3D-OCT对早期原发性青光眼黄斑区视网膜神经节细胞复合体及神经纤维层结构变化的评估

背景 视网膜神经纤维层(RNFL)变薄被认为是能够检测到的青光眼最早期的改变,3D-OCT对黄斑区神经节细胞复合体(mGCC)厚度的检测使得检测黄斑区节细胞的改变成为可能,为更早发现和诊断青光眼提供思路. 目的 利用3D-OCT检查系统检测早期原发性青光眼mGCC厚度及视盘周围RNFL厚度的变化,评估早期原发性青光眼视神经损害的解剖基础. 方法 对2010年12月至2012年12月在中日友好医院眼科就诊的一眼为中晚期而对侧眼为早期的原发性青光眼的10例患者采集的3D-OCT扫描图像进行回顾性分析.所有患者均符合1987年中国青光眼学组推荐的诊断标准,临床检查资料完整.患者均接受常规眼科检查和眼底3D-OCT检查,分别采用3D-macular模式、3D-macular Wide模式和3D-disc模式对原发性青光眼黄斑区、后极部和视盘进行扫描,利用检查系统自带软件对黄斑6 mm×6 mm区域的扫描结果进行分析,由黄斑中心凹向外各方向等距离分成100个小格区,每个格区面积为0.6 mm×0.6 mm,按照mGCC的变薄程度由重到轻依次以红色、黄色和灰色标记,以每个小格中的数字与其正常值比较得到与颜色匹配的、mGCC变薄程度发生的概率值(依次为P＜1％、P＜5％、P≥5％)表示.然后分析视盘旁RNFL厚度和不同部位的厚度曲线改变,并评估视盘生理凹陷的改变. 结果 10例患者患早期青光眼的眼和对侧眼视细胞层和双极细胞层厚度均未发生改变,而患中晚期青光眼的一侧眼视盘周围RNFL厚度概率图呈红色,即视盘周围RNFL层厚度明显变薄,mGCC厚度概率和黄斑区RNFL厚度概率图呈红色,即mGCC和黄斑区RNFL层厚度明显变薄;而患早期青光眼的一侧眼视野均正常,mGCC厚度概率图和黄斑区RNFL区呈黄色,即mGCC和黄斑区RNFL厚度轻微变薄;视盘周围RNFL厚度概率图呈绿色或黄色,即视盘周围RNFL厚度正常或轻微变薄.结论 原发性青光眼mGCC层厚度变薄早于视盘周围RNFL的变薄,提示青光眼视神经结构的损害始于RGCs的细胞体并早于轴突的损伤或丢失.

Evaluation of macular ganglion cell complex and peripheral retinal nerve fiber layer structural damage in early primary glaucomous eyes by 3D-OCT

Background In previous study,peripheral retinal nerve fiber layer (RNFL) thickness is considered to be the earliest structural changes which can be detected.3D-OCT can measure the thickness of macular ganglion cell complex (mGCC),which makes the detection of primary glaucoma possible in the early stage.Objective This study was to measure the thickness of mGCC and disc-peripheral RNFL in early stage of primary glaucomous eyes by 3D-OCT and assess the anatomic basis of glaucoma-induced optical nerve damage.Methods 3D-OCT images from 10 patients with advanced stage primary glaucoma in one lateral eye and early stage glaucoma in fellow eye from December 2010 to December 2012 were prospectively analyzed in China-Japan Friendship Hospital.The patients were diagnosed based on the recommended standard of National glaucoma group (1987 version) and received routine eye examination.3D-OCT scanning was performed using 3D-macular mode,3D-macular Wide mode and 3D-disc mode with TOPCON 3D-OCT 2000 system,and the images at macular 6 mm×6 mm area were analyzed.The posterior pole area was divided into 5 concentric rings from fovea toward periphery and equally subdivided into 100 small checks,with the area of 0.6 mm×0.6 mm for each.The probable values in each check were calculated as the ratio of each figure and corresponding normal value.The probable values were expressed as red color (P＜ 1％),yellow color (P＜5％) and gray color (P≥ 5％).Then the disc-periphery RNFL thickness and disc cup were evaluated.Results No evident abnormality was found in the thicknesses of photoreceptors layer and bipolar cell layer in both advanced glaucomous eyes and the early stage of glaucomous eyes in the 10 patients.Serious damage of visual field was seen in the advanced glaucomous eyes and presented with red color in the parapapillary RNFL area,mGCC area and macular RNFL area,showing an evidently attenuation of the thicknesses of parapapillary RNFL,mGCC and RNFL.However,the visual field was close normal in the early stage glaucomous eyes,and mGCC and macular RNFL showed yellow color,while green or yellow color was exhibited in the parapapillary RNFL area,indicating mGCC and macular RNFL thickness was reduced,but parapapillar RNFL thickness was near normal.Conclusions The change of mGCC thickness is earlier than that of peripheral RNFL at optic disc in primary glaucomaous eyes,which may imply that the disappear of macular ganglion cell body is earlier than that of the axon.