Relationship between the retinal thickness analyzer and the GDx VCC scanning laser polarimeter, Stratus OCT optical coherence tomograph, and Heidelberg retina tomograph II confocal scanning laser ophthalmoscopy

PURPOSE: To assess the relationship between the retinal thickness analyzer (RTA) parameters, and those of the GDx VCC scanning laser polarimeter (GDx VCC), Stratus OCT optical coherence tomography (Stratus OCT), and Heidelberg retinal tomograph II confocal scanning laser ophthalmoscopy (HRT II). METHODS: Twenty-nine primary open-angle glaucoma patients were retrospectively included in this study. Measurements were obtained using the RTA, GDx VCC, Stratus OCT, and HRT II. We calculated the correlation coefficients between the parameters of RTA and those of the other studies. RESULTS: Among the optic disc parameters of RTA, the cup volume was best correlated with Stratus OCT (R=0.780, p<0.001) and HRT II (R=0.896, p<0.001). Among the posterior pole retinal thickness parameters, the posterior pole abnormally thin area (PPAT) of the RTA and the inferior average of the GDx VCC were best correlated (R=-0.596, p=0.001). The PPAT of the RTA and the inferior maximum of the Stratus OCT were best correlated (R=-0.489, p=0.006). The perifoveal minimum thickness (PFMT) of the RTA and the cup shape measurement of the HRT II were best correlated (R=-0.565, p=0.004). CONCLUSIONS: Many RTA optic disc parameters were significantly correlated with those of the Stratus OCT and HRT II. The RTA posterior pole retinal thickness parameters were significantly correlated with those of the GDx VCC, Stratus OCT and HRT II. The RTA optic disc and posterior pole retinal thickness parameters may be valuable in the diagnosis of glaucoma.     

Comparison between GDx VCC scanning laser polarimetry and Stratus OCT optical coherence tomography in the diagnosis of chronic glaucoma

PURPOSE: To compare the abilities of scanning laser polarimetry with the variable corneal compensator (GDx VCC) with those of optical coherence tomography (Stratus OCT) in discriminating between healthy and early-to-moderate perimetric glaucomatous eyes. METHODS: A total of 95 glaucomatous patients (mean deviation - 3.7 +/- 3.0 dB, pattern standard deviation 4.5 +/- 2.7 dB) and 62 control subjects underwent imaging by the GDx VCC and Stratus OCT using both optic nerve head (ONH) and retinal nerve fibre layer (RNFL) scan protocols. One eye per patient was considered. Sensitivity at > or = 90% specificity and area under the receiver operating characteristic curve (AROC) were calculated for each GDx VCC and Stratus OCT index. RESULTS: The largest AROCs with Stratus OCT were associated with cup : disc area ratio (0.88) for ONH scan indices, and with average thickness (0.84) for RNFL scan indices. The nerve fibre indicator provided the greatest AROC for the GDx VCC indices (0.85). CONCLUSIONS: Both the GDx VCC and Stratus OCT instruments were shown to be useful in the detection of glaucomatous damage. The best performing indices for the GDx VCC and Stratus OCT with both ONH and RNFL scans gave similar AROCs, showing a moderate sensitivity in early-to-moderate glaucoma patients.     

Retinal nerve fiber layer evaluation of spectral domain optical coherence tomograph and scanning laser polarimeter to diagnose glaucoma

Purpose

To compare the abilities of retinal nerve fiber layer (RNFL) parameters of spectral domain optical coherence tomograph (SDOCT) and scanning laser polarimeter (GDx enhanced corneal compensation; ECC) in detecting glaucoma.

Methods

In a cross-sectional study, 215 eyes of 165 subjects (106 eyes of 79 glaucoma patients and 109 eyes of 86 controls) referred by general ophthalmologists for glaucoma evaluation underwent RNFL imaging with SDOCT and GDx ECC. Ability of RNFL parameters of SDOCT to discriminate glaucoma eyes from control eyes was compared with that of GDx ECC using area under operating characteristic curves (AUCs), sensitivities at fixed specificities, and likelihood ratios (LRs).

