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La masificación del Internet y comunicación móvil, así como el mayor acceso a herramientas digitales y de dispositivos electrónicos ha modificado la calidad de vida y salud de la población mundial, con un impacto especialmente importante en los niños. El uso desmedido de pantallas constituye un problema en esta población por su impacto en el sedentarismo, sobrepeso, alteraciones en el comportamiento, trastornos depresivos y del sueño, pero también por el efecto que tiene sobre el sistema visual en desarrollo: predispone a síndrome de ojo seco, a un exceso de acomodación-convergencia, provoca un desenfoque hipermetrópico de la fóvea (se cree que esto estimula el crecimiento axial), aumenta la tensión del cuerpo ciliar y músculos extraoculares, además de los efectos nocivos de la luz azul-violeta para las estructuras intraoculares. Estudios sugieren que los niños son más propensos a desarrollar miopía por estar menos expuestos a la luz natural y pasar más tiempo en ambientes cerrados ante pantallas, muchos incluso han demostrado una asociación entre el uso de pantallas, el trabajo cercano y la presencia de miopía, pero no existen datos concluyentes que aíslen un riesgo independiente. A partir de esta revisión se concluye que la prevalencia de la miopía está aumentando con base en una etiología multifactorial(AU)
The massification of the Internet and mobile communication, as well as increased access to digital tools and electronic devices, have changed the quality of life and health of the world's population, with a particularly important impact on children. The excessive use of screens is a problem among this population because of its impact on sedentary lifestyles, overweight, behavioral alterations, depressive and sleep disorders; but also because of its effect on the developing visual system, since it predisposes to dry eye syndrome, excessive accommodation-convergence, causes hypermetropic defocus at the fovea (this is believed to stimulate axial growth), increases the tension of the ciliary body and extraocular muscles, in addition to the harmful effects of blue-violet light on intraocular structures. Studies suggest that children are more prone to developing myopia because they are less exposed to natural light and spend more time in indoor environments in front of screens; many studies have even shown an association between the use of screens, close-eye work and the presence of myopia, but there are no conclusive data that isolate an independent risk. From this review, the prevalence of myopia is concluded to be increasing based on a multifactorial etiology(AU)
Subject(s)
Humans , Quality of Life , Internet , Electronics , Myopia/etiology , Sleep Wake Disorders , Dry Eye Syndromes , Life StyleABSTRACT
Objective:To propose a method of image similarity measurement based on structure information and intuitionistic fuzzy set and measure the similarity between CT image and CBCT image of radiotherapy plan positioning, aiming to objectively measure the setup errors.Methods:A total of four pre-registration images of a nasopharyngeal carcinoma patient on the cross-sectional and sagittal planes and a pelvic tumor patient on the cross-sectional and coronal planes were randomly selected. Five methods were used to quantify the setup errors, including correlation coefficient, mean square error, image joint entropy, mutual information and similarity measure method.Results:All five methods could describe the deviation to a certain extent. Compared with other methods, the similarity measure method showed a stronger upward trend with the increase of errors. After normalization, the results of five types of error increase on the cross-sectional plane of the nasopharyngeal carcinoma patient were 0.553, 0.683, 1.055, 1.995, 5.151, and 1.171, 1.618, 1.962, 1.790, 3.572 on the sagittal plane, respectively. The results of other methods were between 0 and 2 after normalization, and the results of different errors of the same method slightly changed. In addition, the method was more sensitive to the soft tissue errors.Conclusions:The image similarity measurement method based on structure information and intuitionistic fuzzy set is more consistent with human eye perception than the existing evaluation methods. The errors between bone markers and soft tissues can be objectively quantified to certain extent. The soft tissue deviation reflected by the setup errors is of significance for individualized precision radiotherapy.
