三维OCT在开角型青光眼鉴别诊断价值

目的 探讨高分辨率三维OCT在开角型青光眼中的诊断价值.方法 采用CirrusHD-OCT对正常组94人188只眼和试验组46例92只眼进行视网膜神经纤维层厚度的检测,对比分析视盘形态和视网膜神经纤维层厚度改变.结果 正常组各部位神经纤维层厚度与性别、眼别无相关(P＞0.05).正常对照组各部位神经纤维纤维层厚度明显高于实验组,经过独立样本t检验得出差异有统计学意义(P＜0.05).根据OCT结果,并根据视野、眼压等将试验组46例92只眼诊断为青光眼的24例48只眼,大视杯22例44只眼,两个亚组各部位RNFL厚度和正常对照组相比较,视网膜神经纤维层厚度均变薄,差异有统计学意义(P＜0.05);但大视杯亚组各部RNFL厚度均高于青光眼亚组,差别有统计学意义(P＜0.05).结论 OCT可以清晰显示视网膜神经纤维层变薄的范围和区域,再配合其他检查,即可较准确、快捷鉴别原发性开角型青光眼患者,大大提高开角型青光眼的早期诊断水平,是诊断早期青光眼的不可缺少的重要检查方法之一.

Abstract：

Objective To evaluate the diagnostic value of of high-resolution three-dimensional OCT in early primary open-angle glaucoma.Methods The retinal nerve fiber layer thickness in the normal group of 94 cases (188 eyes) and experimental group (glaucoma suspect group) of 46 cases (92 eyes) were detected using the Cirrus HD-OCT,and the comparative analysis of optic disc and retinal nerve fiber layer thickness were taken.The OCT performance of normal and suspected glaucoma image features was compared.Results There was no relationship in different parts of nerve fiber layer thickness (RNFL) with gender and eyes (P ＜0.05).The thickness of nerve fiber layer of normal control group was higher than experimental group,there was statistically significant difference (P ＜0.05) by independent sample t test.Based on the measured thickness of retinal nerve fiber layer,the image features and characteristics of OCT images,vision and intraocular pressure,48 eyes of 24 patients were diagnosed with glaucoma,and 44 eyes of 22 cases were diagnosed with large cup in experimental group.RNFL thickness of different parts of the two sub-group were thinning compared with the control group,the difference was statistically significant (P ＜0.05);but large cup group showed thicker RNFL than glaucoma group,and there was the statistically significant difference (P ＜0.05).Conclusions Cirrus HD-OCT has important diagnostic value in early primary open-angle glaucoma;also can greatly increase early diagnosis in primary open-angle glaucoma.It is an important and indispensable check method.     

Diagnostic evaluation of optical coherence tomography parameters in normal, preperimetric and perimetric glaucoma patients

AIM: To compare the diagnostic ability of glaucoma parameters measured by the optical coherence tomography (OCT) in normal, preperimetric glaucoma (PPG) and perimetric glaucoma (PG) patients. METHODS: This cross-sectional observational study includes 127 eyes of 127 subjects. Patients were divided into PPG (51 eyes), PG (46 eyes), and normal controls (30 eyes) based on clinical optic disc assessment and Humphrey visual field changes. The Heidelberg Spectralis OCT machine using Glaucoma Module Premium Edition software was used to measure the retinal nerve fiber layer (RNFL) and Bruch’s membrane opening-minimum rim width (BMO-MRW) to assess the optic nerve head and ganglion cell layer (GCL) thickness in the macula. RESULTS: RNFL, MRW, and GCL thickness were all significantly thinner in PG compared to PPG and the normal group. The BMO-MRW parameters showed better specificity (>70%) at 90% specificity compared to both RNFL and GCL parameters to discriminate normal, PPG, and PG patients. All BMO-MRW parameters showed higher area under curves (AUC) compared to RNFL and GCL parameters with the highest AUC observed in the superotemporal sector of the BMO-MRW (AUC=0.819 and and 0.897 between normal and PPG and PG groups respectively). CONCLUSION: While the BMO-MRW best discriminates PPG and PG against normal eyes, GCL parameters poorly differentiate the three groups.     

