Follow-Up of Nonarteritic Anterior Ischemic Optic Neuropathy With Optical Coherence Tomography Angiography

Retinal perfusion related to visual field within the same asymmetric thyroid-associated ophthalmopathy

PURPOSE

To quantify interocular differences in the retinal microvasculature between disparate eyes and explore associations between the retinal microvasculature and visual field abnormalities within the same asymmetric thyroid-associated ophthalmopathy (TAO) patients.

METHODS

Within the same asymmetric TAO eye, the eye with a severer visual field abnormality (based on the mean deviation [MD]) was considered a severe eye, and the fellow eye was considered mild. The densities of radial peripapillary capillary (RPC) and superficial retinal capillary plexuses (SRCP) were determined using optical coherence tomography angiography. Interocular differences in RPC and SRCP densities were analyzed. A generalized estimating equation (GEE) was used to form a predictive model for visual field abnormalities. Pearson's correlation was used to show the correlation between MD and the densities of RPC and SRCP.

RESULTS

In 57 asymmetric TAO patients, the global RPC density in severe eyes was lower than that in mild eyes (P < 0.001), but there was no significant difference in SRCP density between the two groups (P = 0.114). In a multivariate GEE model with MD as the outcome, MD was associated only with global RPC density (coefficient β=0.327, P < 0.001). The global RPC density was correlated with MD (r = 0.360, P = 0.003) in severe eyes, but not in mild eyes (r = 0.179, P = 0.092). No significant correlation was observed between global SRCP density and MD in either group (Both P > 0.05).

CONCLUSIONS

RPC density decreased significantly and correlated with visual field abnormalities in severe eyes of TAO patients. Alterations in RPC density may contribute to visual field abnormalities in TAO eyes.

Optical coherence tomography angiography findings in patients affected by giant cell arteritis, with and without ocular involvement: a pilot study

Purpose

We evaluated the clinical features and retinal and disk perfusion characteristics by using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in a subset of giant cell arteritis (GCA) patients who manifested anterior ischemic optic neuropathy (AION), in a subset of GCA patients without ocular involvement, and in a control group composed of healthy controls.

Methods

We performed an observational study on the eyes of GCA patients affected by arteritic AION both in acute and chronic phases, unaffected eyes of AION, eyes of GCA patients without ocular involvement, and in a control group of healthy eyes of healthy individuals. All patients underwent a complete ophthalmic examination and an OCT and OCTA of the macula and the disk.

Results

The study evaluated 10 eyes of GCA patients with AION (AION group), 8 unaffected eyes of GCA patients with AION in another eye (unaffected eyes of AION group), 16 eyes of GCA patients without ocular involvement (non-ocular group), and 22 eyes of healthy patients (healthy group). The ganglion cell complex (GCC) superior and inferior thicknesses were significantly lower in the AION group compared to the unaffected eyes of the AION group (p = 0.045 and p = 0.034, respectively). All OCTA vascular density parameters of the optic disk analyzed in this study (optic nerve head (ONH) whole, superior, inferior, radial peripapillary capillary plexus (RPCP) whole, superior, inferior, lamina cribrosa (LC) whole, superior, inferior) resulted significantly lower in the AION group compared to the unaffected eyes group (p < 0.05 for all the comparisons). The ONH whole and inferior were statistically higher in the healthy group in comparison to the group of GCA patients without ocular involvement (p = 0.008 and p = 0.006, respectively). The ONH inferior was also statistically higher in the unaffected eyes of the AION group in comparison to the non-ocular group (p = 0.045). Regarding the OCTA macular vessel density parameters, the superficial capillary plexus (SCP), whole and inner, were statistically lower in the AION group compared with the unaffected eyes of the AION group.

Conclusion

We found a profound vascular impairment in eyes affected by AION and areas of hypoperfusion in the eyes of patients with GCA without ocular involvement, good BCVA, and no clinically significant features. We hypothesized that these areas of lower vessel density might represent areas of subclinical hypoperfusion that cannot be detected ophthalmoscopically.

Papillary vitreous detachment as a possible accomplice in non-arteritic anterior ischaemic optic neuropathy

AIM

To evaluate the role of papillary vitreous detachment in the pathogenesis of non-arteritic anterior ischaemic optic neuropathy (NAION) by comparing the features of vitreopapillary interface between NAION patients and normal individuals.