Results

AUC of the average RNFL thickness of SDOCT to differentiate glaucoma from control eyes (0.868) was comparable (P=0.32) to that of GDx ECC (0.855). Sensitivity at 95% specificity was 63.2% for average RNFL thickness of SDOCT and 48.1% for the average RNFL measurement of GDx ECC. LRs of outside normal limits category of SDOCT parameters ranged between 5.6 and 7.7 while the same of GDx ECC parameters ranged between 3.1 and 3.7. LRs of within normal limits category of SDOCT parameters ranged between 0.18 and 0.24 while the same of GDx ECC parameters ranged between 0.20 and 0.32.

Conclusion

Though AUCs and sensitivities at fixed specificities were comparable between the RNFL parameters of SDOCT and GDx ECC in diagnosing glaucoma, LRs indicated that the RNFL parameters of SDOCT were better in ‘ruling in'' glaucoma.     

Diagnostic ability of the Heidelberg retina tomograph, optical coherence tomograph, and scanning laser polarimeter in open-angle glaucoma

PURPOSE: To compare the ability to discriminate between healthy and glaucomatous eyes of different criteria based on parameters from 3 optical imaging devices: Heidelberg retina tomograph (HRT-II), optical coherence tomograph (Stratus OCT 3000) and scanning laser polarimeter (GDx VCC). DESIGN: Cross-sectional study. PARTICIPANTS: A total of 139 eyes from 139 subjects were enrolled in this study and classified into 66 healthy subjects and 73 glaucomatous patients according to intraocular pressure and standard automated perimetry. METHODS: All the subjects underwent complete ophthalmic examination, including HRT-II, OCT, and GDx VCC evaluations. MAIN OUTCOME MEASURES: Several parameters were obtained by these techniques and 8 diagnostic criteria were assessed. Receiver operating characteristics curves were plotted and compared among them, and sensitivity for specificity higher than 95% was calculated for every criterion. Agreement among the 3 technologies was assessed by means of Venn diagrams. RESULTS: The best criteria discriminating between healthy and glaucomatous eyes were Moorfields regression analysis out of the 95% confidence interval (HRT-II), OCT retinal nerve fiber layer average thickness <77 microm, and nerve fiber indicator >37 (GDx VCC) with sensitivities of 85%, 66%, and 48%, with specificity higher than 95%. Sixty-six patients out of 73 were correctly identified by at least 1 of the devices and 30 were detected by the 3 of them. CONCLUSIONS: Structural criteria assessed by the optical imaging devices evaluated in this study are useful to discriminate glaucomatous damage.     

Comparison of optic nerve head measurements obtained by optical coherence tomography and confocal scanning laser ophthalmoscopy

PURPOSE: To evaluate the relationship between optic nerve head (ONH) measurements generated by optical coherence tomography (OCT; versions 2 and 3) and confocal scanning laser ophthalmoscopy (CSLO) and to compare the association between OCT and CSLO ONH measurements with glaucoma disease status, as determined by clinical evaluation and perimetry. DESIGN: Cross-sectional study. METHODS: In a prospective study in the glaucoma service of an academic department of ophthalmology, 159 eyes (97 subjects) and 77 eyes (44 subjects) were recruited in two separate periods. All subjects were scanned with a CSLO device. Subjects tested within the first period of recruitment were scanned with OCT version 2 and in the second period with OCT version 3. The main outcome measure was the correlation between automatic and manually defined OCT ONH measurements and the correlation of CSLO and OCT ONH measurements between devices and with glaucoma disease status. RESULTS: A high correlation was found between ONH measurements obtained by the automatic determination of ONH margin and those obtained by manual tracing of the disk margin (r =.93 to.98). Optical coherence tomography and CSLO ONH measurements were highly correlated. Optical coherence tomography-measured mean disk area was significantly larger than that measured by CSLO, as were all other disk size-related parameters. The areas under the receiver operator characteristic (AROC) curves for the associations between CSLO and OCT ONH measurements and clinical diagnosis were found to be similar and in the range of 0.47 to 0.79 for both devices. CONCLUSIONS: Automated OCT ONH measurements correlate highly with those obtained by manual tracing of disk margin. Optical coherence tomography and CSLO ONH analyses are highly correlated and have similar associations with glaucoma disease status.     