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In contrast to many machine vision systems, we human observers can readily recognize solid objects and visually discriminate their 3-D shapes even under changes in viewpoint and variations in object orientation and lighting. While the importance of binocular disparity has been known since the 1830's, the importance and perceptual informativeness of visual contours for object recognition and discrimination is not adequately appreciated. This article will review those scientific contributions that demonstrate that visual contours and their deformations over time (in response to object or observer motion) carry as much or more information about object shape than other forms of visual information.
Em contraste com muitos sistemas artificiais de visão, nós, observadores humanos, podemos reconhecer prontamente objetos sólidos e discriminar visualmente suas formas 3-D, mesmo sob mudanças no ponto de vista e variações na orientação e iluminação do objeto. Embora a importância da disparidade binocular seja conhecida desde a década de 1830, a relevância e a riqueza perceptiva das informações fornecidas pelos contornos visuais para o reconhecimento e discriminação de objetos não são devidamente apreciadas. Este artigo revisará as contribuições científicas que demonstram que os contornos visuais e suas deformações ao longo do tempo (em resposta ao movimento do objeto ou do observador) proporcionam tanto ou mais informações sobre a forma do objeto do que outras formas de informação visual.
A diferencia de los sistemas de visión artificial, los observadores humanos pueden reconocer fácilmente objetos sólidos y discriminar visualmente su forma 3D, incluso cuando se producen cambios en su punto de vista, en la orientación o en la iluminación. Aunque la importancia de la disparidade binocular es conocida desde 1830, la relevancia y la riqueza de la información provista por los contornos visuales para el reconocimiento y discriminación de los objetos no ha sido apreciada adecuadamente. En este artículo se revisan las contribuciones científicas que demuestran que los contornos visuales y sus deformaciones a lo largo del tiempo (en respuesta a los movimentos tanto del observador como del objeto) proporcionan tanto o más información sobre la forma del objeto que otros tipos de información visual.
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The visual system of women changes during pregnancy. Few reports have addressed the effects of pregnancy on color vision. We aimed to compare the color vision of women in the first, second, and third trimesters of pregnancy. Fifty women were divided into first (n=10), second (n=10), third trimester pregnancy groups (n=10), and non-pregnant group (n=20). We used the Farnsworth D15 and Lanthony desaturated D15 (D15d) tests. The hue ordering quantified the amount of error (C-index) and the chromatic selectivity of the errors (S-index). Bland-Altman analysis was applied to the hue ordering data. No difference was found for Farnsworth D15 test results obtained from the pregnant groups and the non-pregnant group (P<0.0083). For the Lanthony D15 desaturated test, the third trimester pregnant group had higher C-index and S-index than non-pregnant women and first-trimester pregnant women (P<0.0083). The Bland-Altman analysis showed that the limits of agreement increased as pregnancy advanced, and the errors were biased to the D15d test. In this study, color vision was impaired during pregnancy. Color vision evaluation could be used as an indicator of the functional status of the central vision during pregnancy.
Subject(s)
Humans , Female , Pregnancy , Adult , Vision Tests/methods , Color Perception , Color Vision , Pregnancy Complications , Pregnancy Trimester, Second , Pregnancy Trimester, Third , Pregnancy Trimester, FirstABSTRACT
ABSTRACT Cichlid fishes are an important group in evolutionary biology due to their fast speciation. This group depends widely of vision for feeding and reproduction. During the evolutionary process it plays a significant role in interspecific and intraspecific recognition and in its ecology. The molecular basis of vision is formed by the interaction of the protein opsin and retinal chromophore. Long-wavelength sensitive opsin (LWS) gene is the most variable among the opsin genes and it has an ecological significance. Current assay identifies interspecific variation of Neotropical cichlids that would modify the spectral properties of the LWS opsin protein and codons selected. Neotropical species present more variable sites for LWS gene than those of the African lakes species. The LWS opsin gene in Crenicichla britskii has a higher amino acid similarity when compared to that in the African species, but the variable regions do not overlap. Neotropical cichlids accumulate larger amounts of variable sites for LWS opsin gene, probably because they are spread over a wider area and submitted to a wider range of selective pressures by inhabiting mainly lotic environments. Furthermore, the codons under selection are different when compared to those of the African cichlids.
