Color-code agreement among stratus, cirrus, and spectralis optical coherence tomography in relapsing-remitting multiple sclerosis with and without prior optic neuritis

Effect of refractive status on retinal nerve fiber layer thickness in Chinese Population

PURPOSE

To evaluate the relationship between retinal nerve fiber layer (RNFL) thickness and other related parameters measured by spectral-domain optical coherence tomography and the refractive error of eyes.

METHODS

A total of 5394 subjects were enrolled in this population-based cohort study, who were divided into three groups by refractive state after they underwent a standardized ophthalmic examination: emmetropia (the absolute value should range from 0 to 0.5 D), low-moderate myopia (the absolute value of myopic error should range from 0.5 to 6 D), and high myopia (the absolute value of myopic error should be over than 6 D). R 3.6.1 software was adopted for statistical analysis.

RESULTS

Two thousand five hundred fifty-two subjects (4548 eyes) were collected in this study, with an average age of 53.14 ± 10.64 years. There were significant differences among groups in average central corneal curvature, spherical equivalent, and axial length (P < 0.001). The measurements of average retinal nerve fiber layer (RNFL) were 113.95 ± 10.62 μm, 112.97 ± 11.59 μm, and 101.88 ± 15.67 μm, respectively, in the emmetropia, low-moderate, and high myopia groups (P < 0.001). Meanwhile, there was a decreasing trend of cup area, cup volume, disc area, and rim area in the high myopia group compared with the emmetropia group (P < 0.001).

CONCLUSION

The measurements of RNFL thickness vary greatly with refractive error, and this study indicated that it is of great significance for the accurate diagnosis of glaucoma to establish an individualized RNFL thickness database.

Correlation analysis between foveal avascular zone and near peripheral retinal hypoperfusion in multiple sclerosis: a wide field optical coherence tomography angiography study

The identification of non-invasive biomarkers to investigate and monitor retinal structural and vascular changes in multiple sclerosis (MS) represents an interesting source of debate. Until now optical coherence tomography angiography (OCTA) evaluated the foveal avascular zone (FAZ) and areas of retinal non-perfusion only in the macular region in MS patients. It could be interesting to identify possible biomarkers, useful in assessing the ischemic areas also in the near peripheral retina, since FAZ enlargement and the areas of peripheral retinal non-perfusions share common pathogenic processes. In this cross-sectional study, we investigated the correlation between the FAZ area and retinal vessel density (VD) in the near peripheral retina by new wide-field optical coherence tomography angiography (OCTA) in patients affected by relapsing-remitting multiple sclerosis (RR-MS). Moreover, we compared the FAZ area and the VD of superficial and deep capillary plexuses in the fovea region and in the near peripheral retina (6.4 × 6.4 mm) between RR-MS patients and healthy controls by means of a Solix full-range OCTA. Last, we also detected the changes in structural OCT parameters (ganglion cell complex and retinal nerve fiber layer). Thirty-three eyes of 33 RR-MS patients and 35 eyes of 35 healthy controls were enrolled. RR-MS patients showed a lower VD in the superficial capillary plexus and a significant increase in the FAZ area compared with controls. The deep capillary plexus revealed a reduced VD although not statistically significant in patients with respect to controls. In the patients' group, the FAZ area showed significantly negative correlations with VD of superficial capillary plexuses in the foveal and whole region, while the FAZ area did not negatively correlate with the VD of the deep capillary plexus. The significant correlations among OCTA parameters could demonstrate the FAZ area as a possible biomarker for assessing the perfusion status in the near peripheral retina, useful in RR-MS management. These findings could confirm the role of vascular dysfunction in the pathogenetic mechanisms of MS.

Synthetic OCT Data Generation to Enhance the Performance of Diagnostic Models for Neurodegenerative Diseases

Purpose

Optical coherence tomography (OCT) has recently emerged as a source for powerful biomarkers in neurodegenerative diseases such as multiple sclerosis (MS) and neuromyelitis optica (NMO). The application of machine learning techniques to the analysis of OCT data has enabled automatic extraction of information with potential to aid the timely diagnosis of neurodegenerative diseases. These algorithms require large amounts of labeled data, but few such OCT data sets are available now.

