Inferior Retinal Nerve Fiber Layer Thickness Research Articles

Degeneration of retinal nerve fiber layer in patients with multiple sclerosis. Prospective study with three years follow‐up

AbstractPurpose To quantify changes over three years in the retinal nerve fiber layer (RNFL) of patients with multiple sclerosis (MS) and to evaluate if treatments are a protector factor of CFNR degeneration.Methods One hundred and eighty‐eight eyes of 94 MS patients were followed‐up during 3 years. All patients underwent a complete ophthalmic examination that included assessment of visual acuity (Snellen chart), colour vision (Ishihara pseudoisochromatic plates), visual field examination, optical coherence tomography (OCT) and visual evoked potentials (VEP). All patients were re‐evaluated in a period of 12, 24 and 36 months in order to quantify the changes in the retinal nerve fiber layer (RNFL).Results Changes were obtained in the RNFL thickness with a 36‐month follow‐up. There were significant decreases (P<0,05 , t test) in the mean, superior, inferior , nasal and temporal RNFL thickness and macular volume provided by OCT, and in P100 latency of VEP. The greater differences were obtained in the superior and inferior RNFL thickness. Differences were not found between treatments, but untreated patients showed higher degeneration during follow‐up in the mean and superior RNFL thickness (p= 0,045 y p=0,024 respectively).Conclusion Progressive axonal loss can be detected in the optic nerve of MS patients. The analysis of RNFL in OCT can be useful to evaluate MS progression and efficacy of treatments in reduction of axonal degeneration.

Relationship between retinal nerve fiber layer evaluation and visual field results in healthy and glaucoma individuals

AbstractPurpose To determine the relationship between retinal nerve fiber layer (RNFL) thickness measured with spectral‐domain optical coherence tomography (OCT) and the retinal sensitivity tested by standard automated perimetry (SAP).Methods Two hundred and five subjects (100 healthy and 105 with different levels of glaucomatous damage subjects) were prospective and consecutively recruited. Only one eye per participant was randomly chosen. Glaucoma patients had intraocular pressure higher than 21 mmHg and glaucomatous optic disc appearance. All of them underwent imaging with the Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) and at least one reliable perimetry. SAPs were performed with a Humphrey Field Analyzer, using the 24‐2 SITA Standard strategy. Left eye data were converted to a right eye format. The Kolmogorov Smirnov test was applied to check that the data were normally distributed. Threshold values of SAP were converted to a linear scale. Pearson correlations were calculated between the 52 threshold values tested by 24‐2 algorithm of SAP and OCT parametersResults Age was not different between both groups (p=0.09). In the whole sample, the strongest correlation was found between point 15 of SAP and RNFL thickness at inferior quadrant (r=0.670; p<0.001). The healthy group showed few and mild correlations. In the glaucoma group, the strongest correlation was also found between point 15 of SAP and inferior RNFL thickness at inferior quadrant (0.664; p<0.001).Conclusion Normal individuals had mild correlations between few functional and structural parameters, while glaucoma patients showed mild to moderate correlations.

Correlation of Frequency-doubling Perimetry With Retinal Nerve Fiber Layer Thickness and Optic Disc Size in Ocular Hypertensives and Glaucoma Suspects

To determine the structure-function correlation using frequency-doubling technology (FDT) perimetry and optical coherence tomography (OCT) in glaucoma suspects, and analyze their relationship to optic disc size. Sixty eyes of 60 ocular hypertensive patients (OHT) and 54 eyes of 54 subjects with optic disc features suspicious of glaucoma (disc suspects) with normal visual fields on Standard Achromatic Perimetry were recruited. All subjects underwent FDT perimetry using the N-30 program, and the mean deviation (FDT-MD) and FDT-pattern SD were computed. Average and inferior retinal nerve fiber layer (RNFL) thickness and disc area were measured on Stratus OCT. Pearson correlation coefficient was calculated among all the measurements. In disc suspects, FDT-MD correlated significantly with RNFL thickness measurements (P<0.001; P=0.003) and disc area (P<0.001). There was no correlation with the vertical cup-disc area ratio (VCDR) and FDT indices. In OHT, FDT-MD correlated significantly with average RNFL thickness (P=0.038), and there was a significant negative correlation between FDT-MD and the VCDR (0.042). The FDT-pattern SD negatively correlated with RNFL thickness measurements (P=0.008; P=0.03). The disc area correlated significantly with the average and inferior average RNFL thickness measurements in both groups of patients (P=0.029 and P=0.007; P=0.013 and P=0.013, respectively). In OHT, optic discs with larger VCDR and thinner RNFL had lower FDT-MD values. In disc suspects, smaller-sized discs had thinner RNFL and lower values of FDT-MD. FDT perimetry and OCT seem to be useful adjuncts to detect these eyes, which might warrant close follow-up to eventually detect glaucoma by Standard Achromatic Perimetry.