Subject(s)
Animals , Genetic Variation , Rod Opsins/genetics , Cichlids/genetics , Phylogeny , Species Specificity , Brazil , Codon/genetics , Polymerase Chain Reaction , Sequence Analysis, DNA , Africa , Cichlids/classificationABSTRACT
AIM: To evaluate association between mutations in the visual system homeobox 1 (VSX1) gene and keratoconus (KCN) complicated with granular corneal dystrophy (GCD), direct sequencing was performed in an Iranian family affected by KCN and GCD in four generations.METHODS: An Iranian pedigree with keratoconus spanning four generations along with GCD was identified.Whole blood sample was used for genomic DNA extraction.The molecular analysis by using polymerase chain reaction (PCR) of the entire coding region and intron-exon boundaries of VSX1 gene was preformed to investigate the possible linkage between KCN and GCD.Subsequently, direct sequencing was used for PCR products and mutation analysis was conducted in the patients and controls.RESULTS: Mutation analysis in VSX1 gene did not detect evidence for association between KCN and GCD diseases and VSX1 gene.Our data excluded VSX1 as the disease-causing gene for KCN/GCD in this specific pedigree.CONCLUSION: Despite of no association between KCN patients with GCD and VSX1 gene variations, other probable genes involved in pathogenesis of the KCN and GCD diseases need to be investigated in the patients.
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Vision not only plays an important role in the behavior and exploration capacity of new ecology niches but also influences the evolution of species exposed to the heterogeneity of light. Floodplain environments have high habitat heterogeneity and, thus, different light gradients. Cichlids are a group of vertebrates that has stirred interest in evolutionary studies due to their morphological and behavioral diversity and their widely used vision. The molecular basis of vertebrates' vision occurs through the interaction of opsin proteins and retinal chromophores. Proteins are expressed by opsin genes where each is responsible for absorbing certain light wavelengths. Current review analyzes the main characteristics of opsin genes family and the possibility of using them in floodplain and Neotropical cichlids studies. Opsins may have different levels of expression and molecular polymorphisms according to the dispersion of the species. They are also related to such behavior as sexual selection, nourishment and exploration of new habitats. Floodplains are natural experiments and dynamic environments that provide a wide range of habitats. In fact, the integration of studies in floodplains and the opsin genes in Neotropical cichlids seems to be a promising and still unexplored area in Neotropical regions.
A visão desempenha um importante papel no comportamento e capacidade de explorar novos nichos, e também influencia o processo evolutivo de espécies que estão sujeitas à heterogeneidade de luz. Ambientes de planície de inundação têm alta heterogeneidade de habitats, exibindo diferentes gradientes de luminosidade. Um grupo de vertebrados que desperta interesse para estudos evolutivos são os ciclídeos, pela sua diversidade morfológica e comportamental, além de usarem amplamente a visão. A base molecular da visão dos vertebrados ocorre pela interação de proteínas opsinas e cromóforos retinais. Essas proteínas são expressas pelos genes opsins, cada uma responsável por absorver determinado comprimento de onda de luz. Esta revisão aborda as principais características destes genes e a possibilidade de sua utilização em estudos de planície de inundação e ciclídeos neotropicais. Os opsins podem apresentar diferentes níveis de expressão e polimorfismos de acordo com a dispersão das espécies estudadas. São relacionados com comportamentos de seleção sexual, forrageamento, e capacidade de explorar novos habitats. As planícies de inundação representam experimentos naturais, sendo ambientes dinâmicos e que apresentam vários tipos de habitats. Assim, a integração de estudos de planície de inundação e genes opsins em ciclídeos parece ser uma área promissora e ainda inexplorada em regiões neotropicais.
