The fellow eye in NAION: report from the ischemic optic neuropathy decompression trial follow-up study

Correlation of Structure With Function: Future Utilities for Optical Coherence Tomography Angiography in Neuro-Ophthalmology

Optical coherence tomography angiography is a burgeoning imaging modality in Ophthalmology. In this review, we outline the breadth of potential utility for optical coherence tomography angiography for diagnosis and prognostication in neuro-ophthalmology. Further mapping of the characteristics and natural history of the optic disc vascular network in neuro-ophthalmic conditions is necessary to increase the utility of this imaging modality for neuro-ophthalmic conditions, as the specificity and sensitivity of optical coherence tomography angiography are currently limited by the small pool of available observational data.

Optic Neuropathies

OBJECTIVE

This article highlights the clinical features, evaluation, and management of optic neuropathies commonly encountered in clinical practice.

LATEST DEVELOPMENTS

Optic neuropathies encompass all conditions affecting the optic nerve, including those caused by ischemia, inflammation (including infections and autoimmune causes), elevated intracranial pressure, compression and infiltration, toxins, nutritional deficiencies, and hereditary diseases. Surgical and medical treatments targeting the specific causes of optic neuropathies are rapidly expanding, such as surgical options to address papilledema in patients with elevated intracranial pressure and the development of gene therapies for hereditary optic neuropathies. These advances underscore the importance of swift and accurate assessments to identify the cause of optic nerve dysfunction. The evaluation of the patient with an optic neuropathy begins with a careful history and examination. Signs of optic nerve dysfunction include decreased visual acuity, color vision impairment, a relative afferent pupillary defect in the affected eye, and visual field deficits. Neuroimaging of the orbits is one of the most useful tests in determining the cause of an optic neuropathy. Additional diagnostic testing and the formulation of a treatment plan should be guided by the differential diagnosis.

ESSENTIAL POINTS

Optic neuropathies are often misdiagnosed because of errors in eliciting or interpreting the history and physical examination. A systematic approach to identifying the clinical manifestations distinctive to specific optic neuropathies is imperative for directing diagnostic assessments, formulating tailored treatment regimens, and identifying broader central nervous system and systemic disorders.

A case-control study of peripapillary microvascular structure by OCT-angiography in non-arteritic ischaemic optic neuropathy at early and resolutive stages

OBJECTIVES

To analyse peripapillary and papillary superficial microvascularization using OCT-angiography (OCT-A) in patients with non-arteritic ischaemic optic neuropathy (NAION) at the acute and resolutive stages.

METHODS

This retrospective case-control study conducted between October 2018 and November 2019 included 23 NAION subjects at the acute stage (onset <1 month) and 20 patients at the resolutive stage (onset >3 months). NAION and contralateral eyes were compared to control eyes of patients (n = 50) matched 1:1 for refractive error, sex, age, systemic hypertension, diabetes, and sleep apnoea syndrome. The acquisition of OCT-A (OCTA-SD Cirrus 5000, Carl Zeiss) in 6 × 6 mm format centred on the papilla allowed measurement of the radial peripapillary plexus. A commercialized algorithm was used to obtain maps of density and microvascular retinal and papillary retinal perfusion, by positioning an ETDRS grid centred on the optic nerve head.

RESULTS

There was significant decrease in peripapillary density and microvascular perfusion values for NAION eyes both at the acute and resolutive stages compared to the contralateral and control eyes, mainly in the temporal sectors. Papillary vascular density and perfusion were significantly increased in NAION and contralateral eyes compared to control eyes. There was no significant difference in peripapillary density or peripapillary vascular perfusion between contralateral and control eyes.

CONCLUSION

Eyes in the acute and resolutive phases of NAION exhibit decreased microvascular density and peripapillary capillary perfusion. Increased papillary vascular density and perfusion seem to be an intrinsic characteristic of the optic nerves of both eyes in patients who develop NAION.

Compound Heterozygosity for the C6777T Mutation of the MTHFR Gene and the FII G20210A Mutation of the Prothrombin Gene in Sequential Bilateral Anterior Ischemic Optic Neuropathy

Nonarteritic anterior ischemic optic neuropathy (NA-AION) is the most common form of acute painless, usually unilateral, optic neuropathy in the elderly population. Systemic risk factors include diabetes mellitus, arterial hypertension, sleep apnea syndrome, and cardiovascular disease. Α 52-year-old man developed sequential, bilateral NA-AION, involving a worsening, severe vision compromising attack in the secondly affected eye. Thrombophilia testing revealed compound heterozygosity for the C6777T mutation of the MTHFR gene and the prothrombin G20210A (FII mutation). Oral anticoagulation treatment was initiated. A thorough systemic and family history, especially in the absence of major vasculopathic disease, should alert toward investigation for thrombophilia in middle-aged patients with atypical forms of NA-AION and initiation of anticoagulant treatment should be considered.

Optic neuropathy in imaging

The aim of this work is to provide a diagnostic approach to the potential causes of optic neuropathy, focusing on the radiological findings associated with this pathology. Various etiologies have been identified, including inflammatory and demyelinating optic neuritis, developmental and hereditary diseases, neurodegenerative disorders, infectious conditions, post-traumatic causes, ischemic optic neuropathy (with anterior ischemic optic neuropathy being the most common form), and neoplastic etiologies. Optical coherence tomography and magnetic resonance imaging play a fundamental role in the diagnosis of optic neuropathy, allowing to distinguish patterns of optic nerve involvement. These studies are essential to locate and characterize the different pathologies, increasing the precision of the diagnosis in diseases presenting optic neuropathy as the main symptom. In conclusion, the findings obtained from magnetic resonance imaging are essential in the differential diagnosis of optic nerve diseases, aiding in the localization and characterization of various pathologies affecting either the optic pathway alone or multiple levels of the central nervous system and thereby increasing diagnostic accuracy.

Nonadherence to Cardiovascular Drugs Predicts Risk for Non-Arthritic Anterior Ischemic Optic Neuropathy: A Large-Scale National Study

Purpose: While patients with cardiovascular comorbidities are at a higher risk for the occurrence of non-arteritic anterior ischemic optic neuropathy (NAION), it is unclear whether adherence to medication results in risk reduction. The purpose of this study was to investigate whether nonadherence to medical therapy for cardiovascular morbidity correlates with a higher risk for NAION when compared to patients with strict adherence. Methods: A retrospective case-control study was conducted among members of Clalit Health Services in Israel from 2001 to 2022. For each of the 757 NAION cases, three controls (totaling 2271 patients) were matched based on birth year and sex, with a propensity score analysis employed to adjust for a range of comorbidities. A patient was deemed nonadherent with medical treatment if their purchased quantity of medication was less than 60% of the prescribed annual dosage. Mixed models were used to evaluate exposure differences, and conditional logistic regression was applied, incorporating adjustments for socioeconomic status and ethnicity, to examine the impact of medication nonadherence on NAION risk. Results: A total of 3028 patients were included in the study; 757 patients with the diagnosis of NAION and 2271 in the matched control group. The average age of NAION patients was 69 ± 9 years and 55% were male. After adjustments for socioeconomic status and ethnicity, nonadherence to calcium channel blockers (CCBs) (odds ratio [OR]: 1.33, 95% confidence interval [CI]: 1.03-1.71) and anti-arrhythmic (OR: 5.67, 95% CI: 1.89-21.2) medications emerged as significant risk factors. Similarly, nonadherence to cardioprotective medications (OR: 1.46, 95% CI: 1.23-1.74) was also identified as a significant risk factor. Conclusions: Nonadherence to treatments for cardiovascular disease, specifically to medications known to improve prognosis, is associated with a higher risk for NAION.

