Analysis of retinal nerve fiber layer thickness measured by optical coherence tomography in glaucomatous eyes with hemifield defect

PURPOSE: To analyze the retinal nerve fiber layer thickness(NFLT) as measured by optical coherence tomography(OCT) in glaucomatous eyes with hemifield defect and to evaluate the most effective parameter for the diagnosis of glaucoma with OCT. METHODS: One hundred eighty four(184) normal eyes(128 subjects) and 108 open-angle glaucomatous eyes(87 subjects) with superior or inferior hemifield defects verified by Humphrey field analyzer(HFA) were measured for NFLT with OCT. The correlations between NFLT and mean deviation on HFA were calculated. In combination with normal eye data, receiver operating characteristic curve(ROC curve) and AUC(area under the curve) of each NFLT in the affected hemifield were evaluated for the diagnosis of glaucoma. RESULTS: NFLT in both affected and unaffected hemifields was significantly correlated with mean deviation in HFA. An average of four 30 degrees segments close to the temporal side in the affected hemifield (parameter A120) had the highest correlation(r = 0.571) and the highest AUC(0.948) among all parameters. CONCLUSIONS: NFLT in the unaffected visual field decreases with the progression of glaucomatous damage. We suggest that the parameter A120 is the best indication in a diagnosis of glaucoma when measuring NFLT by OCT.     

Evaluation of the effect of aging on retinal nerve fiber layer thickness measured by optical coherence tomography

PURPOSE: To evaluate the relationship between age and retinal nerve fiber layer (RNFL) thickness in normal subjects, as measured by optical coherence tomography (OCT). METHODS: One hundred and forty-four normal subjects (144 eyes), ranging from 16 to 84 years of age, were enrolled in this cross-sectional study. The RNFL thickness was determined using OCT with three circle scans 3.4 mm in diameter. RESULTS: The average RNFL thickness was inversely correlated with age (r = -0.348, p < 0.001). Analyzing the quadrants as a parameter, RNFL thickness in the superior, temporal and inferior quadrants also decreased with age. Using 30-degree segments, there were significant correlations between age and the RNFL thickness of temporal segments (7-11 o'clock). The average RNFL thickness had the highest correlation among all parameters (r = -0.348, p < 0.001). Regarding nasal quadrant thickness, RNFL ratios (average, superior, temporal and inferior RNFL thickness relative to the nasal quadrant thickness) were not significantly correlated with age. The refractive error did not affect RNFL thickness (r = 0.091, p = 0.276). CONCLUSION: Our study revealed that RNFL thickness, in particular in the temporal quadrant, measured by OCT significantly decreased with age. Age has to be taken into consideration when we compare RNFL thickness between normal and glaucomatous eyes.     

相干光断层扫描仪检测视网膜神经纤维层厚度影响因素分析

目的运用相干光断层扫描仪(OCT)测量正常人视网膜神经纤维层(RNFL)厚度并探讨其影响因素。方法运有Stratus OCT 4.0测量202例不同年龄及不同屈光度正常人(年龄8～74岁,屈光度-8～ 4D)各钟点、象限及平均RNEL厚度,建立多元线性回归方程探讨年龄、屈光度、性别及视盘面积对RNEL厚度的影响。结果①正常人RNFL平均厚度为108.63±9.70μm,下方象限RNFL(I):139.17±15.79μm最厚,其次为上方象限(S):134.61±17.80μm,颞侧象限(T):85.37±21.25μm,鼻侧象限(N):75.19±17.06μm最薄,即I>S>T>N。②平均及上、下、颞侧象限RNFL厚度均随年龄增长而变薄,40岁以后趋势明显,50岁以上者显著变薄,仅鼻侧象限RNFL厚度与年龄无关;平均及上、下、鼻侧象限RNFL厚度均随近视度数增加而变薄,且高度近视者显著薄于正视者。而颞侧象限RNFL厚度却随近视度数增加而变厚,高度近视者显著薄于正视者。而颞侧象限RNFL厚度却随近视度数增加而变厚,高度近视者显著厚于正视者;平均及各象限RNFL厚度除下方外均与性别无关,仅下方像限女性较男性厚;应用机器自动辨认视盘边界时,未发现RNFL厚度与视盘面积有关。结论OCT测得的正常RNFL厚度主要与年龄、屈光度有关;仅下方象限RNFL厚度与性别有关;应用机器自动辨认视盘边界时,未发现RNFL厚度与视盘面积有关;儿童可以较好地配合OCT检查并获得较为可靠的测理结果;应用规范、统一的OCT测量标准,建立人群为基础的并经相关影响因素校正的中国人RNFLJE常值数据库对青光眼的早期诊断是非常必要的。     

Age and retinal nerve fiber layer thickness measured by spectral domain optical coherence tomography

Purpose

To evaluate the association between age and peripapillary retinal nerve fiber layer (RNFL) thickness measured by Cirrus high-definition (HD) spectral domain optical coherence tomography (OCT) in healthy Korean subjects.