The Effects of Retinal Ischemia on Retinal Nerve Fiber Layers of Patients with Retinal Vein Occlusion

Purpose: To demonstrate the effects of retinal ischemia on retinal nerve fiber layer (RNFL) and the associated visual dysfunctions.Methods :52 subjects with retinal vein occlusin (RVO) were studied both in RVO eyes and in the contra-lateral eyes via red-free light fundus photography. The semi-quantitative analysis of RNFL defects was done,and the severity of RNFL defects of the ischemic and the non-ischemic groups were compared.Results: The RNFL defects occurred in 75.5% of the total 53 eyes with RVO. The incidences of RNFL defects were significantly higher in eyes with cotton-wool spots and capillary non-perfusion than in other RVO eyes and controls. The RNFL defects were significantly severer in ischemic eyes than in non-ischemic ones. Conclusion : Retinal ischemia can result in RNFL defects, and the severity of RNFL defects was closely related to that of ischemia. Eye Science 1997; 13 :21 - 24 .     

Clinical Application of Photopic Negative Response of the Flash Electroretinogram in Primary Open-angle Glaucoma

 PURPOSE: To evaluate the diagnostic performance of the photopic negative response (PhNR) for the detection of primary open-angle glaucoma (POAG). METHODS: Fifty-two normal subjects (52 eyes) and 173 POAG patients (173 eyes) were studied. The PhNR was elicited using a white stimuli on a white background. The mean deviation (MD) and pattern standard deviation (PSD) of the visual field were measured using standard automated perimetry (SAP). Spectral domain optical coherence tomography (SD-OCT) was used to measure the mean thickness of the retinal nerve fiber layer (RNFL). RESULTS: In the glaucoma group, as compared to the normal group, the amplitudes of a-waves, b-waves and PhNR were significantly smaller (P<0.001), and the PhNR implicit time was significantly longer (P=0.004). The MD, PSD and mean thickness of the RNFL were significantly correlated with the amplitude of the PhNR (P<0.001). The area under the receiver operating characteristic curve (AUCs) for the amplitudes of a-waves, b-waves and PhNR were 0.853, 0.830 and 0.918, respectively. When the specificity was ≥95%, the sensitivities were 60.4%, 54.2% and 85.4% respectively. CONCLUSION：The PhNR amplitude was reduced even when the loss in visual field sensitivity was mild, which suggests that PhNR might be a useful indicator of early glaucoma disease.       

Comparison of the Diagnostic Ability of Retinal Nerve Fiber Layer Thickness Measured using Time Domain and Spectral Domain Optical Coherence Tomography in Primary Open Angle Glaucoma

 Purpose: To evaluate and compare the diagnostic ability of retinal nerve fiber layer (RNFL) thickness measurements using time domain (Stratus) and spectral domain (Cirrus HD) optical coherence tomography (OCT) in preperimetric and early primary open angle glaucoma (POAG). Methods: A total 62 eyes of 62 normal subjects, 47 eyes of 47 early perimetric damage POAG patients and 30 eyes of 30 preperimetric glaucoma patients were chosen in the study. All the subjects underwent peripapillary RNFL thickness measurements using Stratus OCT and Cirrus HD-OCT on the same day by a single trained operator. The RNFL thickness measured by Stratus OCT and Cirrus HD-OCT was statistically compared using paired t-tests. The relationship between RNFL thickness measured by two OCT instruments was evaluated using Pearson’s correlation coefficient. Areas under the receiver operating characteristic curves (AROC) were calculated and compared. Results: RNFL thickness measured using Stratus OCT was generally thicker than that using Cirrus HD-OCT(P＜0.05). A highly significant correlation between the two OCT instruments measurements was found in four quadrants and average RNFL thickness measurements (P＜0.001). The average RNFL thickness of Cirrus HD-OCT had significantly (P = 0.006) higher diagnostic ability (AROC = 0.951) than that of Stratus OCT (AROC = 0.881) in preperimetric glaucoma. There were no significant differences between the AROCs for other RNFL thickness parameters from Cirrus HD-OCT and Stratus OCT in preperimetric and early glaucoma (P＞0.05). Conclusion: Significant differences and an excellent correlation were noted in terms of RNFL thickness measurements using Stratus OCT and Cirrus HD-OCT. Cirrus HD-OCT presented higher diagnostic ability for preperimetric glaucoma.     

