Papillomacular Bundle and Inner Retinal Thicknesses Correlate With Visual Acuity in Nonarteritic Anterior Ischemic Optic Neuropathy

Imaging the optic nerve with optical coherence tomography

Optical coherence tomography (OCT) is a non-invasive imaging technology, which may be used to generate in vivo quantitative and qualitative measures of retinal structure. In terms of quantitative metrics, peripapillary retinal nerve fiber layer (pRNFL) thickness provides an indirect evaluation of axonal integrity within the optic nerve. Ganglion layer measures derived from macular scans indirectly reflect retinal ganglion cell status. Notably, ganglion layer indices are platform dependent and may include macular ganglion cell inner plexiform layer (mGCIPL), ganglion cell layer (GCL), and ganglion cell complex (GCC) analyses of thickness or volume. Interpreted together, pRNFL thickness and ganglion layer values can be used to diagnose optic neuropathies, monitor disease progression, and gauge response to therapeutic interventions for neuro-ophthalmic conditions. Qualitative assessments of the optic nerve head, using cross-sectional transverse axial, en face, and circular OCT imaging, may help distinguish papilledema from pseudopapilloedema, and identify outer retinal pathology. Innovations in OCT protocols and approaches including enhanced depth imaging (EDI), swept source (SS) techniques, and angiography (OCTA) may offer future insights regarding the potential pathogenesis of different optic neuropathies. Finally, recent developments in artificial intelligence (AI) utilizing OCT images may overcome longstanding challenges, which have plagued non-vision specialists who often struggle to perform reliable ophthalmoscopy. In this review, we aim to discuss the benefits and pitfalls of OCT, consider the practical applications of this technology in the assessment of optic neuropathies, and highlight scientific discoveries in the realm of optic nerve imaging that will ultimately change how neuro-ophthalmologists care for patients.

Variability of relationship between inner-retinal structural changes and visual dysfunction in optic neuropathy

Optical coherence tomography (OCT) displays the retinal nerve fiber layer (RNFL) or macular ganglion cell and inner plexiform layer (GCIPL) thickness below 1st percentile in red color. This finding generally indicates severe inner-retinal structural changes and suggests poor visual function. Nevertheless, some individuals show preserved visual function despite these circumstances. This study aimed to identify the correlation between best-corrected visual acuity (BCVA) and inner-retinal thickness based on OCT parameters in various optic neuropathy patients with extremely low RNFL/GCIPL thickness, and determine the limitation of OCT for predicting visual function in these patients. 131 patients were included in the study. The mean BCVA in logMAR was 0.55 ± 0.70 with a broad range from - 0.18 to 3.00. Among the OCT parameters, temporal GCIPL (r = - 0.412) and average GCIPL (r = - 0.366) exhibited the higher correlations with BCVA. Etiological comparisons of optic neuropathies revealed significantly lower BCVA in LHON (all p < 0.05). Idiopathic optic neuritis (ON) and MOGAD exhibited better and narrower BCVA distributions compared to the other optic neuropathies. OCT had limited utility in reflecting BCVA, notwithstanding significant inner-retinal thinning after optic nerve injuries. Caution is needed in interpreting OCT findings, especially as they relate to the etiology of optic neuropathy.

Effect of Focal Laser Photocoagulation on the Ganglion Cell Complex Thickness in Acute Central Serous Chorioretinopathy

This study investigated the changes in the ganglion cell complex (GCC) of patients with acute central serous chorioretinopathy (CSC) following focal laser photocoagulation (FLP) and sought to determine its correlation with visual acuity (VA). Our retrospective study was conducted on 30 patients diagnosed with acute CSC between January 2015 and April 2022, who underwent FLP within 3 months of symptom onset. The study assessed GCC changes by measuring the thickness of its inner retinal layers-retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) using optical coherence tomography (OCT). GCC thickness was compared between the affected and unaffected eyes and a healthy control group. VA was also assessed at baseline and at 1, 3, and 6 months post-treatment. VA showed significant improvement from 0.20 ± 0.14 at baseline to 0.10 ± 0.12 logMAR at 6 months post-treatment (p = 0.003). There was no significant change in GCC thickness over the 6-month period. No significant differences in GCC thickness were observed when comparing CSC eyes with fellow eyes or with normal controls at any time point. Final VA was significantly related only to baseline VA, with no correlation found with other factors, including RNFL, GCL, and IPL thickness. In summary, for patients with acute CSC undergoing FLP, our findings indicate that there is no significant change in GCC thickness detectable by OCT before and after the resolution of subretinal fluid (SRF), despite improvements in VA post-laser treatment. This suggests that any potential impact of FLP on GCC thickness may be minimal and not discernible with the current measurement methods, such as OCT, emphasizing that VA improvements may be primarily associated with alterations in the outer retina rather than the inner retina. Further studies with extended follow-up durations are warranted to evaluate any potential long-term changes in GCC.

Longitudinal changes in the ganglion cell complex thickness in acute central serous chorioretinopathy using spectral-domain optical coherence tomography

In this retrospective longitudinal cohort study, we investigated the temporal changes in the peripapillary retinal nerve fiber layer (pRNFL) and inner retinal thickness in patients with acute central serous chorioretinopathy (CSC) using spectral-domain optical coherence tomography (SD-OCT). We followed up with these patients for 6 months, and during this period, the thickness of the pRNFL and the ganglion cell complex (GCC) in CSC patients were compared with the eyes of normal healthy individuals. The study also examined the correlation between the pRNFL thickness, GCC thickness, and visual acuity. The research sample consisted of 67 patients (43 male and 24 female) with an average age of 49.72 ± 9.87 years. The initial findings showed no significant differences in the pRNFL and GCC thickness between the study and fellow eye, study and normal healthy eyes, and fellow and normal healthy eyes. There was no significant difference in the pRNFL and GCC thickness when comparing the study eye with the fellow eye for 6 months. In the study eye, no significant difference was observed when comparing the initial GCC and pRNFL thickness with those at 1, 3, and 6 months. Visual acuity improved significantly from 0.18 ± 0.23 logMAR to 0.04 ± 0.06 logMAR (p < 0.001). The GCC and pRNFL thickness did not significantly affect visual acuity. In conclusion, acute CSC patients did not show significant changes in the pRNFL and inner retinal thickness, suggesting that the GCC and pRNFL do not substantially influence the short-term visual prognosis in these patients.

Morphological and functional involvement of the inner retina in retinitis pigmentosa

BACKGROUND

To investigate the morphological retinal parameters associated with retinal sensitivity status in retinitis pigmentosa (RP) through a quantitative multimodal imaging approach.

METHODS

The study was designed as an observational, prospective case series, including RP patients and healthy controls. Multimodal imaging included fundus autofluorescence (FAF), structural optical coherence tomography (OCT), OCT angiography (OCTA) and microperimetry (MP). The follow-up lasted 12 months. For each imaging modality, we performed an overall quantitative analysis and a detailed investigation based on the ETDRS-9 sectors grid. Quantitative parameters included the thickness of each retinal and choroidal layer, vessel density (VD), choriocapillaris porosity (CCP), FAF intensity and MP retinal sensitivity.

RESULTS

We included 40 eyes (40 patients) affected by RP and 40 healthy eyes (40 controls). Mean baseline BCVA was 0.14 ± 0.18 LogMAR, with 0.18 ± 0.24 LogMAR after 1-year of follow-up. RP eyes showed statistically significant alterations of retinal and choroidal layers on the ETDRS-9 sectors grid, significant reduction of VD values and MP retinal sensitivity, and significantly higher CCP than controls. The inner retinal layers proved closely associated with the functional integrity of the posterior pole. In addition, our ROC analysis provided quantitative cutoffs connected significantly with a high probability of observing a partial sparing of MP retinal sensitivity.

CONCLUSIONS

The inner retinal layers are closely associated with the functional integrity of the posterior pole in RP. FAF intensity reduction may be interpreted as lipofuscin metabolism impairment inducing increased phototoxic distress for retinal structures. Vascular involvement contributes to the morpho-functional deterioration of the macular region in RP.

