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.     

Correlation of automated visual field parameters and peripapillary nerve fiber layer thickness as measured by scanning laser polarimetry

PURPOSE: To correlate Humphrey visual field mean sensitivity and peripapillary nerve fiber layer thickness as measured by scanning laser polarimetry. METHODS: The authors studied 54 eyes of 34 patients who visited a university-based glaucoma clinic and had undergone scanning laser polarimetry and Humphrey perimetry within 6 months. The study population included normal patients and those with glaucoma, ocular hypertension, and glaucoma suspect. The authors correlated visual field sensitivity with peripapillary nerve fiber thickness, and visual field mean deviation with the average deviation from the normal nerve fiber layer thickness. They also correlated the visual field mean deviation with all available GDx Nerve Fiber Analyzer parameters. RESULTS: The visual field mean sensitivity and deviation showed a bilinear correlation to peripapillary nerve fiber layer thickness. The visual field mean sensitivity changed little when the nerve fiber layer thickness was greater than 70 microm. The nerve fiber layer thickness below this level was associated with a rapid decrease in the visual field sensitivity. Similarly, the visual field mean deviation was close to 0 dB when the nerve fiber layer was within -10 microm of the normal value; below this thickness, the mean deviation became substantially more negative. There was a large individual variability around the bilinear fit. Of the scanning laser polarimetry parameters, a calculated index, referred to as the number, had the highest correlation with the Humphrey mean deviation. CONCLUSION: The bilinear correlation and its variability between the scanning laser polarimetry and visual field parameters make it difficult to predict the result of one from the other. In general, the correlation between the two is better when there is a significant visual field defect than when the visual field is close to normal.     

视野缺损计分与OCT测量RNFL厚度的关系

目的:探讨视野缺损计分值与视网膜神经纤维层损害的关系。方法:收集开角型青光眼患者30例30眼,分别进行OCT视网膜神经纤维层厚度及视野检查。根据视野结果进行视野缺损计分并分组。组间分析各象限视网膜神经纤维层厚度值与视野缺损计分,平均缺损(MD)的关系和相关性。结果:根据视野缺损计分将患者分为四组,上侧、下侧,平均视网膜神经纤维层厚度在组间有显著性差异(P=0.010,P<0.01,P<0.01)。四组间随视野缺损程度加重,上侧、下侧,平均视网膜神经纤维层厚度变薄。在重度缺损组视网膜神经纤维层厚度最薄。视野缺损计分与上、下、鼻、颞侧及平均视网膜神经纤维层厚度均明显负相关(r=-0.610,P=0.001;r=-0.779,P<0.01;r=-0.463,P=0.015;r=-0.500,P=0.008;r=-0.782,P<0.01),视野指数MD与上侧,下侧及平均RNFL厚度明显正相关(r=0.557,P=0.003;r=0.431,P=0.025;r=0.532,P=0.004)。结论:视野缺损计分对视野缺损的客观评估,与OCT测得的视网膜神经纤维层厚度的结果负相关,是反应青光眼视神经损伤的可靠的观察指标。     

Normal retinal nerve fiber layer thickness in the peripapillary region measured by scanning laser polarimetry.

PURPOSE: To measure retinal nerve fiber layer thickness (RNFLT) as a function of distance from the optic nerve head using a confocal scanning laser polarimeter, such as the Nerve Fiber Analyzer (GDx). METHODS: Twenty eyes of 20 healthy patients were recruited for this study. Each patient had a normal visual field and a healthy optic nerve head, which was assessed by slit-lamp biomicroscopy using a 90-diopter lens and by a scanning laser ophthalmoscope. Using the GDx, RNFLT was calculated from 1.1 disc diameters (DD) to 2.5 DD in 0.1-DD increments from the outer edge of the optic disc rim. RNFLT was successively evaluated for the entire annulus surface, for each quadrant, and for every 10 degree sector. RNFLT was calculated in retardation degrees. Differences in RNFLT were calculated by analysis of variance. RESULTS: When the entire RNFLT was considered, the measurements close to the optic nerve head (at 1.1 and 1.2 DD) were found to be significantly (0.05 < or = P < or = 0.01) different from those measured far from the disc (at 2.4 and 2.5 DD). The inferior quadrant had the greatest RNFLT followed by the superior quadrant. When RNFLT was analyzed for every 10 degrees, RNFLT at 1.1 and 1.2 DD was significantly (P < or = 0.001) different from that measured at 2.4 and 2.5 DD in almost all 36 sectors. In the 36 considered sectors, no significant difference was found for all the RNFLT values that were calculated in all the positions of the annulus surface between 1.1 and 1.7 DD. CONCLUSION: From these data, peripapillary RNFLT is shown to be significantly (P < or = 0.001) thinner in the periphery (2.5 DD) than around the optic disc (1.1 DD). However, the lack of any difference in RNFLT from 1.1 to 1.7 DD suggested that the mild variations to locate the optic disc contour line do not change the results of the analysis if the RNFLT is calculated within 1.8 DD.     