正常人黄斑厚度及视盘旁神经纤维频域OCT分析

Objective To determine normal values for macular thickness, volume and peripapillary retinal nerve fiber layer thickness(RNFL)measured by spectral domain Optical Coherence Tomography (SD-OCT)in subjects with no known retinal disease and to examine the relationship of RNFL with macular thickness. Methods Sixty-two healthy adults(124 eyes, 21-58 years old)with no known eye disease,best-corrected visual acuity 20/20, and normal intraocular pressure were enrolled. All subjects underwent a complete ophthalmologic examination to rule out any retinal diseases or glaucoma. All the OCT scans were performed by a single operator, Central point thickness(CPT)and retinal thickness(Th)in 9 Early Treatment Diabetic Retinopathy Study(ETDRS)subfields, including central subfield(CSF), were analyzed. Statistical analyses were carried out using the analysis of variance. RNFL thickness was measured around the optic nerve head using 16 automatically averaged, consecutive circular B-scans with 3.4 mm diameter. The automatically segmented RNFL thickness was divided into 7 segments. Results Overall, the mean CPT was(215.11±15.475)μ m, and mean CSF was(255.56± 16.709)μ m. The macular thickness mapping in normal persons was "horse shoe" shaped open to the temporal side. Among the ETDRS subfields, the outer nasal quadrant had the maximum thickness(352.87± 15.886)μ m. The nasal quadrant had a larger thickness and volume than temporal side(P 0.05); in the inner circle area, there was no difference between the superior and inferior retinal average thickness; on the contrary, there was a significant difference between the superior and inferior retinal average thickness and volume in outer circle area. While the distribution of peripapillary retinal nerve fiber also had marked difference. The inferior-temporally side had the most, while the nasal side had the least. Conclusions Normative values for macular thickness in otherwise healthy eyes ware measured to be(215.11 ±15.475)μ m(CPT)and(255.56± 16.709)μ m(CSF)using commercially available Spectralis SD-OCT. Normal RNFL results with SD-OCT are comparable to those reported with time-domain OCT. Due to the legible imaging characters, the SD-OCT can measure normal macular thickness and the distribution of peripapillary retinal nerve fiber accurately, which can provide objective and quantitative indexs for diagnosis and therapy of macular disease and optical neuropathy.     

The Retinal Nerve Fiber Layer Defects in Patients with Anterior Ischemic Optic Neuropathy

Purpose: To demonstrate the effects of optic nerve ischemia on retinal nerve fiber layer (RNFL) and the associated visual dysfunction.Methods: 23 patients (25 eyes) with anterior ischemic optic neuropathy (AION) underwent fundus fluorescein angiography (FFA), and then red-free light pictures were taken via SE-40 exceiter filter. All pictures were printed for RNFL analysis. Humphrey central field analysis was conducted. All data obtained from FFA and visual field defects were analysed statistically.Results: The RNFL defects and the corresponding visual field defects were presented in 23 of 25 eyes (92%). The optic disc filling defects, RNFL defects and visual field defects were found to be highly correspondent to each other. The RNFL defects were mainly the local losses of RNFL which were correspondent to the ischemic regions.Conclusion: The poor optic disc filling or ischemia can result in the RNFL defects which cause the associated visual dysfunction. Because RNFL defects are irrever-siable changes, th     

GDxVCC检测原发性开角型与可疑青光眼视网膜神经纤维层损害的对比研究

目的采用GDxVCC系统检测正常人、可疑开角型青光眼(suspected open angle glaucoma，SOAG)以及原发性开角型青光眼(primary open angle glaucoma，POAG)患者的视盘周围视网膜神经纤维层(retinal nerve fiber layer，RNFL)厚度，并进行对比分析，探讨GDxVCC系统在青光眼早期诊断中的价值。设计前瞻性对照研究。研究对象42例SOAG，36例POAG以及年龄相匹配的36例正常人参加此项研究。方法所有参加者进行视野与GDxVCC系统检查，选择一眼进行分析。采用方差分析，对SOAG、POAG、正常人的RNFL参数进行两两比较。主要指标GDxVCC检测RNFL厚度。结果POAG组与正常组问所有RNFL参数差异均有极显著意义(P=0．000)；POAG组与SOAG组间所有RNFL参数差异均有极显著意义(P=0．000)；SOAG组与正常组间椭圆平均值差异无统计学意义(P=0．234)，但其上方平均值与下方平均值及神经纤维指数差异均有统计学意义(P=0．044、P=0．045、P=0．035)，TSNIT标准差有极显著意义(P=0．000)。结论GDxVCC系统能更早地发现青光眼性RNFL结构损害，不仅可用于青光眼诊断和随访，亦可用于对可疑青光眼进行追踪。     

