Nonarteritic Anterior Ischemic Optic Neuropathy Research Articles

Optical coherence tomography analysis of the optic nerve head and macula of the fellow eye in acute unilateral nonarteritic anterior ischemic optic neuropathy

The objective of the study was to compare the thickness of the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) of the fellow eyes of patients with acute nonarteritic anterior ischemic optic neuropathy (NAAION) to those of control subjects. This study included 46 patients with NAAION matched for age, sex and refraction data (spherical equivalent and/or axial length) to 46 control subjects. The anatomical parameters assessed using the Cirrus SD-OCT were the mean RNFL thickness, in the 4 quadrants (inferior, nasal, temporal, superior) and according to the 12 hourly meridians, GCC mean and in 6 quadrants centered on the fovea (infero-nasal, supero-nasal, infero-temporal, supero-temporal, superior and inferior) and parameters of the optic disc (Cup ratio - Vertical and Average Disc, Rim Area, Disc Area, Cup Volume). Compared to the control group, the eyes contralateral to those affected by NAAION showed a greater value of the area of the neuro-retinal rim (rim area), and a smaller vertical cup/disc (C/D) ratio, mean C/D, and cup volume than the control group. There was no significant difference between the two groups for peripapillary RNFL thickness and GCC parameters. The absence of damage to the RNFL or GCC of the unaffected fellow eyes of patients with NAAION does not explain the perimetric damage. The eyes contralateral to those affected by NAAION are characterized by an overall size of the optic disc identical to those of the control subjects, but a smaller cup, a recognized risk factor for NAAION.

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

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). 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. 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). 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.

Race Distribution in Nonarteritic Anterior Ischemic Optic Neuropathy

To describe the racial distribution of patients diagnosed with nonarteritic anterior ischemic optic neuropathy (NAION) in 2 large urban academic centers in the United States. Retrospective cross-sectional study. All patients with NAION evaluated between 2014 and 2022 in tertiary neuro-ophthalmology services in Atlanta, GA, and New York, NY, respectively, were included. In order to assess the racial accessibility to our services, similar numbers of patients with idiopathic intracranial hypertension seen in the same services were included. Self-reported race at the time of neuro-ophthalmologic examination was collected for all patients. Results were compared with data published by the US Bureau of Census for Decennial Census in 2020 for the states of Georgia and New York, and for the total population of the United States. In both locations, the vast majority of patients with NAION reported being White (91.06% in Atlanta and 78.9% in New York). Only 7.27% of patients in Atlanta and 3% in New York reported being Black, and 1.24% of patients in Atlanta and 5.9% in New York reported being Asian. There were a much higher proportion of White people among NAION patients than in the group of patients with idiopathic intracranial hypertension and in each respective state and in the United States. Our results show that the majority of patients with NAION are White, followed by Black and Asian races, respectively, thus confirming the NAION race distribution reported by past clinical trials.

The correlation between non-arteritic anterior ischemic optic neuropathy and cerebral infarction.

The aim of this study was to explore the correlation between non-arteritic anterior ischemic optic neuropathy (NAION) and cerebral infarction (CI). Moreover, the ocular and systemic parameters are also compared between NAION patients with or without CI. Retrospective analysis is performed for NAION patients and the controls. The controls were collected at the eye outpatient with cranial computed tomography (CT), and data of blood triglyceride, cholesterol, low-density lipoprotein, high-density lipoprotein, and apolipoprotein B were drawn. The diagnosed NAION patients with cranial CT are included, and data of clinical history and routine clinical examination were drawn from the medical record. Visual acuity, intraocular pressure (IOP), visual field, and visual evoked potential were also drawn. Eighty-two unilateral and 6 bilateral patients, totally 94 eyes for 88 NAION patients and 69 controls are included. NAION and control patients have matched age, gender, and weight. There is no difference in triglyceride, cholesterol, low-density lipoprotein, high-density lipoprotein, and apolipoprotein B between these two groups. NAION patients (43.18%, 38/88) have a higher ratio of CI than the controls (14.49%, 10/69) (p = 0.000). For NAION, the odds ratio (OR) of CI is 2.691 (p = 0.011). Body mass index, height, and IOP show no significant difference between NAION patients with or without CI. NAION patients with CI have a significant higher ratio of hypertension than those without CI, and the OR of HBP is 2.623 (p = 0.008). The correlation between NAION and CI is possible as NAION patients have a significant higher ratio with CI. In NAION patients, hypertension is a risk factor for those with CI.