Morphological changes of the retinal layers in the central macula in children with anisometropic amblyopia

PURPOSE

The goal of this study was to evaluate the morphological characteristics of the retinal layers in the central macula in children with anisometropic amblyopia.

METHODS

This comparative, observational, prospective study included 28 patients who were diagnosed with anisometropic amblyopia and 30 age- and sex-matched healthy controls. All children were evaluated using the automatic calculation software system available on spectral-domain optical coherence tomography (SD-OCT) for automated segmentation of the macula.

RESULTS

Of the included patients, 18 (64.3%) were male and 10 (35.7%) were female, with a mean age of 10.3±3.4 years. Mean spherical equivalent and best-corrected visual acuity (BCVA) were 4.13±1.95 diopters and 0.707±0.36 logMAR, respectively. The mean axial length was significantly lower in amblyopic eyes compared to fellow eyes (22.1±0.34mm vs. 23.3±0.42mm, P<0.0001), and control eyes (22.1±0.34mm vs. 23.1±0.40mm, P<0.0001). The mean thickness of the outer nuclear layer was significantly lower in amblyopic eyes compared to fellow eyes (79.8±11.9μm vs. 86.8±7.9μm, P=0.007), and healthy controls (79.8±11.9μm vs. 87.4±10.5μm, P=0.012).

CONCLUSION

The results of this study showed that there are quantitative differences in retinal microstructures of the macula in eyes with anisometropic amblyopia compared to fellow eyes and healthy controls. These findings suggest that anisometropic amblyopia may result in abnormal development of macular structure in the inner retinal layer. A detailed analysis of retinal layers may be able to provide a guide to the depth of amblyopia and visual prognosis.

The Role of Optical Coherence Tomography Angiography in Optic Nerve Head Edema: A Narrative Review

Optic nerve head (ONH) edema is a clinical manifestation of many ocular and systemic disorders. Ocular and central nervous system imaging has been used to differentiate the underlying cause of ONH edema and monitor the disease course. ONH vessel abnormalities are among the earliest signs of impaired axonal transportation. Optical coherence tomography angiography (OCTA) is a noninvasive method for imaging ONH and peripapillary vessels and has been used extensively for studying vascular changes in ONH disorders, including ONH edema. In this narrative review, we describe OCTA findings of the most common causes of ONH edema and its differential diagnoses including ONH drusen.

Posterior segment spectral domain oct in the differential diagnosis of bilateral temporal optic neuropathy and its correlation with visual acuity

PURPOSE

To identify the underlying etiologies and to evaluate the differential diagnostic value of posterior segment spectral domain OCT measurements and their correlation with best-corrected visual acuity (BCVA) in a group of patients with OCT documented bilateral optic neuropathy limited to the temporal quadrants.

METHODS

Retrospective study.

RESULTS

We included 61 patients: 35 presented with presumed "classic" acquired mitochondrial optic neuropathy (MON) (18 nutritional, 11 toxic, 6 mixed toxic-nutritional) and 2 with suspected hereditary MON. Nine patients were identified as 'MON mimickers' (especially multiple sclerosis), and 4 were found to have a mixed mechanism, while 11 remained undiagnosed. Across all etiologies, the strongest positive relationship between BCVA and tested OCT parameters was with macular GCL (ganglion cell layer) and GCIPL (combined ganglion cell and inner plexiform layer) volumes rather than peripapillary retinal nerve fiber layer (RNFL) thicknesses (all statistically significant). There was an inverse relationship between BCVA and inner nuclear layer (INL) volumes, with significant differences for BCVA and all tested OCT parameters between eyes with and without INL microcystoid lesions. OCT (absolute values and intereye differences) was not helpful in distinguishing between presumed acquired mitochondrial disease and patients with multiple sclerosis without optic neuritis. However, significantly greater intereye differences in global RNFL and inner plexiform layer and GCIPL volumes were found in patients with a previous history of unilateral optic neuritis.

CONCLUSIONS

The strongest positive relationship with BCVA was found for macular GCL and GCIPL volumes. OCT could not differentiate between acquired mitochondrial disease and multiple sclerosis without optic neuritis.

Long-term Effect of Permanent Demyelination on Axonal Survival in Multiple Sclerosis

Background and Objectives

To investigate the long-term effect of permanent demyelination on axonal attrition by examining an association between intereye asymmetry of the multifocal visual evoked potential (mfVEP) latency delay and subsequent thinning of retinal ganglion cell axons in patients with a long-standing history of unilateral optic neuritis (ON).

Methods

Only patients with a significant degree of chronic demyelination (intereye latency asymmetry >5 ms) were included in this study. The level of optic nerve demyelination was estimated at baseline by the latency delay of mfVEP, while the degree of axonal loss was assessed by thinning of the retinal nerve fiber layer (RNFL) thickness between baseline and follow-up visits. Low-contrast visual acuity (LCVA) was also evaluated at baseline and follow-up. Patients were examined twice with an average interval of 6.1 ± 1.4 years.

Results

From 85 examined patients with multiple sclerosis, 28 satisfied inclusion criteria. Latency of the mfVEP was delayed, and RNFL thickness was reduced in ON eyes compared with fellow eyes at both visits. There was significant correlation between latency asymmetry and baseline or follow-up intereye RNFL thickness asymmetry. Intereye asymmetry of LCVA at baseline correlated with baseline latency asymmetry of mfVEP and baseline asymmetry of RNFL thickness. Latency of the mfVEP in ON eyes improved slightly during the follow-up period, whereas latency of the fellow eye remained stable. By contrast, RNFL thickness significantly declined in both ON and fellow eyes during the follow-up period. The rate of RNFL thinning in ON eyes, however, was more than 2 times faster compared with the fellow eyes (p < 0.001). Furthermore, baseline latency asymmetry significantly correlated with the rate of RNFL thinning in ON eyes during the follow-up (p < 0.001), explaining almost half of the variability of temporal RNFL progression. For each millisecond of latency delay (i.e., ∼0.5 mm of demyelination along the optic nerve), temporal RNFL thickness was annually reduced by 0.05%.

Discussion

Our study provides clear in vivo evidence that chronic demyelination significantly accelerates axonal loss. However, because this process is slow and its effect is mild, long-term monitoring is required to establish and confidently measure the neurodegenerative consequences of demyelination.

Comparison of Visual Evoked Potentials in Patients Affected by Optic Neuritis From Multiple Sclerosis or Neuromyelitis Optica Spectrum Disorder

PURPOSE

To compare the visual evoked potentials (VEPs) of optic neuritis (ON) patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and controls. To evaluate correlations between VEP and optical coherence tomography (OCT), contrast sensitivity (CS), and automated perimetry.

METHODS

Fifty-five eyes with ON from 29 patients (MS = 14 and NMOSD = 15) and 57 eyes from 29 controls were evaluated using VEP, automated perimetry, CS, and optical coherence tomography. Three groups were analyzed: 1) MS eyes with history of ON (ON-MS), 2) NMOSD eyes with ON (ON-NMOSD), and 3) healthy controls. Groups were compared and associations between the parameters were tested.

RESULTS

Compared to controls, ON-MS eyes showed significantly delayed N75 and P100 latencies when using a medium-sized stimulus (30'), and delayed P100 latency when using a large stimulus (1.5°), but similar amplitudes. Compared to controls, ON-NMOSD eyes showed significantly lower N75/P100 amplitudes (both stimulus sizes) and P100/N135 amplitudes (with the 30' stimulus), but latencies did not differ, except for a delayed P100 latency with the 30' stimulus. When comparing the 2 ON groups using the 1.5° stimulus, there was significant delay in P100 latency in ON-MS eyes and a reduction in N75/P100 amplitude in ON-NMOSD eyes. Peripapillary retinal nerve fiber layer, macular inner retinal layers, and CS measurements were significantly smaller in ON patients than in controls. A strong correlation was found between VEP parameters and inner retinal layer thickness in ON-NMOSD eyes.