Retinal nerve fiber layer measurements in indian eyes using the scanning laser polarimeter, GDx

PURPOSE: To obtain retinal nerve fiber layer (RNFL) measurements in normal Indian subjects of different age groups; and to determine the differences between the right and the left eye of a subject and variations between male and female gender using the scanning laser polarimeter GDx. MATERIALS AND METHODS: Prospective cross-sectional study of 180 eyes of 94 subjects. The RNFL values were obtained with the nerve fiber analyser GDx using default quadrant positions supplied by the manufacturer. Fourteen parameters were studied. Of these 6 were average-based parameters (average thickness, superior maximum, inferior maximum, ellipse average, superior average, inferior average), 4 ratio-based parameters (symmetry, superior ratio, inferior ratio, superior/nasal), 4 "other" parameters (maximum modulation, number, ellipse modulation, superior integral). The main outcome measures were effect of age on RNFL values, comparison of males and females and the right and the left eye of a subject. RESULTS: There was a negative linear correlation with age. Three ratio-based parameters showed a statistically significant negative correlation with age. "Number" increased with age. Superior maximum, superior average, superior integral, symmetry and superior ratio were higher for the left eye. 'Number' was higher for the right eye. Superior ratio and maximum modulation were more in females than males, no difference was noted with other parameters. CONCLUSION: There was a gradual decrease of RNFL values with increasing age - the superior quadrant values were higher for the left eye than the right eye, suggesting asymmetry. No significant differences were detected between males and females.     

Quantitative analysis of axonal loss in band atrophy of the optic nerve using scanning laser polarimetry

AIMS: To measure axonal loss in patients with band atrophy from optic chiasm compression using scanning laser polarimetry (GDx, Laser Diagnostic Technologies, Inc, San Diego, CA, USA) and to evaluate the ability of this instrument to identify this pattern of retinal nerve fibre layer (RNFL) loss. METHODS: 19 eyes from 17 consecutive patients with band atrophy of the optic nerve and permanent temporal hemianopia due to chiasmal compression, and 19 eyes from an age and sex matched control group of 17 healthy individuals were prospectively studied. All patients were submitted to an ophthalmic examination including Goldmann perimetry and evaluation of the RNFL using scanning laser polarimetry. Mean RNFL thickness around the optic disc were compared between the two groups. The diagnostic performance of the deviation from normal analysis provided by the GDx software was also assessed. RESULTS: The peripapillary RNFL thickness (mean (SD)) of eyes with band atrophy was 47.9 (7.63) micro m, 37.1 (8.48) micro m, 57.0 (9.31) micro m, and 37.2 (8.86) micro m in the superior, temporal, inferior, and nasal regions, respectively. The total average was 43.7 (12.0) micro m. In the control group, the corresponding values were 71.1 (12.2) micro m, 40.4 (10.9) micro m, 85.4 (14.0) micro m, and 49.8 (10.1) micro m. The total average measured 67.9 (11.2) micro m. The measurements from eyes with optic atrophy were significantly different from those in the control group in all regions but the temporal. The deviation from normal analysis provided by the GDx software failed to identify the majority of abnormalities in the temporal and nasal regions of patients with band atrophy. CONCLUSIONS: Scanning laser polarimetry was able to identify axonal loss in the superior, inferior, and nasal regions, but failed to detect it in the temporal region of the optic disc, despite the fact that this area was clearly altered in eyes with band atrophy. This examination also showed poor sensitivity to detect axonal loss in the nasal region when GDx software analysis was used. The results of this study emphasise that RNFL evaluation using scanning laser polarimetry should be interpreted with caution in the study of eye diseases that lead to axonal loss predominantly in the nasal and temporal areas of the optic disc.     

OCT和SLP定量检测视网膜神经纤维层的研究进展

研究表明青光眼的视网膜神经纤维层(retinal nerve fiber layer,RNFL)损害早于视野改变。视网膜神经纤维层结构性损害的检测是青光眼早期诊断的重要手段。现代激光及计算机技术可以作为青光眼监测的有效方式。本文对OCT和SLP在RNFL定量检测方面的临床研究进展情况进行了综述。     

Diagnostic laser in glaucoma: scanning laser polarimetry (GDx VCC) and confocal scanning laser tomography (HRT)

Automated structural measurements of retinal nerve fibers and optic nerve head are possible with new lasers providing objective and reproductible data for analysis. Scanning laser polarimetry (GDx VCC), based on retardation of polarized light, assesses peripapillary nerve fiber layer thickness. Confocal scanning laser tomography yields precise topographic maps of the optic disc and peripapillary retina. The advantages, applications for glaucoma detection, both in a screening setting as well as for monitoring progression, limitations and pitfalls need to be well known and results should be analyzed with clinical data.     