Longitudinal relationship between retinal nerve fiber layer thickness parameters assessed by scanning laser polarimetry (GDxVCC) and visual field in glaucoma

Purpose  

To investigate the longitudinal relationship between retinal nerve fiber layer (RNFL) thickness parameters assessed by scanning laser polarimetry with variable corneal compensation (GDxVCC) and visual field parameters obtained with the Humphrey field analyzer (HFA) in patients with glaucoma, and to assess the usefulness of GDxVCC in longitudinal follow-up.     

Retinal nerve fiber layer thickness measurements with scanning laser polarimetry predict glaucomatous visual field loss

PURPOSE: To assess whether baseline retinal nerve fiber layer (RNFL) measurements obtained with a scanning laser polarimeter, the GDx Nerve Fiber Analyzer, (Laser Diagnostic Technologies Inc., San Diego, California) are predictive of development of repeatable glaucomatous visual field damage in glaucoma suspect eyes. DESIGN: Cohort study. METHODS: Participants were recruited from the UCSD longitudinal Diagnostic Innovations in Glaucoma Study (DIGS). One eye from each of 160 glaucoma suspects with normal standard automated perimetry (SAP) visual fields at baseline was studied. Study eyes were divided into convert and nonconvert groups based on the development of three consecutive glaucomatous visual fields during follow-up. SLP parameters, IOP, vertical cup disk ratio, stereophotograph assessment as glaucoma or normal, corneal thickness, and visual field indices were included in univariate and multivariate Cox proportional hazards models to determine which SLP RNFL and ocular parameters were predictive of visual field conversion. RESULTS: Sixteen (10%) eyes developed repeatable visual field damage (converts) and 144 (90%) did not (nonconverts). Mean (95%CI) follow-up time until visual field conversion for convert eyes was 2.7 (1.7, 3.6) years. Mean total follow-up of nonconvert eyes was 3.8 (3.5, 4.1) years. Four out of thirteen examined baseline SLP parameters and baseline SAP Mean Deviation (MD), SAP Pattern Standard Deviation (PSD), and glaucomatous stereophotograph assessment were significant univariate predictors of visual field conversion. In multivariate models adjusted for age, IOP and CCT, SLP parameters inferior ratio, ellipse modulation, and UCSD linear discriminant function (LDF) were significant predictors of visual field conversion. When SAP PSD and stereophotograph assessment were also included in the multivariate model inferior ratio and UCSD LDF remained independently predictive of visual field loss. CONCLUSIONS: Thinner baseline SLP RNFL measurements were independent predictors of visual field damage. In addition to thinner SLP RNFL measurements, higher baseline SAP PSD, and baseline glaucomatous stereophotograph assessment each contributed to an increased risk of the development of abnormal visual fields in glaucoma suspect patients. SLP RNFL measurements were independently predictive of future visual loss even when age, IOP, CCT, vertical cup disk ratio, and SAP PSD were included in the model.     