Retinal Nerve Fiber Layer Thickness/Minimum Rim Width Ratio Differentiates Glaucoma from Other Optic Neuropathies.

Global peripapillary retinal nerve fiber layer thickness/Bruch membrane opening- minimum rim width ratio is an objective and effective parameter to separate glaucomatous optic neuropathies (GONs) from nonglaucomatous optic neuropathies (NGONs). This study was undertaken to evaluate the diagnostic capability of the peripapillary retinal nerve fiber layer (pRNFL)/ Bruch membrane opening-minimum rim width (BMO-MRW) ratio to differentiate glaucomatous optic neuropathies (GONs) from nonglaucomatous optic neuropathies (NGONs). This retrospective study included patients with an optic neuropathy (ON), visual loss for>6 months and a confirmed single etiology. pRNFL thickness and BMO-MRW were measured with spectral-domain OCT (Spectralis®, Heidelberg Engineering, Heidelberg, Germany). The diagnostic accuracies of pRNFL, BMO-MRW and the global pRNFL/BMO-MRW ratio were evaluated with the areas under receiver operating characteristics curves (AUROCs). One eye each from 171 patients was investigated: 50 primary open-angle glaucomas, 15 normal pressure glaucomas, 50 optic neuritises, 15 nonarteritic anterior ischemic ONs, 24 compressive ONs, 10 dominant optic atrophies and 7 nutritional ONs. The global pRNFL/BMO-MRW ratio had the highest AUROC [0.97 vs. 0.92; P =0.01]. It was able to distinguish between GONs and NGONs with a cut-off value of 0.34. Increased mean deviation of the visual field-defect severity was associated with a higher ratio for GONs and a lower ratio for NGONs. Compared to NGONs and for the same degree of pRNFL thinning, lower BMO- MRW was found to be a specific marker of glaucoma, reflecting the neuroglial architecture changes within the optic nerve head typical of glaucoma and supporting fundamental pathophysiological differences.

The Twilight Zone Where Margins Are Blurred: A Retrospective Analysis of Unilateral and Bilateral Optic Disc Swelling in a Tertiary Center in Malaysia.

Background To analyze the etiology of optic disc swelling (ODS) and compare the clinical features between non-arteritic anterior ischemic optic neuropathy (NA-AION) and optic neuritis (ON) at our center from January 2019 to January 2020. Methodology Clinical records of all patients who presented with ODS between January 2019 and January 2020 were reviewed. The collected data were analyzed using IBM SPSS Statistics for Windows (Version 23.0,IBM Corp., Armonk, NY, USA). Results A total of 70 eyes among 47 patients were included in this review. There were 24 patients (51%) who had unilateral ODS, while 23 patients (49.0%) had bilateral ODS. The most common etiology of unilateral ODS was ON (45.7%), NA-AION (25%), and neuroretinitis (12.5%). Among bilateral ODS, the most common cause was papilledema (30.4%), hypertensive retinopathy (21.7%), diabetic papillitis (13.1%), and optic disc drusen (13.1%). Among unilateral ODS, the mean onset age was significantly older in NA-AION cases than that in ON cases (57.5 years vs. 40.3 years, P= 0.016). Ocular pain was a significant clinical finding observed in ON cases (54.5%) and none in NA-AION cases (P= 0.043). Although there was no significant difference in the initial visual acuity (VA) between NA-AION and ON, the final VA was significantly improved in ON compared to NA-AION (0.31 ± 0.34 vs. 1.14 ± 1.00, P = 0.029). Conclusions Many differential diagnoses must be considered when a patient is presented with ODS. With the increased prevalence of hypertension and diabetes in Malaysia, it is not a surprise that both hypertensive retinopathy and diabetic papillitis together accounted for one-third of the bilateral ODS patients.

Assessment of macular and peripapillary choroidal thickness in non-arteritic anterior ischemic optic neuropathy: A meta-analysis.

Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common optic neuropathy in adults aged ≥ 50 years. Transient non-perfusion or hypoperfusion of the optic nerve head circulation is believed to be the underlying cause of NAION. It has been suggested that peripapillary choroidal thickness (PCT) is altered after ischemic disorders of the optic nerve head, but the results have not always been consistent. To address this issue and provide evidence for the pathogenesis of NAION, we performed a meta-analysis to systematically evaluate macular choroidal thickness (MCT) and PCT in patients with NAION. A comprehensive literature search of PubMed, Embase, Cochrane Library, and Web of Science databases was performed until August 31, 2022. The main inclusion criterion was a case-control study in which MCT and PCT were measured using optical coherence tomography in patients with NAION. Mean difference (MD) and 95% confidence interval were calculated for continuous estimates. The Review Manager (V5.40) was used for the analysis. Nine studies comprising 663 eyes (283 NAION eyes and 380 healthy control eyes) were included (Newcastle-Ottawa Scale score ≥ 5). MCT and PCT were higher in eyes with chronic NAION (MD = 19.16, P = .04; MD = 35.36, P < .00001) and NAION fellow eyes (MD = 30.35, P = .0006; MD = 29.86, P = .04) than in healthy controls. No difference was noted in the MCT between eyes with acute NAION and healthy controls (MD = 2.99, P = .87). Increased MCT and PCT may be important anatomical and physiological features of the eyes in patients with NAION.

Correction to: Optical Coherence Tomography Angiography Acute of Non-Arteritic Anterior Ischemic Optic Neuropathy.

Correction to: Optical Coherence Tomography Angiography Acute of Non-Arteritic Anterior Ischemic Optic Neuropathy.

Investigation of the Protective Effect of Extracellular Vesicle miR-124 on Retinal Ganglion Cells Using a Photolabile Paper-Based Chip.

Photolabile paper-based chips were developed to isolate extracellular vesicles (EVs) from small-volume samples (less than 30 µL), such as vitreous humor. Putative neuroprotective effects of EVs' microRNAs were investigated by using the paper chip and a rodent model with nonarteritic anterior ischemic optic neuropathy (rNAION). rNAION was established using laser-induced photoactivation of rose bengal administered intravenously. On days 0, 0.25, 1, 3, and 7 after rNAION induction, CD63-positive EV microRNAs (CD63+-EV miRNAs) in vitreous humor samples were enriched using the paper chip and assessed using microarray and quantitative RT-PCR analyses. The viability and visual function of retinal ganglion cells (RGCs) were further assessed by measuring photopic flash visual evoked potentials (FVEPs). We identified 38 different variations of CD63+-EV miRNAs with more than twofold altered expressions. Among them, M1-related miRNA, mR-31a-5p, and M2-related miRNA, miR-125a-5p, miR-182, miR-181a-5p, and miR-124-3, were capable of coordinating anti-inflammatory reactions during rNAION because of their capacity to activate macrophages. In particular, miR-124, having the most dramatic alteration of gene expression, was synthesized and injected intravitreally. Compared to controls, rats that received miR-124 had shown increased RGC survivability and improved visual function. Our research team has developed a paper-based chip capable of capturing EVs that can be released after UV exposure. The quantity and quality of EV-miRNAs extracted are adequate for microarray and quantitative RT-PCR analyses. Animal studies suggest that miR-124 may play a neuroprotective role in the natural recovery of rNAION and holds the potential to be a novel treatment option.

Hormone Replacement Therapy and the Incidence of Nonarteritic Anterior Ischemic Optic Neuropathy: a Nationwide Population-Based Study (2009-2018).

This study aimed to assess the association between hormone replacement therapy (HRT) and the prevalence of nonarteritic anterior ischemic optic neuropathy (NAION) in menopausal women using national data from the entire Korean population. The health screening data of 1,381,605 women between 40 and 90 years of age collected by the National Health Insurance Service (NHIS) of Korea between January 1, 2009, and December 31, 2018, were retrospectively reviewed. Before data analysis, the potential cofounders were adjusted for among all participants. Based on HRT use and its duration (classified into four groups), the hazard ratio (HR) and 95% confidence interval (CI) of NAION development were calculated via a Cox proportional hazards regression analysis using the nonuser group as a reference. Overall, 7824 NAION diagnoses were made during the mean follow-up of 8.22 years (standard deviation: 1.09 years) in 1,381,605 post-menopausal women. NAION was more common in the HRT group than in the non-HRT group (HR [95% CI]: 1.268 [1.197-1.344]). Furthermore, the risk of NAION increased along with increased HRT duration (p < 0.0001). In the multivariate analysis, the adjusted HRs of the < 2-year HRT group, the 2-5-year HRT group, and the ≥ 5-year HRT group were 1.19 (95% CI: 1.10-1.28), 1.3 (95% CI: 1.17-1.45), and 1.473 (95% CI: 1.31-1.65), respectively. Compared to women younger than 65 years, the HR of HRT for NAION was significantly higher than that of women older than 65 years (p < 0.0001). Our population-based cohort study found that HRT was significantly associated with increased incidence of NAION. The incidence of NAION also increased with the duration of HRT.

