The effect of multifocal contact lenses on the dynamic accommodation step response.

PURPOSE: To measure the dynamic accommodation response (AR) to step stimuli with and without multifocal contact lenses (MFCLs), in emmetropes and myopes. METHODS: Twenty-two adult subjects viewed alternating distance (0.25D) and near (3D) Maltese crosses placed in free space, through two contact lens types: single vision (SVCL) or centre-distance multifocal (MFCL; +2.50D add). The AR level was measured along with near to far (N-F) and far to near (F-N) step response characteristics: percentage of correct responses, magnitude, latency, peak velocity and duration of step response. RESULTS: There was no difference between N-F and F-N responses, or between refractive groups in any aspect of the accommodation step response dynamics. The percentage of correct responses was unaffected by contact lens type. Through MFCLs, subjects demonstrated smaller magnitude, longer latency, shorter duration and slower peak velocity steps than through SVCLs. When viewing the near target, the AR through MFCLs was significantly lower than through SVCLs. When viewing the distance target with the MFCL, the focal points from rays travelling through the distance and near zones were approximately 0.004D behind and 2.50D in front of the retina, respectively. When viewing the near target, the respective values were approximately 1.89D behind and 0.61D in front of the retina. CONCLUSION: The defocus error required for accommodation control appears not to be solely derived from the distance zone of the MFCL. This results in reduced performance in response to abruptly changing vergence stimuli; however, these errors were small and unlikely to impact everyday visual tasks. There was a decrease in ocular accommodation during near tasks, which has previously been correlated with a reduced myopic treatment response through these lenses. With MFCLs, the estimated dioptric myopic defocus was the largest when viewing a distant stimulus, supporting the hypothesis that the outdoors provides a beneficial visual environment to reduce myopia progression.

Speed and accuracy of saccades in patients with glaucoma evaluated using an eye tracking perimeter.

BACKGROUND: To examine the speed and accuracy of saccadic eye movements during a novel eye tracking threshold visual field assessment and determine whether eye movement parameters may improve ability to detect glaucoma. METHODS: A prospective study including both eyes of 31 patients with glaucoma and 23 controls. Standard automated perimetry (SAP) and eye tracking perimetry (saccadic vector optokinetic perimetry, SVOP) was performed. SVOP provided data on threshold sensitivity, saccade latency, and two measures of accuracy of saccades (direction bias and amplitude bias). The relationship between eye movement parameters and severity of glaucoma was examined and Receiver Operating Characteristic curves were used to assess ability to detect glaucoma. RESULTS: Patients with glaucoma had significantly slower saccades (602.9 ± 50.0 ms versus 578.3 ± 44.6 ms for controls, P = 0.009) and reduced saccade accuracy (direction bias = 7.4 ± 1.8 versus 6.5 ± 1.5 degrees, P = 0.006). There was a significant slowing of saccades and saccades became less accurate with worsening SAP sensitivity. Slower saccades were associated with increased odds of glaucoma; however, the AUC for saccade latency was only 0.635 compared to 0.914 for SVOP sensitivity. CONCLUSION: Patients with glaucoma had significant differences in eye movements compared to healthy subjects, with a relationship between slower and less accurate eye movements and worse glaucoma severity. However, in a multivariable model, eye movement parameters were not of additional benefit in differentiating eyes with glaucoma from healthy controls.

Assessing the magnitude and uncertainties of the burden of selected diseases attributable to extreme heat and extreme precipitation under a climate change scenario in Michigan for the period 2041-2070.