Effects of Changing Operators and Instruments on Time-Domain and Spectral-Domain OCT Measurements of Retinal Nerve Fiber Layer Thickness

To determine the amount of interoperator and interinstrument variability introduced into retinal nerve fiber layer (RNFL) thickness measured with Stratus OCT and Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA) in normal and glaucomatous eyes. Thirty-seven eyes from 37 subjects (20 normal and 17 with glaucoma) were included in the study. Each eye was scanned with one Stratus OCT and one Cirrus OCT by two operators. The eyes were then scanned with a different Stratus OCT and Cirrus OCT by one of the operators. Average, quadrant, and clock-hour RNFL measurements were compared between operators and between instruments after determining the proportion of variance due to subjects, operators, and instruments by means of variance component analysis. Significant differences were observed between Stratus OCT instruments, but not between Cirrus OCT instruments, in average (P = .01), inferior (P = .006), and nasal (P < .001) quadrant RNFL thickness in glaucomatous eyes. Interoperator differences in RNFL thickness measured with both types of instruments were non-significant. The interoperator variability ranged from 0% to 1% on Stratus OCT and was 0% on Cirrus OCT, whereas the interinstrument variability ranged from 0% to 3% for Stratus OCT and from 0% to 1% for Cirrus OCT. The interoperator variability of RNFL thickness measured with Stratus OCT and Cirrus OCT, as well as the interinstrument variability of measurements obtained with Cirrus OCT, are non-significant. However, there is significant variability between RNFL measurements performed on two different Stratus OCT instruments.

Comparison of Diagnostic Accuracy of the RTVue Fourier-Domain OCT and the GDx-VCC/ECC Polarimeter to Detect Glaucoma

To compare sensitivity and specificity of retinal nerve fiber layer thickness (RNFLT) measurements made using RTVue-100 Fourier-domain optical coherence tomography (RTVue-OCT) and scanning laser polarimetry with variable (GDx-VCC) or enhanced compensation (GDx-ECC). One eye of each of 177 consecutive patients was imaged. Healthy (n=50) and ocular hypertensive (n = 28) eyes were defined as structurally undamaged, preperimetric (n=33) and perimetric (n=66) glaucoma eyes as diseased. For average RNFLT, sensitivity was higher (χ(2) test, p=0.002) with RTVue-OCT (65.7%) than with GDx-VCC (49.5%). For superior and inferior RNFLT, sensitivity was similar with all methods. For the different nerve fiber bundle parameters, sensitivity of RTVue-OCT (64.6% to 84.8%) was consistently up to 35% higher (p<0.001) than that of GDx-VCC/ECC (28.3% to 72.7%). Specificity ranged from 84.6% to 98.7% with RTVue-OCT, 92.3% to 100% with GDx-VCC, and 94.9% to 100% with GDx-ECC, with no significant difference between the methods except for one nerve fiber bundle parameter, for which RTVue-OCT was less specific than either GDx method (p ≤ 0.004). Diagnostic accuracy of the GDx-VCC/ECC nerve fiber indicator (NFI) and RTVue-OCT average RNFLT were similar. Of the detected glaucoma cases, 87.7% were identified both by GDx-VCC/ECC NFI and average RNFLT of RTVue-OCT. In this clinical setting, all methods were similarly highly specific, but for localized RNFLT damage RTVue-OCT was statistically and clinically significantly more sensitive than GDx-VCC and GDx-ECC. Most detected glaucoma cases were identified with all 3 methods.

GDx Staging System

To provide a reliable and easy-to-use method for classifying retinal nerve fiber layer (RNFL) damage using the parameters obtained by the scanning laser polarimeter with variable corneal compensator (GDx VCC). GDx Staging System is a new method that uses the superior and inferior RNFL thickness values plotted on an x-y diagram to classify GDx VCC results. RNFL defects are classified into 6 stages of increasing severity and 3 classes of defect localization (superior, inferior, or diffuse defect). The diagram was created based on 320 GDx VCC tests from 84 healthy controls and from 236 patients affected by ocular hypertension or chronic open-angle glaucoma. Sensitivity and specificity of the method were assessed in a different cohort that included 161 patients with either ocular hypertension or open-angle glaucoma, and 34 normal participants. The results were correlated with both a clinical classification of the GDx VCC results and with visual field defects classified with the Glaucoma Staging System 2. Sensitivity and specificity of the GDx Staging System were, respectively, 88.2% and 100%. Correlations with the clinical classification and the Glaucoma Staging System 2 results were statistically significant (Spearman correlation coefficient 0.92 and 0.57, respectively; P<0.0001). The GDx Staging System is an easy and quick method for interpreting GDx VCC results. It can be clinically useful, especially for nonexpert ophthalmologists.