Methods

A total of 302 eyes from 155 healthy Korean subjects (age range, 20 to 79 years) underwent RNFL thickness measurements using the Cirrus HD-OCT. Average, quadrant, and clock-hour RNFL thickness parameters were analyzed in terms of age using linear mixed effect models.

Results

Average RNFL demonstrated a slope of -2.1 µm per decade of age (p < 0.001). In quadrant analysis, superior (-3.4 µm/decade, p < 0.001) and inferior (-2.9 µm/decade, p < 0.001) quadrants showed steeper slopes, whereas temporal (-1.1 µm/decade, p < 0.001) and nasal (-1.0 µm/decade, p < 0.001) quadrants revealed shallower slopes. Among the 12 clock-hour sectors, clock hours 6 (-4.5 µm/decade, p < 0.001) and 1 (-4.1 µm/decade, p < 0.001) showed the greatest tendency to decline with age; RNFLs of the 3 (-0.2 µm/decade, p = 0.391) and 4 (-0.6 µm/decade, p = 0.052) o''clock hour sectors did not show significant decay.

Conclusions

RNFL thickness was associated with age, especially in superior and inferior areas. The topographic distribution of correlation between age and RNFL thickness was not uniform.     

Retinal sensitivity and retinal nerve fiber layer thickness measured by optical coherence tomography in glaucoma

PURPOSE: To define the relationship between retinal light sensitivity and peripapillary retinal nerve fiber layer (RNFL) thickness as measured using the Stratus optical coherence tomograph (OCT). DESIGN: Prospective study. METHODS: SETTING: Institutional. STUDY POPULATION: A total of 126 healthy subjects, 42 patients with ocular hypertension (OHT) and 64 patients with primary open-angle glaucoma (POAG) were examined by the 24/II program of the Humphrey Field Analyzer (Carl Zeiss Meditec, Inc, Dublin, California, USA), and the Fast RNFL Thickness examination of the OCT. Individual visual field (VF) test scores and peripapillary RNFL thickness measurements were grouped into six topographically corresponding sectors whose mean values were then calculated. One eye per patient was randomly chosen. MAIN OUTCOME MEASURES: The correlations between mean retinal sensitivity (expressed both in decibel and unlogged scales) and RNFL thickness were described with linear and logarithmic regression analyses. RESULTS: With reference to all 232 individuals, the equation that best explained the model was logarithmic when using the decibel scale, and either linear or logarithmic when using the unlogged scale. A statistically significant, age-adjusted correlation between function and structure was found in most sectors both using the decibel (logarithmic regression analysis r(2) 0.24 to 0.61, P < .001), and the unlogged scale (r(2) 0.37 to 0.53, P < .001 in both linear and logarithmic regression analyses). CONCLUSIONS: When using the decibel scale, the logarithmic equation may better explain the function/structure relationship between retinal sensitivity and OCT-measured RNFL thickness along a wide spectrum of glaucoma continuum. These results support the need to combine functional and structural tests in the detection of early glaucoma.     

Evaluation of heredity as a determinant of retinal nerve fiber layer thickness as measured by optical coherence tomography