Review of evidence for treatments of acute non arteritic anterior ischemic optic neuropathy

OBJECTIVE

To review treatment modalities that have been studied in acute non arteritic anterior ischemic optic neuropathy (NAION).

METHODS

We performed a comprehensive literature search of English language publications in the last 5 years, with human species and NAION. Articles were reviewed to identify those that described original research on treatment of acute NAION. Study type, setting, duration, interventions, and results were extracted and articles were reviewed for biases and limitations.

RESULTS

We identified 22 kinds of treatment varying by compound and modality. These include topical, intravitreal, and systemic drugs as well as surgical approaches. Evidence for efficacy ranges from expert opinion to randomized control trials.

CONCLUSIONS

Although several treatments are utilized in practice, none of these have high quality evidence of efficacy to improve visual outcomes.  Continued collaborative research is necessary to complete high quality studies in order identify effective therapies for this rare and blinding disease.

Ophthalmic and Systemic Factors of Acute Nonarteritic Anterior Ischemic Optic Neuropathy in the Quark207 Treatment Trial

PURPOSE

We describe the baseline ophthalmic and cardiovascular risk factors across countries, race, and sex for the Quark207 treatment trial for acute nonarteritic anterior ischemic optic neuropathy (NAION).

DESIGN

Prospective, randomized controlled clinical trial.

PARTICIPANTS

Adults 50 to 80 years of age with acute NAION recruited from 80 sites across 8 countries.

MAIN OUTCOME MEASURES

Ophthalmic features of NAION and cardiovascular risk factors.

METHODS

We evaluated demographics and clinical and ophthalmologic data, including best-corrected visual acuity (BCVA) and average visual field total deviation (TD), in affected eyes and cup-to-disc ratio in fellow eyes at enrollment. We report the prevalence (mean and standard devition, and median and interquartile range [IQR]) of ophthalmic features and cardiovascular risk factors, stratified by country, race, and sex. We corrected for multiple comparisons using Dunn's test with Bonferroni correction for continuous variables and chi-square testing with Holm-Bonferroni correction for categorical variables.

RESULTS

The study enrolled 500 men and 229 women with a median age of 60 and 61 years (P = 0.027), respectively. Participants were predominantly White (n = 570) and Asian (n = 149). The study eye BCVA was 71 characters (IQR, 53-84 characters; approximately 0.4 logarithm of the minimum angle of resolution), and the TD was -16.5 dB (IQR, -22.2 to -12.6 dB) for stimulus III and -15.7 dB (IQR, -20.8 to -10.9 dB) for stimulus V. The vertical and horizontal cup-to-disc ratio was 0.1 (IQR, 0.1-0.3) for unaffected fellow eyes. The prevalence of cardiovascular risk factors varied among countries. The most notable differences were in the baseline comorbidities and ophthalmologic features, which differed between Asian and White races. Men and women differed with respect to a few clinically meaningful features.

CONCLUSIONS

The cardiovascular risk factors in the NAION cohort varied among the 7 countries, race, and sex, but were not typically more prevalent than in the general population. Ophthalmic features, typical of NAION, generally were consistent across countries, race, and sex, except for worse BCVA and TD in China. Men have a frequency of NAION twice that of women. Having a small cup-to-disc ratio in the fellow eye was the most prevalent risk factor across all demographics. This study suggests that factors, not yet identified, may contribute to the development of NAION.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

A rare case of simultaneous occurrence of non-arteritic anterior ischemic optic neuropathy and corpus callosum ischemia

PURPOSE

To report a case of non-arteritic anterior ischemic optic neuropathy (NAION) in an elderly patient with ischemia of the left splenium of the corpus callosum, providing details of the diagnostic work-up and subsequent follow-up.

METHODS SECTION

Case report.

RESULTS

A pseudophakic 80 years-old woman referred complaining sudden visual impairment in the left eye (LE) in concomitance with episode of hypertensive crisis. Fundus examination showed diffuse swelling of optic disc associated with flame peripapillary hemorrhages in LE and small crowded disc in right eye (RE). A superior altitudinal defect with arcuate defect including the blind spot were detected at the visual field in the LE. The patient was diagnosed with NAION. Five days later the patient complained a further vision loss and a pathological area within the left splenium of corpus callosum, consistent ischemia, was depicted at magnetic resonance imaging of brain. Corpus callosum infarction was completely asymptomatic and neurological evaluation was normal. At 45 days follow-up fundus examination showed white ischemic nerve while visual field was irreversibly constricted with tubular defect in LE.

CONCLUSION

In case of NAION linked with corpus callosum ischemia multimodal imaging and systemic work-up play a pivotal role for an early diagnosis.

Acute Optic Neuropathy in Older Adults: Differentiating Between MOGAD Optic Neuritis and Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND AND OBJECTIVES

Myelin oligodendrocyte glycoprotein antibody-associated disease optic neuritis (MOGAD-ON) and nonarteritic anterior ischemic optic neuropathy (NAION) can cause acute optic neuropathy in older adults but have different managements. We aimed to determine differentiating factors between MOGAD-ON and NAION and the frequency of serum MOG-IgG false positivity among patients with NAION.

METHODS

In this international, multicenter, case-control study at tertiary neuro-ophthalmology centers, patients with MOGAD presenting with unilateral optic neuritis as their first attack at age 45 years or older and age-matched and sex-matched patients with NAION were included. Comorbidities, clinical presentations, acute optic disc findings, optical coherence tomography (OCT) findings, and outcomes were compared between MOGAD-ON and NAION. Multivariate analysis was performed to find statistically significant predictors of MOGAD-ON. A separate review of consecutive NAION patients seen at Mayo Clinic, Rochester, from 2018 to 2022, was conducted to estimate the frequency of false-positive MOG-IgG in this population.

RESULTS

Sixty-four patients with unilateral MOGAD-ON were compared with 64 patients with NAION. Among patients with MOGAD-ON, the median age at onset was 56 (interquartile range [IQR] 50-61) years, 70% were female, and 78% were White. Multivariate analysis showed that eye pain was strongly associated with MOGAD-ON (OR 32.905; 95% CI 2.299-473.181), while crowded optic disc (OR 0.033; 95% CI 0.002-0.492) and altitudinal visual field defect (OR 0.028; 95% CI 0.002-0.521) were strongly associated with NAION. On OCT, peripapillary retinal nerve fiber layer (pRNFL) thickness in unilateral MOGAD-ON was lower than in NAION (median 114 vs 201 μm, p < 0.001; median pRNFL thickening 25 vs 102 μm, p < 0.001). MOGAD-ON had more severe vision loss at nadir (median logMAR 1.0 vs 0.3, p < 0.001), but better recovery (median logMAR 0.1 vs 0.3, p = 0.002). In the cohort of consecutive NAION patients, 66/212 (31%) patients with NAION were tested for MOG-IgG and 8% (95% CI 1%-14%) of those had false-positive serum MOG-IgG at low titers.