METHODS

This study included 22 acute NAION patients (25 eyes), 21 non-acute NAION patients (23 eyes) and 23 normal individuals (34 eyes). All study participants underwent swept-source optical coherence tomography to assess the vitreopapillary interface, peripapillary wrinkles and peripapillary superficial vessel protrusion. The statistical correlations between peripapillary superficial vessel protrusion measurements and NAION were analysed. Two NAION patients underwent standard pars plana vitrectomy.

RESULTS

Incomplete papillary vitreous detachment was noted in all acute NAION patients. The prevalence of peripapillary wrinkles was 68% (17/25), 30% (7/23) and 0% (0/34), and the prevalence of peripapillary superficial vessel protrusion was 44% (11/25), 91% (21/23) and 0% (0/34) in the acute, non-acute NAION and control groups, respectively. The prevalence of peripapillary superficial vessel protrusion was 88.9% in the eyes without retinal nerve fibre layer thinning. Furthermore, the number of peripapillary superficial vessel protrusions in the superior quadrant was significantly higher than that in the other quadrants in eyes with NAION, consistent with the more damaged visual field defect regions. Peripapillary wrinkles and visual field defects in two patients with NAION were significantly attenuated within 1 week and 1 month after the release of vitreous connections, respectively.

CONCLUSION

Peripapillary wrinkles and superficial vessel protrusion may be signs of papillary vitreous detachment-related traction in NAION. Papillary vitreous detachment may play an important role in NAION pathogenesis.

[Primary open angle glaucoma and sleep apnea syndrome: A review of the literature]

The relationship between glaucoma and Obstructive Sleep Apnea Syndrome (OSAS) has long been discussed, with conflicting study findings. OSAS appears in the most recent studies to be more of an aggravating factor than an independent risk factor for glaucoma. Patients with OSAS may develop a more rapid progression of primary open-angle glaucoma (POAG). OSAS may damage the optic nerve not only by increasing the intraocular pressure (IOP) but also by altering the blood supply to the optic nerve as shown by more recent work with OCT-Angiography. Although the systemic benefits of Continuous Positive Airway Pressure (CPAP) have been demonstrated, few studies have evaluated its effect on the optic nerve. CPAP might act on glaucomatous neuropathy by improving the blood supply to the optic nerve. The study of this mechanism of action might provide new insights into the relationship between OSAS and glaucoma.

Non-Arteritic Anterior Ischemic Optic Neuropathy (NA-AION): A Comprehensive Overview

Non-arteritic anterior ischemic optic neuropathy (NA-AION) represents one of the most important causes of blindness or severely impaired vision in middle-aged and elderly people. Unilateral optic disc edema and abrupt, painless vision loss are its defining features. It is commonly assumed that NA-AION is caused by an ischemic infarction of the optic nerve head, and, although the exact pathogenesis is still unknown, several risk factors and comorbidities associated with its development have been found. NA-AION occurs generally in patients older than 50 years who have small optic discs and vasculopathy risk factors. Even though numerous treatment options have been proposed, no available effective medical or surgical therapy or prophylactic measure for NA-AION currently exists. The purpose of present-day therapeutic strategies is therefore to identify and possibly control any underlying modifiable risk factors, aiming to prevent the development of new NA-AION episodes in the affected and fellow eye. A thorough assessment of NAION, including its history, epidemiology, etiology, pathophysiology, risk factors, associated comorbidities, clinical findings, diagnostic tests, treatment choices, prognosis, and future research, is the goal of this work.

Non-Arteritic Anterior Ischemic Optic Neuropathy (NA-AION): A Comprehensive Overview

Non-arteritic anterior ischemic optic neuropathy (NA-AION) represents one of the most important causes of blindness or severely impaired vision in middle-aged and elderly people. Unilateral optic disc edema and abrupt, painless vision loss are its defining features. It is commonly assumed that NA-AION is caused by an ischemic infarction of the optic nerve head, and, although the exact pathogenesis is still unknown, several risk factors and comorbidities associated with its development have been found. NA-AION occurs generally in patients older than 50 years who have small optic discs and vasculopathy risk factors. Even though numerous treatment options have been proposed, no available effective medical or surgical therapy or prophylactic measure for NA-AION currently exists. The purpose of present-day therapeutic strategies is therefore to identify and possibly control any underlying modifiable risk factors, aiming to prevent the development of new NA-AION episodes in the affected and fellow eye. A thorough assessment of NAION, including its history, epidemiology, etiology, pathophysiology, risk factors, associated comorbidities, clinical findings, diagnostic tests, treatment choices, prognosis, and future research, is the goal of this work.