Better performance of RTVue than Cirrus spectral-domain optical coherence tomography in detecting band atrophy of the optic nerve

Background

To assess the agreement and diagnostic performance between retinal nerve fiber layer (RNFL) thickness measurements obtained using the Cirrus (Carl Zeiss Meditec) and RTVue (Optovue Inc.) devices for detection of band atrophy (BA) in patients with permanent temporal hemianopia.

Methods

In this retrospective study, 26 eyes with BA and 64 control eyes were enrolled. The Cirrus optic disc cube protocol and the RTVue optic nerve head map protocol were used. The Cirrus measurements were extracted and regrouped to be topographically matched with the RTVue measurements. Concordance correlation and 95?% limits of agreement were assessed. Areas under the receiver operating characteristic curves (AUC) and the Spearman’s correlation coefficient between average Humphrey total deviation in the temporal hemifield and average RNFL thickness were calculated.

Results

RTVue measured consistently thicker values than Cirrus in controls, whereas in eyes with BA, nasal segment measurements from the RTVue were thinner than those obtained using the Cirrus. Each quadrant showed moderate to close agreement in controls, whereas in eyes with BA, the nasal and temporal quadrants exhibited poor agreement. The RTVue measurements demonstrated significantly higher AUCs for nasal segments just above (0.95) and below (0.96) the horizontal meridian than Cirrus measurements (0.80 and 0.66, respectively) and a significant correlation with visual field loss (r_s?=?0.46, P?=?0.02 for RTVue vs. r_s?=?0.26, P?=?0.22 for Cirrus).

Conclusions

The RTVue RNFL thickness measurements in nasal sectors showed better diagnostic performance in detecting BA and higher correlations with temporal hemianopia than the Cirrus measurements.     

Diagnostic ability of optical coherence tomography with a normative database to detect band atrophy of the optic nerve

PURPOSE: To evaluate the diagnostic ability of stratus optical coherence tomography (OCT) with a normative database to detect band atrophy (BA) of the optic nerve. DESIGN: Cross-sectional study. METHODS: StratusOCT retinal nerve fiber layer thickness scans were obtained in 37 eyes with BA and permanent temporal visual field defect and 37 healthy eyes. The categorization of eyes according to the normative database of the instrument and sensitivity and specificity values were reported. RESULTS: The average thickness parameter demonstrated the highest sensitivity for detection of abnormalities in eyes with BA, followed by the parameters related to the temporal and nasal quadrants. Values of sensitivity were relatively lower for the 30 degree segments. CONCLUSION: StratusOCT with a normative database performed well in detecting retinal nerve fiber layer (RNFL) loss in eyes with BA. Clinicians should be aware of possible detection failure in the 30 degree segmental analysis, particularly at the 3 o'clock meridian.     

Optical coherence tomography analysis of axonal loss in band atrophy of the optic nerve

AIMS: To measure axonal loss in patients with band atrophy of the optic nerve caused by optic chiasm compression using optical coherence tomography and to evaluate its ability in identifying this pattern of retinal nerve fibre layer (RNFL) loss. METHODS: Twenty eyes from 16 consecutive patients with band atrophy of the optic nerve and permanent temporal hemianopia due to chiasmal compression, and 20 eyes from an age and sex matched control group of 16 healthy individuals, were studied prospectively. All patients were submitted to an ophthalmic examination including perimetry and evaluation of the RNFL using optical coherence tomography. Mean RNFL thickness around the optic disc was compared between the two groups. RESULTS: The mean (SD) peripapillary RNFL thickness of eyes with band atrophy was 101.00 (9.89) microm, 62.21 (12.71) microm, 104.89 (12.60) microm, and 50.13 (16.88) microm in the superior, temporal, inferior, and nasal regions, respectively. The total RNFL mean was 79.94 (7.17) microm. In the control group, the corresponding values were 140.10 (16.06) microm, 86.50 (12.17) microm, 144.60 (15.70) microm, and 97.94 (16.02) microm. The total RNFL mean was 117.72 (9.53) microm. The measurements were significantly different between the two groups. Measurements in each of twelve 30 degrees divisions provided by the equipment also showed significantly different values between eyes with band atrophy and normal controls. CONCLUSIONS: Optical coherence tomography was able to identify axonal loss in all four quadrants as well as in each of the twelve 30 degrees segments of the disc. Thus, it seems to be a promising instrument in the diagnosis and follow up of neuro-ophthalmic conditions responsible for RNFL loss, even if predominantly in the nasal and temporal areas of the optic disc.     