CONCLUSIONS

ON-MS eyes had normal amplitude and delayed VEP latency, whereas ON-NMOSD eyes displayed reduced amplitude and preserved latency when elicited by checkerboard stimulus with large 1.5° checks. Under such conditions, VEP may help distinguish resolved MS-related ON from resolved NMOSD-related ON.

Optical Coherence Tomography Angiography Characteristics and Predictors of Visual Outcomes in Patients With Acute and Chronic Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND

To investigate the correlation between optical coherence tomography angiography (OCTA) characteristics and visual outcomes in patients with acute and chronic nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

We retrospectively reviewed clinical data and OCTA images of 26 eyes of 26 patients who had been diagnosed with unilateral NAION. OCTA images were acquired from 17 eyes at the acute stage and from 21 eyes at the chronic stage of NAION. We analyzed the peripapillary vessel density (VD) and macular VD in various layers of the retina and choroid for all images. Possible correlations between the OCTA parameters and visual outcomes were investigated.

RESULTS

Among the OCTA parameters for the acute stage of NAION, the temporal peripapillary VD was found to be positively correlated with final visual acuity and visual field with statistical significance (P = 0.039 and 0.009, respectively). In the chronic stage of NAION, both peripapillary and superficial macular VDs were positively correlated with visual outcomes. The nasal perifoveal VD in the superficial capillary plexus (SCP) also had a significant correlation with final visual acuity for both acute and chronic stages (the Spearman correlation coefficient = 0.565 and 0.685, respectively).

CONCLUSIONS

In patients with NAION, significant correlations were found between OCTA parameters and visual outcomes. The temporal peripapillary VD measured during the acute stage was a significant predictor of final visual outcomes. The decreased nasal perifoveal VD in the SCP was strongly associated with poor visual prognosis.

Macular ganglion cell complex injury in different stages of anterior ischemic optic neuropathy

BACKGROUND

Anterior ischemic optic neuropathy (AION) is a group of ophthalmic diseases in which the optic nerve is injured causing blindness. However, the pathogenesis, clinical manifestations, and clinical treatments of AION are yet elusive. Only a few related experimental or clinical reports are available on the disease. In this study, spectral domain optical coherence tomography (SD-OCT) was used to examine the morphology of thickness swelling and atrophic changes of macular ganglion cell complex (mGCC) in the different stages of AION that were then compared with the visual fields. Thus, the clinical value of mGCC examination was alleged to be similar to that of the visual field.

AIM

To explore the mGCC injury at different stages in AION and the clinical significance.

METHODS

Cases with AION were analyzed in a retrospective study. SD-OCT was used to analyze the correlation between mGCC and peripapillary retinal nerve fiber layer thicknesses at different stages of AION and the changes in the corresponding stages of visual fields.

RESULTS

A total of 21 cases (28 eyes) presented AION. The onset time of AION was defined as early stage (within 3 wk of onset), middle stage (from 3 wk to 2 mo), and late stage (disease span > 2 mo). In the early stage, the mGCC thickness of SD-OCT was within the normal high limit, and the perioptic nerve fibers thickness was more than the normal. The changes in the visual field in early stage were not consistent with the swelling changes in mGCC and peri-disc nerve fibers. In addition, atrophy and thinning appeared in mGCC, and the perioptic nerve fibers were swollen. However, the thickness was lower in the middle period than that in the early stage. The change in visual field was consistent with that of mGCC in this period. In the late stage, mGCC shrank and thinned, and the thickness of the nerve fibers around the optic disc in the corresponding region shrank and thinned.

CONCLUSION

The changes in mGCC thickness in patients with AION showed early, middle, and late stages of development by SD-OCT. Although the early stage visual field changes of AION were not consistent with the swelling changes of mGCC, the horizontal delimitation or annular atrophy of mGCC was consistent with that in the middle and late stage of the disease. The atrophy of peripheral nerve fibers was later than that of the mGCC atrophy.

Optical coherence tomography angiography helps distinguish multiple sclerosis from AQP4-IgG-seropositive neuromyelitis optica spectrum disorder

INTRODUCTION

The aim was to characterize the optical coherence tomography (OCT) angiography measures in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) and to evaluate their disease discrimination capacity.

METHODS

Patients with MS (n = 83) and AQP4-IgG-seropositive NMOSD (n = 91) with or without a history of optic neuritis, together with healthy controls (n = 34), were imaged. The main outcome measures were peripapillary retinal nerve fiber layer (pRNFL) thickness, macular ganglion cell-inner plexiform layer (GC-IPL) thickness, macular vessel density (VD), and perfusion density (PD) in the superficial capillary plexus. Diagnostic accuracy was assessed using the area under the receiver operating characteristics curve.

RESULTS

Compared with patients with MS, those with NMOSD had a significantly smaller average thickness of the pRNFL and GC-IPL (80.0 [59.0; 95.8] μm versus 92.0 [80.2; 101] μm, p < .001; 68.0 [56.0; 81.0] μm, versus 74.5 [64.2; 81.0] μm, p < .001) and significantly smaller whole VD and PD areas (15.6 [12.6; 17.0] mm^-1 versus 16.7 [14.8; 17.7] mm^-1 , p < .001; 0.38 [0.31; 0.42] mm^-1 versus 0.40 [0.37; 0.43] mm^-1 , p < .01). The combination of structural parameters (average thickness of the pRNFL and GC-IPL) with microvascular parameters (temporal-inner quadrant of VD, temporal-inner, nasal-inferior, and nasal-outer quadrant of PD) was revealed to have a good diagnostic capability for discriminating between NMOSD and MS.

CONCLUSIONS

OCT angiography reveals different structural and microvascular retinal changes in MS and AQP4-IgG-seropositive NMOSD. These combined structural and microvascular parameters might be promising biomarkers for disease diagnosis.

Health screening program revealed risk factors associated with development and progression of papillomacular bundle defect

BACKGROUND/AIMS

The papillomacular bundle (PMB) area is an important anatomical site associated with central vision. As preventive medicine and health screening examinations are now becoming commonplace, the incidental detection of papillomacular bundle defect (PMBD) on fundus photography has been increasing. However, clinical significance of incidental PMBD has not been well documented to date. Thus, through long-term and longitudinal observation, we aimed to investigate the risk factors for the development and progression of PMBD and its predictive role associated with systemic diseases and glaucoma.

METHODS

This longitudinal study included subjects who had undergone standardized health screening. We retrospectively reviewed patients for whom PMBD had been detected in fundus photography and followed up for more than 5 years. For a comparative analysis, non-PMBD groups of age- and gender-matched healthy controls were selected.

RESULTS

A total of about 67,000 fundus photographs were analyzed for 8.0 years, and 587 PMBD eyes were found. Among them, 234 eyes of 234 patients who had had fundus photographs taken for more than 5 years were finally included. A total of 216 eyes (92.3%) did not progress during the 8.1 ± 2.7 years, whereas 18 eyes (7.7%) showed progression at 7.6 ± 2.9 years after initial detection. A multivariate logistic regression analysis using 224 non-PMBD healthy controls revealed low body mass index (BMI < 20 kg/m2), systemic hypertension, and sclerotic changes of retinal artery as the significant risk factors for the development of PMBD. Regarding PMBD progression, low BMI, concomitant retinal nerve fiber layer defect (RNFLD) at non-PMB sites, optic disc hemorrhage, and higher vertical cup/disc ratio were individual significant risk factors.

CONCLUSION

PMBD is associated with ischemic effects. Although the majority of PMBD do not progress, some of cases are associated with glaucomatous damage in a long-term way. PMBD might be a personalized indicator representing ischemia-associated diseases and a predictive factor for diagnosis and preventive management of glaucoma.