应用GDx VCC检测原发性开角型青光眼视网膜神经纤维层

目的 采用GDx VCC检测青光眼和正常人视网膜神经纤维层厚度(retinal nerve fiber layer,RNFL),并进行对比分析.方法 选择正常人44人44眼,原发性开角型青光眼患者45例45眼行GDx VCC检查.将获取的参数(椭圆平均值、上方平均值、下方平均值、TSNIT标准差、眼间对称性、视神经纤维指征)进行分析.结果 所有参数在正常人组与青光眼组比较中均有统计学意义(P＜0.01).GDxVCC不同参数检测青光眼RNFL缺损敏感性为68.9%～82.2%,特异性84.1%～100.0%.其中下方平均值、视神经纤维指征ROC曲线下面积为0.959、0.964.结论 GDx VCC在RNFL检查中有较高的敏感性和特异性,可客观反应受检者的RNFL情况,对于青光眼的早期诊断有一定的临床价值.     

Foveal pit morphological changes in asymptomatic carriers of the G11778A mutation with Leber’s hereditary optic neuropathy

AIM: To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy (LHON) patients with the G11778A mutation from one family. METHODS: This study was a prospective cross-sectional study. Both eyes from 16 family members (age from 9 to 47y) with the G11778A mutation were analyzed and compared with 1 eye from 20 normal control subjects. Eleven family members with the G11778A mutation but without optic neuropathy were classified as unaffected carriers (n=22 eyes). Five family members (n=10 eyes) expressed the LHON phenotype and were classified as affected patients. Retinal images of all the subjects were taken by optical coherence tomography (OCT), and an automatic algorithm was used to segment the retina to eight layers. Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry. RESULTS: Thicker foveal thickness, thinner foveal pit depth, and flatter foveal slopes were observed in unaffected carriers and affected LHON patients (all P<0.001). Further, the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers (all P<0.001). Compared with the control group, affected LHON patients had a thinner retinal nerve fiber layer (RNFL), ganglion cell layer and inner plexiform layer (GCL+IPL), and total retina (all P<0.01). The retinal nerve fiber layer (RNFL) of affected patients was 38.0% thinner than that of controls while the GCL+IPL was 40.1% thinner. CONCLUSION: The foveal pit morphology shows changes in both unaffected carriers and affects patients. RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.     

GDxVCC和SWAP及SAP在开角型青光眼早期诊断中的敏感性及特异性

目的:评价并比较青光眼早期诊断仪GDxVCC、短波视野计(SWAP)、标准自动视野计(SAP)各参数诊断早期开角型青光眼的敏感性和特异性。方法:采用GDxVCC和SWAP及SAP对正常人42例42眼和早期开角型青光眼患者84例84眼进行检查,绘制GDxVCC各参数(TSNIT,SA,IA,IES,NFI)ROC(receive operating characteristic curve)曲线,比较GDxVCC,SAP,SWAP的敏感性和特异性。结果:TSNIT,SA,IA,IES,NFI的ROC面积分别为0.77,0.76,0.80,0.85,0.87。GDxVCC,SWAP,SAP的敏感性分别为80.6%,74.2%,67.8%;特异性分别为95.2%,85.7%,76.2%。结论:GDxVCC参数中,NFI和IES是区分正常人和青光眼最有效指标。GDxVCC诊断能力优于SWAP,SWAP优于SAP。     

The retinal nerve fibre layer thickness in glaucomatous hydrophthalmic eyes assessed by scanning laser polarimetry with variable corneal compensation in comparison with age‐matched healthy children