Detecting changes in the blood flow of the optic disk in patients with nonarteritic anterior ischemic optic neuropathy via optical coherence tomography-angiography

Purpose

This study aimed to evaluate the changes in the blood flow of the optic disk in patients with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography-angiography (OCTA) and to investigate the relationship among the changes in the blood flow of the optic disk, visual field defect, peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell complex (mGCC).

Methods

This was a prospective observational case series study. A total of 89 patients (89 eyes) with NAION were included in this study. All patients underwent best corrected visual acuity (BCVA), slit-lamp and direct ophthalmoscopic examinations, color fundus photography, visual field test, and blood flow indicators of the radial peripapillary capillaries (RPC) including whole en face image vessel density (VD), peripapillary VD by OCTA, the peripapillary RNFL, and mGCC by spectral-domain optic coherence tomography (OCT). The changes of blood flow in the optic disk at ≤3, 4-8, 9-12, 13-24, and >24 weeks of the natural course of NAION were measured, and the relationship among the changes in the blood flow of the optic disk, visual field defect, peripapillary RNFL, and mGCC was also analyzed.

Results

The mean age of 89 patients with NAION was 56.42 ± 6.81 years (ranging from 39 to 79). The initial RPC whole en face image VD was significantly reduced after acute NAION (≤3 weeks) (F = 45.598, P < 0.001) and stabilized from the eighth week onward. Over the course of NAION, the superonasal RPC, superior mGCC, and superotemporal RNFL decreased mostly with time (F = 95.658, 109.787, 263.872, respectively; P < 0.001). Maximal correlations were found between superior mGCC and temporosuperior RPC in the NAION phase (R = 0.683, P < 0.01) and between superonasal RPC and superonasal RNFL (R = 0.740, P < 0.01). The mean defect was correlated with temporosuperior RPC (R = -0.281, P < 0.01) and superior mGCC (R = -0.160, P = 0.012).

Conclusion

Over the course of NAION, OCTA shows a tendency toward change in the retinal capillary plexus of the optic disk. OCTA is proved to be a practical and useful tool for observing papillary perfusion in NAION.

Peripapillary and macular microvasculature features of non-arteritic anterior ischemic optic neuropathy

Purpose

The hallmark of non-arteritic anterior ischemic optic neuropathy (NAION) is vascular compromise to the anterior optic nerve and thinning of the retinal nerve fiber layer (RNFL) and secondary degeneration of the retinal ganglion cell body or thinning of the ganglion cell complex (GCC). This study investigates optical coherence tomography (OCT) and OCT Angiography (OCTA) changes in chronic NAION and identifies imaging biomarkers that best predict disease.

Methods

We performed a retrospective case-control study of 24 chronic NAION eyes (18 patients) and 70 control eyes (45 patients) to compare both whole-eye and regional OCT, OCTA, static perimetry measurements. OCT measurements were quantified automatically using commercial software, and OCTA was analyzed using custom MATLAB script with large vessel removal to measure 154 total parameters per eye.

Results

We confirmed that static perimetry mean deviation (MD) was significantly worse in chronic NAION (-13.53 ± 2.36) than control (-0.47 ± 0.72; P < 0.001) eyes, and NAION eyes had 31 μm thinner RNFL (control: 95.9 ± 25.8 μm; NAION: 64.5 ± 18.0, P < 0.001), and 21.8 μm thinner GCC compared with controls (control: 81.5 ± 4.4 μm; NAION: 59.7 ± 10.5, P < 0.001). Spearman correlation analysis of OCTA parameters reveal that vessel area density (VAD) and flux are highly correlated with visual field MD and OCT measurements. Hierarchical clustering two distinct groups (NAION and control), where standardized measurements of NAION eyes were generally lower than controls. Two-way mixed ANOVAs showed significant interaction between patient status (control and chronic NAION) and structure (optic disk and macula) for annulus VAD and flux values and mean RNFL and GCC thickness. Post-hoc tests showed this effect stems from lower peripapillary values in NAION compared to controls. Separate logistic regression models with LASSO regularization identified VAD and flux are one of the best OCTA parameters for predicting NAION.