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

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. 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. 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. 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.

COVID-19 presenting as a non-arteritic anterior ischemic optic neuropathy.

We present a case of a 61-year-old woman with an atypical non-arteritic anterior ischemic optic neuropathy (NA-AION) as a unique manifestation of COVID-19. Furthermore, the patient worsened after Pfizer-BioNTech COVID-19 vaccine administration. Our findings suggest that NA-AION could result from microangiopathic/thrombotic events that may occur during SARS-CoV-2 infection and/or vaccination against COVID-19. This report sheds light on possible ophthalmologic complications of COVID-19.

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

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. 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. 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. 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.

Macular and Optic Disc Head Morphology on OCT and Visual Prognosis in Non-Arteritic Anterior Ischemic Optic Neuropathy

Introduction: Non-arteritic anterior ischemic optic neuropathy (NAION) shows an acute painless unilateral visual loss due to a reduced perfusion of the optic nerve head (ONH). Aim of this study was to analyse ONH respective macula morphology after NAION by optical coherence tomography and the correlation to visual acuity.

Clinical and Demographic Characteristics of Patients with Neuro-ophthalmological Disorders Starting Later in Life

Objectives: To determine the demographic, etiological and clinical features as well as treatment modalities of patients with neuro-ophthalmological disorders starting at a later age. Materials and Methods: We retrospectively reviewed the clinical data related to the neuro-ophthalmology patients who presented at the age of ≥ 65 years at two tertiary eye care referral centers from 2004 to 2022. Results: Of the 2,127 patients who applied to the Neuro-Ophthalmology Department during this period, 162 (7.6%) were ≥ 65 years old at the time of diagnosis and their data were analyzed. The mean age at the onset of disease was 73.2 ± 6.7 (65–95) years, and mean follow-up time was 1.1±0.4 (1-3) years. Non-arteritic anterior ischemic optic neuropathy (NAAION) (n=85, 52.5%), isolated cranial nerve palsies (n=28, 17.3%), and cerebral vascular disorders (CVD) (n=14, 8.6%) were the most frequent diagnosis. The most common symptoms were as follows: sudden visual loss in 79 (48.8%), diplopia in 31 (19.1%), and blurred vision in 21 (13%) cases. The most common accompanying systemic disease was hypertension (HT) and diabetes mellitus (DM) in 31 (27.4%), followed by HT in 29 (25.7%) cases. There was no accompanying systemic disease in 49 (30.2%) patients. The diagnosis of NAAION and AAION resulted in poor visual outcomes, while CVD presented with homonymous hemianopsia. Conclusion: NAAION and CVD were the most common age-related neuro-ophthalmological disorders that cause visual acuity loss and a visual field defect at an advanced age. Identifying these disorders and managing the visual problems are essential to preserve the protection of the patient's quality of life.

Isolated ocular motor nerve palsy associated with raised homocysteine

Ocular motor mono-neuropathies frequently occur from micro-vascular ischemia to the nerve in the presence of atherosclerotic risk factors such as old age, diabetes mellitus, hypertension, and dyslipidemia. Other possible causes include trauma, intra-cranial neoplasm, aneurysm, inflammation, infection, and brainstem infarction. Recently, hyper-homocysteinemia has emerged as an independent risk factor for systemic and ocular vaso-occlusive disorders. Ocular pathologies such as retinal vascular occlusion and non-arteritic anterior ischemic optic neuropathy have been found to be associated with mild hyper-homocysteinemia. This case series describes four patients with isolated third and sixth cranial nerve palsy where hyper-homosysteinemia was the only risk factor.

Retracted: The Efficacy of Glucocorticoids in the Treatment of Nonarteritic Anterior Ischemic Optic Neuropathy: A Systematic Review and Meta-Analysis.

[This retracts the article DOI: 10.1155/2022/2935992.].

