Wayfinding and Glaucoma: A Virtual Reality Experiment.

PurposeWayfinding, the process of determining and following a route between an origin and a destination, is an integral part of everyday tasks. The purpose of this study was to investigate the impact of glaucomatous visual field loss on wayfinding behavior using an immersive virtual reality (VR) environment.MethodsThis cross-sectional study included 31 glaucomatous patients and 20 healthy subjects without evidence of overall cognitive impairment. Wayfinding experiments were modeled after the Morris water maze navigation task and conducted in an immersive VR environment. Two rooms were built varying only in the complexity of the visual scene in order to promote allocentric-based (room A, with multiple visual cues) versus egocentric-based (room B, with single visual cue) spatial representations of the environment. Wayfinding tasks in each room consisted of revisiting previously visible targets that subsequently became invisible.ResultsFor room A, glaucoma patients spent on average 35.0 seconds to perform the wayfinding task, whereas healthy subjects spent an average of 24.4 seconds (P = 0.001). For room B, no statistically significant difference was seen on average time to complete the task (26.2 seconds versus 23.4 seconds, respectively; P = 0.514). For room A, each 1-dB worse binocular mean sensitivity was associated with 3.4% (P = 0.001) increase in time to complete the task.ConclusionsGlaucoma patients performed significantly worse on allocentric-based wayfinding tasks conducted in a VR environment, suggesting visual field loss may affect the construction of spatial cognitive maps relevant to successful wayfinding. VR environments may represent a useful approach for assessing functional vision endpoints for clinical trials of emerging therapies in ophthalmology

The Relative Odds of Progressing by Structural and Functional Tests in Glaucoma.

PurposeThe purpose of this study was to evaluate the effect of disease severity and number of tests acquired during follow-up on the relative odds of identifying progression by structural or functional tests in glaucoma.MethodsThis was an observational cohort study involving 462 eyes of 305 patients with glaucoma and 62 eyes of 49 healthy subjects. Glaucoma patients and healthy subjects were followed for an average of 3.6 ± 0.9 and 3.8 ± 0.9 years, with a median (interquantile range) of 8 (6-9) and 7 (6-8) visits, respectively. At each visit, subjects underwent visual field assessment with standard automated perimetry (SAP) and retinal nerve fiber layer (RNFL) evaluation by spectral-domain optical coherence tomography (SD-OCT). Slopes of change in SAP mean sensitivity and OCT RNFL thickness over time were estimated by linear regression using progressively cumulative visits over time. Cutoff values for age-related expected rates of change for each test were obtained from the healthy group. Progression by SD-OCT and/or SAP was determined if the slope of change was statistically significant and also lower (faster) than the fifth percentile cutoff calculated from the healthy group. A generalized estimating equation logistic regression model was used to evaluate the relative odds of progressing by OCT versus SAP in glaucoma eyes.ResultsEyes with less severe disease at baseline had a higher chance of being detected as progressing by SD-OCT but not by SAP, whereas an increase in disease severity at baseline increased the chance that the eye would be detected as progressing by SAP but not SD-OCT. Each 1 dB higher MD was associated with a 5% increase in the odds of detecting progression by SD-OCT versus SAP (odds ratio = 1.05 per 1 dB; 95% confidence interval: 1.01-1.09; P = 0.005).ConclusionsThe ability to detect glaucoma progression by SAP versus SD-OCT is significantly influenced by the stage of disease. Our results may provide useful information for guiding clinicians on the relative utility of these tests for detecting change throughout the disease continuum

Deep-Layer Microvasculature Dropout by Optical Coherence Tomography Angiography and Microstructure of Parapapillary Atrophy.