DISCUSSION

Acute unilateral optic neuropathy with optic disc edema in older adults can be caused by either MOGAD-ON or NAION. Detailed history, the degree of pRNFL swelling on OCT, and visual outcomes can help differentiate the entities and prevent indiscriminate serum MOG-IgG testing in all patients with acute optic neuropathy.

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.

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.

[Nonarteritic anterior ischemic optic neuropathy (nAION)]

Nonarteritic anterior ischemic optic neuropathy (nAION) is the second most common degenerative disease of the optic nerve. The pathogenesis remains elusive. A transient ischemia in the short posterior ciliary arteries not triggered by thromboembolic events is suspected. The typical history of a sudden onset of scotoma without associated pain in conjunction with (sectorial) optic disc swelling, an afferent pupillary defect and a visual field defect are of decisive diagnostic importance. The most urgent diagnostic measure is the exclusion of arteritic AION. There are no proven treatment approaches. Frequently used but without clear study results, is the treatment with steroids and secondary prophylaxis with acetylsalicylic acid (ASA). Recurrence in the ipsilateral or contralateral eye is possible.

Intravitreal Aflibercept for Patients with Acute Nonarteritic Anterior Ischemic Optic Neuropathy: A Retrospective Trial

PURPOSE

This study aimed to investigate whether intravitreal aflibercept was safe and effective in patients with acute nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

This was a chart study of 25 individuals with acute NAION (25 eyes). An intravitreal injection of 2 mg/0.05 mL of aflibercept was administered to fifteen participants. The remaining ten patients in the control group were given standard care. The researchers measured the initial visual acuity, retinal nerve fiber layer thickness (RNFLT), and automated perimetry. During the follow-up period, the researchers measured the final visual acuity, RNFLT, automated perimetry, and side effects.

RESULTS

Visual acuity and visual field assessment were significantly improved in the study group, and optical coherence tomography testing demonstrated significant disc edema resolution. The therapy results differed significantly between the two groups regarding visual outcomes (F = 0.027, p = 0.039) and RNFLT decrease (F = 5.507, p = 0.003). However, the difference in visual field alterations was not significant (F = 0.724, p = 0.387).

CONCLUSIONS

Intravitreal injection of aflibercept can significantly improve visual acuity and resolve disc edema in patients with acute NAION. Intravitreal aflibercept may be an alternative treatment for acute NAION. However, a large series investigation is needed to assess the long-term therapeutic benefit and safety of intravitreal aflibercept in patients with acute NAION.

Risk Factors and Visual Sequel of Non-Arteritic Ischemic Optic Neuropathy in Saudi Arabia

Objective

To provide the demographic data, risk factors, and visual prognosis of patients from a Saudi population diagnosed with non-arteritic anterior ischemic optic neuropathy (NAION).

Materials and Methods

A retrospective observational case series of 120 patients (146 eyes) with NAION from the King Khaled Eye Specialist Hospital or King Abdulaziz University Hospital from 1998 to 2015. Patients with other retinal pathology or glaucoma were excluded from the study. Additionally, a subgroup analysis was performed to compare the long-term assessment between diabetic and non-diabetic patients and its effects on NAION.

Results

The mean duration of follow-up was 1.7 ± 2.4 years. The mean age of the study population was 55.0 ± 10.1 years. NAION was present in the fellow eye of 26 patients, and the median time for involvement was less than 1 year from the presentation. There was no significant difference in the best-corrected visual acuity between diabetics and non-diabetics at presentation or last visit (P = 0.868, P = 0.599, respectively).

Conclusions

The majority of patients with NAION also had coexisting diabetes mellitus. Diabetes mellitus had no significant effect on NAION during the presentation, follow-up, and last visit.

Bilateral Simultaneous Nonarteritic Anterior Ischemic Optic Neuropathy: Demographics, Risk Factors, and Visual Outcomes

BACKGROUND

Although nonarteritic anterior ischemic optic neuropathy is a well-known cause of vision loss, it typically presents unilaterally. Simultaneous, bilateral nonarteritic anterior ischemic optic neuropathy (sNAION) is rare and poorly studied in comparison. This study seeks to characterize the clinical features and risk factors of patients with sNAION compared with unilateral NAION (uNAION).

METHODS

In this retrospective case-control study, we reviewed 76 eyes (38 patients) with sNAION and 38 eyes (38 patients) with uNAION (controls) from 4 academic institutions examined between 2009 and 2020. Demographic information, medical history, medication use, symptom course, paraclinical evaluation, and visual outcomes were collected for all patients.

RESULTS

No significant differences were observed in demographics, comorbidities and their treatments, and medication usage between sNAION and uNAION patients. sNAION patients were more likely to undergo an investigative work-up with erythrocyte sedimentation rate measurement ( P = 0.0061), temporal artery biopsy ( P = 0.013), lumbar puncture ( P = 0.013), and MRI ( P < 0.0001). There were no significant differences between the 2 groups for visual acuity, mean visual field deviation, peripapillary retinal nerve fiber layer thickness, or ganglion cell-inner plexiform layer thickness at presentation, nor at final visit for those with ≥3 months of follow-up. The sNAION eyes with ≥3 months of follow-up had a smaller cup-to-disc ratio (CDR) at final visit ( P = 0.033). Ten patients presented with incipient NAION, of which 9 suffered vision loss by final visit.

CONCLUSION

Aside from CDR differences, the risk factor profile and visual outcomes of sNAION patients seem similar to those of uNAION patients, suggesting similar pathophysiology.

Asymptomatic Fellow Eye Involvement in Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND

Sequential nonarteritic anterior ischemic optic neuropathy (NAION) has been reported to occur in approximately 15% of patients within 5 years of the first episode. However, the incidence of presumed previous asymptomatic episode of NAION in fellow eye of patients presenting with acute NAION has not been previously reported. We reviewed charts of patients with acute NAION seen over a 5-year period to determine the frequency of visual field (VF) defect in the fellow eye secondary to presumed previous asymptomatic episode of NAION.

METHODS

Retrospective chart review of all patients presenting to single, tertiary university-affiliated neuro-ophthalmology practice from January 2016 to September 2021 with diagnosis of acute NAION. Patients were determined to have had a presumed previous episode of asymptomatic NAION in the fellow eye if VF defect and corresponding optic nerve head pallor as well as thinning on peripapillary ocular coherence tomography (OCT) and ganglion cell analysis of macular complex were present and alternate causes of VF were excluded.

RESULTS

One hundred ninety-two patients with the diagnosis of acute NAION were identified. One hundred thirty-nine had reliable VFs and were included in this study. VF defects in the fellow eye were present in 63 patients (45.4%). Of these, 54 (39%) were determined to represent previous NAION. In 14 of 139 patients (10%), a presumed episode of previous NAION in the fellow eye was asymptomatic. The most prevalent defect in asymptomatic eye was inferior altitudinal defect sparing fixation (7 of 14, 50%). The presence of obstructive sleep apnea, hypertension, diabetes, age, or sex was not predictive of previous episode of asymptomatic NAION.

CONCLUSION

Unrecognized presumed previous episode of NAION occurred in a significant proportion of patients with acute NAION (14 of 139, 10.1%). In 100% of cases, the VF defect in the asymptomatic fellow eye was in a hemifield where there was a new loss in the symptomatic eye.

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

INTRODUCTION

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.

METHODS

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).

RESULTS

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.

CONCLUSION

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.