Subject(s)
Opsins , Genes , Retinal Pigments , Perciformes , Cichlids , EcologyABSTRACT
Background Pupillary light reflex has been widely used in the diagnosis and evaluation of visual system and nervous system diseases.However,in animal experiments,functional evaluation of the visual system and nervous system needs more advanced technology and are affected by many factors.Objective This study was to explore the use of the dynamic pupillometer in evaluating pupillary light reflex and to discuss the influence of brightness of stimulate on relevant curve parameters in C57BL/6 mouse.Methods Ten healthy SPF male C57BL/6 mice were collected in this experiment.White light of five luminance levels (2,8,32,128,256 cd/m2) was used to stimulate the mice following a 2-hour dark adaptation.The stimulation was given at the 60-second intervals,for a duration of 100 ms at every stimulation.An infrared camera and video capture card were used to capture digital images during the measuring process in a scotopic environment,at a speed of 60 frames per second.Measuring outcome was saved in the*.AVI format.A software that was developed by our group was used to determine pupil diameter and output pupillary light reflex curve offline.Pupil initial diameter (R1),constriction amplitude (CA),constriction velocity (CV),latency (T1),time for maximum velocity (T2),time for maximum constriction (T3),time for maximun con-striction to 10.1％ R1 re-dilation (RT)and re-dilation velocity (RV)were assessed,and the correlations between luminosity and measuring parameters were analyzed using the Spearman rank correlation.The use of animals followed the Regulations for thd Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results R1 values showed no statistically significant difference among the 5 different luminosity groups(F=1.117,P=0.361).A positive linear correlation was found between stimulating luminosity and CA(r=0.508,P＜ 0.01),but negative correlations were seen between stimulating luminosity and CV or RV (r=-0.625,-0.609,P＜0.01).T1 and T2 values in the 5 different luminosity groups were not statistically significant (F =0.202,P =0.936 ; F =1.584,P =0.195).The different levels of stimulating luminosity showed positive linear correlations with T3 and RT values (r =0.791,0.609,P＜ 0.01).Conclusions The dynamic pupillometer can quantitatively measure the pupillary light reflex of C57BL/6 mice.The pupillary light reflex dynamic curve parameters of mouse were affected by stimulus luminosity levels.These outcomes offer a basis for the application of the dynamic pupillometer system for measuring pupillary light reflex in animal models.
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The classical Romberg's test based on stabilometric tests in eyes open (EO) and closed (EC) conditions was used for investigating the influence of visual feedback in the body sway control in healthy adult subjects. Stabilograms from 144 subjects (aged 18-40) resting over a force platform were recorded for 30 s in EO and 30 s in EC conditions. The mean velocity was obtained for EO (VmEO) and EC (VmEC) in both anterior-posterior (y) and medial-lateral (x) directions and in the (x,y) plane, and thus used for computing the respective Romberg's quotient (RQ V). All Vm and RQ V parameter histograms presented unimodal asymmetric shapes, which were adequately fitted to lognormal distributions (Kolmogorov-Smirnov test, p > 0.05). These findings suggest a single homogeneous group in terms of visual strategy. Taking the threshold scores (95% confidence interval) of the Vm and RQ V distributions, only four subjects (2.7%) presented values below the lower limit, as expected by the confidence level (two tailed, 5%). A strong dependence was also found between each RQ V and the respective VmEC (Spear correlation > 0.86, R² > 74.0%), with VmEO presenting almost negligible coefficients of determination (R² < 2.9%). One can conclude that RQ V derived from a single stabilometric trial could be not sufficient for the diagnosis of body sway control impairment by vision. Nevertheless, the RQ V could be useful to indicate subjects to carry out additional tests to investigate a possible deficit in the integration of the visual information in the postural control system.