Purpose:To investigate the association between the microstructure of β-zone parapapillary atrophy (βPPA) and parapapillary deep-layer microvasculature dropout assessed by optical coherence tomography angiography (OCT-A). Methods:Thirty-seven eyes with βPPA devoid of the Bruch's membrane (BM) (γPPA) ranging between completely absent and discontinuous BM were matched by severity of the visual field (VF) damage with 37 eyes with fully intact BM (βPPA+BM) based on the spectral-domain (SD) OCT imaging. Parapapillary deep-layer microvasculature dropout was defined as a dropout of the microvasculature within choroid or scleral flange in the βPPA on the OCT-A. The widths of βPPA, γPPA, and βPPA+BM were measured on six radial SD-OCT images. Prevalence of the dropout was compared between eyes with and without γPPA. Logistic regression was performed for evaluating association of the dropout with the width of βPPA, γPPA, and βPPA+BM, and the γPPA presence. Results:Eyes with γPPA had significantly higher prevalence of the dropout than did those without γPPA (75.7% versus 40.8%; P = 0.004). In logistic regression, presence and longer width of the γPPA, worse VF mean deviation, and presence of focal lamina cribrosa defects were significantly associated with the dropout (P < 0.05), whereas width of the βPPA and βPPA+BM, axial length, and choroidal thickness were not (P > 0.10). Conclusions:Parapapillary deep-layer microvasculature dropout was associated with the presence and larger width of γPPA, but not with the βPPA+BM width. Presence and width of the exposed scleral flange, rather than the retinal pigmented epithelium atrophy, may be associated with deep-layer microvasculature dropout

Optical Coherence Tomography Angiography Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes.

PurposeThe purpose of this study was to compare retinal nerve fiber layer (RNFL) thickness and optical coherence tomography angiography (OCT-A) retinal vasculature measurements in healthy, glaucoma suspect, and glaucoma patients.MethodsTwo hundred sixty-one eyes of 164 healthy, glaucoma suspect, and open-angle glaucoma (OAG) participants from the Diagnostic Innovations in Glaucoma Study with good quality OCT-A images were included. Retinal vasculature information was summarized as a vessel density map and as vessel density (%), which is the proportion of flowing vessel area over the total area evaluated. Two vessel density measurements extracted from the RNFL were analyzed: (1) circumpapillary vessel density (cpVD) measured in a 750-μm-wide elliptical annulus around the disc and (2) whole image vessel density (wiVD) measured over the entire image. Areas under the receiver operating characteristic curves (AUROC) were used to evaluate diagnostic accuracy.ResultsAge-adjusted mean vessel density was significantly lower in OAG eyes compared with glaucoma suspects and healthy eyes. (cpVD: 55.1 ± 7%, 60.3 ± 5%, and 64.2 ± 3%, respectively; P < 0.001; and wiVD: 46.2 ± 6%, 51.3 ± 5%, and 56.6 ± 3%, respectively; P < 0.001). For differentiating between glaucoma and healthy eyes, the age-adjusted AUROC was highest for wiVD (0.94), followed by RNFL thickness (0.92) and cpVD (0.83). The AUROCs for differentiating between healthy and glaucoma suspect eyes were highest for wiVD (0.70), followed by cpVD (0.65) and RNFL thickness (0.65).ConclusionsOptical coherence tomography angiography vessel density had similar diagnostic accuracy to RNFL thickness measurements for differentiating between healthy and glaucoma eyes. These results suggest that OCT-A measurements reflect damage to tissues relevant to the pathophysiology of OAG

