clinical use. Patients will not be misdiagnosed with reduced FD.     

Depressive symptoms as risk factor of cardiovascular mortality in older European men: the Finland, Italy and Netherlands Elderly (FINE) study.

BACKGROUND: Depressive symptoms have been suggested to increase the risk of cardiovascular diseases, but this may reflect reversed causality. We investigated to what extent depressive symptoms are a true risk factor for cardiovascular mortality in elderly men. DESIGN: The Finland, Italy and Netherlands Elderly (FINE) study is a prospective cohort study conducted in Finland, Italy and The Netherlands. METHODS: Depressive symptoms were measured with the Zung self-rating Depression Scale in 799 elderly men, aged 70-90 years, free from cardiovascular diseases. Using Cox models, hazard ratios (HRs) were calculated for specific cardiovascular mortality endpoints. The analyses were adjusted for potential confounders, stratified on country and repeated after exclusion of men who died from cardiovascular diseases up to 5 years after baseline. RESULTS: During 10-years of follow-up 224 (28%) men died from cardiovascular diseases. The adjusted hazard for a five-point increase in depressive symptoms was 1.15 [95% confidence interval (CI) 1.08-1.23] for cardiovascular mortality. This risk was stronger for mortality from stroke (HR 1.35; 95% CI 1.19-1.53) and heart failure (HR 1.16; 95% CI 1.00-1.35) in comparison with mortality from coronary heart disease (HR 1.08; 95% CI 0.97-1.20) and other degenerative heart diseases (HR 1.06; 95% CI 0.91-1.23). Exclusion of men who died from cardiovascular diseases within 5 years after baseline did not change the strength of the associations. There were no significant differences in HRs between northern and southern Europe. CONCLUSIONS: This study provides further and more convincing prospective evidence for depressive symptoms as a risk factor for cardiovascular mortality in elderly men.     

The dystrophin gene and cognitive function in the general population

The aim of our study is to investigate whether single-nucleotide dystrophin gene (DMD) variants associate with variability in cognitive functions in healthy populations. The study included 1240 participants from the Erasmus Rucphen family (ERF) study and 1464 individuals from the Rotterdam Study (RS). The participants whose exomes were sequenced and who were assessed for various cognitive traits were included in the analysis. To determine the association between DMD variants and cognitive ability, linear (mixed) modeling with adjustment for age, sex and education was used. Moreover, Sequence Kernel Association Test (SKAT) was used to test the overall association of the rare genetic variants present in the DMD with cognitive traits. Although no DMD variant surpassed the prespecified significance threshold (P<1 × 10⁻⁴), rs147546024:A>G showed strong association (β=1.786, P-value=2.56 × 10⁻⁴) with block-design test in the ERF study, while another variant rs1800273:G>A showed suggestive association (β=−0.465, P-value=0.002) with Mini-Mental State Examination test in the RS. Both variants are highly conserved, although rs147546024:A>G is an intronic variant, whereas rs1800273:G>A is a missense variant in the DMD which has a predicted damaging effect on the protein. Further gene-based analysis of DMD revealed suggestive association (P-values=0.087 and 0.074) with general cognitive ability in both cohorts. In conclusion, both single variant and gene-based analyses suggest the existence of variants in the DMD which may affect cognitive functioning in the general populations.     

Glucose tolerance,insulin sensitivity,and insulin secretion in children born small for gestational age

Intrauterine growth retardation is associated with an increased risk of developing adult diseases, such as noninsulin-dependent diabetes mellitus (NIDDM). NIDDM could result from a decreased insulin sensitivity or a reduced insulin secretion or a combination of both. Glucose tolerance, insulin sensitivity, and insulin secretion were studied in prepubertal children born small for gestational age (SGA). Twenty-nine SGA children with a mean age of 9.1 +/- 1.1 yr and 24 children born appropriate for gestational age (AGA), with a mean age of 9.0 +/- 1.1 yr, were studied. All children were born at term and were prepubertal. Children were studied on two separate days after 12 h of overnight fasting. Day 1: Glucose tolerance was studied with an oral glucose tolerance test. AUC(ins0-120 min)/AUC(gluc0-120 min) was used to estimate beta-cell function in the two groups. Day 2: A hyperinsulinemic euglycemic clamp study was performed to determine insulin sensitivity (M-value). Glucose tolerance and beta-cell function were not different between the two groups. M-value in SGA children was significantly lower than M-value in AGA children: 12.9 +/- 4.0 mg/kg.min vs. 15.6 +/- 2.3 mg/kg.min [P = 0.009; after adjustment for appropriate gestational age body mass index (BMI), P = 0.001]. The M-value tended to be higher in SGA children without catch-up growth compared with SGA children with catch-up growth (15.8 +/- 4.3 vs. 12.3 +/- 3.8 mg/kg.min; P = 0.079) and was comparable to AGA controls (15.6 +/- 2.3 mg/kg.min). The M-value in SGA children who had shown catch-up growth was comparable to AGA children (13.4 +/- 3.4 vs. 15.6 +/- 2.3 mg/kg.min; P = 0.06), provided they had a BMI of 17 kg/m(2) or less. However, the SGA children with catch-up growth and a BMI greater than 17 kg/m(2) were those having the lowest M-values (9.3 +/- 3.4 mg/kg.min). In conclusion, during oral glucose tolerance tests, no differences were found in glucose tolerance and beta-cell function between the SGA and AGA groups. However, the hyperinsulinemic clamp showed a reduced insulin sensitivity in SGA children, which may contribute to the enhanced risk of developing NIDDM in adult life, especially in SGA children with catch-up growth and a high BMI. The implications of our findings in relation to height are unclear, but might be of potential importance when considering GH treatment. In addition, interventions to improve fetal growth and to control obesity in childhood seem to be important factors in the prevention of NIDDM.     