Evaluation of Retinal Nerve Fiber Layer Progression in Glaucoma: A Comparison between Spectral-Domain and Time-Domain Optical Coherence Tomography

To compare the performance of a spectral-domain optical coherence tomography (OCT) device and a time-domain OCT device to detect retinal nerve fiber layer (RNFL) progression in glaucoma patients. Prospective study. One hundred twenty-eight eyes of 81 glaucoma patients. Patients were followed up at 4-month intervals for at least 24 months for RNFL imaging and visual field examination. Both eyes were imaged by the Cirrus HD-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) and the Stratus OCT (Carl Zeiss Meditec, Inc.) and underwent visual field testing at the same visit. Linear regression analyses between circumpapillary RNFL measurements (average, superior, and inferior RNFL thicknesses), visual field index (VFI), and follow-up time were performed. RNFL progression and RNFL improvement were identified when a significant negative or positive trend was detected, respectively. The agreement between the OCT instruments for progression detection was analyzed with κ statistics. Number of eyes with RNFL progression and improvement, agreement of progression detection between RNFL measurements and VFI, and rate of change of average RNFL thickness. Twenty-two eyes (19 patients) and 4 eyes (4 patients) had progression, and 0 and 5 eyes (5 patients) had improvement detected by the Cirrus HD-OCT and the Stratus OCT average RNFL measurements, respectively. The agreement for detection of RNFL progression was poor between the 2 OCT instruments (κ = 0.188, 0.027, and 0.267 for average, superior, and inferior RNFL thicknesses, respectively). The respective agreement between VFI and average RNFL thickness progression determined by the Cirrus HD-OCT and the Stratus OCT was 0.125 and 0.047. The rate of average RNFL thickness progression ranged between -1.52 μm/year and -5.03 μm/year for the Cirrus HD-OCT and between -2.22 μm/year and -7.60 μm/year for the Stratus OCT. The Cirrus HD-OCT outperformed the Stratus OCT in detecting more eyes with RNFL progression and fewer eyes with RNFL improvement. Because of reduced measurement variability, the Cirrus HD-OCT could detect changes in RNFL thickness sooner than the Stratus OCT. Proprietary or commercial disclosure may be found after the references.

Evaluation of Macular Thickness and Peripapillary Retinal Nerve Fiber Layer Thickness for Detection of Early Glaucoma Using Spectral Domain Optical Coherence Tomography

To evaluate the diagnostic ability of macular parameters and peripapillary retinal nerve fiber layer (RNFL) parameters for early glaucoma using spectral domain optical coherence tomography (SD-OCT). One eye from 32 early glaucoma patients (including preperimetric glaucoma) and 32 normal participants underwent macular scans and peripapillary RNFL scans with SD-OCT 3 times on the same day. The discrimination power of each parameter to detect early glaucoma was determined by areas under receiver operating characteristics curve (AROC) and sensitivity at fixed specificity. Correlation of OCT data with visual field defects was evaluated by linear regression analysis. Reproducibility was also evaluated. Significant differences between early glaucoma and normal participants were found for all parameters except fovea in macular scans and in the superior and inferior quadrants, at 12, 3, 6, 7, 11 o'clock, and average RNFL thickness in RNFL scans. The best parameters based on AROC and sensitivity at a specificity of >90% were temporal outer macula thickness (AROC, 0.79; sensitivity, 63%) in macular parameters and inferior quadrant (AROC, 0.82; sensitivity, 53%) in RNFL parameters. The highest correlation with mean deviation was found in inferior inner macular volume (r=0.50, P<0.001). The mean intraclass correlation coefficient was 0.96 in macular scans and 0.84 in RNFL scans. Test-retest variability ranged from 2.3 to 10.1 μm in macular thickness, 0 to 0.06 mm in macular volume, and 5.8 to 18.9 μm in RNFL thickness. For the diagnosis of early glaucoma by SD-OCT, macular parameters had high discriminating power and high reproducibility comparable with peripapillary RNFL parameters.