PURPOSE: To study to what extent genetic factors determine the retinal nerve fiber layer thickness (RNFLT) in healthy subjects. METHODS: In vivo peripapillary optical coherence tomography (OCT), clinical examination, lens fluorescence, and fundus photography were performed on both eyes of 25 monozygotic and 25 dizygotic same-sex pairs of twins. The cross-sectional study included twins aged from 20 to 45 years recruited from a population-based register. Only healthy eyes were included. Main outcome variables: peripapillary OCT RNFLT, reproducibility, and heritability (the proportion of the total observed variance statistically attributable to genetic factors). RESULTS: The within-pair difference in RNFLT was 4.6% (0.7%-15.2%; median [range]) in monozygotic versus 7.3% (0.2%-20%) in dizygotic twins (P = 0.032, Mann-Whitney test). The RNFLT heritability was 66%. The RNFLT measurement was found to decrease 3.8 microm per decade (P = 0.003). The RNFLT heritability increased to 82%, when corrected for the effect of age and excluding within-pair refractive differences of 2 D or more. The signal-to-noise ratio correlated with lens transmittance (r = 0.25, P = 0.012), age (r = -0.29, P = 0.004), and RNFLT (r = 0.43, P < 0.001). Intravisit RNFLT reproducibility was 4.2%. CONCLUSIONS: Peripapillary RNFLT in healthy adults, as measured by OCT, was determined predominantly by genetic factors in this study population. Theoretically, these factors may involve variations in the number of ganglion cells and nerve fiber formations early in life and/or in the rate at which these structures are subsequently lost.     

Peripapillary retinal nerve fiber layer thickness in normal Japanese eyes measured with optical coherence tomography

Purpose  

To measure peripapillary retinal nerve fiber layer (RNFL) thickness in healthy Japanese individuals using optical coherence tomography (OCT).     

Relationship between visual field sensitivity and retinal nerve fiber layer thickness as measured by optical coherence tomography

PURPOSE: To evaluate the strength and pattern of the relationship between visual field (VF) sensitivity and retinal nerve fiber layer (RNFL) thickness as measured by StratusOCT (Carl Zeiss Meditec, Inc., Dublin, CA). METHODS: Three hundred eleven subjects--45 normal, 102 with preperimetric glaucoma (PPG), and 164 with primary open-angle glaucoma (POAG)--were enrolled in this cross-sectional study. The relationship between RNFL thickness and VF sensitivity, expressed as mean deviation (MD) and mean sensitivity (MS), were evaluated with linear and nonlinear regression models, and the coefficient of determination (R(2)) was calculated. The association between RNFL/VF was described by bivariate Pearson correlation coefficients. RESULTS: The correlation of RNFL and the VF parameters MS and MD in normal and PPG eyes was not significant. In POAG eyes, RNFL and both MS (r = 0.733) and MD (r = 0.718) correlated significantly. Linear regression plots of MS or MD against RNFL thickness demonstrated a negligible degree of determination in normal (R(2) = 0.0378 and 0.0121, respectively) and PPG groups (R(2) = 0.0215 and 0.0151, respectively), whereas their relationship fit a curvilinear regression model (R(2) = 0.6947 and 0.723) in the POAG group. Receiver operating characteristic (ROC) curves describing the VF parameters and average RNFL thickness (AVG) were evaluated to differentiate PPG from POAG eyes. Repeated analysis with the best-performing test parameter, pattern standard deviation (PSD) (AUROC = 0.937) with a cutoff of 1.9 dB, showed that regression profiles in the POAG group with PSD >1.9 dB maintained a strong curvilinear RNFL/VF relationship, whereas those with PSD <1.9 dB exhibited a relationship almost indistinguishable from the PPG group. CONCLUSIONS: Evaluation of the structure-function relationship in normal subjects and those with PPG or POAG showed strong curvilinear regression in POAG eyes with PSD >1.9 dB and RNFL AVG thickness below 70 microm, whereas no correlation was detectable above these values.     

光学相干断层成像术测量视网膜神经纤维层厚度在青光眼早期诊断中的意义

目的:探讨光学相干断层成像术(optical coherence tomography,OCT)测量视网膜神经纤维层厚度(retinal nerve fiber layer,RNFL)在青光眼早期诊断中的意义.方法:应用OCT测量正常人62例101眼和青光眼患者41例64眼的RNFL厚度,将正常人和青光眼患者的各象限和平均RNFL厚度进行比较;并比较各期青光眼的RNFL厚度;计算平均RNFL厚度和视野平均缺损的相关性,计算OCT测量平均RNFL厚度的敏感性和特异性.结果:青光眼患者和早期青光眼患者的各象限和平均RNFL厚度均比正常人减少,差异有统计学意义(P＜0.05).随着青光眼病程的发展,RNFL厚度逐渐下降.平均RNFL厚度和视野平均缺损呈高度正相关(r=0.722,P=0.000),OCT测量平均RNFL厚度的敏感性为85.9%,特异性为97.0%.结论:OCT测量RNFL厚度为青光眼早期诊断提供了一种新的手段.     