O Teste de Romberg clássico, baseado em testes estabilométricos nas condições de olhos abertos (EO) e fechados (EC), tem sido utilizado para investigar a influência da realimentação visual no controle das oscilações posturais em sujeitos adultos saudáveis. Estabilogramas de 144 sujeitos (18 a 40 anos) em posição ortostática sobre uma plataforma de força foram coletados durante 30 s na condição EO e 30 s em EC. As velocidades médias para EO (VmEO) e EC (VmEC), obtidas nas direções anteroposterior (y), mediolateral (x) e no plano (x,y), foram utilizadas no cálculo dos respectivos quocientes de Romberg (RQV). Os histogramas dos parâmetros Vm e RQV apresentaram morfologia unimodal assimétrica, aos quais foram ajustadas distribuições lognormais (Teste de Kolmogorov-Smirnov, p > 0,05). Tais distribuições sugerem haver um único grupo homogêneo no que concerne à estratégia visual. Considerando o intervalo de confiança de 95%, somente quatro sujeitos (2,7%) apresentaram valores de Vm e QRV abaixo do limite inferior, percentual este compatível com o teste bicaudal. A Correlação de Spear entre o RQV e seu respectivo VmEC foi sempre superior a 0,86, sendo o coeficiente de determinação R2 > 74,0%, enquanto que com VmEO R2 < 2,9%. Tais achados sugerem que o RQV obtido a partir de um único teste estabilométrico não seria adequado ao diagnóstico de problemas de controle das oscilações posturais ocasionados pela visão. No entanto, o RQV pode ser útil para indicar a realização de testes adicionais com vistas a investigar possível déficit na integração da informação visual no sistema de controle postural.
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OBJECTIVES: There has been continuous development in the area of stereoscopic medical imaging devices, and many stereoscopic imaging devices have been realized and applied in the medical field. In this article, we review past and current trends pertaining to the application stereo-imaging technologies in the medical field. METHODS: We describe the basic principles of stereo vision and visual issues related to it, including visual discomfort, binocular disparities, vergence-accommodation mismatch, and visual fatigue. We also present a brief history of medical applications of stereo-imaging techniques, examples of recently developed stereoscopic medical devices, and patent application trends as they pertain to stereo-imaging medical devices. RESULTS: Three-dimensional (3D) stereo-imaging technology can provide more realistic depth perception to the viewer than conventional two-dimensional imaging technology. Therefore, it allows for a more accurate understanding and analysis of the morphology of an object. Based on these advantages, the significance of stereoscopic imaging in the medical field increases in accordance with the increase in the number of laparoscopic surgeries, and stereo-imaging technology plays a key role in the diagnoses of the detailed morphologies of small biological specimens. CONCLUSIONS: The application of 3D stereo-imaging technology to the medical field will help improve surgical accuracy, reduce operation times, and enhance patient safety. Therefore, it is important to develop more enhanced stereoscopic medical devices.
Subject(s)
Asthenopia , Depth Perception , Diagnostic Imaging , Laparoscopy , Patient Safety , Vision Disparity , Vision, OcularABSTRACT
Background Keratoconus is a bilateral,noninflammatory,gradually progressive corneal disorder characterized by progressive thinning and steepening of the central cornea.It is significant to investigate keratoconusrelated pathogenic gene for elaborating the pathogenesis and establishing early diagnosis standard and taking clinical measurement.Objective The aim of the study was to explore the relationship of visual system homeobox gene (VSX1) polymorphism and the risk of sporadic keratoconus.Methods This study was approved by Ethic Commission of First Hospital of Xi' an.Written informed consent was obtained from each subject prior to enrollment.A case-controlled study was conducted.One hundred and one Han nationality patients with sporadic keratoconus were included in this study.These keratoconus patients were clinically diagnosed by slit lamp examination and corneal tomography.Single nucleolide polymorphism (SNP) of VSX1 gene was assayed and classified using the MassARRAY SNP technique.Demography and relevant risk factors were collected from each subject by questionnaire.Eighty healthy volunteers served as controls.Chi-square test and Binary logistic regression were used to evaluate the difference in the distribution of allele frequency and genotype frequency and to analyze the association with keratoconus risks.Results SNP of two genes was found in the Chinese Han population (rs743018 (c.843+140 C＞T) and rs6138482(R217H C＞T)).There were no significant differences in the genotype frequency and allele frequency of the SNP of two genes in the keratoconus group in comparison with the normal control group (P＞0.05).After adjustment by age and sex,SNP of two genes was not significantly associated with the risk of keratoconus (regression model:rs743018 (C＞T) adjusted:P=0.35,OR=0.72,95％ CI:0.37-1.43 ;rs6138482 (C＞T) adjusted:P =0.48,OR=0.76,95％ CI:0.35-1.64).Conclusions Gene polymorphisms of rs743018(c.843+140 C＞T) and rs6138482(R217H C＞T) in the Chinese Han population is not associated with the risk of keratoconus.Due to the racial difference in genotype and allele frequency,the role of the VSX1 gene in the pathogenesis of keratoconus still remains controversial,and further study needs to be developed.
