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1.
For the rehabilitation of people with impaired vision, it is essential to have adequate (preferably quantitative) information about their residual visual functions. Special attention is given to the extra information provided by the results of measurement of the contrast sensitivity, especially in combination with the results of other measurements, such as the visual field, the amount of intraocular straylight and the visual acuity. The value of the contrast sensitivity function as a predictor of the extent of dysfunctioning in the visual activities of everyday life, such as outdoor vision, reading and recognition of faces, will be discussed. As far as this is concerned, a comparison is made between the value of visual acuity and contrast sensitivity as measures of the extent of vision and visual dysfunctioning.  相似文献   

2.
Levine MW  McAnany JJ 《Vision research》2005,45(21):2820-2830
Visual performance is better in the lower visual hemifield than in the upper field for many classes of stimuli. The origin of this difference is unclear. One theory associates it with finer-grained attention in the lower field, an idea consistent with a change in relative efficacy with task difficulty. The first experiment in this study confirmed a lower hemifield advantage for discriminating a range of stimuli, including those that differ in contrast, hue, and motion. An identical paradigm revealed an upper field advantage when stimuli differed in their apparent distances from the observer. Presentations of stimuli in the upper or lower hemifield were interlaced to reduce the likelihood of possible artifacts or biases. A second experiment varied the difficulty of these discriminations, showing that difficulty does not determine field preference. Thus, an attentional mechanism is not a likely explanation for these preferences.  相似文献   

3.
目的研究合并高度近视的青光眼和非高度近视的青光眼的视野改变有无差别。方法 利用Octopus 101全自动视野计对36例(51眼)合并高度近视的原发性开角型青光眼(primary open angle glaucoma,POAG)和16例(23眼)非高度近视的POAG进行静态中心阈值视野检查,并分析其视野缺损形式,视野缺损与生理盲点及固视点的关系和视野指数的改变。结果合并高度近视的POAG视野缺损形式与非高度近视的POAG视野缺损形式相似,差异无显著性(早期POAG,X~2=0.000138,P>0.05,中晚期POAG,X~2=1.1494,P>0.05)。合并高度近视的POAG视野缺损较多的与生理盲点相速或/和与固视点相近(或相连),但与非高度近视的POAG相比,差异无显著性(早期POAG,X~2=1.3892,P>0.05,中晚期POAG,X~2=2.6852,P>0.05)。随着近视度数的增加,MS值逐渐下降,MD和LV值逐渐升高。结论 合并高度近视的POAG视野缺损较多的与生理盲点和/或固视点相连或相近,近视度数越高,其视野损害越明显。  相似文献   

4.
应用Humphrey三区筛选法检查垂体大腺瘤患者的视野缺损   总被引:2,自引:0,他引:2  
目的评价Humphrey三区筛选法检查垂体大腺瘤(pituitarymacroadenoma,PMA)患者视野缺损的临床价值.方法采用全自动Humphrey静态视野计的三区筛选法,对经MRI和CT确诊的128例PMA患者和门诊30例轻度近视患者,进行中心30°76个点视野检查.结果PMA组127例(99.2%)的患者有视野缺损,111例(86.7%)的患者以颞侧(包括单眼颞侧)视野缺损为主并且呈现或趋向中线垂直分界.其敏感性(相对检查例数的百分比)为99.2%,每眼视野平均检查时间(5.8±2.2)min,而采用全阈值方法检查中心30°76个点视野的平均检查时间为(14.8±2.8)min,两者比较差异有非常显著性(t=63.6396,P<  相似文献   

5.
梁莉  凌士营  柯根杰 《实用防盲技术》2013,8(3):103-105,138
目的探讨颅咽管肿瘤患者视功能检查的重要意义及眼科医生对于颅咽管瘤患者的早期诊断的重要性。方法回顾性分析2010.7—2013.6在我院南区神经外科手术证实的73名颅咽管瘤患者的临床资料包括术前的视力、视野检查结果。结果73名颅咽管瘤患者男女比例一致,41—60岁患者所占比例最高。52%患者首发症状为视功能障碍,视力下降的患者中有71%双眼视力均低于0.3。偏盲性视野占68.6%。结论重视颅咽管瘤患者的视功能损害情况,有助于眼科医生早期诊断颅咽管瘤,有助于神经外科医生的术前、术后评估,达到控制肿瘤、降低复发率的目的。  相似文献   

6.
Visual field testing with automated perimetry is hampered by the amount of noise present in the readings. Here, we derive a physiologically accurate spatial filter to be applied to the data after patient examination. The filter was tested by a Virtual Eye computer simulation. By simulating series of stable fields it was shown that specificity of determining visual field changes was improved; while simulating progressing fields (based on a map of the optic nerve head) it was shown that sensitivity was also improved. The filter appears to reduce the noise in glaucomatous visual field data and may be clinically useful.  相似文献   