Patterns of Retinal Ganglion Cell Damage in Nonarteritic Anterior Ischemic Optic Neuropathy Assessed by Swept-Source Optical Coherence Tomography

OBJECTIVE

To evaluate the ability of macular ganglion cell and inner plexiform layer (mGCIPL) and retinal nerve fiber layer (RNFL) thickness measurements by long-wavelength swept-source optical coherence tomography (SS-OCT) to assess retinal ganglion cell (RGC) damage in nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

A retrospective study of 20 patients with unilateral NAION was performed. SS-OCT scanning of the macular and peripapillary areas was performed to measure the total and six-sector thicknesses of macular RNFL (mRNFL) and mGCIPL, as well as peripapillary RNFL (pRNFL) thicknesses in global and 12 clock-hour sectors. Further comparison of these thicknesses between NAION involved eyes and uninvolved counterparts was performed in 12 of the 20 patients at 4 visits. The thickness map and en face images generated by volume data of the posterior pole over a 12 × 9-mm area were used for RNFL analysis.

RESULTS

Median time intervals between the visual symptom onset and first thinning occurrences of mGCIPL, mRNFL, and pRNFL were 17 days (95% Confidence Interval [CI] 14-18 days), 43 days (95% CI 32-48 days), and 70 days (95% CI 62-80 days), respectively. The thickness map indicated a significantly reduced pRNFL in the superior temporal sectors or temporal sectors after 9 weeks, and retinal damage corresponded to the superior hemisphere's mRNFL and mGCIPL. En face images showed that the RNFL thinning area gradually expanded along the retinal nerve fiber direction and progressed toward the optic nerve head.

CONCLUSIONS

The patterns of RGC damage in the macular and peripapillary areas of NAION eyes can be revealed by SS-OCT. Objective measurement of SS-OCT is valuable in characterizing NAION.

Comparison of macular structural and vascular changes in neuromyelitis optica spectrum disorder and primary open angle glaucoma: a cross-sectional study

AIMS

To compare macular structure and vasculature between neuromyelitis optica spectrum disorder (NMOSD) and primary open angle glaucoma (POAG) using optical coherence tomography angiography.

METHODS

NMOSD patients (n=124) with/without a history of optic neuritis (ON) (NMO+ON: 113 eyes; NMO-ON: 95 eyes), glaucomatous patients (n=102) with early/advanced glaucoma (G-E: 74 eyes; G-A: 50 eyes) and healthy controls (n=62; 90 eyes) were imaged. The main outcome measures were macular ganglion cell-inner plexiform layer (GC-IPL) thickness, vessel density (VD) and perfusion density (PD) in the superficial capillary plexus, and diagnostic capabilities of the parameters as calculated by area under the curve (AUC).

RESULTS

Significant losses in GC-IPL, VD and PD were detected in both patients with NMOSD and POAG. With matched losses in the peripapillary retinal nerve fibre layer, NMOSD group showed significant thinning of GC-IPL in the nasal-superior quadrant, whereas in POAG group, significant thinning was observed in the inferior and temporal-inferior quadrants. GC-IPL thinning was more prominent in the superior, nasal-superior and nasal-inferior quadrants in NMO+ON eyes. In G-A eyes, significant GC-IPL thinning was seen in the temporal-inferior quadrant. The specific structural parameters combining VD and foveal avascular zone (FAZ) indices showed the best diagnostic accuracies. The FAZ area in eyes with NMOSD was significantly smaller than the eyes of healthy controls and POAG.

CONCLUSION

NMOSD and POAG have specific patterns of macular structural and vascular changes associated with pathophysiology. Our results indicate that FAZ could be a sensitive biomarker of macular changes in NMOSD.

Correlations between visual morphological, electrophysiological, and acuity changes in chronic non-arteritic ischemic optic neuropathy

PURPOSE

To study whether there is a correlation between the macular and optic nerve morphological condition and the retinal ganglion cells (RGCs) and visual pathways' function, and to investigate whether visual acuity (VA) changes might be related to the morpho-functional findings in chronic non-arteritic ischemic optic neuropathy (NAION).

METHODS

In this retrospective study, 22 patients (mean age 62.12 ± 6.87) with chronic unilateral NAION providing 22 affected and 22 fellow eyes without NAION (NAION-FE), and 20 (mean age 61.20 ± 7.32) healthy control subjects were studied by spectral domain optical coherence tomography (Sd-OCT) for investigating macular thickness (MT) and volume (MV) of the whole (WR), inner (IR) and outer retina (OR), and the peripapillary retinal nerve fiber layer thickness (RNFL-T) measured overall and for all quadrants. Also, simultaneous 60' and 15' pattern electroretinogram (PERG) and visual evoked potentials (VEP) and VA were assessed. Differences of MT and MV of WR, IR, OR, and RNFL-T overall and for all quadrants, PERG amplitude (A), VEP implicit time (IT), and A and VA values between NAION eyes and controls were assessed by one-way analysis of variance. Pearson's test was used for regression analysis. A p value < 0.01 was considered as significant.

RESULTS

In NAION eyes as compared to NAION-FE eyes and controls, significant (p < 0.01) changes of MT, MV of WR and IR, RNFL-T, 60' and 15' PERG A, VEP IT and A, and VA were found. No significant (p > 0.01) OR changes were observed between groups. In NAION eyes, significant (p < 0.01) correlations between MV of WR and IR and 15' PERG A were found. Overall, RNFL-T values were significantly correlated (p < 0.01) with those of 60' PERG A and VEP IT and A; temporal RNFL-T values were correlated (p < 0.01) with 15' PERG A and VEP IT and A ones. Temporal RNFL-T, MV-IR, and 15' PERG A as well as VEP IT were significantly (p < 0.01) correlated with VA. Significant (p < 0.01) linear correlations between 60' and 15' PERG A findings and the corresponding values of 60' and 15' VEP A were also found.

CONCLUSION

Our findings suggest that in chronic NAION, there is a morpho-functional impairment of the IR, with OR structural sparing. VA changes are related to the impaired morphology and function of IR, to the temporal RNFL-T reduction and to the dysfunction of both large and small axons forming the visual pathway.

The role of optical coherence tomography in the diagnosis of afferent visual pathway problems: A neuroophthalmic perspective

Optical coherence tomography (OCT) is a noninvasive ocular imaging technique that has become a standard tool in neuroophthalmic practice. Specifically, OCT captures retinal manifestations of neuroaxonal injury caused by lesions along anterior and posterior regions of the afferent visual pathway, in patients presenting with vision loss. More recently, the advent of OCT angiography (OCTA) has enabled evaluation of the choroidal and retinal microvasculature, thus informing our understanding regarding vascular mechanisms associated with optic nerve and retinal injuries. Much of our longitudinal experience with OCT in the field of neuroophthalmology has been acquired from the study of optic neuritis (ON) caused by inflammatory disorders of the central nervous system (CNS). Over the past two decades, OCT has emerged as a surrogate endpoint for CNS neuroaxonal injury in multiple sclerosis (MS) research trials. On a more pragmatic level, OCT is used in the clinical arena to diagnose ON associated with: MS, neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease (MOGAD). Subsequent advancements in swept-source (SS) and enhanced depth imaging (EDI) have established OCT as the new "gold standard" in the diagnosis of optic disc drusen. Recent studies have highlighted pathognomonic OCT features that distinguish cases of true papilledema from pseudopapilledema, in patients presenting with undifferentiated optic disc elevation. Preoperative OCT measures of neuroaxonal integrity have shown prognostic value in predicting postoperative visual outcomes for patients with compressive anterior visual pathway lesions. Finally, OCT is indispensable in differentiating optic neuropathies from retinal diseases in patients with visual loss and a nondiagnostic fundus examination. An in-depth discussion regarding the technical aspects of OCT is beyond the scope of this chapter. Instead, we wish to highlight the value OCT brings to the diagnosis and management of common neuroophthalmic conditions, with emphasis on optic neuropathies and retinal disorders.

Thicknesses of Macular Inner Retinal Layers in Children with Anisometropic Amblyopia

Objective

To investigate the thicknesses of macular inner retinal layers in children with anisometropic amblyopia using spectral domain optical coherence tomography (SD-OCT).

