EARLY DETECTION OF GLAUCOMA DAMAGE

青光眼是世界范围内不可逆失明的主要原因之一。由于它是一种病程长的慢性疾病，并且直到晚期才出现症状，因此诊断和监测对于防止视神经永久性损伤至关重要。国家眼科研究所在其“视力研究：国家计划”中指出，“改进的诊断技术，包括视觉功能，视神经和神经纤维层结构的测量......“是计划目标。 在寻求更好的工具，青光眼损伤的早期诊断，我们提出了一种新的方法的基础上评估视网膜组织损失的后极，那里有丰富的神经节细胞，这是必不可少的中央视觉和青光眼丢失。我们已经开发了一种计算机化的光学方法，视网膜厚度分析仪（RTA），映射视网膜厚度在后极。 在青光眼患者的后极部通过RTA检测到视网膜厚度的大的损失，这是由于与记录的视野缺损的位置相对应的神经节细胞和神经纤维的损失。此外，在没有视野缺损的区域中发现视网膜厚度损失。根据NEI的建议，我们将使用流行病学方法，以RTA为基础，制定原发性开角型青光眼诊断和进展的可靠、有效标准。NEI已经确定了一个重要的研究问题：“青光眼中视功能丧失与视神经和视网膜神经纤维层结构变化之间的关系是什么？".我们建议研究RTA用于青光眼诊断和监测的实用性，并首次评估中枢神经节细胞和神经纤维的损失。 我们将研究：1）在横断面研究中，RTA是否可以检测到视网膜厚度相对于正常厚度的减少，在有充分记录的青光眼损伤的区域中; 2）在纵向研究中，RTA测量的特征在确诊的青光眼患者中先于新的视野丧失。 此外，第二个有前途的技术，GDx神经纤维分析仪（NFA），一种扫描激光偏振仪，测量神经纤维层延迟损失在视乳头周围区域，将进行评估和比较与RTA。总之，我们建议评估和比较RTA和NFA在识别青光眼和识别青光眼视野缺损进展风险增加的眼睛方面的敏感性、特异性、有效性和可靠性。对RTA和NFA的评估将有助于确定其作为青光眼临床管理、流行病学研究和临床试验结果指标的实用性。

Glaucoma is one of the leading causes of irreversible blindness worldwide. Because it is a chronic disease with a long course and is symptomless until the late stages, diagnosis and monitoring are essential to prevent permanent damage to the optic nerve. The National Eye Institute, in its "Vision Research: A National Plan", states that the development of "improved diagnostic techniques encompassing measures of visual function, optic nerve, and nerve fiber layer structure..." are program goals. In seeking better tools for the early diagnosis of glaucoma damage, we propose a new approach based on the assessment of retinal tissue loss at the posterior pole, where there is an abundance of ganglion cells which are essential to central vision and which are lost in glaucoma. We have developed a computerized optical method, the Retinal Thickness Analyzer (RTA), to map the retinal thickness at the posterior pole. Large losses in retinal thickness were detected by the RTA at the posterior pole of glaucoma patients due to the loss of ganglion cells and nerve fibers corresponding to the locations of documented visual field defects. Moreover, retinal thickness loss was found in areas devoid of visual field defects. In accordance with the NEI recommendation, we will use epidemiologic methods to develop reliable, valid criteria for the diagnosis and progression of primary open-angle glaucoma, based on the RTA. The NEI has identified an important research question to be addressed: "what is the relationship between visual function loss and structural changes to the optic nerve and retinal nerve fiber layer in glaucoma?". We propose to investigate the utility of the RTA for diagnosis and monitoring of glaucoma and assess, for the first time, the loss of the central ganglion cells and nerve fibers. We will examine: 1) in a cross-sectional study, whether the RTA can detect decreased retinal thickness, relative to normal thickness, in areas with well documented glaucomatous damage; 2) in a longitudinal study, the characteristics of RTA measurements which precede new visual field loss in established glaucoma patients. In addition, a second promising technology, the GDx Nerve Fiber Analyzer (NFA), a scanning laser polarimeter that measures nerve fiber layer retardation loss in the peripapillary area, will be evaluated and compared with the RTA. In sum, we propose to evaluate and compare the sensitivity, specificity, validity, and reliability of the RTA and the NFA in identifying eyes with glaucoma and in identifying eyes at increased risk of progression of glaucomatous visual field defects. This assessment of the RTA and NFA will help to establish their utility as outcome measures for clinical management of glaucoma, epidemiological research, and clinical trials.