BACKGROUND: Extreme heat (EH) and extreme precipitation (EP) events are expected to increase with climate change in many parts of the world. Characterizing the potential future morbidity and mortality burden of EH and EP and associated costs, as well as uncertainties in the estimates, can identify areas for public health intervention and inform adaptation strategies. We demonstrate a burden of disease and uncertainty assessment using data from Michigan, USA, and provide approaches for deriving these estimates for locations lacking certain data inputs. METHODS: Case-crossover analysis adapted from previous Michigan-specific modeling was used to characterize the historical EH-mortality relationship by county poverty rate and age group. Historical EH-associated hospitalization and emergency room visit risks from the literature were adapted to Michigan. In the U.S. Environmental Protection Agency's BenMAP software, we used a novel approach, with multiple spatially-varying exposures, to estimate all non-accidental mortality and morbidity occurring on EH days (EH days; days where maximum temperature 32.2-35 C or > 35 C) and EP days. We did so for two time periods: the "historical" period (1971-2000), and the "projected" period (2041-2070), by county. RESULTS: The rate of all non-accidental mortality associated with EH days increased from 0.46/100,000 persons historically to 2.9/100,000 in the projected period, for 240 EH-attributable deaths annually. EH-associated ED visits increased from 12/100,000 persons to 68/100,000 persons, for 7800 EH-attributable emergency department visits. EP-associated ED visits increased minimally from 1.7 to 1.9/100,000 persons. Mortality and morbidity were highest among those aged 65+ (91% of all deaths). Projected health costs are dominated by EH-associated mortality ($280 million) and EH-associated emergency department visits ($14 million). A variety of sources contribute to a moderate-to-high degree of uncertainty around the point estimates, including uncertainty in the magnitude of climate change, population composition, baseline health rates, and exposure-response estimates. CONCLUSIONS: The approach applied here showed that health burden due to climate may significantly rise for all Michigan counties by midcentury. The costs to health care and uncertainties in the estimates, given the potential for substantial attributable burden, provide additional information to guide adaptation measures for EH and EP.

Vulnerability to extreme-heat-associated hospitalization in three counties in Michigan, USA, 2000-2009.

With climate change, extreme heat (EH) events are increasing, so it is important to understand who is vulnerable to heat-associated morbidity. We determined the association between EH and hospitalizations for all natural causes; cardiovascular, respiratory, and renal diseases; diabetes mellitus; and acute myocardial infarction in Michigan, USA, at different intensities and durations. We assessed confounding by ozone and how individual characteristics and health insurance payer (a proxy for income) modified these associations. We obtained Michigan Inpatient Database, National Climatic Data Center, and US Environmental Protection Agency ozone data for May-September, 2000-2009 for three Michigan counties. We employed a case-crossover design and modeled EH as an indicator for temperature above the 95th, 97th, or 99th percentile thresholds for 1, 2, 3, or 4 days. We examined effect modification by patient age, race, sex, and health insurance payer and pooled the county results. Among non-whites, the pooled odds ratio for hospitalization on EH (97th percentile threshold) vs. non-EH days for renal diseases was 1.37 (95 % CI = 1.13-1.66), which increased with increasing EH intensity, but was null among whites (OR = 1.00, 95 % CI = 0.81, 1.25). We observed a null association between EH and cardiovascular hospitalization. EH (99th percentile threshold) was associated with myocardial infarction hospitalizations. Confounding by ozone was minimal. EH was associated with hospitalizations for renal disease among non-whites. This information on vulnerability to heat-associated morbidity helps characterize the public health burden of EH and target interventions including patient education.

Breast cancer among women in Michigan following exposure to brominated flame retardants.

In this updated follow-up, we investigated the breast cancer experience among women in Michigan exposed to brominated flame retardants, some 30 years following exposure. Michigan residents were enrolled in a study cohort after exposure to polybrominated biphenyls (PBBs) through the consumption of contaminated food products. PBB concentrations were measured in serum at the time of enrolment. Cancer experience was determined by linkage to the Michigan Cancer Registry. We conducted a nested case-control study that included 51 women diagnosed with breast cancer during 1974-2004 and 202 age-matched controls. While the data suggest an increase in breast cancer risk with higher PBB exposure, this did not reach statistical significance. The OR of having breast cancer among women with PBB concentrations ≥10 ng/mL compared to women with PBB concentrations at or below the limit of detection of 1 ng/mL was 2.60, 95% CI 0.93 to 7.27, (p=0.07), when adjusted for age and family history of cancer in a first-degree female relative. It remains important to examine exposure to brominated chemicals and possible health effects, and to continue following the cancer experience of participants in this study.