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

PURPOSE: To investigate the spatial relationship between retinal nerve fiber layer (RNFL) thickness measured with optical coherence tomography (OCT) and visual field sensitivity (VFS) measured by standard automated perimetry (SAP) in chiasmal compression. METHODS: Twenty-six patients with chiasmal compression were enrolled. RNFL thickness was measured with the StratusOCT and VFS with SAP (Humphrey Field Analyzer; both from Carl Zeiss Meditec, Dublin, CA). Relationships between RNFL thickness (in clock hours, hemifields, and sectors) and VFS (zones were divided into hemifields, quadrants, and sectors based on a validated visual field map) expressed in a decibel scale and 1/lambert (L) were evaluated by linear and nonlinear regression. Coefficients of determination (R(2)) were calculated by using a multivariate model. RESULTS: Average RNFL thickness correlated strongly with pattern standard deviation (PSD; R = 0.622) and mean deviation (MD; R = 0.413). The four strongest correlations were between the 8 o'clock OCT position (temporal disc), with the temporal hemifield (R = -0.813), the superotemporal quadrant (R = -0.847), the inferotemporal quadrant (R = -0.855), and the field sector representing the papillomacular bundle (R = -0.809). Coefficients of determination improved significantly in all sectors when time since surgery was included in the regression model-most notably, average thickness and 1/L (R(2) = 0.35-0.49), the decibels (R(2) = 0.31-0.47), and the temporal sector (R(2) = 0.44-0.57). CONCLUSIONS: This is the first study to compare the structure-function correlation of RNFL measured by OCT with SAP in patients with chiasmal compression. RNFL is topographically related globally and sectorally to decreased SAP, with the temporal sectors showing the strongest correlations. The correlation between RNFL and VFS strengthens as the time from surgical intervention increases.     

OCT检测原发性开角型青光眼神经纤维层厚度与视野光敏感度相关性分析

目的探讨光学相干断层成像（optical coherence tomography,OCT）检测原发性开角型青光眼（primary open angle glaucoma,POAG）视网膜神经纤维层（retinal nerve fiber layer,RNFL）厚度与视野光敏感度均值（meansensitivity,MS）的相关性。方法分别采用Zeiss-Humphrey,Stratus TM,Version3.0OCT和OCTOPUS101全自动电脑视野分析仪中对正常组患者（25例30眼）和POAG组患者（52例81眼）进行检测,将各个POAG组中心30°视野内全视网膜MS和OCT检测的RNFL厚度值与正常组进行比较,并做相关性分析。结果早、中期和晚期POAG组MS分别为（22.13±1.96）dB、（18.22±2.66）dB、（12.75±4.05）dB均低于正常组（26.55±2.11）dB,P〈0.05;中期和晚期POAG组RNFL值（87.95±15.60）μm、（65.31±15.88）μm均低于正常组（99.65±12.17）μm,P〈0.05;早期POAG组总RNFL值虽低于正常组,但与正常组相比差异无统计学意义（P〉0.05）。将其RNFL厚度测量值按4个象限进行独立分析,发现在早期PO-AG组其颞上（95.06±23.46）μm和颞下（92.52±24.31）μmRNFL值与正常组（106.37±16.12）μm、（107.32±12.70）μm分别相比差异有统计学意义（P〈0.05）。所有被检测者视野MS与RNFL厚度呈正的直线相关（r=0.648,P=0.000）;POAG组MS与RNFL厚度呈正的直线相关（r=0.634,P=0.000）;正常组MS与RNFL厚度无直线相关性（r=0.263,P=0.168）。结论MS与RNFL厚度有很好的直线相关性,通过OCT对RNFL厚度的检测,有助于了解和监测POAG对RNFL的损伤,是一种很有价值和潜力的POAG客观辅助诊断方法。     

Effect of laser in situ keratomileusis on retinal nerve fiber layer thickness measurements by scanning laser polarimetry

PURPOSE: To determine the effect of laser in situ keratomileusis (LASIK) on retinal nerve fiber layer measurements by scanning laser polarimetry in a large clinical trial. SETTING: Asan Medical Center, University of Ulsan, Department of Ophthalmology, Seoul, Korea. METHODS: Scanning laser polarimetry measurements were performed in 59 eyes of 59 consecutive patients who had LASIK. The mean retardation values of the whole measurement ellipse and of the superior, inferior, temporal, and nasal sectors of the ellipse before and after LASIK were compared statistically. RESULTS: The mean spherical equivalent refractive error was -6.10 diopters (D) +/- 2.34 (SD) (range -1.19 to -15.50 D) preoperatively and -0.31 +/- 0.52 D (range +0.68 to -2.13 D) postoperatively. The mean ablation depth was 94.0 +/- 30.49 microm (range 28.0 to 161.1 microm). The mean postoperative retardation values of all the sectors and of the superior, temporal, inferior, and nasal sectors showed reduced nerve fiber layer thickness (P =.000, P =.000, P =.011, P =.000, and P=.002, respectively). CONCLUSION: Laser in situ keratomileusis affected nerve fiber layer thickness measurements by scanning laser polarimetry. The change in nerve fiber layer thickness was probably due to modification of the corneal architecture. This effect of keratorefractive surgery should be considered when using scanning laser polarimetry as a diagnostic and follow-up tool for glaucoma.     