Fear of falling and postural reactivity in patients with glaucoma

Purpose To investigate the relationship between postural metrics obtained by dynamic visual stimulation in a virtual reality environment and the presence of fear of falling in glaucoma patients. Methods This cross-sectional study included 35 glaucoma patients and 26 controls that underwent evaluation of postural balance by a force platform during presentation of static and dynamic visual stimuli with head-mounted goggles (Oculus Rift). In dynamic condition, a peripheral translational stimulus was used to induce vection and assess postural reactivity. Standard deviations of torque moments (SDTM) were calculated as indicative of postural stability. Fear of falling was assessed by a standardized questionnaire. The relationship between a summary score of fear of falling and postural metrics was investigated using linear regression models, adjusting for potentially confounding factors. Results Subjects with glaucoma reported greater fear of falling compared to controls (-0.21 vs. 0.27P = 0.039). In glaucoma patients, postural metrics during dynamic visual stimulus were more associated with fear of falling (R-2 = 18.8%P = 0.001) than static (R-2 = 3.0%P = 0.005) and dark field (R-2 = 5.7%P = 0.007) conditions. In the univariable model, fear of falling was not significantly associated with binocular standard perimetry mean sensitivity (P = 0.855). In the multivariable model, each 1 Nm larger SDTM in anteroposterior direction during dynamic stimulus was associated with a worsening of 0.42 units in the fear of falling questionnaire score (P = 0.001). Conclusion In glaucoma patients, postural reactivity to a dynamic visual stimulus using a virtual reality environment was more strongly associated with fear of falling than visual field testing and traditional balance assessment.National Institutes of Health/National Eye Institute [EY021818]Brazilian National Council for Scientific and Technological Development (CNPq) [233829/2014-8]Alcon Laboratories (Fort Worth, TX)Bausch & Lomb (Garden City, NY)Carl Zeiss Meditec (Jena, Germany)Heidelberg Engineering (Heidelberg, Germany)Merck (White House Station, NJ)Allergan (Irvine, CA)Sensimed (Lausanne, Switzerland)Topcon (Livermore, CA)Reichert (Dewey, NY)National Eye Institute (Bethesda, MD)Novartis (Basel, Switzerland)nGoggle (San Diego, CA)Duke Univ, Duke Eye Ctr, Durham, NC 27708 USADuke Univ, Dept Ophthalmol, Durham, NC 27708 USAUniv Fed Sao Paulo, Dept Ophthalmol & Vis Sci, Sao Paulo, BrazilUniv Calif San Diego, Dept Ophthalmol, La Jolla, CA 92093 USAUniv Fed Sao Paulo, Dept Ophthalmol & Vis Sci, Sao Paulo, BrazilCNPq [233829/2014-8]Web of Scienc

Variabilidade diária da temperatura do solo: Um estudo de caso

Mesmo sabendo-se que a temperatura do solo é um dos fatores ambientais de maior importância para a agricultura, poucas pesquisas foram realizadas até então a respeito dessa variável. Logo, o presente trabalho tem como objetivo o estudo das características térmicas do solo através de dados coletados no Instituto Nacional do Semiárido (INSA), durante os meses de julho a dezembro do ano de 2012. Para avaliar a magnitude da difusividade térmica do solo foram utilizados os métodos da amplitude, do arco tangente e o logarítmico. A partir da análise dos resultados verificou-se boa consistência das estimativas da difusividade térmica do solo obtidas pelos métodos distintos