Conclusion

Ischemic insult to the optic disk is more severe likely from primary degeneration of the affected peripapillary region while macula is affected by secondary retrograde degeneration and loss of retinal ganglion cells. In addition to OCT measurements, peripapillary and macular vascular parameters such as VAD and flux are good predictors of optic nerve and retinal changes in NAION.

A Deep Learning System Using Optical Coherence Tomography Angiography to Detect Glaucoma and Anterior Ischemic Optic Neuropathy

INTRODUCTION

Glaucoma and non-arteritic anterior ischemic optic neuropathy (NAION) are optic neuropathies that can both lead to irreversible blindness. Several studies have compared optical coherence tomography angiography (OCTA) findings in glaucoma and NAION in the presence of similar functional and structural damages with contradictory results. The goal of this study was to use a deep learning system to differentiate OCTA in glaucoma and NAION.

MATERIAL AND METHODS

Sixty eyes with glaucoma (including primary open angle glaucoma, angle-closure glaucoma, normal tension glaucoma, pigmentary glaucoma, pseudoexfoliative glaucoma and juvenile glaucoma), thirty eyes with atrophic NAION and forty control eyes (NC) were included. All patients underwent OCTA imaging and automatic segmentation was used to analyze the macular superficial capillary plexus (SCP) and the radial peripapillary capillary (RPC) plexus. We used the classic convolutional neural network (CNN) architecture of ResNet50. Attribution maps were obtained using the "Integrated Gradients" method.

RESULTS

The best performances were obtained with the SCP + RPC model achieving a mean area under the receiver operating characteristics curve (ROC AUC) of 0.94 (95% CI 0.92-0.96) for glaucoma, 0.90 (95% CI 0.86-0.94) for NAION and 0.96 (95% CI 0.96-0.97) for NC.

CONCLUSION

This study shows that deep learning architecture can classify NAION, glaucoma and normal OCTA images with a good diagnostic performance and may outperform the specialist assessment.

Analysis of Vessel Density Using OCTA in Nonarteritic Anterior Ischemic Optic Neuropathy

Purpose: To investigate the intraocular vessel density in patients with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA).Methods: Medical records of patients with NAION were retrospectively analyzed. Their age, sex, best corrected visual acuity, color vision results, mean deviation of visual field test were analyzed. Using results of OCT and OCTA that was performed at first visit within 3 weeks of symptom onset, vessel densities in eyes with NAION were evaluated by comparing contralateral unaffected eyes. Furthermore, in only affected eyes, the correlation between visual acuity at the time of diagnosis and anatomical factors such as mean vessel density and retinal nerve fiber layer (RNFL) thickness was investigated.Results: Twenty-five patients (11 males and 14 females) were enrolled in this study and the mean age was 65.92 ± 9.37 years. Whole RNFL thickness in affected eye was significantly lower than that in unaffected eye (<i>p</i> < 0.001). The average peripapillary vessel density was also significantly lower in affected eyes, 45.63% ± 7.60% compared to that in the contralateral eyes, 51.44% ± 3.40% (<i>p</i> = 0.004). In analysis of only 25 affected eyes, there was no significant correlation between each sectoral peripapillary RNFL thickness and vessel density. There was also no significant correlation between the visual acuity and the vessel density and retinal nerve fiber layer thickness in the ischemic peripapillary hemisphere. However, there was a significant negative correlation between the visual acuity and the un-ischemic peripapillary hemisphere with a coefficient of -0.608 (<i>p</i> = 0.001).Conclusions: The higher vessel density of nonaffected sector, the better visual acuity at the time of diagnosis in patients with NAION. Patency of blood supply in the preserved peripapillary intraretinal vessel density sector may affect the visual function.

Optical Coherence Tomography of Peripapillary Vessels in Giant Cell Arteritis and Ischaemic Ocular Disease