Relationships between standard automated perimetry, HRT confocal scanning laser ophthalmoscopy, and GDx VCC scanning laser polarimetry

PURPOSE: This study was designed to determine and compare the relationships between visual function measured with standard automated perimetry (SAP) and structure, either as neuroretinal rim area measured with confocal scanning laser ophthalmoscopy (CSLO), or as retinal nerve fiber layer thickness determined by scanning laser polarimetry with variable corneal compensation (SLP-VCC). METHODS: Forty-six healthy subjects and 76 glaucoma patients were examined with SAP, with CSLO by means of the commercially available Heidelberg Retina Tomograph I (HRT), and with SLP-VCC by means of the commercially available GDx VCC. The relationships between SAP, expressed either in the typically used decibel scale or as number of abnormal points in the total deviation probability plot, and CSLO and between SAP and SLP-VCC were described with linear and logarithmic regression analysis for global data and six individual sectors. The relationship between measurements with CSLO and SLP-VCC was fit with linear regression analysis. RESULTS: The relationships between SAP and CSLO and between SAP and SLP-VCC appeared curvilinear for all sectors except the temporal one between SAP and SLP-VCC. For CSLO, a logarithmic fit was significantly better than a linear one for the global data and in the superotemporal and inferonasal sectors. For SLP-VCC, a curvilinear fit was better for the global data and in the superotemporal, superonasal, and inferonasal sectors. CSLO data correlated linearly with SLP-VCC data in all sectors, except temporally. CONCLUSIONS: CSLO and SLP-VCC showed a very similar curvilinear relationship with SAP. The observed curvilinear relationships confirm earlier reports that these imaging devices appear to detect glaucomatous loss earlier than SAP.     

Comparison of retinal nerve fibre layer measurements using optical coherence tomography versions 1 and 3 in eyes with band atrophy of the optic nerve and normal controls

AIMS: To compare retinal nerve fibre layer (RNFL) measurements were carried out with two different versions of an optical coherence tomography device in patients with band atrophy (BA) of the optic nerve and in normal controls. METHODS: The RNFL of 36 eyes (18 with BA and 18 normals) was measured using an earlier version of an optical coherence tomography device (OCT-1). The measurements were repeated using a later version of the same equipment (OCT-3), and the two sets of measurements were compared. RESULTS: Using OCT-1, the peripapillary RNFL thickness (mean+/-SD, in microm) in eyes with BA measured 80.42+/-6.94, 99.81+/-14.00, 61.69+/-13.02, 101.70+/-12.54, and 57.36+/-16.52 corresponding to the total RNFL average, superior, temporal, inferior, and nasal quadrants, respectively. Using OCT-3, the corresponding measurements were 63.11+/-6.76, 81.22+/-13.34, 39.50+/-8.27, 86.72+/-15.16, and 45.05+/-8.03. Each of these measurements was significantly smaller with OCT-3 than with OCT-1. In normal eyes, RNFL average and temporal quadrant OCT-3 values were significantly smaller than OCT-1 values, but there was no significant difference in measurements from the superior, inferior, and nasal quadrant. CONCLUSIONS: RNFL measurements were smaller with OCT-3 than with OCT-1 for almost all parameters in eyes with BA and in the global average and temporal quadrant measurements in normal eyes. Investigators should be aware of this fact when comparing old RNFL measurement with values obtained with later versions of the equipment.