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

Background

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.

Methods

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.

Results

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).

Conclusions

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.

Risk Factors for Fellow Eye Involvement in Patients with Nonarteritic Anterior Ischemic Optic Neuropathy

INTRODUCTION

The aim of the study was to investigate the possible risk factors for fellow eye involvement in patients with nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

A total of 113 patients with unilateral NAION attack were included and divided into two groups according to whether fellow eye involvement was present over a mean follow-up period of 2.70 years (P25-P75: 0.77-3.54 years). General characteristics (including age, sex, diabetes, hypertension, hyperlipidemia, and obstructive sleep apnea syndrome [OSAS]) and ocular characteristics (including initial best-corrected visual acuity, initial visual field damage of the first eye, and the presence/absence of a crowded disc) were analyzed and compared between the two groups. Cox regression was used to assess the risk factors for fellow eye involvement.

RESULTS

During the follow-up period, 40 patients developed fellow eye involvement. The initial best-corrected visual acuity (p = 0.048) and mean deviation of the visual field (VF) (p = 0.039) of the first eye in patients with fellow eye involvement were worse than those in patients without it. Diabetes (HR = 3.06, 95% CI: 1.50, 6.26, p = 0.002) and increased VF damage (moderate vs. mild, HR = 2.92, 95% CI: 1.03, 8.25, p = 0.043; severe vs. mild, HR = 5.01, 95% CI: 1.65, 15.20, p = 0.004) were associated with a significantly increased risk of fellow eye involvement. In 57 patients with apnea-hypopnea index (AHI) data for further study, an AHI score ≥23.2 was also found to be a risk factor (HR = 3.36, 95% CI: 1.17, 9.69, p = 0.025).

CONCLUSION

Diabetes, severer initial VF damage, and more severe OSAS were risk factors for fellow eye involvement in NAION. For patients with these risk factors, more intensive follow-ups might be warranted.

Peripapillary Microvascular and Structural Parameters in Atrophic Nonarteritic Anterior Ischemic Optic Neuropathy and Their Unaffected Fellow Eyes

BACKGROUND

This cross-sectional study aimed to evaluate the peripapillary vessel density (VD), peripapillary retinal nerve fiber layer (RNFL) thickness values of eyes with atrophic nonarteritic anterior ischemic optic neuropathy (NAION), and unaffected fellow eyes.

METHODS

Peripapillary VDs and RNFL thicknesses in the peripapillary region and 4 sectors (superior, inferior, nasal, and temporal) were evaluated using optical coherence tomography angiography among 19 atrophic NAION eyes, 19 unaffected fellow eyes, and 22 age-matched and sex-matched healthy controls.

RESULTS

The NAION eyes had lower peripapillary VD and RNFL thickness values in all areas compared with both the fellow and the healthy control eyes ( P < 0.001 for all). The fellow eyes also demonstrated lower peripapillary VD values ( P = 0.02) despite similar RNFL thickness values ( P = 0.99) in the peripapillary region compared with the age-matched and sex-matched healthy controls. The peripapillary RNFL thickness values significantly correlated with peripapillary VD values in both NAION and fellow eyes.

CONCLUSIONS

Diminished RNFL thickness and peripapillary VD values were observed in atrophic NAION eyes. In addition, a tendency for a lower peripapillary VD despite similar RNFL thickness values in the fellow eyes may indicate the potential vascular risk factors for NAION.

Treatment of nonarteritic anterior ischemic optic neuropathy with an endothelin antagonist: ENDOTHELION (ENDOTHELin antagonist receptor in Ischemic Optic Neuropathy)—a multicentre randomised controlled trial protocol

Background

Nonarteritic anterior ischemic optic neuropathy (NAAION) is a major cause of blindness in individuals over 50 years of age, with no available effective treatment. The oral dual endothelin receptor antagonist, bosentan, increases retinal optic nerve head blood flow in healthy humans and glaucoma patients. The objective of this trial is to assess the efficacy of bosentan administered at the acute stage in improving outcomes in NAAION patients.

Methods

ENDOTHELION (ENDOTHELin antagonist receptor in Ischemic Optic Neuropathy) is a phase III, interventional, prospective, multicentre, placebo-controlled randomised double-blind clinical trial. The primary outcome is change in the visual field mean deviation (MD) at 3 months (Humphrey 30-2 SITA standard programme). Secondary outcomes include MD and visual acuity changes up to 24 months, changes in peripapillary retinal nerve fibre and macular ganglion cell layer thickness in the affected eye, as measured by optical coherence tomography, rate of NAAION bilateralisation at 2 years, and quality-of-life. Patients over 50 years of age presenting with typical NAAION of recent onset (less than 21 days) are randomly assigned to either 125 mg oral bosentan or placebo, twice a day, during 8 weeks. Besides visits during the treatment phase, patients attend follow-up visits at 2, 3, 6, 12 and 24 months. The inclusion of patients began in August 2015 at five French University hospital ophthalmology departments and two specialised ophthalmology centres. It is planned to include 86 patients in this trial. To date we have included 72 patients and 49 have completed the full follow-up process.

Discussion

An endothelin receptor antagonist is a potential approach to improving the anatomical and functional prognosis of patients with NAAION. This multicentre double-blind randomised controlled trial is an opportunity to assess (1) the effect of bosentan on the structure and function of the optic nerve in NAAION, at 3 months, (2) the effect of bosentan on the bilateralisation rate at 24 months and (3) the tolerance profile of bosentan in this population.

Trial registration

ClinicalTrials.gov NCT02377271. Registered on March 3, 2015.

Analysis of Systemic Risk Factors and Post-Insult Visual Development in a Danish Cohort of Patients with Nonarteritic Anterior Ischemic Optic Neuropathy

Purpose

Nonarteritic anterior ischemic optic neuropathy (NAION) is associated with vascular as well as anatomical risk factors. Following the insult, the visual development varies from minor to severe deterioration. The aim of this study was to examine possible prognostic systemic risk factors and their eventual impact on post-insult visual development in NAION patients.

Methods

A retrospective chart review of all NAION patients (18-79 years at time of diagnosis) seen a minimum of two times in a tertiary eye department during a 10-year period in regard to systemic diseases, medication, lifestyle factors and ophthalmic examination was performed. Visual outcome was assessed according to the development of best corrected visual acuity (BCVA) and visual field from initial to final visit.

Results

There were 163 eligible patients. A greater proportion of the patients in the total cohort were over 50 years of age (79.8%) and men (66.3%). In total, 59.5% of the patients had a stable BCVA, while 25.8% experienced improvement, and 14.7% had deterioration. Seventy-two percent of the patients had a stable visual field, while 14% had improvement, and 14% had deterioration. No association between visual outcome and clinical characteristics, medication or systemic risk factors were identified.

Conclusion

We did not find any association between patient characteristics and systemic risk factors at time of diagnosis and visual development post-insult. This could suggest that the optic nerve head anatomy plays a larger role for visual outcome than previously estimated.

Ischemic Optic Neuropathies: Current Concepts

Ischemic optic neuropathy (ION) is the term ascribed to optic nerve disease that is the result of a transient or permanent interruption of the blood supply to any portion of the optic nerve. Anterior ischemic optic neuropathy (AION) refers to ischemia of the optic nerve head, whereas posterior ischemic optic neuropathy (PION) indicates ischemia of the posterior optic nerve. IONs are primarily classified as arteritic ION and non-arteritic ION. A subset of ION that occurs around the time of surgery is termed peri-operative ION. These phenomena will be discussed as distinct entities.