Methods

To address this challenge, here we propose a synthetic data generation method yielding a tailored augmentation of three-dimensional (3D) OCT data and preserving differences between control and disease data. A 3D active shape model is used to produce synthetic retinal layer boundaries, simulating data from healthy controls (HCs) as well as from patients with MS or NMO.

Results

To evaluate the generated data, retinal thickness maps are extracted and evaluated under a broad range of quality metrics. The results show that the proposed model can generate realistic-appearing synthetic maps. Quantitatively, the image histograms of the synthetic thickness maps agree with the real thickness maps, and the cross-correlations between synthetic and real maps are also high. Finally, we use the generated data as an augmentation technique to train stronger diagnostic models than those using only the real data.

Conclusions

This approach provides valuable data augmentation, which can help overcome key bottlenecks of limited data.

Translational Relevance

By addressing the challenge posed by limited data, the proposed method helps apply machine learning methods to diagnose neurodegenerative diseases from retinal imaging.

Decreases in ganglion cell layer and inner plexiform layer volumes correlate better with disease severity in schizophrenia patients than retinal nerve fiber layer thickness: Findings from spectral optic coherence tomography

Background

Optic coherence tomography (OCT) is a new, contactless and fast neuroimaging method. Previous studies have observed thinning of the retinal nerve fibre layer (RNFL) in many neurodegenerative diseases, and researchers have suggested that correlations exist between the thinning of the RNFL and the neurodegeneration detected with other imaging methods or the severity of illness. More recently, OCT has been used in patients with schizophrenia. RNFL thinning has also been detected in these patients. With more sophisticated devices, segmentation of the retina and measurements of the ganglion cell layer (GCL) and internal plexiform layer (IPL) can be performed.

Methods

We measured the RNFL thickness and the GCL and IPL volumes in 40 treatment refractory patients with schizophrenia, 41 treatment responsive refractory patients and 41 controls using spectral-OCT, and we evaluated the correlations between the disease severity and OCT measurements.

Results

The global RNFL thickness and GCL and IPL volumes were decreased in the patients with schizophrenia compared with the controls. In addition, the GCL and IPL volumes were lower in the treatment refractory patients with schizophrenia compared to the treatment responsive patients. Using parameters such as the Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression (CGI) scores, the disease duration and number of hospitalizations, correlations between the GCL and IPL volumes and disease severity were stronger than the correlations between the RNFL and the disease parameters.

Conclusion

Our findings suggest that OCT can be used to detect neurodegeneration in schizophrenia and that the GCL and IPL volumes can also be used to monitor the progression of neurodegeneration.

Retinal nerve fiber layer thickness by Stratus and Cirrus OCT in retrobulbar optic neuritis and nonarteritic ischemic optic neuropathy

PURPOSE

To compare retinal nerve fiber layer thickness (RNFLT) measurements by Stratus and Cirrus optical coherence tomography (OCT) and to evaluate agreement between the 2 instruments in retrobulbar optic neuritis (RON), nonarteritic ischemic optic neuropathy (NAION), and healthy controls.

METHODS

A total of 89 eyes with RON, 92 with NAION (6 to 12 months after diagnosis of acute disease), and 159 control eyes were studied. Average RNFLT was measured by Stratus and Cirrus OCTs. Comparisons among groups were performed by analysis of variance. Agreement between the 2 instruments was assessed using intraclass correlation coefficient (ICC) with 95% confidence interval (CI) and Bland-Altman analysis. Statistical significance was set at p≤0.05.

RESULTS

Average RNFLT was lower in NAION eyes than in RON and control ones using both OCT devices (60.0 ± 1.2, 69.9 ± 1.2, and 97.4 ± 0.9 μm, p&lt;0.001 by Cirrus; 49.7 ± 1.5, 65.9 ± 1.9, and 99.2 ± 1.3 μm, p&lt;0.001 by Stratus). The RNFLT values were higher with Cirrus than with Stratus in NAION (+10.30 μm, confidence interval [CI] 7.82-12.79 μm) and RON (+4.01 μm, CI 1.32-6.70 μm) eyes, and slightly lower in control ones (-1.75 μm, CI -3.51 to 0.01 μm). A stronger agreement between the 2 instruments was found in control and RON eyes than in NAION ones (ICC 0.682, CI 0.566-0.771; 0.635, CI 0.467-0.758; 0.321, CI 0.132-0.472, respectively).