Methods

Thirty-seven children with anisometropic amblyopia and fifty-seven children with normal vision were recruited in the study. Both eyes of children with anisometropic amblyopia and the right eyes of normal controls underwent scanning with the Spectralis OCT. The segmentation of retinal layers was performed automatically to measure individual inner retinal layers in the five sectors of the macular. An independent sample t-test was applied to compare the mean layer thicknesses of anisometropic eyes and fellow eyes with those of control eyes.

Results

There was no significant difference in the total macular thickness between amblyopic and control eyes. However, in the peripheral macular area, three of the four quadrants of both the ganglion cell layer (GCL) and the inner plexiform layer (IPL) thicknesses were significantly reduced in amblyopic eyes compared to control eyes. Moreover, two of the four quadrants of the GCL thickness and three of the four quadrants of the IPL thickness in the peripheral macular area were significantly reduced in fellow eyes than in control eyes.

Conclusion

The SD-OCT data revealed differences in the thicknesses of some macular inner retinal layers in both eyes of children with anisometropic amblyopia compared with those with emmetropia, indicating that structural changes might exist in the retina of children with amblyopia.

Prospective analysis of macular and optic disc changes after non-arteritic anterior ischemic optic neuropathy

PURPOSE

To prospectively analyse macular and optic disc changes after the occurrence of non-arteritic anterior ischemic optic neuropathy (NAION) and study possible predictors of final visual outcome.

METHODS

Patients with NAION underwent a complete ophthalmic examination, including spectral-domain optical coherence tomography of the macula and optic nerve head. The examination was repeated 1, 3, 6, 9 and 12 months after onset. Final visual prognosis was evaluated by visual field (VF) and best-corrected visual acuity (BCVA) at the final visit. Data within the NAION group were analysed over the course of the disease and compared to a disease-free control group at each visit.

RESULTS

Twenty-two eyes with NAION and 43 eyes from a control group were included. The retinal nerve fiber layer (RNFL) was significantly thicker in NAION eyes than controls at presentation (P=0.00), and significantly decreased during the next 3 months after presentation (P=0.02). The ganglion cell+inner plexiform layer (GCIPL) was thinner in the NAION group throughout the course of the disease (all P<0.05). Although the acute NAION eyes had significantly lower cup/disc ratios and higher neuroretinal and disc sizes (all P=0.00), there were no significant differences between groups from the third month onwards (all P>0.05). The best predictors of BCVA and VF were GCIPL at 3 months of follow-up (r²=0.32; P=0.03) and RNFL at 6 months of follow-up (r²=0.41; P=0.01) respectively.

CONCLUSIONS

RNFL and optic disc changes occur during the first 3 months after the onset of NAION, whereas GCIPL is affected soon after the onset of symptoms. GCIPL and RNFL are useful predictors of final visual outcome.

German Diabetes Study - Baseline data of retinal layer thickness measured by SD-OCT in early diabetes mellitus

PURPOSE

Recent studies highlighted that early diabetic neurodegeneration is present before microvascular changes are visible. Retinal neurodegeneration can decrease retinal layer thickness. We aimed to determine whether decreased retinal layer thickness is present already in the early time course of disease.

METHODS

A cross-sectional analysis of patients and healthy adults from the German Diabetes Study (GDS, ClinicalTrials.gov Identifier number: CT01055093, https://clinicaltrials.gov/ct2/show/NCT01055093). Inclusion criteria were a diagnosis of diabetes mellitus (DM) within the last 12 months. Retinal layers thickness in the nasal pericentral segment was measured by spectral domain ocular coherence tomography (SD-OCT). For statistical analysis proc mixed (sas-version 9.4) was used.

RESULTS

One hundred and seventy-eight eyes of 89 patients with type 1 DM (58 males, age 36 ± 11 years, BMI 25.5 ± 4.2 kg/m²) and 242 eyes of 121 patients with type 2 DM (84 males, age 53 ± 10 years, BMI 31.9 ± 6.3 kg/m²) with a disease duration of less than 1 year were compared to 76 eyes of 38 controls (27 males, age 41 ± 16 years, BMI 27.3 ± 6.4 kg/m²). Analysis of retinal layer thickness and visual function did not reveal a significant difference between patients and controls.

CONCLUSION

In the early course of DM potential, neurodegeneration does not relate to measureable changes of retinal layer thickness.

Structural changes of macula and optic disk of the fellow eye in patients with nonarteritic anterior ischemic optic neuropathy

PURPOSE

The aim was to assess the ganglion cell complex (GCC) thickness, retinal nerve fiber layer (RNFL) thickness and optic disk features in the affected eyes (AE) and unaffected fellow eyes (FE) of subjects with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) and to compare with healthy control eyes (CE) using spectral domain-optical coherence tomography (SD-OCT).

METHODS

This study included 28 patients and age, sex and refraction-matched 28 control subjects. Mean GCC thickness and peripapillary RNFL thickness in four quadrants measured by cirrus SD-OCT were evaluated in both AE and FE of patients and CE. In addition, optic disk measurements obtained with OCT were evaluated.

RESULTS

Mean GCC thickness was significantly lower in AE compared with both FE and CE (P < 0.001), and mean GCC thickness in FE was significantly lower than CE (P = 0.022). In addition, mean RNFL thickness in superior and nasal quadrants significantly decreased in FE compared with CE (P = 0.020 and 0.010, respectively). Furthermore, AE had significantly greater optic disk cupping compared with both FE and CE (P < 0.001).

CONCLUSIONS

GCC and RNFL thickness decreased significantly at late stages of NAION, in both AE and FE compared with CE, suggesting that some subclinical structural changes may occur in FE despite lack of obvious visual symptoms. In addition, there was no significant difference in optic disk features between the CE and FE. And significantly greater optic disk cupping in the AE compared with both FE and CE supports the acquired enlargement of cupping after the onset of NAION.

Correction of ischemic optic neuropathy in rats by carbamylated darbepoetin

Introduction: The protective effects of carbamylated darbepoetin on the model of ischemic optic neuropathy in rats were revealed.

Objectives: To increase the effectiveness of pharmacological correction of experimental ischemic optic neuropathy in an experiment by using carbamylated darbepoetin.

Methods: Measuring the microcirculation level in the retina of rats was carried out using laser Doppler flowmetry (LDF). Registration was done by the data acquisition system Biopac-systems MP-150 and AcqKnowledge 4.2 programme.

For microscopy and morphometry, the prepared microslides were scanned using Mirax Desk, a computerised archiving and image analysis system. Image analysis and morphometry were carried out by Pannoramic Viewer 1.15.4.

Results and discussion: In the group with correction of ischemic optic neuropathy by carbamylated darbepoetin, 300 μg/kg, the microcirculation level increases by 41.9%, p&lt;0.05 in comparison with the control group, but also below the norm values by 20.3%, p&lt;0.05. In the group with correction by recombinant erythropoietin, 50 IU/kg, the microcirculation rate increases by 36.7%, p&lt;0.05 in comparison with the control group and significantly lower - by 23.3%, p&lt;0.05 - in comparison with the group of intact animals. Qualitative and quantitative morphological indices (thickness of retinal layers) helped to reveal a neuroprotective effect of carbamylated darbepoetin to a greater extent than that of recombinant erythropoietin.

Conclusion: The obtained data allow drawing a conclusion about partial restoration of blood flow and preservation of neuronal retinal structures when correcting ischemic optic neuropathy in rats with carbamylated darbepoetin to a greater extent than with recombinant erythropoietin.

Analysis of retinal layer thickness in diabetic macular oedema treated with ranibizumab or triamcinolone

PURPOSE

To evaluate detailed changes in retinal layer thickness in spectral-domain optical coherence tomography (SD-OCT) images during a 1-year follow-up of patients treated for diabetic macula oedema (DME).

METHODS

Post hoc analysis of retinal layer thickness changes applying the automated layer segmentation of SD-OCT images in eyes with DME that were randomly assigned to receive pro re nata (PRN) treatment with either 0.5 mg ranibizumab or 8 mg triamcinolone. In each patient, seven retinal layers were segmented in 49 scans covering a 20° × 20° area of the macula at baseline and after 1 year of treatment. Changes in individual layer thickness were correlated with visual acuity (VA) and compared between treatment arms.