Quality of Self-Care of Patients with Asthma

In order to assess the quality of self-care of asthmatic patients in family practice, 150 patients were asked what they did when they felt an attack of asthma coming on. Twenty-four percent said they took no medication. Of the remaining 114 patients, only 49 took appropriate medication. Of these, however, most were not able to demonstrate correct use of their inhaler. This poor quality of self-care may contribute to the undertreatment of asthma in family practice. To improve the quality of care of asthmatic patients, comprehensive treatment is recommended, with the emphasis on improving self-care skills.     

Enhancing Syndromic Surveillance With Online Respondent-Driven Detection

Objectives. We investigated the feasibility of combining an online chain recruitment method (respondent-driven detection) and participatory surveillance panels to collect previously undetected information on infectious diseases via social networks of participants.Methods. In 2014, volunteers from 2 large panels in the Netherlands were invited to complete a survey focusing on symptoms of upper respiratory tract infections and to invite 4 individuals they had met in the preceding 2 weeks to take part in the study. We compared sociodemographic characteristics among panel participants, individuals who volunteered for our survey, and individuals recruited via respondent-driven detection.Results. Starting from 1015 panel members, the survey spread through all provinces of the Netherlands and all age groups in 83 days. A total of 433 individuals completed the survey via peer recruitment. Participants who reported symptoms were 6.1% (95% confidence interval = 5.4, 6.9) more likely to invite contact persons than were participants who did not report symptoms. Participants with symptoms invited more symptomatic recruits to take part than did participants without symptoms.Conclusions. Our findings suggest that online respondent-driven detection can enhance identification of symptomatic patients by making use of individuals’ local social networks.Syndromic surveillance provides information necessary to monitor trends in disease incidence and implement and evaluate response plans.1,2 To date, most efforts have focused on developing systems based on data from inpatient and ambulatory care health records.3 In a majority of high-income countries, including the Netherlands, influenza surveillance is based on a combination of reports of influenza-like illness (ILI) collected by sentinel surveillance clinics and additional microbiological testing of subgroups of symptomatic patients.4 This type of system excludes symptomatic patients who do not visit a general practitioner, and such patients are likely to account for the majority of cases in most influenza outbreaks.5Many communicable diseases (e.g., influenza, severe acute respiratory syndrome, measles) spread largely between socially connected individuals, such as household members and schoolchildren, and they often occur in clusters.6,7 Therefore, cases of infection are expected to cluster in social networks (i.e., contacts of an infected individual are infected at a level of probability higher than that expected if the distribution was random), and clusters can be detected via local social networks of individuals reporting symptoms.Increased Internet use facilitated the emergence of participatory surveillance (PS) systems, which enable real-time monitoring of diseases through regular submission of syndromic information by volunteers.8,9 These systems provide information that is not collected in regular surveillance, such as the proportion of symptomatic individuals who actually visit a general practitioner and the proportion who are hospitalized.To test the feasibility of eliciting information about infections in local networks of symptomatic individuals, we combined a chain recruitment method with existing online PS platforms. Under certain conditions, such a recruitment method permits stepwise and controlled sampling of contacts of contacts, and so forth, in social networks in the general population.10 We asked PS volunteers to complete a questionnaire and to invite their contacts into the study. In this way, we collected data on chains of contacts to analyze whether other symptomatic individuals could be detected via the local social network of symptomatic respondents. Our aims were to determine whether respondents can be recruited via respondent-driven detection, to report on which individuals are reached, and to assess whether there is clustering of symptomatic patients.