CONCLUSIONS

Both Stratus and Cirrus OCT can identify RNFLT reduction in previous RON and NAION. Absolute RNFLT values differ between the 2 instruments; hence they are not to be considered interchangeable.

Retinal ganglion cell and axonal loss in optic neuritis: risk factors and visual functions

PurposeThe peripapillary retinal nerve fiber layer (pRNFL) and the macular ganglion cell-inner plexiform layer (GCIPL) are important predictive factors for the prognosis of optic neuritis (ON). We investigated the risk factors for pRNFL and GCIPL thinning in ON and its relationship with visual function.Patients and methodsWe analyzed 33 eyes of 33 patients with a first attack of unilateral ON. Patients were divided into two groups according to pRNFL and GCIPL thinning, using spectral-domain optical coherence tomography. We evaluated patients' age, sex, color vision, visual acuity (VA), optic nerve findings on MRI, elapsed period from onset of visual symptoms to steroid treatment, visual field (VF) mean deviation (MD), average pRNFL thickness, and GCIPL thickness.ResultsThere was no patient with residual VF defect in the groups without pRNFL or GCIPL thinning. Significant correlations were found between pRNFL (some sectors) and GCIPL (all sectors) thickness and BCVA and VF MD (P<0.03 for all). Multivariate logistic regression analysis revealed that only worse initial VF MD was a significant risk factor of pRFNL and GCIPL thinning after ON (OR, 0.841; 95% CI, 0.730-0.970; P=0.017 and OR, 0.871; 95% CI, 0.761-0.998; P=0.046, respectively).ConclusionRetinal ganglion cell and axonal losses occurred in ON cases showing severe initial VF loss. Therefore, it is necessary to pay more attention to the degree of initial VF loss in ON while considering the possibility of residual VF loss accompanying pRNFL and GCIPL thinning.

Visual Outcomes, Visual Fields, and Optical Coherence Tomography in Paediatric Craniopharyngioma

Ten patients with craniopharyngioma treated for the first time when younger than 18 were included. This study reviews the visual outcomes and provides information on visual field (VF) and optical coherence tomography (OCT) examination of craniopharyngioma. The best kappa concordance coefficients between VF and OCT parameters of atrophy were obtained for the ganglion cell (GC) thickness and the mean retinal nerve fibre layer (RNFL) thickness. The agreement between GC colour maps and VF defects was good. Optic nerve compression may be detected by RNFL measurement and GC analysis, and this may be valuable to predict visual recovery and in uncooperative patients to evaluate visual damage.

Ganglion cell layer analysis unmasks axonal loss in anterior optic neuritis

Optical coherence tomography is a valuable tool for evaluating patients with neuro-ophthalmic disorders. In the acute phase of anterior optic neuritis (ON), peripapillary retinal nerve fiber layer (pRNFL) measurements can underestimate the amount of damage as axonal swelling could mask the true degree of RNFL loss. Contrary to pRNFL evaluation, we hypothesize that macular ganglion cell layer analysis could detect true neuronal loss before swelling resolution in anterior ON. We describe 4 patients with anterior ON in whom ganglion cell layer and inner plexiform layer (GCIPL) thinning was detected earlier than pRNFL loss. GCIPL analysis may provide more accurate information than pRNFL thickness and serve as an early structural indicator of irreversible neuronal loss.

Using spectral-domain optical coherence tomography to detect optic neuropathy in patients with craniosynostosis

BACKGROUND

Detecting and monitoring optic neuropathy in patients with craniosynostosis is a clinical challenge due to limited cooperation, and subjective measures of visual function. The purpose of this study was to appraise the correlation of peripapillary retinal nerve fiber layer (RNFL) thickness measured by spectral-domain ocular coherence tomography (SD-OCT) with indication of optic neuropathy based on fundus examination.

METHODS

The medical records of all patients with craniosynostosis presenting for ophthalmic evaluation during 2013 were retrospectively reviewed. The following data were abstracted from the record: diagnosis, historical evidence of elevated intracranial pressure, current ophthalmic evaluation and visual field results, and current peripapillary RNFL thickness.