RESULTS

Twenty-five patients (seven female, 60.2 ± 15.1 years) were evaluated. Thickness decrease of retinal nerve fibre layer (RNFL) was associated with a gain in VA over 12 months (r > 0.54; p < 0.05). Decrease in ganglion cell layer (GCL) and GCL+IPL thickness pooled for nasal Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields correlated with VA as follows: ranibizumab r = 0.74 (GCL) and r = 0.63 (GCL+IPL); and triamcinolone r = 0.45 (GCL) and r = 0.46 (GCL+IPL).

CONCLUSION

In DME therapy, reduction in RNFL thickness may have a considerable impact on retinal function, unrelated to the type of pharmacological treatment. Precise morphologic quantification of neurosensory layers by SD OCT offers new insight into disease pathology and therapeutic targets.

Track-weighted imaging for neuroretina: Evaluations in healthy volunteers and ischemic optic neuropathy

BACKGROUND

The use of MRI-tractography to explore the human neuroretina is yet to be reported. Track-weighted imaging (TWI) was recently introduced as a qualitative tractography-based method with high anatomical contrast.

PURPOSE

To explore the human retina in healthy volunteers and patients with anterior ischemic optic neuropathy (AION) using TWI reconstructions.

STUDY TYPE

Prospective.

POPULATION

Twenty AION patients compared with 20 healthy volunteers.

FIELD STRENGTH/SEQUENCE

3.0T MRI diffusion-weighted imaging (DWI) with b-value of 1000 s/mm2 and 60 diffusion-weighting noncollinear directions.

ASSESSMENT

We performed constrained spherical deconvolution from the diffusion-weighted signal and volumetric tractography method, whereby 10 million streamlines are initiated from seed points randomly distributed throughout the orbital area. We then reconstructed TWI maps with isotropic voxel size of 300 μm.

STATISTICAL TESTS

We tested the effect of the number of diffusion-weighting directions, ocular laterality, and ocular dominance on healthy retinal fascicles distribution. We then performed factorial analysis of variance to test the effects of the presence/absence of the fascicles on the visual field defect in patients.

RESULTS

In healthy volunteers, we found more temporal fascicle in right eyes (P = 0.001), more superior fascicles in dominant eyes (P = 0.014), and fewer fascicles with tractography maps based on 30 directions than those based on 45 directions (P = 9 × 10-8 ) and 60 directions (P = 6 × 10-7 ). Eight out of 20 AION patients presented with complete absence of neuroretinal fascicle, side of the disease, which was correlated with visual field mean deviation at the 6-month visit [F(1,17) = 6.97, P = 0.016]. Seven patients presented with a temporal fascicle in the injured eye; this fascicle presence was linked to visual field mean deviation at the 6-month visit [F(1,17) = 8.43, P = 0.009].

DATA CONCLUSION

In AION patients, the presence of the temporal neuroretinal fascicle in the affected eye provides an objective outcome radiological sign correlated with visual performance.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

Stem Cell Ophthalmology Treatment Study: bone marrow derived stem cells in the treatment of non-arteritic ischemic optic neuropathy (NAION)

Background

Ten patients with bilateral visual loss due to sequential non-arteritic ischemic optic neuropathy (NAION) underwent autologous Bone Marrow Derived Stem Cell (BMSC) therapy within the Stem Cell Ophthalmology Treatment Study (SCOTS). SCOTS is an Institutional Review Board approved clinical study utilizing autologous BMSC in the treatment of optic nerve and retinal diseases that meet inclusion criteria.

Methods

The average age of the patients treated was 69.8 years. The average duration of visual loss in eyes treated was 9.8 years and ranged from 1 to 35 years. Affected eyes were treated with either retrobulbar, subtenons and intravenous BMSC or, following vitrectomy, intra-optic nerve, subtenons and intravenous BMSC. The primary outcome was visual acuity as measured by Snellen or converted to LogMAR.

Results

Following therapy in SCOTS, 80% of patients experienced improvement in Snellen binocular vision (P=0.029) with 20% remaining stable; 73.6% of eyes treated gained vision (P=0.019) and 15.9% remained stable in the post-operative period. There was an average of 3.53 Snellen lines of vision improvement per eye with an average 22.74% and maximum 83.3% improvement in LogMAR acuity per eye. The average LogMAR change in treated eyes was a gain of 0.364 (P=0.0089). Improvements typically manifested no later than 6 months post procedure.

Conclusions

The use of BMSC in the Stem Cell Ophthalmology Treatment Study achieved meaningful visual improvements in a significant percentage of the NAION patients reported. Improvements typically manifested no later than 6 months post-procedure. Duration of visual loss did not appear to affect the ability of the eyes to respond to treatment. Possible mechanisms by which visual improvement occurred may include BMSC paracrine secretion of proteins and hormones, transfer of mitochondria, release of messenger RNA or other compounds via exosomes or microvesicles and neuronal transdifferentiation of the stem cells.

Structure-Function Analysis of Nonarteritic Anterior Ischemic Optic Neuropathy and Age-Related Differences in Outcome

BACKGROUND

The optic nerve head is vulnerable to ischemia leading to anterior ischemic optic neuropathy (AION), the most common acute optic neuropathy in those older than 50 years of age.

METHODS

We performed a cross-sectional study of 55 nonarteritic anterior ischemic optic neuropathy (NAION) eyes in 34 patients to assess clinical outcome and perform structure-function correlations.

RESULTS

The peak age of NAION onset was between 50 and 55 years. Sixty-seven percent of patients presented with their first event between the ages of 40 and 60 years, and 32% presented at ≤50 years. Those with NAION onset at age ≤50 years did not have significantly better visual outcome per logMAR visual acuity, automated perimetric mean deviation (PMD) or optical coherence tomography (OCT) measurements. Kaplan-Meier survival curve and multivariate Cox proportional regression analysis showed that age >50 years at NAION onset was associated with greater risk of second eye involvement, with hazard ratio of 20. Older age at onset was significantly correlated with greater thinning of the ganglion cell complex (GCC) (P = 0.022) but not with logMAR visual acuity, PMD, or thinning of retinal nerve fiber layer (RNFL). Using area under receiver operating characteristic curve analyses, we found that thinning of RNFL and GCC was best able to predict visual outcome, and that mean RNFL thickness >65 μm or macular GCC thickness >55 μm significantly correlated with good visual field outcome.

CONCLUSIONS

We showed that NAION onset at age >50 years had a greater risk of second eye involvement. Patients with OCT mean RNFL thickness >65 μm and mean macular ganglion cell complex thickness >55 μm had better visual outcomes.

Microvasculature dropout detected by the optical coherence tomography angiography in nonarteritic anterior ischemic optic neuropathy

OBJECTIVE

To investigate microcirculation characteristics of peripapillary superficial retina and optic disc in eyes with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA).

METHODS

Forty-one eyes of 30 NAION patients and 30 eyes of 30 normal subjects were evaluated with OCTA (AngioVue, Optovue). The whole vessel density, inside disc vessel density, peripapillary vessel density, and vessel densities based on the sectorial division in the nerve head mode peripapillary superficial retina and RPC mode optic disc were measured respectively.

RESULTS

In the NAION group, vessel densities in both the peripapillary superficial retina and optic disc were significant reduced (P < 0.01), as compared with the control group. The whole vessel density of the optic disc in chronic NAION group were significantly lower than that in acute NAION group (P < 0.01). The whole and temporal vessel density of the peripapillary superficial retina was significantly correlated with log MAR VA (r = -0.381 and r = -0.337, both P < 0.05). Vessel densities in both the peripapillary superficial retina and optic disc were reduced (P < 0.05) in unilateral involved eyes, as compared to the unaffected fellow eyes, except for the inside disc (P = 0.270) and SN (P = 0.054) vessel density in the optic disc, while there was no difference in the fellow eyes compared to the normal eyes.