Clinical application of Optovue RTVue OCI' and Heidelberg Retina Tomograph III in early diagnosis of glaucoma

Background Many studies showed that attenuation of retinal nerve fiber layer(RNFL)in early glaucoma is one of the important signs.How to accurately and quantitatively measure RNFL thickness is very important for the early diagnosis and monitoring of glaucoma.0bjective This study was to evaluate the clinical value of Optovue RTVue OCT and Heidelberg Retina Tomograph Ⅲ(HRT-Ⅲ)confocal scanning laser ophthalmoscopy in glaucomatous eyes. Methods This cross-sectional study included 40 eyes of 26 patients with suspected open-angle glaucoma(SOAG),48 eyes of 29 patients with open-angle glaucoma and 48 eyes of 27 healthy subjects.Optical nerve head(ONH) parameters and peripapillary RNFL thickness were measured in all the subjects with Optovue RTVue OCT and HRT-Ⅲ,meanwhile all the eyes received perimetry with Humphrey 750-I.Glaucoma variables obtained from Optovue RTVue OCT and HRT-Ⅲ were analyzed among the groups.Topographic Optovue RTVue OCT and HRT-Ⅲ parameters,including disc area(DA),cup area(CA),rim area(RA),rim volume(RV),cup volume(CV),cup/disc area ratio(C/DAR)as well as superior,temporal,inferior and nasal average RNFL thickness,were analyzed.The relationship of ONH parameters and RNFL thickness was analyzed using a linear correlation.The correlation between the mean defect(MD)of the visual field and the tomography parameters in glaucomatous eyes was described by bivariate Pearson correlation coefficients.Resuits The ONH parameters and RNFL thickness obtained by HRT-Ⅲ and OCT showed significant difference(P<0.05).ONH parameters such as RA,C/DAR,CA and RV were statistically changed in SOAG and the POAG patients compared with the normal subjects(q=6.47,q=7.67,P<0.05).The superior and inferior RNFL thickness parameters in three groups were positively correlated between HRT-Ⅲand OCT(r=0.362,r=0.441,r=0.395,P<0.05),Topographic Optovue RTVue OCT and HRT-Ⅲ parameters including CV,CA,RA and C/DAR fitted Pearson analysis(all P<0.05).In POAG group。The RA,RV,CV,C/DAR from Optovue RTVue OCT were correlated with MD with the significant coefficient 0.284,0.286,0.340,0.371 respectively(P<0.05),and evidently correlations also were found between RA,RV,C/DAR with MD respectively with the coefficient 0.339,0.859,0.422(P<0.05)by HRT-Ⅲ. Conclusion Both Optovue RTVue OCT and HRT-Ⅲ can difierentiate ONH analysis with a similar outcome in glaucomatous eye.The C/D value.RA,superior and inferior RNFL thickness based on Optovue RTVue OCT and HRT-Ⅲare distinguishing indexes in the diagnosis of early glaucomatous damage. Key words: Glaucoma; Optovue RTVue OCT; Heidelberg Retina Tomograph Ⅲ confocal scanning laser ophthalmoscopy; Retinal nerve fiber layer thickness; Optical disc; Perimetry

Retinal nerve fibre layer attenuation: clinical indicator for vigabatrin toxicity

To investigate whether persistent visual field defects among patients exposed once to the antiepileptic drug vigabatrin (VGB) were associated with peripapillary retinal nerve fibre layer thickness (RNFLT) attenuation. Nine individuals with partial epilepsy and VGB-attributed visual field loss (group 1; 18 eyes) and seven age- and gender-matched individuals with epilepsy and no previous VGB exposure (group 2; 14 eyes) were included in the study. Full-field 120 point screening perimetry out to 60 degrees from central fixation using the Humphrey Field Analyzer was performed. RNFLT was quantified by optical coherence tomography (OCT) using Fast RNFLT protocol, Stratus OCT (3.0) after pupillary dilation. The results from the right eye are presented in this article. Among the patients with VGB-attributed visual field loss, five patients had only peripheral field defect (group 1a) and the remaining four had advanced field defects both in the periphery and within 30° from central fixation (group 1b). None of the patients in the control group had manifest visual field loss. The mean RNFLT among the patients with VGB-attributed visual field loss was significantly attenuated compared to the controls [mean total RNFLT: group 1: 75.6 ± 12.7 μm, group 2: 103.5 ± 9.7 μm, mean difference 27.9 μm, (CI 15.9-39.9; p < 0.001)]. RNFLT values classified as borderline according to normative database (Stratus OCT) occurred more frequently among individuals with VGB-attributed visual field loss than in controls (frequency in group 1: 6/9; group 2: 0/7, p = 0.011). The nasal, superior and inferior quadrants of RNFLT in individuals with VGB-attributed visual field loss were significantly attenuated, while no difference was detected in temporal quadrants compared to controls. Both individuals with peripheral and those with advanced visual field losses in the VGB group had attenuated mean total RNFLT compared to controls (p = 0.006, p = 0.002, respectively). Occurrence of borderline classification of total RNFLT ≤5th percentile was more frequent among individuals with advanced visual field loss than among controls (p = 0.048). Persistent visual field loss attributed to VGB is associated with reduced peripapillary RNFLT and was detected both among patients with advanced and among patients with only peripheral visual field defects. Measurements of RNFLT with OCT might be considered as a diagnostic supplement in the follow-up of patients exposed to vigabatrin.