Assessing perceptions and priorities for health impacts of climate change within local Michigan health departments.

Climate change affects Michigan's public health in several primary ways, including increased incidences of vector-borne, waterborne, heat-related, and respiratory illness. Because local health departments (LHDs) play a central role in surveillance and preventative health services, they are among the first institutions to contend with the local impacts of climate change. To assess current perceptions among Michigan public health officials, an online survey was conducted in partnership with the Michigan Association for Local Public Health (MALPH). Most of the Michigan respondents (62%, n = 34) agreed that their jurisdictions have experienced climate change in the last 20 years, and 77% agreed that climate change will impact their jurisdictions in the coming 20 years. However, only 35% (n = 34) of Michigan officials agreed that climate change is a priority in their departments. About one quarter (25%, n = 34) of Michigan LHD respondents did not know about the level of expertise of either the state and federal agencies, responsible for assisting them with information and programs related to climate change and health. Uncertainty regarding the resources available to them may hinder LHDs from developing necessary preparedness, so meeting this need could bolster the public health response to climate change. Supplementary Information: The online version contains supplementary material available at 10.1007/s13412-021-00679-0.

A case control study examining the feasibility of using eye tracking perimetry to differentiate patients with glaucoma from healthy controls.

To explore the feasibility of using Saccadic Vector Optokinetic Perimetry (SVOP) to differentiate glaucomatous and healthy eyes. A prospective case-control study was performed using a convenience sample recruited from a single university glaucoma clinic and a group of healthy controls. SVOP and standard automated perimetry (SAP) was performed with testing order randomised. The reference standard was a diagnosis of glaucoma based a comprehensive ophthalmic examination and abnormality on standard automated perimetry (SAP). The index test was SVOP. 31 patients with glaucoma and 24 healthy subjects were included. Mean SAP mean deviation (MD) in those with glaucoma was - 8.7 ± 7.4 dB, with mean SAP and SVOP sensitivities of 23.3 ± 0.9 dB and 22.1 ± 4.3 dB respectively. Participants with glaucoma were significantly older. On average, SAP sensitivity was 1.2 ± 1.4 dB higher than SVOP (95% limits of agreement = - 1.6 to 4.0 dB). SVOP sensitivity had good ability to differentiate healthy and glaucomatous eyes with a 95% CI for area under the curve (AUC) of 0.84 to 0.96, similar to the performance of SAP sensitivity (95% CI 0.86 to 0.97, P = 0.60). For 80% specificity, SVOP had a 95% CI sensitivity of 75.7% to 94.8% compared to 77.8% to 96.0% for SAP. SVOP took considerably longer to perform (514 ± 54 s compared to 267 ± 76 s for SAP). Eye tracking perimetry may be useful for detection of glaucoma but further studies are needed to evaluate SVOP within its intended sphere of use, using an appropriate design and independent reference standard.

The Assessment of Visual Fields in Infants Using Saccadic Vector Optokinetic Perimetry (SVOP): A Feasibility Study.

Purpose: To examine the feasibility of saccadic vector optokinetic perimetry (SVOP), an automated eye tracking perimeter, as a tool for visual field (VF) assessment in infants. Methods: Thirteen healthy infants aged between 3.5 and 12.0 months were tested binocularly using an adapted SVOP protocol. SVOP uses eye tracking technology to measure gaze responses to stimuli presented on a computer screen. Modifications of SVOP for testing infants included adjusting the fixation target to display a short animation, increasing the stimulus size to equivalent to Goldmann V, and introducing a tiered test pattern strategy. Binocular, single-quadrant confrontation VF testing and Keeler preferential looking cards visual acuity testing was also performed. Results: Using multiple test attempts when required, all but the youngest infant (12 of 13 [92.3%]) successfully completed a 4-point screening test. Seven infants (53.8%) successfully completed the 12-point test, four (30.8%) successfully completed the 20-point test, and three (23.1%) successfully completed the 40-point test. The effect of multiple test attempts and the complexity of the test pattern (number of test points) on performance was investigated, including test completion rate, percentage of correctly seen stimuli, and average time per tested stimulus. Conclusions: The modified SVOP test strategy allowed successful assessment of binocular VFs in healthy infants. Future data collection from larger cohorts of infants is needed to derive normative limits of detection and assess accuracy in detecting and monitoring infant VF abnormalities. Translational Relevance: Eye tracking perimetry may provide a useful method of automated VF assessment in infants.