CONCLUSION

In NAION patients, a dropout of microvasculature in peripapillary superficial retina and optic disc could be detected by OCTA directly. OCTA might become a useful tool for detection and monitoring of NAION. Lasers Surg. Med. 50:194-201, 2018. © 2017 Wiley Periodicals, Inc.

Retinal Ganglion Cell Loss Precedes Retinal Nerve Fiber Thinning in Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND

Loss of retinal ganglion cell-inner plexiform layer (GCIPL) thickness has been shown in different optic neuropathies. In this study, we evaluated the capability of GCIPL analysis by optical coherence tomography (OCT) to detect early neuronal loss during the time course of nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

Twenty-four patients with unilateral NAION participated in this prospective, comparative study. Affected and unaffected eyes underwent spectral domain OCT measurement of the retinal nerve fiber layer (RNFL), total macula, and GCIPL thicknesses. These measurements were recorded in the acute phase (within 7 days) and at 1, 3, and 6 months.

RESULTS

At the initial presentation and 1, 3, and 6 months, the mean RNFL thickness in the NAION eyes was 236.5 μm ± 74.2, 157.1 μm ± 45.7, 61.4 μm ± 6.1, and 55.0 μm ± 19.5, respectively. Similar to RNFL, thinning of the mean total macular thickness in inner and outer rings started after 3 months and thicknesses decreased to 307.7 μm ± 15.3 and 273.1 μm ± 21.2 after 3 months and to 309.1 μm ± 15.0 and 273.4 μm ± 13.8 after 6 months, compared with unaffected contralateral eyes, respectively (all P < 0.0001). Thinning of the GCIPL was first evident in the affected NAION eyes at 1 month, and the mean inner and outer GCIPL thicknesses were 62.8 μm ± 14.6 and 53.9 μm ± 7.2 at 1 month in the NAION eyes compared with unaffected eyes (P < 0.001). After 3 and 6 months, the inner and outer GCIPL thicknesses were 51.1 μm ± 8.1 and 47.4 μm ± 5.31, and 50.6 μm ± 11.5 and 47.9 μm ± 5.6, respectively.

CONCLUSIONS

Thinning of the GCIPL is first detectable at 1 month after NAION and persists for 3 months. GCIPL thinning occurs before RFNL thinning in NAION.

Thickness of macular inner retinal layers and peripapillary retinal nerve fibre layer in neuromyelitis optica spectrum optic neuritis and isolated optic neuritis with one episode

PURPOSE

The aim of this study was to evaluate the differences between macular inner retinal layers and peripapillary retinal nerve fibre layer (pRNFL) thickness in Chinese patients with neuromyelitis spectrum optic neuritis (NMOSD-ON) and isolated optic neuritis (ION) with only one episode.

METHODS

This cross-sectional study included 35 patients (35 eyes) with NMOSD-ON (NMO-IgG seropositive) and 46 patients (46 eyes) with ION after one episode. Spectral domain optical coherence tomography (SD-OCT) was used to quantify pRNFL, macular RNFL (mRNFL), ganglion cell and inner plexiform layers (GCIPL) and inner nuclear layer (INL) thickness using an automated algorithm. Differences in OCT parameters between NMOSD-ON and ION were compared after adjusting for age, sex and disease duration.

RESULTS

The pRNFL and mRNFL in some locations (average pRNFL, nasal pRNFL, nasal inferior (NI) pRNFL, nasal/temporal (N/T) ratio pRNFL, average mRNFL, inner temporal mRNFL, outer nasal mRNFL and outer temporal mRNFL) in NMOSD-ON differed significantly from those in ION (all p < 0.05). These parameters had moderate diagnostic accuracy, with area under curves (AUCs) ranging from 0.684 to 0.762 for pRNFL and from 0.660 to 0.700 for mRNF. The thickness of GC-IPL and INL in all sectors was similar in NMOSD-ON and ION (p > 0.05). This study and our meta-analysis of four previous studies obtained consistent results, with pooled mean difference (MD) -10.4 μm (95% CI: -12.4 to -8.4, p < 0.001) for pRNFL, -1.5 μm (95% CI: -3.5 to 0.6, p = 0.158) for mRNFL and 0.2 μm (95% CI: -0.4 to 0.9, p = 0.490) for GC-IPL, respectively.

CONCLUSIONS

Neuromyelitis spectrum optic neuritis (NMOSD-ON) patients had more pRNFL and mRNFL loss compared to ION patients after one episode. Spectral domain optical coherence tomography (SD-OCT) may help to distinguish NMOSD-ON from ION with only moderate diagnostic accuracy.

Macular Evaluation wıth Spectral Domain Type Optic Coherence Tomography in Eyes with Acute Nonarteritic Ischemic Optic Neuropathy at the Presentation Visit

Purpose:

To evaluate the macula with spectral domain type optic coherence tomography (OCT) in eyes with acute nonarteritic anterior ischemic optic neuropathy (NAION) at the presentation visit.

Methods:

Medical charts of the 133 patients who received the diagnosis of acute NAION between January 2008 and July 2014 at the Neuro-ophthalmology unit of Dokuz Eylul University were reviewed retrospectively. Sixtythree patients within 30 days of symptom onset with available baseline spectral domain type macular OCT were included in this study. Clinical and macular characteristics of the affected eye were assessed and compared to the fellow eyes.

Results:

Sixty-three eyes of 63 patients comprised the study group. Twenty one study eyes (33.3%) had normal posterior pole, 22 (34.9%) some evidence of subretinal fluid, 10 (15.8%) vitreomacular adhesion, five (7%) age-related macular degeneration related changes, four (6%) epiretinal membrane and one (1%) previous grid laser scars. On the other hand, 41 of 63 the fellow eyes (65%) had normal posterior pole, ten (15.8%), vitreomacular adhesion, seven (10.7%), age-related macular degeneration related changes, three (4%) epiretinal membrane and two (3%) other type of changes. OCT scan passing through the fovea exhibited 10 or more hyperreflective dots in 10 (15%) of the study eyes whereas two of the fellow eyes (3.2%) had 10 or more hyperreflective dots.

Conclusion:

Macular OCT can be a part of the routine neuroophthalmologic examination in patients with acute NAION not only to show the NAION related changes such as the subretinal fluid accumulation but also to identify the other coexistent macular abnormalities.

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.

Ganglion cell analysis at acute episode of nonarteritic anterior ischemic optic neuropathy to predict irreversible damage. A prospective study

PURPOSE

To assess the capability of ganglion cell-inner plexiform layer (GCIPL) thickness analysis by optical coherence tomography (OCT) to detect early neuronal loss in nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

Sixteen patients with unilateral NAION participated in this prospective study. Complete ophthalmologic evaluation including visual acuity, visual field (VF) test, and spectral domain optical coherence tomography (SD-OCT) of peripapillary retinal nerve fiber layer (pRNFL) and GCIPL thickness were performed in the acute phase (within 1 week: 2.7 ± 2.1 days) and at 2 weeks, 1 month, 3 and 6 months after diagnosis. The mean time elapsed from acute episode to irreversible damage detection by GCIPL and pRNFL analysis was registered. Correlations between the GCIPL thinning and functional parameters such as best-corrected visual acuity (BCVA) and visual field indices [mean deviation (MD) and visual field index (VFI)] in acute and chronic phase were also analyzed.

RESULTS

NAION eyes showed a significant thinning of the mean GCIPLminimum (min) compared to the unaffected eyes as early as 2.2 days after symptoms onset (p = 0.017) and at each follow-up visit. (p ≤ 0.003). The mean GCIPL average (av) was also thinner in NAION eyes compared to uninvolved eyes at 1 (p = 0.003), 3 (p = 0.002) and 6 months (p < 0.001). At the acute phase, 100 % of NAION eyes showed significant pRNFL thickening, while abnormal thinning was evident in GCIPLav, GCIPLmin, and GCIPL deviation map analysis in 31.3, 56.3, and 62.5 % of NAION eyes. The abnormal thinning rates increased to 43.8, 75, and 81.3 % at 2 weeks and to 62.5, 100, and 100 % at 1 month, respectively. At 2 weeks, GCIPLmin thickness significantly correlated with both acute and chronic BCVA, MD, and VFI. Furthermore, the mean superior and inferior GCIPL thicknesses at 2 weeks associated with corresponding mean inferior and superior hemifield MD at 6 months.