Evaluation of retinal nerve fiber layer thickness in the area of apparently normal hemifield in glaucomatous eyes with optical coherence tomography

PURPOSE: The authors investigated the correlation between visual field defects detected by automated perimetry and the thickness of the retinal nerve fiber layer measured with optical coherence tomography, and examined whether there is a decrease in retinal nerve fiber layer thickness in the apparently normal hemifield of glaucomatous eyes. PATIENTS AND METHODS: Forty-one patients with glaucoma and 41 normal control subjects were included in this study. Statistical correlations between the sum of the total deviation of 37 stimuli of each hemifield and the ratio of decrease in retinal nerve fiber layer thickness were evaluated. The statistical difference between the retinal nerve fiber layer thickness of the apparently normal hemifield in glaucomatous eyes and that of the corresponding hemifield in normal subjects was also evaluated. RESULTS: There was a statistically significant correlation in the sum of the total deviation and retinal nerve fiber layer thickness decrease ratio (superior hemifield, P = 0.001; inferior hemifield, P = 0.003). There was no significant decrease in retinal nerve fiber layer thickness in the area that corresponded to the normal visual field in the hemifield defect with respect to the horizontal meridian in glaucomatous eyes (superior side, P = 0.148; inferior side, P = 0.341). CONCLUSIONS: Optical coherence tomography was capable of demonstrating and measuring retinal nerve fiber layer abnormalities. No changes in the retinal nerve fiber layer thickness of the apparently normal hemifield were observed in glaucomatous eyes.     

高度近视眼后极部视网膜厚度的光学相干断层成像测量

目的 应用光学相干断层成像(OCT)技术探讨高度近视眼黄斑区及视盘周围视网膜神经纤维层(RNFL)的厚度变化 方法 前瞻性病例对照研究随机选取2011年3月至2011年8月在金华市中心医院眼科就诊并行OCT检查的高度近视患者33例(33眼)和正常对照者35例(35眼),分别测量其黄斑中心凹和距中心凹750μm处的四q个方向上的RNFL厚度,并测量视盘周围12个钟点方向上的RNFL厚度,比较两组之间有无显著性差异.两组间的比较采用独立样本t检验 结果 高度近视眼组黄斑区各方向RNFL.厚度均明显小于正常对照组(t=3.08,P＜0.01),而视盘周围RNFL厚度较正常对照组有变薄趋势,但差异无统计学意义 结论 高度近视眼黄斑区RNFL厚度明显低于正常眼视盘周围的RNFL厚度有变薄的趋势,因此在对合并高度近视的青光眼眼患者进行视盘周围RNFL厚度评价时,需持谨慎的态度,0CT能够精确量化RNFL厚度,可重复性好.     

Retinal nerve fibre thickness measured with optical coherence tomography accurately detects confirmed glaucomatous damage

AIM: To assess the accuracy of optical coherence tomography (OCT) in detecting damage to a hemifield, patients with hemifield defects confirmed on both static automated perimetry (SAP) and multifocal visual evoked potentials (mfVEP) were studied. METHODS: Eyes of 40 patients with concomitant SAP and mfVEP glaucomatous loss and 25 controls underwent OCT retinal nerve fibre layer (RNFL), mfVEP and 24-2 SAP tests. For the mfVEP and 24-2 SAP, a hemifield was defined as abnormal based upon cluster criteria. On OCT, a hemifield was considered abnormal if one of the five clock hour sectors (3 and 9 o'clock excluded) was at <1% (red) or two were at <5% (yellow). RESULTS: Seventy seven (43%) of the hemifields were abnormal on both mfVEP and SAP tests. The OCT was abnormal for 73 (95%) of these. Only 1 (1%) of the 100 hemifields of the controls was abnormal on OCT. Sensitivity/specificity (one eye per person) was 95/98%. CONCLUSIONS: The OCT RNFL test accurately detects abnormal hemifields confirmed on both subjective and objective functional tests. Identifying abnormal hemifields with a criterion of 1 red (1%) or 2 yellow (5%) clock hours may prove useful in clinical practice.     