Development of an Age-corrected Normative Database for Saccadic Vector Optokinetic Perimetry (SVOP).

PRECIS: Normal age-corrected threshold sensitivity values were determined for a new eye tracking perimeter and compared with standard automated perimetry (SAP). PURPOSE: The purpose of this study was to determine threshold visual field sensitivities in normal subjects performing saccadic vector optokinetic perimetry (SVOP), a new eye tracking perimeter. PATIENTS AND METHODS: A total of 113 healthy participants performed SVOP and SAP in both eyes with the order of testing randomized. The relationship between SAP and SVOP sensitivity was examined using Bland-Altman plots and 95% limits of agreement. The relationship between sensitivity and age was examined by pointwise linear regression and age-corrected normal threshold sensitivities were calculated. RESULTS: After excluding unreliable tests, 97 participants with a mean age of 65.9±10.1 years were included. Average SAP mean deviation was -0.87±1.56 dB, SAP sensitivity was 29.20±1.68 dB and SVOP sensitivity was 32.18±1.96 dB. SVOP had a longer test duration (431±110 compared with 307±42 seconds for SAP, P<0.001). On average, the mean sensitivity obtained using SVOP was 2.98 dB higher than average SAP sensitivity, with 95% limits of agreement of -0.11 to 6.15 dB. For each decade older, SAP sensitivity decreased by 0.93 dB (95% confidence interval: 1.21 to 0.64) and SVOP sensitivity decreased by 1.15 dB (95% confidence interval: 1.47 to 0.84). CONCLUSIONS: The results provide age-corrected normative values for threshold sensitivities from SVOP. Overall, SVOP provided a similar shaped hill of vision as SAP however threshold sensitivities were higher, meaning results are not interchangeable.

Time series analysis of total and direct associations between high temperatures and preterm births in Detroit, Michigan.

OBJECTIVES: Preterm births (PTBs) represent significant health risks, and several studies have found associations between high outdoor temperatures and PTB. We estimated both the total and natural direct effects (independent of particulate matter, ozone and nitrogen dioxide air pollutants) of the prior 2-day mean apparent temperature (AT) on PTB. We evaluated effect modification by maternal age, race, education, smoking status and prenatal care. DESIGN AND SETTING: We obtained birth records and meteorological data for the Detroit, Michigan, USA area, for the warm months (May to September), 1991 to 2001. We used a time series Poisson regression with splines of AT, wind speed, solar radiation and citywide average precipitation to estimate total effects. To accommodate multiple mediators and exposure-mediator interactions, AT inverse odds weights, predicted by meteorological and air pollutant covariates, were added in a subsequent model to estimate direct effects. RESULTS: At 24.9°C relative to 18.6°C, 10.6% (95% CI: 3.8% to 17.2%) of PTBs were attributable to the total effects of AT, and 10.4% (95% CI: 2.2% to 17.5%) to direct effects. Relative excess risks of interaction indicated that the risk of PTB with increasing temperature above 18.6°C was significantly lower among black mothers and higher among mothers less than 19, older than 30, with late or no prenatal care and who smoked. CONCLUSION: This additional evidence of a direct association between high temperature and PTB may motivate public health interventions to reduce extreme heat exposures among pregnant women, particularly among those who may have enhanced vulnerability.

A cohort study of the association between secondary sex ratio and parental exposure to polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB).