RESULTS

A total of 54 patients were included (mean age, 10.6 years [range, 2.4-33.8 years]). Thirteen (24%) had evidence of optic neuropathy based on current fundus examination. Of these, 10 (77%) demonstrated either peripapillary RNFL elevation and papilledema or depression with optic atrophy. Sensitivity for detecting optic atrophy was 88%; for papilledema, 60%; and for either form of optic neuropathy, 77%. Specificity was 94%, 90%, and 83%, respectively. Kappa agreement was substantial for optic atrophy (κ = 0.73) and moderate for papilledema (κ = 0.39) and for either form of optic neuropathy (κ = 0.54). Logistic regression indicated that peripapillary RNFL thickness was predictive of optic neuropathy (P < 0.001). Multivariable analysis demonstrated that RNFL thickness measurements were more sensitive at detecting optic neuropathy than visual field testing (likelihood ratio = 10.02; P = 0.002). Sensitivity and specificity of logMAR visual acuity in detecting optic neuropathy were 15% and 95%, respectively.

CONCLUSIONS

Peripapillary RNFL thickness measured by SD-OCT provides adjunctive evidence for identifying optic neuropathy in patients with craniosynostosis and appears more sensitive at detecting optic atrophy than papilledema.

OCT: New perspectives in neuro-ophthalmology

Optical coherence tomography (OCT) has become essential to evaluate axonal/neuronal integrity, to assess disease progression in the afferent visual pathway and to predict visual recovery after surgery in compressive optic neuropathies. Besides that OCT testing is considered a powerful biomarker of neurodegeneration and a promising outcome measure for neuroprotective trials in multiple sclerosis (MS). Currently, spectral-domain OCT (SD-OCT) technology allows quantification of retinal individual layers. The Ganglion Cell layer (GCL) investigation has become one of the most useful tools from a neuro-ophthalmic perspective. It has a high correlation with perimetry, is predictive of future progression and is a highly sensitive, specific of several neuro-ophthalmic pathologies. Moreover the superior correlation with clinical measures compared to peripapillary retinal nerve fiber layer (pRNFL) suggests that GCL analysis might be a better approach to examine MS neurodegeneration. In disorders with optic disk edema, such as ischemic optic neuropathy, papillitis and papilledema, reduction in RNFL thickness caused by axonal atrophy is difficult to distinguish from a swelling resolution. In this setting, and in buried optic nerve head drusen (ONHD), GCL analysis may provide more accurate information than RNFL analysis and it might be an early structural indicator of irreversible neuronal loss. Enhanced depth imaging OCT (EDI-OCT) provides in vivo detail of ONHD, allowing to evaluate and quantify the drusen dimensions. OCT is improving our knowledge in hereditary optic neuropathies. Furthermore, there is growing evidence about the role of OCT as an adjunctive biomarker of disorders such as Alzheimer and Parkinson's disease.

Comparative diagnostic accuracy of ganglion cell-inner plexiform and retinal nerve fiber layer thickness measures by Cirrus and Spectralis optical coherence tomography in relapsing-remitting multiple sclerosis

Objective. To estimate sensitivity and specificity of several optical coherence tomography (OCT) measurements for detecting retinal thickness changes in patients with relapsing-remitting multiple sclerosis (RRMS), such as macular ganglion cell-inner plexiform layer (GCIPL) thickness measured with Cirrus (OCT) and peripapillary retinal nerve fiber layer (pRNFL) thickness measured with Cirrus and Spectralis OCT. Methods. Seventy patients (140 eyes) with RRMS and seventy matched healthy subjects underwent pRNFL and GCIPL thickness analysis using Cirrus OCT and pRNFL using Spectralis OCT. A prospective, cross-sectional evaluation of sensitivities and specificities was performed using latent class analysis due to the absence of a gold standard. Results. GCIPL measures had higher sensitivity and specificity than temporal pRNFL measures obtained with both OCT devices. Average GCIPL thickness was significantly more sensitive than temporal pRNFL by Cirrus (96.34% versus 58.41%) and minimum GCIPL thickness was significantly more sensitive than temporal pRNFL by Spectralis (96.41% versus 69.69%). Generalised estimating equation analysis revealed that age (P = 0.030), optic neuritis antecedent (P = 0.001), and disease duration (P = 0.002) were significantly associated with abnormal results in average GCIPL thickness. Conclusion. Average and minimum GCIPL measurements had significantly better sensitivity to detect retinal thickness changes in RRMS than temporal pRNFL thickness measured by Cirrus and Spectralis OCT, respectively.