With normal retinal blood flow, cross-sectional optical coherence tomography (OCT) of retinal vessels shows a structured intravascular reflectivity profile, resembling a 'figure-of-8'. Altered profiles have been reported in vascular occlusive and haematological diseases. Giant cell arteritis (GCA) can cause visual loss, usually due to anterior ischaemic optic neuropathy (AION) or retinal artery occlusion. Our aim was to extend the assessment of OCT vascular profiles to patients with suspected GCA and to determine if any abnormalities were related to GCA per se or to ischaemic ocular conditions. This nested retrospective study included 61 eyes of 31 patients (13 with GCA). Six eyes had arteritic and seven eyes non-arteritic AION, three eyes had non-arteritic retinal artery occlusion, 11 eyes had other ocular conditions and 34 were unaffected control eyes. For each eye the appearance of structured intravascular profiles on peripapillary OCT was graded as present, partial, absent or uncertain. Non-presence of structured intravascular profiles was more frequent in AION and retinal artery occlusion than in other ocular conditions or unaffected eyes (Fisher's test, p = .0047). Based on follow-up of 25 eyes, reflectivity profiles normalised in three out of four eyes after 85 (35-245) days. Vessel profiles were not associated with GCA (p = .32) and were similar in arteritic and non-arteritic AION (p = .66). In conclusion, absence of structured intravascular reflectivity profiles may be a marker of acute ischaemia in the anterior optic nerve or inner retina. However, it did not seem specific for GCA. The prognostic value warrants further studies.

Vision-Related Quality of Life and Association Between Retinal Parameters in Patients with Non-Arteritic Anterior Ischemic Optic Neuropathy

Purpose

To evaluate visual-related quality of life (VR-QoL) and its association with optic nerve head microvasculature in individuals with nonarteritic anterior ischemic optic neuropathy (NAION) evaluated at the acute stage.

Methods

In this retrospective case-control study, 23 NAION eyes at the acute stage and 25 age and gender matched healthy eyes were included, respectively. All included eyes underwent a complete ophthalmic examination including optical coherence tomography (OCT) and OCT angiography (OCTA). The Chinese version of the National Eye Institute Visual Function Questionnaire-25 (CHI-NEI-VFQ-25) was applied to assess VR-QoL in individuals consecutively visited at an ophthalmic center. Descriptive and analytic statistics were employed.

Results

There were no significant differences on age, gender, socioeconomic and education level (P > 0.05), but best-corrected visual acuity (BCVA) differences were reported between cases and controls (P < 0.05). Each peripapillary retinal nerve fiber layer (RNFL) thickness was higher but peripapillary vessel density (VD) and VR-QoL scores for all subscales were significantly lower in cases when compared with controls, respectively (P < 0.05). Particularly, pearson's partial correlation analysis restricted to eyes with NAION revealed stronger correlations between peripapillary RNFL measurements, VD and VR-QoL.

Conclusion

NAION at the acute stage affects VR-QoL in Chinese individuals. Some peripapillary RNFL measurements and VD correlated with VR-QoL. Retinal anatomic and blood flow examinations and inventions in patients with NAION are necessary to facilitate VR-QoL and disease control.

Genetic polymorphisms of apolipoprotein E in nonarteritic anterior ischemic optic neuropathy

PURPOSE

To elucidate the potential role of genetic polymorphisms of apolipoprotein E (APOE) in nonarteritic anterior ischemic optic neuropathy (NAION) and the association between APOE and NAION-induced ocular impairments.

METHODS

A total of 73 NAION patients and 73 sex- and age-matched healthy controls were recruited for the study. Genomic DNA was isolated from peripheral blood samples. The alleles and genotypes of APOE were explored. The interaction between APOE and medical comorbidities was assessed by the multifactor dimensionality reduction (MDR) method. Among 81 affected eyes of NAION patients, an additional association study of APOE isoforms with visual impairments was carried out.

RESULTS

The allele and genotype frequencies for APOE showed significant differences when comparing NAION cases and controls. Multivariate analysis adjusted for age, sex, hypertension, dyslipidemia, diabetes mellitus, cardiovascular disease, and cerebrovascular disease revealed that the ε3/ε4 genotype (OR = 3.86, 95% CI = 1.13-13.25, p = 0.032) and ε4 allele (OR = 3.55, 95% CI = 1.05-11.99, p = 0.041) were strong independent risk factors for NAION. Compared to eyes with the ε3/ε3 + ε2/ε4 genotype, individuals with the ε4/ε4 + ε3/ε4 genotype had worse visual field defects (VFDs) and thinner macular ganglion cell complex (mGCC) thicknesses with larger focal loss of volume (FLV) and general loss of volume (GLV). Compared to ε4 noncarriers, ε4 carriers also tended to have more serious VFD and mGCC loss.

CONCLUSIONS

APOE polymorphisms conferred a significant risk of NAION and were significantly related to ocular impairments caused by NAION.