BACKGROUND: Polybrominated biphenyl (PBB), a brominated flame retardant, was accidently mixed into animal feed in Michigan (1973-1974) resulting in human exposure through consumption of contaminated meat, milk and eggs. Beginning in 1976 individuals who consumed contaminated products were enrolled in the Michigan Long-Term PBB Study. This cohort presents a unique opportunity to study the association between parental exposures to PBB and offspring sex ratio. METHODS: We identified offspring of female PBB cohort participants (born 1975-1988) and obtained electronic birth records for those born in the state of Michigan. We linked this information to parental serum PBB and PCB concentrations collected at enrollment into the cohort. We modeled the odds of a male birth with generalized estimating equations accounting for the non-independence of siblings born to the same parents. We explored potential confounders: parental age and education at offspring's birth, parental body mass index at cohort enrollment, birth order, gestational age and year of offspring's birth. RESULTS: The overall proportion of male offspring among 865 live births to cohort mothers was 0.542. This was higher than the national male proportion of 0.514 (binomial test: p = 0.10). When both parents were in the cohort (n = 300), we found increased odds of a male birth with combined parents' enrollment PBB exposure > or = the median concentrations (3 microg/L for mothers; 6 microg/L for fathers) compared to combined parents' PBB exposure < the median concentrations (AOR = 1.43, 95% CI: 0.89-2.29), although this did not reach statistical significance. In addition, there was a suggestion of increased odds of a male birth for combined parents' enrollment PCB exposure > or = the median concentrations (6 microg/L for mothers; 8 microg/L for fathers) compared to combined parents' enrollment PCB exposure < the median concentrations (AOR = 1.53, 95% CI: 0.93-2.52). CONCLUSION: This study adds to the body of literature on secondary sex ratio and exposure to environmental contaminants. In this population, combined parental exposure to PBBs or PCBs increased the odds of a male birth. Further research is needed to corroborate these findings and shed light on the biological mechanisms by which these types of chemicals may influence the secondary sex ratio.

Assessing inter-generational transfer of a brominated flame retardant.

Studies have shown that the lipophilic nature of polybrominated biphenyl (PBB) causes it to preferentially accumulate in breast milk posing a potential hazard for suckling infants. The purpose of this study was to examine the inter-generational transfer of PBB from mother to child and whether this association was modified by maternal breast-feeding patterns. One hundred and forty-five mother-child pairs that were participants of the Michigan Long-Term PBB Study were included in this analysis. Mothers were exposed to PBB via contaminated food between 1973 and 1974 and children were exposed in utero and for some, through breast-feeding. Seventy-three percent of children had a non-detectable serum PBB concentration (limit of detection (LOD) = 1 microg L(-1)). Mothers' serum PBB concentration at enrollment ranged from or =8 microg L(-1), breast-feeding > or =5.5 months, maternal age at child's birth > or =28 years, and being born during the PBB exposure period. Among mothers with a detectable serum PBB concentration, those who breast-fed > or =5.5 months were 6 times more likely to have a child with a detectable serum PBB concentration, compared to a non-breast-fed child (95% C.I., 2.0-19.6).

An investigation into the relationships between bullying, discrimination, burnout and patient safety in nurses and midwives: is burnout a mediator?

BACKGROUND: Bullying and discrimination may be indirectly associated with patient safety via their contribution to burnout, but research has yet to establish this. AIMS: The aims of this study were to investigate the relationships between workplace bullying, perceived discrimination, levels of burnout and patient safety perceptions in nurses and midwives and to assess whether bullying and discrimination were more frequently experienced by Black, Asian and minority ethnic than White nurses and midwives. METHODS: In total, 528 nurses and midwives were recruited from four hospitals in the United Kingdom to complete a cross-sectional survey between February and March 2017. The survey included items on bullying, discrimination, burnout and individual level and ward level patient safety perceptions. Data were analysed using path analysis. RESULTS: The results were reported according to the STROBE checklist. Bullying and discrimination were significantly associated with higher burnout. Higher burnout was in turn associated with poorer individual- and ward-level patient safety perceptions. Experiences of discrimination were three times more common among Black, Asian and minority ethnic than White nurses and midwives, but there was no significant difference in experiences of bullying. CONCLUSIONS: Bullying and discrimination are indirectly associated with patient safety perceptions via their influence on burnout. Healthcare organisations seeking to improve patient care should implement strategies to reduce workplace bullying and discrimination.