Retinal nerve fiber layer thickness measured with optical coherence tomography is related to visual function in glaucomatous eyes

PURPOSE: To determine the relationship between areas of glaucomatous retinal nerve fiber layer thinning identified by optical coherence tomography and areas of decreased visual field sensitivity identified by standard automated perimetry in glaucomatous eyes. DESIGN: Retrospective observational case series. PARTICIPANTS: Forty-three patients with glaucomatous optic neuropathy identified by optic disc stereo photographs and standard automated perimetry mean deviations >-8 dB were included. METHODS: Participants were imaged with optical coherence tomography within 6 months of reliable standard automated perimetry testing. MAIN OUTCOME MEASURES: The location and number of optical coherence tomography clock hour retinal nerve fiber layer thickness measures outside normal limits were compared with the location and number of standard automated perimetry visual field zones outside normal limits. Further, the relationship between the deviation from normal optical coherence tomography-measured retinal nerve fiber layer thickness at each clock hour and the average pattern deviation in each visual field zone was examined by using linear regression (R(2)). RESULTS: The retinal nerve fiber layer areas most frequently outside normal limits were the inferior and inferior temporal regions. The least sensitive visual field zones were in the superior hemifield. Linear regression results (R(2)) showed that deviation from the normal retinal nerve fiber layer thickness at optical coherence tomography clock hour positions 6 o'clock, 7 o'clock, and 8 o'clock (inferior and inferior temporal) was best correlated with standard automated perimetry pattern deviation in visual field zones corresponding to the superior arcuate and nasal step regions (R(2) range, 0.34-0.57). These associations were much stronger than those between clock hour position 6 o'clock and the visual field zone corresponding to the inferior nasal step region (R(2) = 0.01). CONCLUSIONS: Localized retinal nerve fiber layer thinning, measured by optical coherence tomography, is topographically related to decreased localized standard automated perimetry sensitivity in glaucoma patients.     

光学相干断层成像术测量视网膜神经纤维层厚度对开角型青光眼早期诊断的意义

目的 评价光学相干断层成像术（ＯＣＴ）测量视网膜神经纤维层（ＲＮＦＬ）厚度在原发性开角型青光眼（ＰＯＡＧ）早期诊断中的意义。方法 正常对照组共１２０例（１６９眼）,青光眼患者９６例（１３２眼）并分为早期、进展期及晚期３组。采用ＯＣＴ进行盘周ＲＮＦＬ厚度的测量。结果 青光眼各期ＲＮＦＬ厚度均显著薄于正常对照组,其中早期ＲＮＦＬ厚度异常率为５０％。ＲＮＦＬ在青光眼诊断中的敏感性和特异性分别为７９．５４％与８０．４７％。结论 青光眼早期ＲＮＦＬ厚度已异常变薄,ＯＣＴ对ＲＮＦＬ厚度的测量为青光眼诊断提供了一项新的指标。     

Modelling the normal retinal nerve fibre layer thickness as measured by Stratus optical coherence tomography

Background The variation in retinal nerve fibre layer thickness (RNFLT) as measured by Stratus optical coherence tomography (OCT) in healthy subjects may be reduced when the effect on RNFLT measurements of factors other than disease is corrected for, and this may improve the diagnostic accuracy in glaucoma. With this perspective we evaluated the isolated and combined effects of factors potentially affecting the Stratus OCT RNFLT measurements in healthy subjects.Methods We included 178 healthy eyes of 178 subjects between 20 and 80 years of age. Participants underwent an extensive eye examination. Stratus OCT RNFLT was measured by three standard protocols, two with high and one with standard image resolution. Effects on RNFLT of age, gender, refractive error, axial length, lens nuclear colour and opalescence, intra-ocular pressure (IOP), and optic disc size were examined by univariate and multivariate analyses.Results Age, refractive error, axial length, and lens nuclear colour and opalescence affected RNFLT in univariate analyses, whereas gender, IOP, and optic disc size had no significant effect. In multivariate analyses only age in combination with refractive error, or with axial length, was significant and explained 14.7–17.6% (R ²) of the total variation of RNFLT, approximately 50% more than age alone. RNFLT decreased by 2.6–2.9 μm per increasing decade of age and increased by 1.5–1.8 μm per more positive diopter of spherical equivalent using full-circle measurements of the three standard protocols. These effects varied between measurement sectors.Conclusions RNFLT as measured by Stratus OCT standard protocols was significantly affected by age and refractive status. The effect on global RNFLT of a difference in refractive error of 10 diopters corresponded to the effect of a difference in age of 60 years. Theoretically, the effect of refractive status may be explained by artefacts of RNFLT measurement circle placement. The results suggest that the diagnostic accuracy of Stratus OCT may be improved by considering refractive status in addition to age when RNFLT is measured. For this purpose spherical equivalent seems as effective as axial length.