Effect of pupillary dilation on retinal nerve fiber layer thickness as measured by scanning laser polarimetry in eyes with and without cataract.

PURPOSE: This study was conducted to evaluate the effect of pupillary dilation on retinal nerve fiber layer (RNFL) thickness as measured by scanning laser polarimetry (SLP) in cataractous and noncataractous eyes. METHODS: The study included 31 eyes of 31 consecutive patients (mean age, 62.5 +/- 14.0 years; range, 30-76 years). Eyes with refractive error exceeding 5.0 D sphere or 2.0 D cylinder, nonlenticular media opacity, cup-to-disc ratio > 0.9, corneal disease, ocular inflammation, or previous intraocular surgery were excluded. A standard reticule was used to measure pupillary diameter. Cataract grade was evaluated by a single observer using the Lens Opacities Classification System (LOCS III). RNFL thickness measurements were obtained by means of SLP before and after pupillary dilation. RESULTS: Of the patients, 10 had clear lenses and 21 had variable degrees of lenticular opacification. In four eyes, imaging could not be performed because of dense cataracts. Mean pupillary diameters before and after dilation were 2.5 +/- 0.7 mm and 7.3 +/- 1.1 mm, respectively. There were no significant differences in global RNFL thickness before and after dilation in noncataractous and cataractous eyes. Among cataractous eyes in which imaging was possible, there was no correlation between difference in RNFL thickness before and after dilation and nuclear opalescence, nuclear color, and cortical and posterior subcapsular grading of the LOCS III score. Six of 27 eyes (22.2%) had a change of more than 10% in RNFL thickness after pupillary dilation. CONCLUSION: Although pharmacologic mydriasis does not statistically alter RNFL thickness as measured by SLP, approximately one fifth of such eyes will have a change of more than 10% in retardation. Uniformity in pupil size is recommended when longitudinally evaluating RNFL measurements.     

Relationship between patterns of visual field loss and retinal nerve fiber layer thickness measurements

PURPOSE: To investigate the association between patterns of visual field (VF) loss and retinal nerve fiber layer (RNFL) thickness measurements. DESIGN: Observational cross-sectional study. METHODS: One hundred twenty-one glaucoma patients and 65 healthy subjects from the Diagnostic Innovations in Glaucoma Study (DIGS) were included. All glaucoma patients had repeatable abnormal VFs and scanning laser polarimetry (SLP) RNFL thickness measurements. RNFL measurements were obtained from 16 equal parapapillary sectors. Patterns of VF loss were classified as arcuate, partial arcuate, nasal step, or paracentral in each VF hemifield. Logistic regression analysis was performed to determine which RNFL sectors were associated with each VF pattern. The ability of SLP to discriminate between eyes with different VF patterns and healthy eyes using receiver operating characteristic (ROC) curve analyses also was investigated. RESULTS: VF patterns in the superior hemifield were significantly associated with RNFL sectors in the temporal inferior hemiretina (P < .05). ROC curve areas for discrimination between eyes with different VF patterns and healthy eyes ranged from 0.85 to 0.95. VF patterns in the inferior hemifield were most strongly associated with temporal superior RNFL sectors (P < .05). ROC curve areas for discrimination between different VF patterns and healthy eyes ranged from 0.73 to 0.98. SLP could discriminate between apparently unaffected VF hemifields in glaucoma eyes and VF hemifields in healthy eyes. CONCLUSIONS: Parapapillary RNFL thickness was topographically related to patterns of VF loss. SLP can differentiate between apparently unaffected VF hemifields in glaucoma eyes and normal VF hemifields in healthy eyes.     

Reproducibility of retinal nerve fiber layer thickness measurements using scanning laser polarimetry in pseudophakic eyes