Climate change and temperature extremes: A review of heat- and cold-related morbidity and mortality concerns of municipalities.

Cold and hot weather are associated with mortality and morbidity. Although the burden of temperature-associated mortality may shift towards high temperatures in the future, cold temperatures may represent a greater current-day problem in temperate cities. Hot and cold temperature vulnerabilities may coincide across several personal and neighborhood characteristics, suggesting opportunities for increasing present and future resilience to extreme temperatures. We present a narrative literature review encompassing the epidemiology of cold- and heat-related mortality and morbidity, related physiologic and environmental mechanisms, and municipal responses to hot and cold weather, illustrated by Detroit, Michigan, USA, a financially burdened city in an economically diverse metropolitan area. The Detroit area experiences sharp increases in mortality and hospitalizations with extreme heat, while cold temperatures are associated with more gradual increases in mortality, with no clear threshold. Interventions such as heating and cooling centers may reduce but not eliminate temperature-associated health problems. Furthermore, direct hemodynamic responses to cold, sudden exertion, poor indoor air quality and respiratory epidemics likely contribute to cold-related mortality. Short- and long-term interventions to enhance energy and housing security and housing quality may reduce temperature-related health problems. Extreme temperatures can increase morbidity and mortality in municipalities like Detroit that experience both extreme heat and prolonged cold seasons amidst large socioeconomic disparities. The similarities in physiologic and built-environment vulnerabilities to both hot and cold weather suggest prioritization of strategies that address both present-day cold and near-future heat concerns.

Detection and characterisation of visual field defects using Saccadic Vector Optokinetic Perimetry in children with brain tumours.

PURPOSE: To determine the ability of Saccadic Vector Optokinetic Perimetry (SVOP) to detect and characterise visual field defects in children with brain tumours using eye-tracking technology, as current techniques for assessment of visual fields in young children can be subjective and lack useful detail. METHODS: Case-series study of children receiving treatment and follow-up for brain tumours at the Royal Hospital for Sick Children in Edinburgh from April 2008 to August 2013. Patients underwent SVOP testing and the results were compared with clinically expected visual field patterns determined by a consensus panel after review of clinical findings, neuroimaging, and where possible other forms of visual field assessment. RESULTS: Sixteen patients participated in this study (mean age of 7.2 years; range 2.9-15 years; 7 male, 9 female). Twelve children (75%) successfully performed SVOP testing. SVOP had a sensitivity of 100% and a specificity of 50% (positive predictive value of 80% and negative predictive value of 100%). In the true positive and true negative SVOP results, the characteristics of the SVOP plots showed agreement with the expected visual field. Six patients were able to perform both SVOP and Goldmann perimetry, these demonstrated similar visual fields in every case. CONCLUSION: SVOP is a highly sensitive test that may prove to be extremely useful for assessing the visual field in young children with brain tumours, as it is able to characterise the central 30° of visual field in greater detail than previously possible with older techniques.

Arsenic in drinking water and cerebrovascular disease, diabetes mellitus, and kidney disease in Michigan: a standardized mortality ratio analysis.