7.
池滢 《眼科研究》2011,29(11):1042-1045
葡萄膜炎是造成视功能损害的重要病因之一。视功能的评价手段包括视力、视野、对比敏感度、色党、视觉电生理等,其中,视力是最直观实用的手段。各种病因所引起的葡萄膜炎视力预后差异较大,炎症的严重程度、炎症部位、并发症不同,对视力的影响程度也不同。视力损害最常见于全葡萄膜炎患者,且年龄较大的全葡萄膜炎患者发生严重视力损害的风险增加,双眼葡萄膜炎患者炎症一般较重且不易控制。在各种病因中,结节病性葡萄膜炎、Behcet病、青少年类风湿性关节炎伴发葡萄膜炎者视力预后较差。葡萄膜炎的并发症也可以直接引起视功能损害,黄斑囊样水肿(CME)是葡萄膜炎最常见的并发症,也是引起葡萄膜炎患者视力损害最常见的原因。葡萄膜炎患者的对比敏感度、视野、视网膜电图检查同样可以遗留异常。就葡萄膜炎的视功能预后及其影响因素进行综述。  相似文献   

8.
While it is often said that structural damage due to glaucoma precedes functional damage, it is not always clear what this statement means. This review has two purposes: first, to show that a simple linear relationship describes the data relating a particular functional test (standard automated perimetry (SAP)) to a particular structural test (optical coherence tomography (OCT)); and, second, to propose a general framework for relating structural and functional damage, and for evaluating if one precedes the other. The specific functional and structural tests employed are described in Section 2. To compare SAP sensitivity loss to loss of the retinal nerve fiber layer (RNFL) requires a map that relates local field regions to local regions of the optic disc as described in Section 3. When RNFL thickness in the superior and inferior arcuate sectors of the disc are plotted against SAP sensitivity loss (dB units) in the corresponding arcuate regions of the visual field, RNFL thickness becomes asymptotic for sensitivity losses greater than about 10 dB. These data are well described by a simple linear model presented in Section 4. The model assumes that the RNFL thickness measured with OCT has two components. One component is the axons of the retinal ganglion cells and the other, the residual, is everything else (e.g. glial cells, blood vessels). The axon portion is assumed to decrease in a linear fashion with losses in SAP sensitivity (in linear units); the residual portion is assumed to remain constant. Based upon severe SAP losses in anterior ischemic optic neuropathy (AION), the residual RNFL thickness in the arcuate regions is, on average, about one-third of the premorbid (normal) thickness of that region. The model also predicts that, to a first approximation, SAP sensitivity in control subjects does not depend upon RNFL thickness. The data (Section 6) are, in general, consistent with this prediction showing a very weak correlation between RNFL thickness and SAP sensitivity. In Section 7, the model is used to estimate the proportion of patients showing statistical abnormalities (worse than the 5th percentile) on the OCT RNFL test before they show abnormalities on the 24-2 SAP field test. Ignoring measurement error, the patients with a relatively thick RNFL, when healthy, will be more likely to show significant SAP sensitivity loss before statistically significant OCT RNFL loss, while the reverse will be true for those who start with an average or a relatively thin RNFL when healthy. Thus, it is important to understand the implications of the wide variation in RNFL thickness among control subjects. Section 8 describes two of the factors contributing to this variation, variations in the position of blood vessels and variations in the mapping of field regions to disc sectors. Finally, in Sections 7 and 9, the findings are related to the general debate in the literature about the relationship between structural and functional glaucomatous damage and a framework is proposed for understanding what is meant by the question, ‘Does structural damage precede functional damage in glaucoma?’ An emphasis is placed upon the need to distinguish between “statistical” and “relational” meanings of this question.  相似文献   

9.
目的探讨原发性开角型青光眼(primaryopen-angleglaucoma,POAG)和低压性青光眼(lowtensionglaucoma,LTG)早期视野损害及视网膜神经纤维层缺损的特点。方法应用QZS-2型自动视野计全阈值程序对26例(41只眼)早期POAG和13例(15只眼)早期LTG进行定量视野测定,所有患者散瞳做视盘和视网膜神经纤维层照像,分析视网膜神经纤维层缺损的类型和程度。结果早期POAG和LTG视野损害多表现为局限性视网膜光敏感度下降,少数表现为弥漫性光敏感度下降,视野损害主要位于中心视野,少数可合并周边视野损害。中心视野平均光敏感度和短期波动与正常对照组之间差异有显著性,两型青光眼早期视野损害和视网膜神经纤维层缺损的类型及损害部位分布差异无显著性。结论早期POAG和LTG视野损害特征及视网膜神经纤维层缺损形态一致  相似文献   

10.
It is still unclear whether the contralateral line bisection error in unilateral homonymous hemianopia is caused by the visual field defect, strategic oculomotor adaptation or by additional extrastriate brain injury. We therefore simulated hemianopia in healthy participants using a gaze-contingent display paradigm and investigated its effects on manual and ocular line bisection performance and eye-movements. Although simulated hemianopia impaired line bisection and induced the adaptive oculomotor eye-movement pattern of hemianopic patients, it did not induce the contralateral bisection error, suggesting that neither the visual field defect nor oculomotor adaptation to it are the primary causes of the hemianopic bisection error.  相似文献   

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