Comparison of Peripapillary Retinal Nerve Fiber Layer Thickness Measured by Spectral vs. Time Domain Optical Coherence Tomography

Purpose: To compare the peripapillary retinal nerve fiber layer (RNFL) thickness measured by spectral and time domain optical coherence tomography (OCT).Patients and Methods: One hundred and eighty-eight subjects (normal tension glaucoma, n = 80; primary open angle glaucoma, n = 49; healthy controls, n = 59) were included in this study. Peripapillary RNFL thickness was measured by an Optic Disc Cube 200 × 200 scan of the spectral domain Cirrus HD OCT and by a Fast RNFL scan of the time domain Stratus OCT. They were compared using linear regression (R2), Bland-Altman plots, weighted Kappa (Kw) coefficients, and areas under the receiver operating characteristic curve (AROC).Results: Except for the inferior quadrant, RNFL thickness measurements by Cirrus HD OCT were thinner than Stratus OCT (all p < 0.001); for the inferior quadrant, this tendency was vice versa (p = 0.043). Average RNFL thicknesses of the two OCTs showed a good correlation (R2, 0.852) but not excellent agreement (mean of difference, 4.0 μm; +1.96 SD, 10.7 μm; -1.96 SD, -18.6 μm). Regarding the probability codes, only the average RNFL thickness had almost perfect agreement (Kw, 0.983). In addition, Cirrus HD OCT had the largest AROC for the superior quadrant (0.795), but Stratus OCT had the largest AROC for average RNFL thickness (0.764) (p = 0.281).Conclusions: Except for the inferior quadrant, the average and quadrants RNFL thickness measured by the Cirrus HD OCT were thinner than the Stratus OCT. Regarding discriminating power for glaucoma detection, the Cirrus HD OCT was better than the Stratus OCT for the superior and inferior quadrant RNFL thicknesses but not for the average RNFL thickness.

Spectral-domain optical coherence tomography and scanning laser polarimetry in glaucoma diagnosis

To evaluate glaucoma diagnostic capability of the retinal nerve fiber layer (RNFL) imaging by spectral-domain optical coherence tomography (Cirrus OCT) and scanning laser polarimetry (GDx VCC). We imaged 88 glaucomatous and 77 healthy eyes using both devices. Areas under the receiver-operating characteristic curves (area under the curves, AUCs) and sensitivities at fixed specificities of average, superior, and inferior RNFL thickness were compared. Likelihood ratios (LRs) and diagnostic agreement based on normative classifications yielded by both devices were determined. The best performing parameter was the nerve fiber indicator (NFI) in GDx VCC and inferior RNFL thickness in Cirrus OCT (AUC = 0.912, 0.961, P = 0.045). The AUCs of the Cirrus OCT were significantly higher than those of GDx VCC in all parameters. Most of the parameters in Cirrus OCT were more sensitive than GDx VCC in the detection of glaucoma at fixed specificity values. Cirrus OCT had an infinite LR with abnormal classification results in both average and superior RNFL thickness. There was good agreement between the two instruments with respect to abnormal classifications (kappa, 0.611-0.766) Both Cirrus OCT and GDx VCC RNFL measurements showed good glaucoma diagnostic capabilities. Cirrus OCT showed higher sensitivities than GDx VCC.

Evaluation of factors associated with variability in retinal nerve fiber layer thickness in myopic juveniles aged 7-18 years

To evaluate the relationship between retinal nerve fiber layer thickness(RNFLT)measured by optical coherence tomography (OCT) and age, spherical equivalent (SE), axial length, and gender in myopic juveniles. Cross-sectional observational study. One hundred and fifty-four juveniles (age range, 7-18 years) underwent ophthalmic examinations. Peripapillary Fast RNFL scans were performed by Stratus OCT with a nominal diameter of 3.46 mm centered on the optic disc on one randomly selected eye of each subject. Axial length was measured by A-ultrasound. The effects of several factors (age, SE, axial length, gender and eye) on RNFLT were investigated in univariate and multivariate stepwise regression analyses. The mean global RNFLT (x(-) ± s) was (114.106 ± 11.473) µm. The RNFLT was thickest superiorly (145.468 ± 19.064) µm and inferiorly (138.091 ± 20.464) µm, thinner temporally (94.396 ± 18.544) µm, and thinnest nasally (78.558 ± 16.981) µm. Both global and superior peripapillary RNFLT had no significant relationship with age (r = 0.129, 0.014; P > 0.05), SE (r = 0.006, 0.123; P > 0.05), axial length (r = -0.067, -0.141; P > 0.05), gender (r = -0.095, 0.025; P > 0.05) and laterality (r = -0.148, 0.095; P > 0.05). In multivariate stepwise regression analyses, there was significant inverse linear correlation between temporal RNFLT and SE (r = -0.465, P < 0.05). There was significant inverse linear correlation between nasal RNFLT and axial length and laterality (r = -0.327, P < 0.05). There was significant inverse linear correlation between inferior RNFLT and axial length (r = -0.276, P < 0.05), and direct linear correlation between inferior RNFLT and age (r = 0.276, P < 0.05). When we assess the RNFLT in myopic juveniles, we should consider the influence of age, refraction, axial length, spherical equivalent and laterality comprehensively.