BACKGROUND: Exposure to arsenic concentrations in drinking water in excess of 300 microg/L is associated with diseases of the circulatory and respiratory system, several types of cancer, and diabetes; however, little is known about the health consequences of exposure to low-to-moderate levels of arsenic (10-100 microg/L). METHODS: A standardized mortality ratio (SMR) analysis was conducted in a contiguous six county study area of southeastern Michigan to investigate the relationship between moderate arsenic levels and twenty-three selected disease outcomes. Disease outcomes included several types of cancer, diseases of the circulatory and respiratory system, diabetes mellitus, and kidney and liver diseases. Arsenic data were compiled from 9251 well water samples tested by the Michigan Department of Environmental Quality from 1983 through 2002. Michigan Resident Death Files data were amassed for 1979 through 1997 and sex-specific SMR analyses were conducted with indirect adjustment for age and race; 99% confidence intervals (CI) were reported. RESULTS: The six county study area had a population-weighted mean arsenic concentration of 11.00 microg/L and a population-weighted median of 7.58 microg/L. SMR analyses were conducted for the entire six county study area, for only Genesee County (the most populous and urban county), and for the five counties besides Genesee. Concordance of results across analyses is used to interpret the findings. Elevated mortality rates were observed for both males (M) and females (F) for all diseases of the circulatory system (M SMR, 1.11; CI, 1.09-1.13; F SMR, 1.15; CI, 1.13,-1.17), cerebrovascular diseases (M SMR, 1.19; CI, 1.14-1.25; F SMR, 1.19; CI, 1.15-1.23), diabetes mellitus (M SMR, 1.28; CI, 1.18-1.37; F SMR, 1.27; CI, 1.19-1.35), and kidney diseases (M SMR, 1.28; CI, 1.15-1.42; F SMR, 1.38; CI, 1.25-1.52). CONCLUSION: This is some of the first evidence to suggest that exposure to low-to-moderate levels of arsenic in drinking water may be associated with several of the leading causes of mortality, although further epidemiologic studies are required to confirm the results suggested by this ecologic SMR analysis.

Maternal exposure to polybrominated and polychlorinated biphenyls: infant birth weight and gestational age.

Understanding the influence of maternal exposures on gestational age and birth weight is essential given that pre-term and/or low birth weight infants are at risk for increased mortality and morbidity. We performed a retrospective analysis of a cohort exposed to polybrominated biphenyls (PBB) through accidental contamination of cattle feed and polychlorinated biphenyls (PCB) through residual contamination in the geographic region. Our study population consisted of 444 mothers and their 899 infants born between 1975 and 1997. Using restricted maximum likelihood estimation, no significant association was found between estimated maternal serum PBB at conception or enrollment PCB levels and gestational age or infant birth weight in unadjusted models or in models that adjusted for maternal age, smoking, parity, infant gender, and decade of birth. For enrollment maternal serum PBB, no association was observed for gestational age. However, a negative association with high levels of enrollment maternal serum PBB and birth weight was suggested. We also examined the birth weight and gestational age among offspring of women with the highest (10%) PBB or PCB exposure, and observed no significant association. Because brominated compounds are currently used in consumer products and therefore, are increasingly prevalent in the environment, additional research is needed to better understand the potential relationship between in utero exposure to brominated compounds and adverse health outcomes.

Comparison of Saccadic Vector Optokinetic Perimetry and Standard Automated Perimetry in Glaucoma. Part I: Threshold Values and Repeatability.

PURPOSE: We evaluated threshold saccadic vector optokinetic perimetry (SVOP) and compared results to standard automated perimetry (SAP). METHODS: A cross-sectional study was done including 162 subjects (103 with glaucoma and 59 healthy subjects) recruited at a university hospital. All subjects underwent SAP and threshold SVOP. SVOP uses an eye tracker to monitor eye movement responses to stimuli and determines if stimuli have been perceived based on the vector of the gaze response. The test pattern used was equivalent to SAP 24-2 and stimuli were presented at Goldmann III. Average and pointwise sensitivity values obtained from both tests were compared using Pearson's correlation coefficient. Two versions of SVOP were evaluated. RESULTS: A total of 124 tests were performed with SAP and SVOP version 2. There was excellent agreement between mean threshold values obtained using SVOP and SAP (r = 0.95, P < 0.001). Excluding the blind spot, correlation between SVOP and SAP individual test point sensitivity ranged from 0.61 to 0.90, with 48 of 54 (89%) test points > 0.70. Overall SVOP showed good repeatability with a Pearson correlation of 0.88. The repeatability on a point-by-point basis ranged from 0.66 to 0.98, with 45 of 54 points (83%) > 0.80. Repeatability of SAP was 0.87, ranging from 0.69 to 0.96, with 47 of 54 (87%) points > 0.80. CONCLUSION: Eye-tracking perimetry is repeatable and compares well with the current gold standard of SAP. The technique has advantages over conventional perimetry and could be useful for evaluating glaucomatous visual field loss, particularly in patients who may struggle with conventional perimetry. TRANSLATIONAL RELEVANCE: Suprathreshold SVOP already is in the field. To our knowledge, this is the first report of threshold SVOP and provides a benchmark for future iterations.