A Potential Role of Acute Choroidal Expansion in Nonarteritic Anterior Ischemic Optic Neuropathy

Purpose

Nonarteritic anterior ischemic optic neuropathy (NAION) has been associated with a thickened choroid at the optic nerve head (ONH). Here, we use computational modeling to better understand how choroidal expansion and choroidal geometry influence tissue deformation within the ONH relative to intraocular pressure (IOP) and intracranial pressure (ICP) effects.

Methods

Using a model of the posterior eye that included the sclera, peripapillary sclera, annular ring, pia mater, dura mater, neural tissues, Bruch's membrane, choroid, and lamina cribrosa, we examined how varying material properties of ocular tissues influenced ONH deformations under physiological and supra-physiological, or “pathological,” conditions. We considered choroidal expansion (c. 35 µL of expansion), elevated IOP (30 mm Hg), and elevated ICP (20 mm Hg), and calculated peak strains in the ONH relative to a baseline condition representing an individual in the upright position.

Results

Supra-physiological choroidal expansion had the largest impact on strains in the prelaminar neural tissue. In addition, compared to a tapered choroid, a “blunt” choroid insertion at the ONH resulted in higher strains. Elevated IOP and ICP caused the highest strains within the lamina cribrosa and retrolaminar neural tissue, respectively.

Conclusions

Acute choroidal expansion caused large deformations of the ONH and these deformations were impacted by choroid geometry. These results are consistent with the concept that compartment syndrome due to the choroid geometry and/or expansion at the ONH contributes to NAION. Prolonged deformations due to supra-physiological loading may induce a mechanobiological response or ischemia, highlighting the potential impact of choroidal expansion on biomechanical strains in the ONH.

Peripapillary Choroidal Vascularity and Visual Correlates in Non-Arteritic Anterior Ischemic Optic Neuropathy Using Swept-Source Optical Coherence Tomography

Introduction

The peripapillary choroid shares a blood supply with and is directly apposed to the optic nerve, and therefore may contribute to the pathogenesis of non-arteritic anterior ischemic optic neuropathy (NAION). Prior studies evaluating peripapillary choroidal thickness (PCT) or choroidal vascularity index (CVI; the ratio of the perfused area to total choroid area) have produced mixed results. None investigated the relationship between PCT and CVI or demonstrated functional correlates. We hypothesized that greater PCT and lower CVI would correlate with visual function in patients presenting with NAION.

Methods

Seventeen eyes with NAION (9 acute, 8 non-acute) and 6 unaffected "fellow" eyes in 13 patients, and 18 eyes in 18 age-matched control subjects were imaged using swept-source optical coherence tomography (SS-OCT) prospectively between 2017-2018. Mean PCT and CVI measurements were compared across groups and with respect to corresponding automated perimetric performance at the same visit.

Results

Analysis of variance showed significantly greater PCT (NAION: 278 ± 65 μm, Fellow: 221 ± 50 μm, Control: 158 ± 27 μm, p<0.001) and lower CVI (NAION: 0.35 ± 0.03, Fellow: 0.35 ± 0.04, Control: 0.38 ± 0.02, p<0.005) in patients with NAION compared to control subjects. Bonferroni-corrected pairwise comparisons showed greater PCT and lower CVI in NAION-affected eyes compared to control eyes (p values<0.008), and no significant differences in PCT or CVI between NAION and fellow eyes (p values>0.06). PCT was negatively correlated with CVI among unaffected fellow eyes (r=-0.8, p<0.05), but not among acute NAION eyes (r=-0.1, p>0.7), non-acute NAION eyes (r=0.1, p>0.7), or controls (r=-0.3, p>0.2). Nasal CVI was positively correlated with mean deviation scores in non-acute NAION (r=0.8, p<0.02), but not among fellow unaffected eyes (r=0.8, p>0.05) or acutely affected NAION eyes (r=-0.3, p>0.4). Mean and temporal PCT correlated with pattern standard deviation scores among unaffected fellow eyes (r=0.8, p<0.04; r=0.9, p<0.03), but not among acute NAION eyes (r=-0.2, p>0.5; r=-0.1, p>0.7) or non-acute NAION eyes (r=0.1, p>0.7; r=0.05, p>0.9).

Conclusion

NAION and unaffected fellow eyes demonstrate increased choroidal thicknesses and reduced vascular density. Perimetric performance is directly associated with vascular density among non-acutely affected eyes with NAION. Ongoing work will provide further insights into these structure-function relationships with pathogenic and pathophysiologic relevance.

Bilateral Sequential Non-arteritic Anterior Ischemic Optic Neuropathy (NAION)

This is a case report of a rare case of bilateral sequential non-arteritic anterior ischemic optic neuropathy (NAION). A 50-year-old Indian gentleman, who is a known case of diabetes and an active smoker, presented with a right eye painless inferior visual field defect upon waking up from sleep. Fundoscopy revealed swollen right optic disc with peripapillary splinter hemorrhage while Humphrey visual field (HVF) showed right inferior altitudinal scotoma. Computed tomography of the brain and orbit proceeded to rule out compressive lesions. Thus, a diagnosis of right eye NAION was made. Three months later, he complained of a worsening visual field of the right eye. His right eye's optic disc was pale; however, the left was hyperemic and swollen with peripapillary splinter hemorrhage. HVF showed right eye tunnel vision while the left eye displayed inferior arcuate scotoma. Further investigation revealed suspicious enhancement of both intra-orbital optic nerves in magnetic resonance imaging suggestive of bilateral optic neuritis. Diagnosis of bilateral atypical optic neuritis was made. Thus, the patient was loaded with intravenous methylprednisolone 1 g/day for five days and subsequently oral steroid in tapering doses along with topical brimonidine tartrate 0.2%. Despite that, his left eye's visual field progressively deteriorated to inferior altitudinal scotoma. Subsequently, the lumbar puncture test performed was unremarkable while repeated MRI of the spine and brain showed no focal enhancing lesion. The patient revealed that he had a history of taking phosphodiesterase type 5 (PDE5) inhibitor (tadalafil) on and off over the past year. Diagnosis of bilateral sequential NAION was made and he was co-managed with the endocrine team to optimize his diabetic status. His subsequent visual field remained static with right eye tunnel vision and left eye inferior altitudinal scotoma. In conclusion, progressive NAION of the same eye or fellow eye is rare and mandates further investigations. It is important to identify and manage all the systemic and local risk factors to prevent further attacks. Although there is no rigid evidence stating that intake of PDE5 inhibitors can directly lead to NAION, patients with co-existing predisposing risk factors should be warned about possible ischemic ocular side effects of PDE5 inhibitors.

Peripapillary Choroid Thickness as a Predisposing Factor for Nonarteritic Anterior Ischemic Optic Neuropathy: A Semiautomated OCT Study

Purpose

The purpose of this study was to investigate the correlations between peripapillary choroidal thickness (PCT) and nonarteritic ischemic optic neuropathy (NAION) by using semiautomated optic coherence tomography (OCT).