Purpose: To compare the thickness of the retinal nerve fibre layer (RNFL) in hydrophthalmic glaucomatous eyes in children with age‐matched healthy controls using scanning laser polarimetry with variable corneal compensation (GDxVCC). Methods: Twenty hydrophthalmic eyes of 20 patients with the mean age of 10.64 ± 3.02 years being treated for congenital or infantile glaucoma were included in the analysis. Evaluation of RNFL thickness measured by GDxVCC in standard Temporal‐Superior‐Nasal‐Inferior‐Temporal (TSNIT) parameters was performed. The results were compared to TSNIT values of an age‐matched control group of 120 healthy children published recently as referential values. The correlation between horizontal corneal diameter and RNFL thickness in hydrophthalmic eyes was also investigated. Results: The mean ± SD values in TSNIT Average, Superior Average, Inferior Average and TSNIT SD in hydrophthalmic eyes were 52.3 ± 11.4, 59.7 ± 17.1, 62.0 ± 15.6 and 20.0 ± 7.8 μm, respectively. All these values were significantly lower compared to referential TSNIT parameters of age‐matched healthy eyes (p = 0.021, p = 0.001, p = 0.003 and p = 0.018, respectively). A substantial number of hydrophthalmic eyes laid below the level of 5% probability of normality in respective TSNIT parameters: 30% of the eyes in TSNIT average, 50% of the eyes in superior average, 30% of the eyes in inferior average and 45% of the eyes in TSNIT SD. No significant correlation between enlarged corneal diameter and RNFL thickness was found. Conclusions: The mean values of all standard TSNIT parameters assessed using GDxVCC in hydrophthalmic glaucomatous eyes in children were significantly lower in comparison with referential values of healthy age‐matched children.     

变化角膜补偿器偏振光激光扫描仪对青光眼的临床观察

目的　评价使用变化角膜补偿器的偏振光激光扫描仪 (GDx -VCC)对青光眼患者的定量观察。方法　对青光眼患者 91人 165眼根据有无视野异常及程度分为 :青光眼视野正常组 87眼 ,早期青光眼 5 6眼及中晚期青光眼 2 2眼 ,正常人组 3 6人 3 6眼进行GDx -VCC检查。统计各组平均视神经纤维层厚度 (RNFL)、上方及下方神经纤维层厚度、平均视盘周神经纤维层厚度标准差及视神经纤维索引因素 (NFI)。对各组值进行多组比较统计处理。结果　正常人平均视神经纤维层厚度、上方及下方神经纤维层厚度与视野有异常的青光眼各组值方差分析P <0 0 0 1;与视野正常的青光眼组各对应区域的神经纤维层厚度比较P =0 0 0 9、 0 0 0 5及 0 0 64。结论　使用变化角膜补偿器的偏振光激光扫描仪测量视神经纤维层厚度对正常人与青光眼患者有区别能力 ,能更早于视野反映视神经纤维层异常。     

The relationship between optical coherence tomography and scanning laser polarimetry measurements in glaucoma

PURPOSE: To investigate the relationship between optical coherence tomography (OCT) and scanning laser polarimetry (SLP) in measuring peripapillary retinal nerve fiber layer (RNFL) thickness in glaucomatous eyes. METHODS: Fifty glaucomatous eyes were evaluated in this study. Evaluations were analyzed two ways. First, parameters of the Stratus OCT (average thickness, superior/inferior average) and GDx VCC (TSNIT average, nerve fiber indicator (NFI), superior/inferior average) were correlated using the Pearson's correlation coefficient (r). Secondly, comparison (r) of these parameters was completed using the mean deviation (MD) of visual field defect. RESULTS: The following parameters were found to be significantly correlated (P < 0.005). TSNIT average/average thickness (r = 0.673), NFI/average thickness (r = -0.742), superior average (r = 0.841), and inferior average (r = 0.736). In the correlation analysis using the severity of visual field defect, all these parameters had statistically meaningful correlations (P < 0.005). CONCLUSIONS: GDx VCC and Stratus OCT are highly correlated in glaucomatous eyes. Therefore, peripapillary RNFL thickness measured by Stratus OCT and GDx VCC may be equally helpful in the diagnosis of glaucoma.     

Correlating structure with function in end-stage glaucoma.