Comparison of Threshold Saccadic Vector Optokinetic Perimetry (SVOP) and Standard Automated Perimetry (SAP) in Glaucoma. Part II: Patterns of Visual Field Loss and Acceptability.

PURPOSE: We compared patterns of visual field loss detected by standard automated perimetry (SAP) to saccadic vector optokinetic perimetry (SVOP) and examined patient perceptions of each test. METHODS: A cross-sectional study was done of 58 healthy subjects and 103 with glaucoma who were tested using SAP and two versions of SVOP (v1 and v2). Visual fields from both devices were categorized by masked graders as: 0, normal; 1, paracentral defect; 2, nasal step; 3, arcuate defect; 4, altitudinal; 5, biarcuate; and 6, end-stage field loss. SVOP and SAP classifications were cross-tabulated. Subjects completed a questionnaire on their opinions of each test. RESULTS: We analyzed 142 (v1) and 111 (v2) SVOP and SAP test pairs. SVOP v2 had a sensitivity of 97.7% and specificity of 77.9% for identifying normal versus abnormal visual fields. SAP and SVOP v2 classifications showed complete agreement in 54% of glaucoma patients, with a further 23% disagreeing by one category. On repeat testing, 86% of SVOP v2 classifications agreed with the previous test, compared to 91% of SAP classifications; 71% of subjects preferred SVOP compared to 20% who preferred SAP. CONCLUSIONS: Eye-tracking perimetry can be used to obtain threshold visual field sensitivity values in patients with glaucoma and produce maps of visual field defects, with patterns exhibiting close agreement to SAP. Patients preferred eye-tracking perimetry compared to SAP. TRANSLATIONAL RELEVANCE: This first report of threshold eye tracking perimetry shows good agreement with conventional automated perimetry and provides a benchmark for future iterations.

Feasibility, Accuracy, and Repeatability of Suprathreshold Saccadic Vector Optokinetic Perimetry.

PURPOSE: To evaluate feasibility, accuracy, and repeatability of suprathreshold Saccadic Vector Optokinetic Perimetry (SVOP) by comparison with Humphrey Field Analyzer (HFA) perimetry. METHODS: The subjects included children with suspected field defects (n = 10, age 5-15 years), adults with field defects (n = 33, age 39-78 years), healthy children (n = 12, age 6-14 years), and healthy adults (n = 30, age 16-61 years). The test protocol comprised repeat suprathreshold SVOP and HFA testing with the C-40 test pattern. Feasibility was assessed by protocol completeness. Sensitivity, specificity, and accuracy of SVOP was established by comparison with reliable HFA tests in two ways: (1) visual field pattern results (normal/abnormal), and (2) individual test point outcomes (seen/unseen). Repeatability of each test type was assessed using Cohen's kappa coefficient. RESULTS: Of subjects, 82% completed a full protocol. Poor reliability of HFA testing in child patients limited the robustness of comparisons in this group. Sensitivity, specificity, and accuracy across all groups when analyzing the visual field pattern results was 90.9%, 88.5%, and 89.0%, respectively, and was 69.1%, 96.9%, and 95.0%, respectively, when analyzing the individual test points. Cohen's kappa coefficient for repeatability of SVOP and HFA was excellent (0.87 and 0.88, respectively) when assessing visual field pattern results, and substantial (0.62 and 0.74, respectively) when assessing test point outcomes. CONCLUSIONS: SVOP was accurate in this group of adults. Further studies are required to assess SVOP in child patient groups. TRANSLATIONAL RELEVANCE: SVOP technology is still in its infancy but is used in a number of centers. It will undergo iterative improvements and this study provides a benchmark for future iterations.