Methods

A total of 35 NAION eyes, 29 unaffected fellow eyes, and 40 eyes from an age-matched control group were recruited. Enhanced-depth imaging OCT was performed after the resolution of disc edema. PCT was measured using a customized semiautomated MATLAB program. Regression models adjusted for multiple variables were used to inspect the correlation between mean PCT and NAION.

Results

The mean PCT in NAION eyes, unaffected fellow eyes, and the control group was 197.09 ± 38.09, 196.52 ± 38.47, and 153.53 ± 29.92 µm, respectively. The mean PCT was significantly thicker both in NAION-affected eyes and fellow eyes compared with the control group (P < 0.001). No significant difference existed between NAION-affected eyes and unaffected fellow eyes. The PCT of the superior quadrant was significantly thicker than that of the inferior quadrant in all three groups. In the multivariate logistic regression, PCT was the only predisposing factor for NAION. However, the value of the PCT was not correlated with final visual outcomes.

Conclusions

With a semiautomated program to alleviate the missing measurements, our study demonstrated significantly thicker PCT in both NAION-affected and unaffected eyes of patients, which indicated that peripapillary pachychoroid is a predisposing factor for NAION but may not be a prognostic factor for visual outcomes.

Translational Relevance

Accurate measurement of PCT by using semiautomated OCT illustrates the correlation between choroidal vasculature and NAION.

Anti-NOGO Antibody Neuroprotection in a Rat Model of NAION

Purpose

To evaluate the efficacy and mechanisms of anti-NOGO receptor monoclonal antibody 11C7mAb in a rat model of nonarteritic anterior ischemic optic neuropathy (rNAION).

Methods

The rNAION was induced in one eye of 20 Long-Evans rats, which were studied in 10 groups of two rats, each group containing a sham rat receiving intravitreal injections of vehicle and a treatment rat receiving intravitreal injections of 11C7mAb. Fellow eyes served as naïve controls. The rats were tested using flash electroretinograms (ERGs), flash visual evoked potentials (VEPs), and optical coherence tomography (OCT). Thirty days after induction, they were euthanized, and the eyes were prepared for immunohistochemistry (two groups), hematoxylin and eosin staining (two groups) or transmission electron microscopy (TEM; six groups).

Results

Ninety-five percent of the VEP amplitude was preserved in eyes treated with 11C7mAb, versus 69% in the control eyes. Immunohistochemistry revealed a large reduction in microglia and extrinsic macrophages with axon sparing. In addition to axon preservation, TEM also showed reduced extracellular debris and only slight myelin damage compared with the vehicle-treated animals. There were no significant differences in retinal ganglion cell counts, nor was there a difference in optic nerve swelling as measured by OCT. ERGs were used to exclude eyes with retinal vascular occlusions, an occasional complication of the induction technique.

Conclusions

The 11C7mAb preserves optic nerve integrity and reduces inflammation in rNAION.

Translational Relevance

This study evaluates the efficacy of an anti-NOGO receptor antibody in a rat model of NAION, a disorder that currently has no universally-acknowledged treatment.

Association Between Ischemic Optic Neuropathy and Inflammatory Bowel Disease: A Population-Based Cohort Study in Taiwan

Background: Ischemic optic neuropathy (ION) is a possible extraintestinal manifestation (EIM) of inflammatory bowel disease (IBD). We investigate the relation between IBD and ION and possible risk factors associated with their incidence.

Methods: Medical records were extracted from the National Health Insurance Research Database (NHIRD) from January 1, 2000, to December 31, 2013. The main outcome was ION development. Univariate and multivariate Cox regression analyses were performed.

Results: We enrolled 22,540 individuals (4,508 with IBD, 18,032 without). The cumulative risk of developing ION was significantly greater for patients with IBD vs. patients without (Kaplan–Meier survival curve, p = 0.009; log-rank test). Seven (5%) and five (0.03%) patients developed ION in the IBD and control groups, respectively. Patients with IBD were significantly more likely to develop ION than those without IBD [adjusted hazard ratio (HR) = 4.135; 95% confidence interval: 1.312–11.246, p = 0.01]. Possible risk factors of ION development were age 30–39 years, diabetes mellitus (DM), hypertension, ischemic heart disease (IHD), atherosclerosis, and higher Charlson comorbidity index revised (CCI_R) value.

Conclusion: Patients with IBD are at increased risk of subsequent ION development. Moreover, for patients with comorbidities, the risk of ION development is significantly higher in those with IBD than in those without.

Immunoprofiling of Nonarteritic Anterior Ischemic Optic Neuropathy

Purpose

Nonarteritic anterior ischemic optic neuropathy (NAION) is a common acute optic neuropathy in those older than 50 years. There is no blood diagnostic test or efficient treatment for NAION. We investigated the suitability of blood inflammatory proteins as biomarkers and therapeutic targets of NAION.

Methods

We conducted an exploratory, cross-sectional case-control study including 18 patients with NAION (n = 5 acute, and n = 13 chronic) and 9 controls. NAION was confirmed by clinical examination and optical coherence tomography. Subjects underwent peripheral blood collection; plasma was isolated within 2 hours and analyzed using a 76-plex array of cytokines, chemokines, and growth factors.

Results

In acute NAION, there was increased peripapillary retinal thickness on optical coherence tomography consistent with optic disc edema. Plasma profiling revealed dramatic changes in inflammatory proteins in NAION. Statistical analysis generated a list of 20 top-ranked molecules in NAION, with 15% overlap in acute and chronic NAION. Principal component analysis, hierarchical clustering, and Spearman correlation generally segregated controls, acute and chronic NAION, with some overlap. Longitudinal data from one patient demonstrated an evolving inflammatory pattern from acute to chronic NAION. In acute NAION, Eotaxin-3, MCP-2, TPO, and TRAIL were the top biomarker candidates. In chronic NAION, IL-1α and CXCL10 emerged as the strongest therapeutic targets.

Conclusions

Post-NAION inflammation occurs in both acute and chronic NAION. Statistical analysis of plasma profile changes generated a list of 20 potential biomarker and therapeutic targets of NAION.

Translational Relevance

We identified blood molecular targets to improve NAION diagnosis and treatment.

Atherogenic indices in non-arteritic ischemic optic neuropathy

AIM

To evaluate the atherogenic indices and the relationship with visual acuity and bilateral sequential involvement in patients with non-arteritic ischemic optic neuropathy (NAION).

METHODS

A total of 65 patients with NAION and 48 age-sex matched healthy individuals were included in this retrospective study. The demographic characteristics and laboratory findings of the patients and control subjects were obtained from the electronic medical records. The atherogenic indices were calculated using the lipid parameters. The association between visual acuity, bilateral sequential involvement, and atherogenic indices was investigated.

RESULTS

The mean age was 63.8±12.5y in the NAION group and 64.7±10.1y in control group (P=0.707). Although there were no significant differences in terms of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) between two groups (P=0.089, 0.091), all the non-traditional serum lipid ratios were significantly higher in NAION group (P<0.05). In the NAION subgroup analysis, with visual acuity≤20/200 had higher TC/high-density lipoprotein cholesterol (HDL-c), LDL-c/HDL-c, and non-HDL-c/HDL-c values than the patients in the NAION group with visual acuity >20/200 (P=0.032, 0.025, 0.032, respectively). The values for the atherogenic indices were higher in NAION patients with bilateral sequential involvement in comparison to those with unilateral involvement (P=0.271, 0.127, 0.197, 0.128, 0.127, respectively).