Quantification of Retinal Nerve Fiber Layer Thickness in Normal Eyes, Eyes with Ocular Hypertension, and Glaucomatous Eyes with SD-OCT

To quantitatively evaluate and compare retinal nerve fiber layer (RNFL) thickness between normal eyes, eyes with ocular hypertension (OHT), and glaucomatous eyes in an Indian population using spectral domain optical coherence tomography (SD-OCT). Average and quadrant RNFL values were compared among three groups (66 normal eyes, 55 OHT eyes, and 51 glaucomatous eyes) and the discriminating power of each parameter was evaluated by calculating areas under receiver operator curves (AROCs). The mean RNFL thickness was 93.45 ± 16.9 μm in glaucomatous eyes, significantly less than in normal (112.48 ± 6.8 μm) and OHT (110.09 ± 10.9 μm) eyes. OHT eyes had significantly thinner RNFL thickness in the temporal quadrant (P = .006) than normal eyes. RNFL thickness in glaucomatous eyes differed significantly from normal eyes in most parameters except nasal quadrant (P = .1) and from OHT eyes in most parameters except temporal (P = .4) and nasal quadrants (P = .3). The parameter with the largest AROC to discriminate between OHT and normal eyes was temporal quadrant (0.65). Inferior quadrant RNFL thickness had the largest AROC (0.93) to distinguish between OHT and glaucomatous eyes and normal and glaucomatous eyes. SD-OCT identified differences in most parameters between eyes with glaucoma and normal eyes and also between eyes with glaucoma and OHT. Overlap of RNFL thickness between normal and OHT eyes limits the ability of this instrument to differentiate between normal and OHT subjects.

Diagnostic accuracy of nerve fibre layer, macular thickness and optic disc measurements made with the RTVue-100 optical coherence tomograph to detect glaucoma

To evaluate the diagnostic accuracy of retinal nerve fibre layer thickness (RNFLT), ganglion cell complex (GCC), and optic disc measurements made with the RTVue-100 Fourier-domain optical coherence tomography (OCT) to detect glaucoma in a Caucasian referral population. One randomly selected eye of 286 Caucasian patients (93 healthy, 36 ocular hypertensive, 46 preperimetric glaucoma, and 111 perimetric glaucoma eyes) was evaluated. Using the software-provided classification, for the total population sensitivity did not exceed 73.6% for the optic nerve head parameters, and 62.7% for the other parameters. Specificity was high (94.6-100%) for most RNFLT and GCC parameters, but low (72.0-76.3%) for the optic disc parameters. Positive predictive value varied between 98.1 and 100% for the main RNFLT parameters, 92.6 and 100% for the 16 RNFLT sectors, 92.4 and 99.0% for the GCC parameters, but did not exceed 86.3% for any of the optic disc parameters. Positive likelihood ratio (PLR) was higher than 10 for average, inferior and superior RNFLT (25.5 to infinite), 12 of the 16 RNFLT sectors (12.6 to infinite), and three of the four GCC parameters (40.0 to 48.6). No optic disc parameter had a PLR higher than 3.0. RNFLT and GCC parameters of the RTVue-100 Fourier-domain OCT showed moderate sensitive but high specificity, positive predictive value and PLR for detection of glaucoma. The optic disc parameters had lower diagnostic accuracy than the RNFLT and GCC parameters.

Acute Primary Angle Closure Attack Does Not Cause an Increased Cup-to-Disc Ratio

To determine if an increased cup-to-disc ratio (CDR) and retinal nerve fiber layer (RNFL) loss occur after acute primary angle closure (APAC). Prospective, observational case series. Twenty participants with unilateral APAC provided 20 affected eyes and 20 fellow eyes (controls) for analysis. After initial presentation, participants attended 3 further assessments over a 12-month period (visit 2, within 2 weeks; visit 3, 2-3 months; and visit 4, 6-12 months), in which they underwent the following investigations: Heidelberg Retinal Tomography (Heidelberg Engineering, Dossenheim, Germany), optical coherence tomography of the RNFL and macula, and automated perimetry. Cup-to-disc ratio, optic cup area, neuroretinal rim area, RNFL thickness, macular thickness, and volume. There was no change from visits 2 to 4 in CDR (0.46 ± 0.17 vs. 0.47 ± 0.20; P = 0.94), neuroretinal rim area (1.64 ± 0.55 vs. 1.64 ± 0.57; P = 0.96), or other optic nerve head parameters analyzed in eyes with APAC. The mean overall RNFL thickness decreased from 106.6 ± 17.9 μm to 92.9 ± 18.3 μm between visits 2 and 3 (P<0.01) in affected eyes. The superior quadrant RNFL thickness decreased from 134.8 ± 25.9 μm to 113 ± 25.7 μm (P<0.01), and the inferior quadrant RNFL thickness decreased from 139.1 ± 28.4 μm to 115.6 ± 24.9 μm (P<0.01). There was no significant change in macular thickness or volume. This study demonstrated that an increase in CDR does not occur after APAC that is treated promptly, although RNFL loss does occur.