CONCLUSIONS

GCIPL analysis by SD-OCT can be considered as a useful biomarker to establish ganglion cell damage. GCIPL min and GCIPL deviation map are abnormally thinner in 56.3 % and 62.5 % of eyes at presentation, respectively. Therefore, both parameters are abnormally thinned in more than 50 % of eyes at presentation. At 2 weeks, GCIPL min thickness significantly correlated with chronic BCVA, MD and VFI; therefore, GCIPL min thickness can predict final visual dysfunction.

Retinal Ganglion Cell Layer Thinning Within One Month of Presentation for Non-Arteritic Anterior Ischemic Optic Neuropathy

PURPOSE

Optical coherence tomography reveals retinal ganglion cell layer (GCL) and retinal nerve fiber layer (RNFL) thinning in chronic optic nerve injury. With acute optic nerve injury, as in acute nonarteritic anterior ischemic optic neuropathy (NAION), swelling obscures early demonstration of RNFL thinning, which might be used to evaluate therapies. We hypothesized that measurement of GCL plus inner plexiform layer (IPL) thickness and trajectory of thinning would show it is an earlier and more accurate biomarker of early permanent neuronal injury.

METHODS

We prospectively studied 29 acute NAION eyes with standard automated perimetry and spectral domain (SD) optical coherence tomography for 6 months. We used a three-dimensional layer segmentation (method 1) and a commercial proprietary (method 2), to compute the combined thickness of macular GCL+IPL and method 2 to compute peripapillary RNFL thickness.

RESULTS

At presentation, the mean GCL+IPL thickness (78.7 μm ± 8.9) for NAION eyes, did not differ from unaffected fellow eyes (83 μm ± 6.4), using method 1 while method 2 (66.8 μm ± 18.7) failed in 34% of NAION eyes. At 1 to 2 months, 12% had RNFL loss compared to baseline, while 68% of NAION eyes had GCL+IPL thinning. The ganglion cell layer plus inner plexiform layer reduction was greatest at 1 to 2 months (19.6 μm ± 12.6) and was minimally worse after month 3. Ganglion cell layer plus inner plexiform layer thinning showed moderate to strong significant correlation with the visual acuity and mean deviation at each exam time. The retinal nerve fiber layer was not thinned until month 3.

CONCLUSIONS

Ganglion cell layer plus inner plexiform layer is acutely unaffected and provides a reliable measure of retinal neuronal structure using three-dimensional segmentation. Thinning develops within 1 to 2 months of onset, which is prior to RNFL swelling resolution. This suggests GCL+IPL measurement is better than the RNFL thickness to use as biomarker of early structural loss in NAION.

A Single Intravitreal Injection of Ranibizumab Provides No Neuroprotection in a Nonhuman Primate Model of Moderate-to-Severe Nonarteritic Anterior Ischemic Optic Neuropathy

PURPOSE

Ranibizumab, a vascular endothelial growth factor-antagonist, is said to be neuroprotective when injected intravitreally in patients with nonarteritic anterior ischemic optic neuropathy (NAION). We evaluated the efficacy of a single intravitreal (IVT) injection of ranibizumab in a nonhuman primate model of NAION (pNAION).

METHODS

We induced pNAION in one eye of four adult male rhesus monkeys using a laser-activated rose Bengal induction method. We then immediately injected the eye with either ranibizumab or normal saline (NS) intravitreally. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in three of the animals (one animal developed significant retinal hemorrhages and, therefore, could not be analyzed completely) prior to induction, 1 day and 1, 2, and 4 weeks thereafter. Following the 4-week analysis of the first eye, we induced pNAION in the contralateral eye and then injected either ranibizumab or NS, whichever substance had not been injected in the first eye. We euthanized all animals 5 to 12 weeks after the final assessment of the second eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves of both eyes.

RESULTS

A single IVT dose of ranibizumab administered immediately after induction of pNAION resulted in no significant reduction of clinical, electrophysiological, or histologic damage compared with vehicle-injected eyes.

CONCLUSIONS

A single IVT dose of ranibizumab is not neuroprotective when administered immediately after induction of pNAION.

Ischemic Injury of the Papillomacular Bundle Is a Predictive Marker of Poor Vision in Eyes With Branch Retinal Artery Occlusion

PURPOSE

To propose a novel prognostic feature of spectral-domain optical coherence tomography (SDOCT) in macula-involving branch retinal artery occlusion (BRAO).

DESIGN

Retrospective comparative case study.

METHODS

We analyzed 66 eyes diagnosed with acute BRAO involving the macula from our hospital RAO registry. At presentation, a detailed ophthalmic and medical history was obtained from all patients, and all underwent a comprehensive ophthalmic evaluation, which included visual acuity examination, fundus photography, fluorescein angiography, and SDOCT. This evaluation was performed at each follow-up visit.

RESULTS

The 66 eyes diagnosed with acute BRAO involving the macula were divided into 2 groups according to initial vision: Good Vision (≥20/40, 29 eyes, 44%) and Poor Vision (<20/40, 37 eyes, 56%). The Poor Vision group was further divided into Improvement (18 eyes, 27%) and Nonimprovement (19 eyes, 28%) groups, according to visual recovery at the final examination. Among multiple OCT parameters, the involvement of papillomacular bundle, but not that of the central fovea, was consistently observed in the Poor Vision group (P < .001) and more significantly in the Nonimprovement group (P < .001). Papillomacular bundle involvement features included signs of inner retinal ischemia, including inner retinal thickening, inner retinal hyperreflectivity, and loss of layer-by-layer integrity. Loss of layer-by-layer integrity was seen consistently in the Nonimprovement group. Quantitative analysis of inner retinal thickness also supported this association.

CONCLUSION

In eyes with macula-involving BRAO, ischemic injury of the papillomacular bundle at the acute stage, as seen on OCT, correlates closely with poor vision and can explain the poor visual prognosis.

Thinner Retinal Nerve Fiber Layer in Very Preterm Versus Term Infants and Relationship to Brain Anatomy and Neurodevelopment

PURPOSE

To assess retinal nerve fiber layer (RNFL) thickness at term-equivalent age in very preterm (<32 weeks gestational age) vs term-born infant cohorts, and compare very preterm infant RNFL thickness with brain anatomy and neurodevelopment.

DESIGN

Cohort study.

METHODS

RNFL was semi-automatically segmented (1 eye per infant) in 57 very preterm and 50 term infants with adequate images from bedside portable, handheld spectral-domain optical coherence tomography imaging at 37-42 weeks postmenstrual age. Mean RNFL thickness was calculated for the papillomacular bundle (-15 degrees to +15 degrees) and temporal quadrant (-45 degrees to +45 degrees) relative to the fovea-optic nerve axis. Brain magnetic resonance imaging (MRI) scans clinically obtained in 26 very preterm infants were scored for global structural abnormalities by an expert masked to data except for age. Cognitive, language, and motor skills were assessed in 33 of the very preterm infants at 18-24 months corrected age.

RESULTS

RNFL was thinner for very preterm vs term infants at the papillomacular bundle ([mean ± standard deviation] 61 ± 17 vs 72 ± 13 μm, P < .001) and temporal quadrant (72 ± 21 vs 82 ± 16 μm, P = .005). In very preterm infants, thinner papillomacular bundle RNFL correlated with higher global brain MRI lesion burden index (R(2) = 0.35, P = .001) and lower cognitive (R(2) = 0.18, P = .01) and motor (R(2) = 0.17, P = .02) scores. Relationships were similar for temporal quadrant.

CONCLUSIONS

Thinner RNFL in very preterm infants relative to term-born infants may relate to brain structure and neurodevelopment.