BACKGROUND AND OBJECTIVE: To correlate structure and function in eyes with end-stage glaucoma. PATIENTS AND METHODS: Fifty-six eyes of 48 patients with glaucoma presenting with end-stage glaucoma underwent scanning laser polarimetry (SLP) imaging using a commercially available GDx-variable corneal compensator unit (GDx-VCC; Laser Diagnostics Technologies, Inc., San Diego, CA). End-stage glaucoma was defined by both disc appearance and standard automated perimetry visual field criteria. Standard automated perimetry parameters included: mean deviation, pattern standard deviation, and total deviation plot. GDx parameters included: TSNIT average, superior average, inferior average, TSNIT standard deviation, and nerve fiber indicator. RESULTS: The visual field mean deviation was -26.75 +/- 3.50 dB. The remaining retinal nerve fiber layer measured in this group of eyes was: TSNIT average, 29.76 +/- 5.81 microm; superior average, 30.76 +/- 6.25 microm; and inferior average, 31.14 +/- 7.20 microm. A low structure-function correlation was found when analyzing separately the superior and inferior hemifields (R2 = 0.00001, R2 = 0.0016, respectively). CONCLUSIONS: In eyes with end-stage glaucoma, very thin but existing retinal nerve fiber layer is found on SLP. Such values rarely dropped below 10 to 20 microm. A flattening of the GDx TSNIT pattern was seen, and the correlation between structure and function was not evident.     

Preperimetric glaucoma assessment with scanning laser polarimetry (GDx VCC): analysis of retinal nerve fiber layer by sectors

PURPOSE: To evaluate the capability of the GDx VCC nerve fiber analyzer to detect preperimetric glaucoma across 12 retinal nerve fiber layer (RNFL) peripapillary sectors. METHODS: Data were obtained in a cross-sectional, hospital clinic-based study; 699 eyes from 699 glaucoma suspects were enrolled in this protocol. All subjects underwent ophthalmologic examination, static automated perimetry [Humphrey 24-2 Swedish interactive threshold algorithm (SITA) Standard], optic nerve stereoscopic photographs, red-free digital RNFL photographs and GDx VCC examination. Group S included 283 normal eyes and 39 preperimetric glaucoma eyes with RNFL superior or diffuse defects in the fiber layer photographs. Group I included 324 normal subjects and 24 with preperimetric glaucoma eyes with RNFL inferior or diffuse defects in fiber layer photographs. RESULTS: Mean values of the area under the curve (AUC) for receiver operating characteristic analysis for inferior average (Inf Avg), temporal-superior-nasal-inferior temporal average (TSNIT Avg), superior average (Sup Avg), and the nerve fiber indicator were significantly less in the eyes with RNFL defects than the control group compared with the AUC for thickness at hour 12 and at hour 6 calculated from the RNFL sector density. The AUC for receiver operating characteristic analysis of the new parameters improved by 12% with respect to the best GDx VCC standard values. CONCLUSIONS: Our results confirm that the 12 sector divisions of the GDx VCC have better diagnostic reliability in preperimetric glaucoma, and are able to improve the discrimination capability between normal and early damaged RNFLs.     