Evaluation of the Choroid in Patients with Non Proliferative Diabetic Retinopathy by Optical Coherence Tomography Angiography (OCTA)

Background: Diabetes may cause a wide range of eye disorders, including cataracts, glaucoma and other ocular abnormalities, recurrent styes, non-arteritic anterior ischemic optic neuropathy and diabetic papillopathy.

A Taiwan Nationwide Population-Based Study of Socio-Demographic Factors and Comorbid Conditions Associated with Non-Arteritic Anterior Ischaemic Optic Neuropathy

Aims: The aim of the study was to investigate the socio-demographic factors and systemic conditions associated with non-arteritic anterior ischaemic optic neuropathy (NAION). Methods: This was a nationwide population-based retrospective case-controlled study that recruited 9,261 NAION patients selected from the Taiwan National Health Insurance Research Database. The control group consisted of 9,261 age-, sex-, and index date-matched non-NAION patients recruited from the Taiwan Longitudinal Health Insurance Database, 2000. NAION was designated in the database by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) as “code 377.41: ischaemic optic neuropathy without ICD-9-CM code 446.5: giant cell arteritis.” Associated socio-demographic factors and systemic medical conditions were analysed using the McNemar’s test, and continuous variables were analysed using the paired t test. The odds ratio (OR) and adjusted OR of developing NAION were compared using univariate logistic regression and multivariable logistic regression analyses, respectively. Results: Patients with systemic conditions such as diabetes mellitus, hypertension, hyperlipidaemia, chronic kidney disease, and hypotension were more likely to develop NAION than controls (adjusted OR = 1.81, 95% confidence interval [CI] = 1.67–1.97, p < 0.0001; adjusted OR = 1.46, 95% CI = 1.36–1.57, p < 0.0001; adjusted OR = 1.44, 95% CI = 1.33–1.57, p < 0.0001; adjusted OR = 3.26, 95% CI = 2.65–4.01, p < 0.0001; adjusted OR = 2.32, 95% CI = 1.31–4.10, p = 0.0039, respectively). Conclusions: NAION is strongly associated with diabetes mellitus, hypertension, hyperlipidaemia, chronic kidney disease, and hypotension.

Characteristics of macrophage-like cells in acute nonarteritic anterior ischemic optic neuropathy and the normal fellow eyes on en face optical coherence tomography.

To quantitatively analyze macrophage-like cells (MLCs) at the vitreoretinal interface (VRI) in acute nonarteritic anterior ischemic optic neuropathy (NAION) using en face swept-source optical coherence tomography (OCT). Twenty-five acute NAION eyes and 25 normal fellow eyes from 25 patients were included in the study. MLCs were visualized in a 3 μm 6 mm×6 mm en face OCT slab above the VRI centered on the optic nerve head (ONH). After semiautomatic binarization and quantification, we evaluated the MLC density between the two groups. We also investigated the relationship between MLC density and other OCT parameters, including the increase in peripapillary retinal nerve fiber layer (RNFL) thickness and loss of vessel density (VD) in radical peripapillary capillary (RPC). The MLC density in the affected eye of the ONH was highly correlated with that in the fellow eye (r=0.612, p=0.001). The MLC density significantly increased in acute NAION eyes (NAION vs. normal, 11.97 ± 6.66 vs. 9.31 ± 6.10 cell/mm2, p=0.028). In sectorial analysis, the increase in MLCs was mainly in the superior regions (4.13 ± 7.49 vs. 0.94 ± 5.21 cell/mm2, p=0.001). The VD of RPC decreased significantly in the affected eyes (NAION vs. normal, 37.54 ± 5.25 vs. 40.56 ± 4.25, p=0.016), and the loss of RPC was predominantly in the superior sectors and the temporal sectors when compared to the inferior sectors and the nasal sectors, respectively (superior vs. inferior, -3.54 ± 6.71 vs. -0.37 ± 8.07, p=0.004; temporal vs. nasal, -2.69 ± 8.72 vs. -1.22 ± 6.06, p=0.005). The loss of RPC and the increase in MLC density were greater in affected sector corresponding to the visual field (VF) defect. MLCs located above the VRI increased significantly in acute NAION eyes, especially in subregions corresponding to VF defect, which provides clinical evidence supporting that the inflammatory response participates in the pathological process of NAION. The magnitude of the increase in MLCs corresponds to the RPC loss in the quadrant analysis.