OBJECTIVE: To assess the reproducibility of retinal nerve fiber layer measurements in pseudophakic normal and glaucomatous eyes using scanning laser polarimetry (GDx, Laser Diagnostic Technologies, Inc., San Diego, CA). PATIENTS AND METHODS: Normal and glaucomatous patients with polymethylmethacrylate posterior chamber intraocular lenses that satisfied entry criteria underwent imaging by two experienced operators. Eyes with posterior capsule opacification or vision less than 20/30 were excluded. Baseline images (mean pixel SD less than 8 mm) were obtained on 3 separate days within a 7-week period. Reproducibility, defined as the pooled within eye variance of these 3 measurements and the coefficient of variation for 12 retardation parameters generated by GDx software were calculated. RESULTS: Eighteen eyes (11 glaucoma, 7 normal) of 15 patients (7 female, 8 male) were enrolled (mean age 78 +/- 6 years). Among glaucomatous eyes, the average mean deviation and corrected pattern standard deviation using achromatic automated perimetry (Zeiss-Humphrey, Dublin, CA) was -3.8 +/- 1.5 dB (range, -1.89 to -5.04 dB) and 4.9 +/- 3.3 dB (range 0 to 11.05 dB), respectively. Coefficient of variation was 10% or less for all retardation parameters except ellipse modulation (20.2%) and neural network number (12.4%). Glaucomatous and normal eyes had similar variability for 8 of 12 (66.7%) retardation parameters. Inferior ratio, ellipse modulation, and superior ratio were significantly less variable in glaucomatous eyes (P = 0.007, 0.02, and 0.04 respectively) than normal eyes. Superior integral was more variable in glaucomatous eyes (P = 0.03). CONCLUSION: Retardation measurements may be obtained in pseudophakic eyes with acceptable reproducibility. Normal eyes and eyes with mild glaucomatous damage have similar variability for most retardation parameters.     

Effect of corneal polarization axis on assessment of retinal nerve fiber layer thickness by scanning laser polarimetry

PURPOSE: Scanning laser polarimetry uses an anterior segment compensating device that assumes a fixed axis of corneal birefringence, which we call the corneal polarization axis. The purpose of this investigation was to establish the distribution of corneal polarization axes among a population of normal eyes and to evaluate the relationship between corneal polarization axis and posterior segment retardation. METHODS: We constructed a noninvasive slit lamp-mounted device incorporating two crossed linear polarizers and an optical retarder in order to measure the slow axis of corneal birefringence. Normal subjects underwent corneal polarization axis measurement. A subset of eyes underwent scanning laser polarimetry of the peripapillary retinal nerve fiber layer (n = 32) and macula (n = 29), and retardation measurements were evaluated in each group. RESULTS: One hundred eighteen eyes of 63 normal subjects (35 female, 28 male) underwent corneal polarization axis measurement (mean age, 45.5 +/- 17.1 years). Six eyes (5.1%) demonstrated unmeasurable corneal polarization. In the remaining 112 eyes, the mode of the corneal polarization axis distribution was 10 to 20 degrees nasally downward (range, 90 degrees nasally downward to 54 degrees nasally upward). A significant (P <.0001) correlation was observed between fellow eyes (R(2) =.52), with a mean difference of 11.2 +/- 10.5 degrees (range, 0-52 degrees). Corneal polarization axis was significantly associated (R(2) =.52-.84) with retinal nerve fiber layer and macula summary retardation parameters (average thickness, ellipse average, superior and inferior average, superior and total integral; P <.0001 for all groups). CONCLUSIONS: The mean corneal polarization axis among normal corneas is nasally downward; however, considerable intraindividual and interindividual variability exists. The linear relationship between corneal polarization axis and posterior segment retardation parameters is responsible, in part, for the wide distribution of retinal nerve fiber layer thickness data generated by scanning laser polarimetry.     

Evaluation of retinal nerve fiber layer thickness measurement following laser in situ keratomileusis using scanning laser polarimetry

AIM: To evaluate the effect of laser-assisted in situ keratomileusis (LASIK) on the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry using customized corneal compensation in myopes. MATERIALS AND METHODS: Scanning laser polarimetry was performed on 54 eyes of 54 healthy patients with myopia using the glaucoma diagnostics variable corneal compensation (GDx VCC) instrument (Laser Diagnostic Technologies, San Diego, California) before and a week after LASIK. The various parameters were compared using the Student's t test. RESULTS: No statistically significant change was observed in any of the retinal nerve fiber layer parameters before and after LASIK. CONCLUSIONS: While the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry is affected by anterior segment birefringent properties and LASIK would be expected to produce changes in the same, customized corneal compensation using the GDx VCC seems to adequately compensate for these changes.     

Relationship between changes in retinal nerve fiber layer thickness measured by SD-OCT and changes in visual field parameters in birdshot chorioretinopathy

Graefe's Archive for Clinical and Experimental Ophthalmology - To describe the structure–function relationship in birdshot chorioretinopathy (BSCR) using visual field data and...