GDx在青光眼早期诊断中的作用

目的:评价GDx检测RNFL厚度各参数的敏感性,特异性,准确性,阳性预测值,阴性预测值,阳性似然比,阴性似然比;比较正常人和青光眼患者GDx各参数的不同;确定GDx参数对青光眼早期诊断最有价值的指标和GDx早期诊断青光眼的能力。方法:用GDx对94例188眼正常人和88例173眼青光眼患者RNFL进行检测。将青光眼患者按视野的平均缺损程度分为早、中晚期青光眼两组。用t-test和方差分析,比较正常人RNFL参数与早、中晚期青光眼的不同;绘制GDx参数ROC曲线,比较GDx参数中ROC曲线下面积的大小;用逐步判别分析确定GDx参数中对早期青光眼诊断最有意义的指标。结果:正常人94例,平均年龄为:41.7±8.5岁;青光眼(早、中晚期)患者平均年龄:52.8±14.6岁。早期青光眼122眼,中晚期青光眼51眼,视野平均缺损(meandefect,MD;Octopus1-2-3自动视野计测量)为-1.6～23.2dB。正常人RNFL各参数与各期青光眼患者比较差异有非常显著意义(P<0.01)。GDx的TSNIT参数的敏感性和特异性为:74.0%和74.0%,准确性:86.8%,阳性预测值:73.0%,阴性预测值:76.0%,阳性似然比:2.96,阴性似然比:0.33。SA参数的敏感性和特异性为:71.1%和84.6%,准确性为77.5%,阳性预测值:80.9%,阴性预测值:76.1%,阳性似然比:4.62,阴性似然比:0.34。IA参数的敏感性和特异性为:76.3%和82.4%,准确性:78.8%,阳性预测值:80.0%,阴性预测值:79.1%,阳性似然比:4.34,阴性似然比:0.35。NFI参数的敏感性和特异性为:80.3%和67.0%,准确性:73.4%,阳性预测值:69.2%,阴性预测值:78.8%,阳性似然比:2.43,阴性似然比:0.29。GDx的TSNIT和NFI两个参数综合评价的敏感性和特异性为:76.3%和74.0%,准确性:93.3%,阳性预测值:87.7%,阴性预测值:63.2%,阳性似然比:3.05,阴性似然比:0.32。GDx两个参数综合评价时,NFI+IA结合评价的敏感性最高(88.4%),特异性最高的是SA+IA(84.6%)。如果NFI+TSNIT+SA+IA综合评价其敏感性和特异性达最高,分别是86.7%和85.6%。在特异性相同的情况下,GDx诊断早期青光眼的敏感性为66.4%,准确性:58.5%,阳性预测值:92.0%,阴性预测值:77.5%,阳性似然比:2.56,阴性似然比:0.45。中晚期青光眼诊断的敏感性为:86.3%,准确性:77.4%,阳性预测值:48.4%,阴性预测值:95.3%,阳性似然比:3.45,阴性似然比:0.18。GDx的NFI≥20时,敏感性和特异性分别为78.3%和78.7%,准确性为78.7%,阳性预测值为77.3%,阴性预测值为80.0%,阳性似然比为3.68,阴性似然比为0.28。GDx的NFI≥23时,敏感性和特异性为75.1%和84.0%,准确性为79.8%,阳性预测值为81.3%,阴性预测值为74.9%,阳性似然比为4.69,阴性似然比为0.30。GDx的NFI≥27时,敏感性和特异性分别为64.7%和91.0%,准确性为35.7%,阳性预测值为86.8%,阴性预测值为73.7%,阳性似然比为7.19,阴性似然比为0.39。GDx各参数ROC曲线下面积分别为NFI:0.84,IA:0.79,TSNIT:0.78,SA:0.77,IES:0.76。通过逐步判别分析,筛选出NFI和IA对区分早期青光眼贡献最大(F检验:P<0.01),用IA和NFI进行分析,诊断早期青光眼的敏感性和特异性分别为:88.4%和74.6%。结论:GDx为临床上提供定量检测视网膜神经纤维层厚度参数;NFI和IA是区分正常人和早期青光眼最有效指标。GDx可有助于临床上青光眼的早期诊断。     

The Study of Retinal Nerve Fiber Layer Thickness of Normal Eyes Using Scanning Laser Polarimetry

Purpoe: To evaluate retinal nerve fiber layer (RNFL) thickness measurements in local normal Chinese subjects of different age groups and analyse the correlation of RNFL thickness with age using scanning laser polarimetry (SLP, GDxVCC). To assess the reproducibility of RNFL thickness measurement with GDxVCC.Methods: The RNFL thickness of 67 normal subjects (123 eyes) were measured by GDxVCC. The average TSNIT parameters were calculated. The differences of RNFL thickness between sex, right and left eyes, superior and inferior were compared. The relationship between RNFL thickness and age was analyzed with correlation analysis and linear regression analysis. The intraclass correlation coefficients (ICC) of three images in every eye were calculated.Results: The average peripapillary RNFL thickness at the superior, inferior and whole ellipse regions in 123 eyes of 67 normal subjects were (70.30±6.76)μm, (67.35±6.77) μm and (56.87±4.53) μm, respectively. The average TNSIT standard deviation was 23.68±4.61 and the average inter-eye symmetric value was 0.86±0.11. There were significant difference of RNFL thickness between superior and inferior (t=4.952,P ＜0.001 ). There were significant difference of inferior RNFL thickness and TNSIT standard deviation between right and left eyes (P=0.005 and 0.002),while not significant difference of superior RNFL thickness and whole mean RNFL thickness between right and left eye (P=0.086 and 0.529). There was no significant difference in TSNIT parameters between different genders. There was a slight negative correlation average RNFL thickness in superior sector with age (decreased approximately 0.15 microns per year,P=0.047) in the subjects aged below 60 years old. The ICC values of RNFL thickness were ＞0.8 in superior, inferior and global.Conclusions: The RNFL thickness can be measured accurately by GDxVCC and the reproducibility of RNFL thickness measurement by GDxVCC is good. There was a slight negative correlation between average RNFL thickness in superior with age. More researches on the effects of age on RNFL thickness by GDxVCC are needed.