CONCLUSION

The study reveals a relationship between NAION and the non-traditional lipid ratios. Atherogenic indices may predict the visual loss severity and second eye involvement in patients with NAION.

Intravitreal triamcinolone injections in non-arteritic anterior ischemic optic neuropathy - A retrospective report

BACKGROUND

Non-arteritic anterior ischemic optic neuropathy (NAION) is a common cause of vision loss but no treatment has demonstrated its efficiency. A preliminary study showed an improvement on the visual acuity (VA) in a group of patients who received intravitreal administration of triamcinolone acetonide (IVTA) versus a non-treated group. In the present series, the visual outcome of IVTA in NAION was evaluated on a larger group of patients.

METHODS

This retrospective, unmasked and non-randomized study took place at Reims University Hospital between 2009 and 2017. The data of consecutive patients presenting with isolated optic disc edema characteristic of recent NAION (<1month of visual acuity loss) were included. After informed consent, a single intravitreal injection of filtrated 4mg/0.1mL triamcinolone acetonide were administered. Twenty-seven control patients chose not to be injected and therefore served as controls. LogMar visual acuity (VA), VA rating (VAR) (1 line=0.1LogMAR=5 VAR letters), retinal nerve fiber layer thickness assessed by OCT and static visual field were evaluated at presentation, after 7days, after 3months and after 6months.

RESULTS

Sixty-eight patients with NAION were evaluated. Forty-one received IVTA, 29 were injected within 15days after the onset of symptoms and 12 after 15days. There was a higher proportion of patients improving VA of 2 lines or more (10 or more VAR letters) in the injected group (49%) compared with the non-injected group (11%, P=0.019). Among the patients injected before 15days, the proportion improving for 2 lines or more (55% vs. 11%, respectively, P=0.013) and for 3 lines or more (45% vs. 11%, respectively, P=0.035) were significantly higher than in the non-injected group. Also, comparing the VA at presentation with the VA after 6months in the injected eyes, it improved significantly (P=0.003) and also in the subgroup injected within 15days (P=0.0007) but not in the injected group after 15days (P=0.801). Visual field improvement was only observed in the subgroup of patients injected within 15days with a significant improvement of the mean deviation (dB) within 6months (P=0.015).

CONCLUSIONS

This follow-up study confirms the results of the previous series displaying an apparent benefit of intravitreal steroids injected in the acute phase of NAION. Only patients receiving IVTA within 15days from onset of NAION have a significant improvement of VA and visual field during the follow-up period of 6months.

Neuro-Ophthalmology for Internists

Neuro-ophthalmology is the study of the neurologic underpinnings of vision and includes a fascinating variety of disorders that span the broad spectrum of ophthalmic and neurologic disease. This subspecialty relies heavily on accurate neuroanatomic localization and examination. This article discusses neuro-ophthalmic complaints that frequently present to the internist, including acute vision loss, double vision, and unequal pupils. It focuses on pertinent clinical features of the most common causes of these chief complaints and additionally highlights salient points of history, diagnosis, examination, and management with special emphasis on the signs and symptoms that should prompt expedited evaluation.

Incipient Non-Arteritic Anterior Ischemic Optic Neuropathy in a Patient with Metastatic Small-Cell Lung Cancer

A 70-year-old woman with metastatic small-cell lung cancer was referred for isolated left optic disc edema that was incidentally discovered. She had normal visual function, and dilated fundus examination revealed a small, cupless optic nerve in the right eye and moderate optic disc edema in the left eye. Magnetic resonance imaging (MRI) of the orbits with contrast was normal, and MRI brain and magnetic resonance venography were normal without signs of raised intracranial pressure. Lumbar puncture showed a normal opening pressure and normal cerebrospinal fluid contents. A diagnosis of incipient non-arteritic anterior ischemic optic neuropathy (NAION) was made, and the optic disc edema resolved after 4 months. Incipient NAION is an uncommon cause of unilateral optic disc edema with preserved visual function and is a diagnosis of exclusion. In diagnosing incipient NAION, other causes of optic disc edema must first be ruled out. These alternative causes include papilledema, optic nerve sheath meningioma or other orbital masses, and vitreopapillary traction. Incipient NAION is thought to be caused by subclinical ischemia. This case indicates that incipient NAION may also occur in patients with metastatic cancer and is possibly related to their hypercoagulable state. Although there is no treatment once vision loss develops, the optimization of risk factors may prevent the progression of incipient NAION to classic NAION.

Three-dimensional ophthalmic artery model reconstruction and assessment captured by computed tomographic angiography in non-arteritic anterior ischemic optic neuropathy patients

Background

The ophthalmic artery (OA) was first reconstructed using computer software. The structural differences of ophthalmic arteries in non-arteritic anterior ischemic optic neuropathy (NAION) and normal eyes, in addition to hemodynamic alterations, were assessed.

Methods

Thirty-one NAION eyes, 19 uninvolved eyes with NAION, and a control group of 26 healthy eyes were retrospectively included. Computed tomographic angiography data were recorded, and corresponding three-dimensional OA models were constructed. Initial OA and internal carotid artery (ICA) diameters and the angle between them were analyzed. Three different OA models were used to evaluate hemodynamic performance. The statistical relationships between the initial diameters of the OA and ICA and the angle between the OA and ICA were described.

Results

OA diameters in NAION eyes were significantly smaller than those in both uninvolved and healthy eyes (P<0.05). There was no significant difference between uninvolved and healthy eyes (P=0.31). The initial ICA diameter and the angle between the OA and ICA did not significantly differ among the three groups. In the three models, the blood flow velocity in the initial ophthalmic arteries of uninvolved eyes was higher than that in the NAION eyes. The mass flows of the right and left ophthalmic arteries, accounting for the ipsilateral ICA in the control model, were 0.57%. However, these values in uninvolved and NAION eyes were 1.36% and 0.25%, respectively.

Conclusions

NAION is associated with a smaller initial OA diameter, which may be related to hypoperfusion. To our knowledge, this is the first pilot study to analyze hemodynamic alterations using OA models.

Mammalian Retinal Cell Quantification

Normal retina and its cell layers are essential for processing visual stimuli, and loss of its integrity has been documented in many disease processes. The numbers and the axonal processes of retinal ganglion cells are reduced substantially in glaucoma, leading to vision loss and blindness. Similarly, selective loss of photoreceptors in age-related macular degeneration and hereditary retinal dystrophies also results in the compromise of visual acuity. Development of genetically modified mice has led to increased understanding of the pathogenesis of many retinal diseases. Similarly, in this digital era, usage of modalities to quantify the retinal cell loss has grown exponentially leading to a better understanding of the suitability of animal models to study human retinal diseases. These quantification modalities provide valuable quantifiable data in studying pathogenesis and disease progression. This review will discuss the immunohistochemical markers for various retinal cells, available automated tools to quantify retinal cells, and present an example of retinal ganglion cell quantification using HALO image analysis platform. Additionally, we briefly review retinal cell types and subtypes, salient features of retina in various laboratory animal species, and a few of the main disease processes that affect retinal cell numbers in humans.

Imageology of internal carotid artery siphon in non-arteritic anterior ischaemic optic neuropathy

AIM

To evaluate whether narrowing of internal carotid artery siphon (ICAS) may increase the risk of developing non-arteritic anterior ischaemic optic neuropathy (NAION).