Complicações neurológicas em transplantes cardíacos

OBJECTIVE: Neurologic complications are known as important cause of morbidity and mortality in orthotopic heart transplantation. Our aim was to identify the frequency and outcome of neurologic complications after heart transplantation in a prospective observational study. METHOD: From September 93 to September 99, as part of our routine heart transplantation protocol all patients with end-stage cardiac failure were evaluated by the same neurologist before and at the time of any neurologic event (symptom or complaint) after transplantation. RESULTS: Out of 120 candidates evaluated, 62 were successfully transplanted (53 male; median age 45.5 years, median follow-up 26.8 months). Fifteen patients (24%) had ischemic, 22 (35%) idiopathic, 24 (39%) Chagas' disease and 1 (2%) had congenital cardiomyopathy. Neurologic complications occurred in 19 patients (31%): tremor, severe headache, transient encephalopathy and seizures related to drug toxicity or metabolic changes in 13; peripheral neuropathy in 4; and spinal cord compression in two (metastatic prostate cancer and epidural abscess). No symptomatic postoperative stroke was observed. CONCLUSIONS: Although frequent, neurologic complications were seldom related to persistent neurologic disability or death. Most of the complications resulted from immunosuppression, however, CNS infection was rare. The absence of symptomatic stroke in our series may be related to the lower frequency of ischemic cardiomyopathy.OBJETIVO: Complicações neurológicas são frequentemente descritas como causa de morbidade e mortalidade em transplantes cardíacos. Nosso objetivo foi avaliar a frequência de complicações neurológicas em pacientes submetidos a transplantes cardíacos, bem como sua evolução, através de um estudo prospectivo observacional. MÉTODO: Todos os candidatos a transplantes cardíacos foram avaliados pelo mesmo neurologista, como parte do protocolo de rotina de avaliação pré-transplante no período de 9/93 a 9/99. Após a cirurgia, os pacientes foram reavaliados sempre que houvesse qualquer sintoma ou queixa neurológica. RESULTADOS: Entre 120 pacientes avaliados no período pré-operatório, 62 foram transplantados (53 sexo masculino; idade mediana de 45.5 anos; tempo de seguimento mediano 26.8 meses). A etiologia da miocardiopatia foi isquêmica em 15 pacientes (24%), idiopática em 22 (35%), chagásica em 24 (39%) e congênita em 1 (2%). Complicações neurológicas ocorreram em 19 pacientes (31%): tremor, cefaléia intensa, encefalopatia transitória ou crises relacionados com toxicidade medicamentosa ou alterações metabólicas em 13; neuropatia periférica em 4; compressão medular em 2 (metástase epidural de carcinoma de próstata e abscesso epidural). Nenhum paciente apresentou acidente vascular cerebral (AVC) sintomático no período pós-operatório. CONCLUSÕES: Apesar de frequentes, as complicações neurológicas raramente provocaram seqüelas permanentes ou óbito. A maior parte das complicações foi relacionada com imunossupressão, entretanto, infecções foram raras. A ausência de pacientes com AVC sintomático pode estar associada com a baixa frequência de miocardiopatia isquêmica na presente série.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of NeurologyUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of CardiologyUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of Infectious DiseasesUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of Cardiovascular SurgeryUNIFESP, EPM, Department of NeurologyUNIFESP, EPM, Department of CardiologyUNIFESP, EPM, Department of Infectious DiseasesUNIFESP, EPM, Department of Cardiovascular SurgerySciEL

Middle Childhood Adverse Psychomotor Outcomes from Malaria in Pregnancy: A Study using the Denver Developmental Screening Test-II

Objective: to evaluate changes in the development of premature children aged 5 to 6 years, born to mothers with malaria during pregnancy and to compare them to a control group of premature children born to mothers who did not have malaria during pregnancy. Methods: cross-sectional and analytical study. The Denver test-II was applied to 20 children in the study group and 20 children in the control group. Results: in the group of premature children of mothers with malaria during pregnancy, the vast majority showed abnormal performance with more significant changes in the activities of the language sector "define seven words", "say two compound words", "understand four prepositions" and "account five blocks”, “knows three adjectives”. In the fine-adaptive motor sector, the activities "draw people with six parts", "copy disassembled square", "copy +" and in the gross motor sector "swing your foot for six seconds", "swing your foot for five seconds", "swing the foot for four seconds", "rocks the foot for three seconds", were the most important developmental changes. In the control group, the performance of suspected delay or possible abnormality was more concentrated in the gross motor sector. Conclusions: children from 5 to 6 years of age, born prematurely to mothers with malaria during pregnancy, 80% had suspected abnormal performance, a result much higher than the group of children born prematurely to mothers without malaria. These results strongly suggest that malaria disease during pregnancy alters fetal development, producing developmental sequelae that can be detected even at 5 to 6 years of age. In addition, the results support the use of the Denver test-II as a simple screening method for the assessment of delays in child development, covering broad motor coordination (coarse), fine motor coordination (adaptive), language and personal-social adaptation. This test has been used to identify children who are at risk of developing problems and to monitor the child longitudinally