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To investigate the effect of hyperglycemia on the visual system, we investigated the retinal dopaminergic and cholinergic systems using tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) in the rat retinas of streptozotocin (STZ)-induced diabetes. Diabetes was induced by a single intraperitoneal injection of STZ (50 mg/kg) to Sprague-Dawley rats (250~300 g). We first analyzed morphologic thickness changes in the several retinal layers of 6-week-old control and STZ-diabetic rats after H & E staining. To confirm whether TH and ChAT protein expressions changed, we carried out immunohistochemistry analysis and Western blotting. After induction of diabetes, significant changes were not shown in the retinal thickness at 6 weeks. TH and ChAT immunoreactivities were clearly detected in amacrine cells and sublaminas in the inner retina of both control and diabetic rats, showing continuously reduced positive amacrine cells in the retinas during diabetes. In addition, the decline in TH and ChAT protein expression was already present to a significant extent in the retina at 6 weeks in early diabetes. Our present study demonstrates the possibility that the observed alterations in TH and ChAT in the diabetic retina may cause the visual system changes in the retinal pathophysiology associated with diabetes mellitus.
Subject(s)
Animals , Rats , Amacrine Cells , Blotting, Western , Choline O-Acetyltransferase , Choline , Diabetes Mellitus , Hyperglycemia , Immunohistochemistry , Injections, Intraperitoneal , Rats, Sprague-Dawley , Retina , Retinaldehyde , Streptozocin , Tyrosine 3-Monooxygenase , TyrosineABSTRACT
A acuidade visual e a função de sensibilidade ao contraste são medidas clássicas utilizadas para avaliar a capacidade do sistema visual humano. Estas duas funções são os principais indicadores dos aspectos críticos da percepção e do processamento visual da forma ou do detalhe espacial. O objetivo principal deste trabalho é levantar e discutir alguns aspectos teóricos e experimentais básicos relacionados à acuidade visual e à função de sensibilidade ao contraste. A acuidade visual estima a habilidade do sistema visual para discriminar detalhes espaciais, enquanto a função de sensibilidade ao contraste estima a percepção de qualquer padrão em função de sua freqüência espacial.
This work discusses some important aspects about visual acuity, VA, and contrast sensitivity function, CSF. The VA and the CSF are classical functions or measurements used to appreciate the capacity of the human visual system on perception and on visual processing of form or spatial detail. One of the goals of this paper is to discuss important theoretical and experimental aspects related to VA and CSF that are the principal indicators of perception and visual processing of form in humans. Visual acuity estimates the ability of the visual system to resolve spatial details, whereas CSF estimates the perception of any pattern in function of the spatial frequency.