A comparison of false positives in retinal nerve fiber layer, optic nerve head and macular ganglion cell-inner plexiform layer from two spectral-domain optical coherence tomography devices

BACKGROUND

The incidence of false positive (FP) results of optic coherence tomography (OCT) retinal nerve fiber layer (RNFL) color code in healthy subjects can be very high with Cirrus OCT. Recent evidence has shown that OCT parameters derived from macular ganglion cell-inner plexiform layer (GCIPL) have excellent ability to discriminate between normal eyes and eyes with early glaucoma.

METHODS

This was a prospective, cross-sectional study. One hundred eyes from 50 healthy volunteers underwent circumpapillary scanning by Cirrus and Spectralis OCT and macular scanning using Cirrus OCT. FP rates for each of the OCT parameters, using predefined criteria for an abnormal test were calculated. Comparative analysis was performed using the McNemar test. A generalized estimating equations model (GEE) was used to compare demographic and clinical factors between the eyes with normal findings and eyes with abnormal results.

RESULTS

The overall RNFL color-code FP rate was significantly higher for Cirrus (39 %) than for Spectralis (18 %) (P = 0.000). The Spectralis RNFL FP rate showed no significant difference when compared to the FP rate by Cirrus GCIPL (13 %) and ONH (11 %) analysis. Axial length, mean spherical equivalent, presence of peripapillary atrophy, and tilted disc were significantly related to the RNFL FP occurrence displayed by both devices.

CONCLUSIONS

Spectralis might be more specific than Cirrus when evaluating the RNFL thickness for Caucasians and moderate myopic population. GCIPL and ONH analysis might be more useful than RNFL thickness to evaluate this population using Cirrus OCT.

Retinal layer segmentation in patients with multiple sclerosis using spectral domain optical coherence tomography

PURPOSE

To evaluate the thickness of the 10 retinal layers in the paramacular area of patients with multiple sclerosis (MS) compared with healthy subjects using the new segmentation technology of spectral domain optical coherence tomography (OCT). To examine which layer has better sensitivity for detecting neurodegeneration in patients with MS.

DESIGN

Observational, cross-sectional study.

PARTICIPANTS

Patients with MS (n = 204) and age-matched healthy subjects (n = 138).

METHODS

The Spectralis OCT system (Heidelberg Engineering, Inc., Heidelberg, Germany) was used to obtain automated segmentation of all retinal layers in a parafoveal scan in 1 randomly selected eye of each participant, using the new segmentation application prototype.

MAIN OUTCOME MEASURES

The thicknesses of 512 parafoveal points in the 10 retinal layers were obtained in each eye, and the mean thickness of each layer was calculated and compared between patients with MS and healthy subjects. The analysis was repeated, comparing patients with MS with and without previous optic neuritis. Correlation analysis was performed to evaluate the association between each retinal layer mean thickness, duration of disease, and functional disability in patients with MS. A logistic regression analysis was performed to determine which layer provided better sensitivity for detecting neurodegeneration in patients with MS.

RESULTS

All retinal layers, except the inner limiting membrane, were thinner in patients with MS compared with healthy subjects (P < 0.05). Greater effects were observed in the inner retinal layers (nerve fiber, ganglion cells, inner plexiform, and inner nuclear layers) of eyes with previous optic neuritis (P < 0.05). The retinal nerve fiber layer and ganglion cell layer thicknesses were inversely correlated with the functional disability score in patients with MS. The ganglion cell layer and inner plexiform layer thicknesses could predict axonal damage in patients with MS.

CONCLUSIONS

Analysis based on the segmentation technology of the Spectralis OCT revealed retinal layer atrophy in patients with MS, especially of the inner layers. Reduction of the ganglion cell and inner plexiform layers predicted greater axonal damage in patients with MS.