Comparison of diagnostic accuracy of Fourier‐domain optical coherence tomography and scanning laser polarimetery to detect glaucoma

Abstract Purpose To compare diagnostic accuracy of retinal nerve fiber layer thickness (RNFLT) measurements made using RTVue‐100 Fourier‐domain optical coherence tomography (RTVue‐OCT) and scanning laser polarimetry with variable (GDx‐VCC) or enhanced compensation (GDx‐ECC). Methods One eye of each of 177 consecutive patients was imaged. Healthy (n=50) and ocular hypertensive (n=28) eyes were defined as normal, preperimetric (n=33) perimetric (n=66) glaucoma eyes as diseased. Results For average RNFLT sensitivity was higher (Chi‐square test, p=0.002) with RTVue‐OCT (65.7 %) than with GDx‐VCC (49.5 %). For superior and inferior RNFLT sensitivity was similar with all methods. For the different nerve fiber bundle parameters, sensitivity of RTVue‐OCT (64.6 to 84.8 %) was consistently, up to 35 % higher (p&lt;0.001) than that of GDx‐VCC/ECC (28.3 to 72.7 %). Specificity ranged 84.6 to 98.7 % with RTVue‐OCT, 92.3 to 100 % with GDx‐VCC, and 94.9 to 100 % with GDx‐ECC, with no significant difference between the methods except for one nerve fiber bundle parameter, for which RTVue‐OCT was less specific than either GDx method (p≤0.004). Diagnostic accuracy of the GDx‐VCC/ECC nerve fiber indicator (NFI) and RTVue‐OCT average RNFLT were similar. Of the detected glaucoma cases 87.7 % was identified both by GDx‐VCC/ECC NFI and average RNFLT of RTVue‐OCT. Conclusion In this clinical setting, all methods were similarly highly specific, but for localized RNFLT damage RTVue‐OCT was statistically and clinically significantly more sensitive than GDx‐VCC and GDx‐ECC. Most detected glaucoma cases were identified with all three methods. Commercial interest

Significance of optic disc topography and retinal nerve fiber layer thickness measurement by spectral-domain OCT in diagnosis of glaucoma

To study the significance of optic disc tomography and retinal nerve fiber layer (RNFL) thickness measurement by spectral-domain optical coherence tomography (OCT) in the diagnosis of glaucoma. It was a noninterventional, observational study. The optic disc topographic parameters and total and regional RNFL thickness were measured by RTVue OCT in 60 normal eyes and 97 glaucomatous eyes. One-way analysis of variance was used to compare the parameters above mentioned between normal and glaucomatous groups. The area under the receiver operating characteristic curve (AUC) and the sensitivity at 80% specificity were used to assess the ability of each testing parameter in the differentiation between normal and glaucoma eyes. There were statistically significant differences in all RTVue OCT measurement parameters (F = 1.024, P = 0.596;F = 36.519, 54.464, 27.659, 36.176, 20.562, 63.833, 30.031, 54.652, 98.146, 78.705, 99.839, 43.728, 75.720, 45.709, 39.380, 33.590, 66.887, 78.335, 45.485;P = 0.000) except disc area. The average RNFL thickness in normal, early, moderate and advanced glaucomatous eyes was 109.950, 93.313, 80.374 and 65.570 µm, respectively. Among the eight regions around the optic disc, the thickest RNFL was located at the inferotemporal (150.066 µm) and superotemporal (146.285 µm) regions in normal eyes, and the superotemporal (108.569, 103.420 and 88.708 µm in early, moderate and advanced glaucomatous eyes, respectively) and inferotemporal (108.201, 102.830 and 86.369 µm in early, moderate and advanced glaucomatous eyes, respectively) regions in glaucomatous eyes. Both in normal and glaucomatous eyes, the thinnest RNFL was located at the nasal and temporal regions, respectively. For optic disc topographic parameters, the highest AUC was vertical cup/disc ratio (AUC = 0.762, 0.946 and 0.988 in early, moderate and advanced glaucomatous eyes, respectively), and the sensitivity at 80% specificity was 62.2%, 76.5% and 99.2% in early, moderate and advanced glaucomatous eyes, respectively. For RNFL thickness, the highest AUC was superotemporal region RNFL thickness (AUC = 0.915) and the sensitivity at 80% specificity was 89.5% in early glaucomatous eyes. The highest AUC was inferior average RNFL thickness (AUC = 0.967) and the sensitivity at 80% specificity was 94.1% in moderate glaucomatous eyes. The highest AUC was average RNFL thickness (AUC = 0.985) and the sensitivity at 80% specificity was 99.2% in advanced glaucomatous eyes. Among the eight regions around the optic disc, RNFL thickness of region ST (AUC = 0.915, 0.926 and 0.966 in early, moderate and advanced glaucomatous eyes, respectively) achieved the highest AUC. RNFL thicknesses of the nasal and temporal regions showed the lowest AUCs. RTVue OCT shows fair discriminating ability in distinguishing normal from glaucomatous eyes. RTVue OCT is a useful equipment for the diagnosis of glaucoma.