Subject(s)
Humans , Contrast Sensitivity , Form Perception , Visual Acuity , Visual PerceptionABSTRACT
To evaluate the surgical results, postoperative prognostic factors and visual functional effects of pars plana vitrectomy for proliferative diabetic retinopathy, we investigated retrospectively the surgical records of 103 eyes in 83 patients. Overall anatomic success rate was 76.7%. postoperatively, visual acuity was improved in 60.2%, unchanged in 23.3% and decreased in 16.5%. The surgical outcome varied according to the surgical indication: 88.4% of eyes with vitreous hemorr-hage obtained improvement in final vision, 77.4% of eyes with traction detachment involving macula, 91.7% of eyes with fibrovascular proliferation, and 62.5% of eyes with traction-rhegmatogenous retinal detachment. Factors associated with a favorable visual prognosis were preoperative panretinal photocoagulation, and the avoidance of using long acting intraocular tamponade. Postoperative complications included vitreous hemorrhage, cataract, retinal detachment and neovas-cular glaucoma in order. Main causes of poor visual outcome included retinal detachment, neovascular glaucoma and anterior hyaloid fibrovascular proliferation. The average disability of study eyes(percent visual impairment of the study eye, PVISE) was reduced from 91% preoperatively to 58% postoperatively, and the mean impairment of the visual system(percent impairment of visual system, PIVS) from 87% to 59%.
Subject(s)
Humans , Cataract , Diabetic Retinopathy , Glaucoma , Glaucoma, Neovascular , Light Coagulation , Postoperative Complications , Prognosis , Retinal Detachment , Retrospective Studies , Traction , Vision Disorders , Visual Acuity , Vitrectomy , Vitreous HemorrhageABSTRACT
OBJECTIVES: The purpose of this study was to evaluate the optimal distance and angle of observers by modulation transfer functions(MTFs) and receiver operating characteristics(ROCs). MATERIALS AND METHODS: Digital periapical radiograms were taken from 43 patients who have dental diseases(19 patients : dental caries, 12 patients : periapical lesions, 12 patients : periodontal diseases). Segmental images(4x4cm) were evaluated by 4 MTFs and ROC analysis. RESULTS: The optimal distance(magnification) using MTF by Mannos & Sakrison was 12.97, and those by Nill, Ngan and Rao were 8.39, 4.78, 5.84 respectively. The optimal distance obtained from 4 radiologists by ROC analysis was 32cm(Az value : 0.89), and it was 40cm(Az value : 0.78) from 4 non-radiologists. There were significant differences of Az values between 4 radiologists and 4 non-radiologists at 24, 32 and 40cm (p0.05). The optimal angle obtained from 4 radiologists by ROC analysis was +20 degrees (Az value : 0.91), and no significant differences of Az values were observed among +20, +10, 0, -10 and 20 degrees(p>0.05). The optimal angle obtained from 4 non-radiologists by ROC analysis was 0 degree(Az value : 0.81), and no significant differences of Az values were observed among +20, +10, 0, -10 and 20 degrees(p>0.05). And there was significant difference of Az value between 4 radiologists and 4 non-radiologists at +20 degree(p0.05).
Subject(s)
Humans , Dental Caries , ROC CurveABSTRACT
To investigate the applicability of the Bartha strain of pseudorabies virus(PRV-Ba) as a neurotracer in the visual system, we performed immunohistochemical study of the rat brain after intravitreal injection of the PRV-Ba. Cholera toxin-horseradish peroxidase(CT-HRP), a well known neurotracer, was also injected into the vitreous cavity for comparison. After given survival time the brain was removed and processed immunohistochemical stain for PRV-Ba and neurohistochemical stain for CT-HRP. The CT-HRP positive reactions were observed almost contralaterally in optic chiasm, optic tract, suprachiasmatic nucleus(SCN), olivary pretectal nucleus(OPT), all three subdivision of lateral geniculate body, superficial gray layer and optic layer of superior colliculus and medial, lateral, dorsal terminal nucleus of accessory optic tract. PRV-Ba immunopositive reaction was observed in SCN and OPT, but not in nerve fiber system and dorsal lateral geniculate body. Also PRV-Ba positive cells were distributed mainly in intermediate layer and weakly distributed in superficial layer of the superior colliculus. This study suggests that PRV-Ba is not a useful neurotracer in studying the visual system of the rat.