METHODS

Totally 30 consecutive patients who had unilateral NAION and 30 gender-matched control subjects were recruited in the present study. The diameter of ICAS of all the participants were measured using head-and-neck computed tomographic angiography (CTA). Color doppler flow imaging (CDI) was used to measure the haemodynamics parameters of ICAS and short posterior ciliary arteries (SPCAs) in all subjects. Comparison of parameters between the NAION patients and controls as well as between the two sides within the patients were performed. The correlation between the diameter of ICAS and NAION was analyzed.

RESULTS

A comparison of parameters between the affected side of the NAION patients and the controls, including the diameter of ICAS, the resistance index (RI) of ICAS, the blood flow velocities of SPCAs and RI of SPCAs, showed significantly difference (P<0.01), while there was no significant difference in terms of the mean blood flow velocity (Vm) of ICAS; Similar results were found while comparing all the measurements of the affected and unaffected side of patients (P for RI of SPCAs <0.05). No marked difference was detected in nearly all parameters except for RI of ICAS and SPCAs between the unaffected side of the NAION patients and the controls (P<0.05). The diameter of ICAS were significantly positive correlated with both peak systolic velocity (PSV) of SPCAs and end diastolic velocity (EDV) of SPCAs in patients with NAION (r=0.514, P<0.01 and r=0.418, P<0.05, respectively).

CONCLUSION

Narrowing of ICAS may increase the risk of developing NAION.

Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) Following a Hypovolemic Episode of Gastric Bleeding

Non-arteritic anterior ischemic optic neuropathy (NAION) is a rare complication following acute bleeding. Patients present with varying vision loss and visual field defects. NAION is more commonly developed in patients with systemic disorders that may affect normal blood flow such as hypertension and diabetes. In this case, we report a 54-year-old man who complained of vision blurring following an episode of acute gastric bleeding. This report aims to review the pathology of this condition and present the findings of newer non-invasive imaging modalities of the vascular layers of the posterior pole of the eye like optical coherence tomography angiography (OCTA), which facilitates the proper diagnosis and prognosis of such cases. Finally, we present the management options for this patient with antiplatelet treatment.

Non-Arteritic Anterior Ischaemic Optic Neuropathy - Myths and Misconceptions: Experience from a Tertiary Care Centre in North India

We prospectively evaluated 22 consecutive patients (24 eyes) suffering from non-arteritic anterior ischaemic optic neuropathy (NAION) at a tertiary care centre in Northern India. The mean age was 51.7 years. Visual loss on awakening was noticed only in three (12.5%) eyes. Six (27.3%) patients had headache while three (9.7%) patients had retro-orbital pain at the onset of visual loss. Peripapillary haemorrhages were seen in two (8.3%) eyes. At follow up, only one eye showed improvement in visual acuity. The results of our study suggest that NAION may not always present with the classic clinical picture. Accordingly, a high index of suspicion remains the key to correct diagnosis.

Very Poor Visual Acuity in Non-Arteritic Anterior Ischaemic Optic Neuropathy

Very poor (hand motion or worse) visual acuity at presentation is highly unusual in non-arteritic anterior ischaemic optic neuropathy. We retrospectively reviewed the medical records of 151 consecutive non-arteritic anterior ischaemic optic neuropathy patients seen at our institution between July 2014 and April 2016 to evaluate the frequency and characteristics of patients with very poor visual acuity in non-arteritic anterior ischaemic optic neuropathy. Hand motion or worse visual acuity was documented in 17 patients (11%); all patients had at least one vascular risk factor and 14 (82%) had at least two vascular risk factors. Although severe vision loss at presentation does occur in non-arteritic anterior ischaemic optic neuropathy, an extensive workup should be obtained to rule out another cause, especially arteritic anterior ischaemic optic neuropathy.

Evaluation of enhanced external counterpulsation therapy for nonarteritic anterior ischemic optic neuropathy

Background

To explore the effects of enhanced external counterpulsation (EECP) and its underlying influencing factors in nonarteritic anterior ischemic optic neuropathy (NAION) patients.

Methods

Patients at Zhongshan Ophthalmic Center with recent-onset (< 8 weeks) NAION were retrospectively recruited. The patients had decided whether or not they would undergo EECP treatment, and the patients who declined were included in the control group. The effectiveness of EECP was evaluated by comparing the visual function and fellow eye involvement in patients with and without EECP treatment.

Results

In total, 61 patients (76 eyes) were included. Twenty-nine patients (37 eyes) underwent EECP treatment, while 32 patients (39 eyes) were included in the control group. Mean time from NAION onset to EECP initiation was 27.59 ± 16.70 days. In the EECP group, the mean EECP duration was 31.57 ± 18.45 days. EECP was well tolerated by all patients. However, there was no significant difference in visual function between the EECP and control groups. Furthermore, there was no evidence of the effectiveness of EECP in the subgroup analysis of patients with different systemic health conditions. Among the 42 patients with monocular NAION, the sequential attack rate was comparable between the EECP (27.78%) and control (25.00%) groups.

Conclusion

This study is the first nonrandomized controlled study to evaluate the effectiveness of EECP in NAION patients. Unfortunately, we failed to demonstrate the effectiveness of EECP in NAION at the 6-month follow-up. Any further application of EECP in NAION patients should be cautious.

Randomized Controlled Phase 2a Study of RPh201 in Previous Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND

No proven treatment exists for nonarteritic anterior ischemic optic neuropathy (NAION), either in the acute or late phase.

OBJECTIVE

To assess safety and changes in visual function and structure after RPh201/placebo treatment in participants with previous NAION.

DESIGN AND SETTING

Phase 2a, single-site, prospective, randomized, placebo-controlled, double-masked trial (registration NCT02045212).

MAIN OUTCOMES MEASURES

Early Treatment Diabetic Retinopathy Study best-corrected visual acuity (BCVA), visual fields, retinal nerve fiber layer, and visual evoked potential at weeks 13, 26, and after a 13-week wash-out ("off-drug") period; and safety.

STUDY POPULATION

Twenty-two participants aged 18 years or older with previous NAION.

INTERVENTION(S)

RPh201 (20 mg) or placebo (cottonseed oil vehicle) administered subcutaneously twice weekly at the study site.

RESULTS

Thirteen men and 9 women were randomized, of which 20 completed all visits. The mean (±SD) age was 61.0 ± 7.6 years. In a post hoc analysis, after 26 weeks of treatment, BCVA improved by ≥15 letters in 4/11 (36.4%) eyes with RPh201, compared to 1/8 (12.5%) eyes with placebo (P = 0.24). Overall, 7/11 (63.6%) of participants on RPh201 showed some improvement in BCVA, compared with 3/8 (37.5%) on placebo (P = 0.26). Improvement in BCVA from a calculated baseline was 14.8 ± 15.8 letters for RPh201 and 6.6 ± 15.3 for placebo (P = 0.27). Of the 154 adverse effects (AEs), 52 were considered related to the study procedures/treatment. Across the study and 1,017 injections, the most frequently reported AE was injection site pain (23 events in 5 participants). There were no clinically significant changes in vital signs or laboratory values.

CONCLUSIONS

This Phase 2a was designed to assess safety, feasibility, and explore potential efficacy signals in treating previous NAION with RPh201. No safety concerns were raised. The results support a larger trial in patients with previous NAION.