Comparison of Repeatability of Retinal Nerve Fiber Layer Thickness Measurement Made Using the RTVue Fourier-domain Optical Coherence Tomograph and the GDx Scanning Laser Polarimeter With Variable or Enhanced Corneal Compensation

To compare repeatability of measurements of peripapillary retinal nerve fiber layer thickness (RNFLT) made using the RTVue-100 Fourier-domain optical coherence tomograph against repeatability of those made using scanning laser polarimetry with variable corneal compensation or enhanced corneal compensation (GDx-VCC and GDx-ECC, respectively). One eye of each of 37 participants (14 normal and ocular hypertensive subjects, 11 patients with moderate, and 12 with severe glaucoma; groups 1, 2, and 3, respectively) was imaged using the RTVue Optic Nerve Head Map scan, GDx-VCC, and GDx-ECC, each 5 times on the same day. The coefficient of variation (CV) were compared. The P values <1% were considered as significant. For average RNFLT CV was significantly lower with RTVue (2.11%) than with GDx-ECC (3.22%, P=0.004), for all participants. For temporal quadrant RNFLT in all participants, and group 1, CV with RTVue (4.88% and 3.30%) was significantly lower than with GDx-ECC (7.40% and 5.88%; P=0.004), and tended to be lower than with GDx-VCC (6.81% and 5.80%; P=0.011 and 0.016, respectively). For all participants, CV for inferior quadrant RNFLT was significantly lower with RTVue (3.49%) than with GDx-VCC (5.20%, P=0.002). No other difference was seen for any other parameter in any subject group. Repeatability characterized by CV of RNFLT measurement with the RTVue Optic Nerve Head Map scan and GDx-VCC/GDx-ECC was similar, and sufficient for clinical purposes, both in normal subjects and in glaucoma patients with different disease severity. For average peripapillary RNFLT and temporal quadrant RNFLT, repeatability of RTVue was better than that of GDx-ECC, and tended to be better than that of GDx-VCC.

Structure–Function Relationships in Normal and Glaucomatous Eyes Determined by Time- and Spectral-Domain Optical Coherence Tomography

To compare the relationships between retinal mean sensitivity (MS) and retinal nerve fiber layer (RNFL) thickness, as measured by time-domain (TD) and spectral-domain (SD) optical coherence tomography (OCT). Recruited subjects were divided into normal, glaucoma suspect, and glaucoma groups. RNFL thickness was measured with TD- and SD-OCT, and MS was assessed with visual field perimetry and expressed in decibels and 1/L, where L is luminance in lamberts. The relationship between SUPERIOR MS and INFERIOR RNFL thickness (clock-hour segments 5, 6, 7, and 8) and that between INFERIOR MS and SUPERIOR RNFL thickness (clock-hour segments 10, 11, 12, 1, 2, and 3) were correlated by linear and logarithmic regression analyses. Pearson's correlation coefficients (R), for both OCTs were compared by using Hotelling's t-test. Ninety-five eyes of 76 subjects were prospectively included. Twenty-five eyes were classified as normal, 25 with glaucoma suspect, and 45 with glaucoma. In normal and glaucoma suspect eyes, there were no significant relationships between MS and RNFL thickness. In glaucomatous eyes, the associations between MS and RNFL thickness were R = 0.31 to 0.57 with TD-OCT and R = 0.47 to 0.66 with SD-OCT, and the correlation of SUPERIOR RNFL thickness with INFERIOR MS was significantly better with SD-OCT than with TD-OCT in both linear and logarithmic regression models. The results showed that, in mild-to-moderate glaucoma, SD-OCT offers an improved structure-function correlation compared with TD-OCT, when applied to the detection of INFERIOR MS and SUPERIOR RNFL defects.