Nonarteritic Ischemic Optic Neuropathy Research Articles

Validity of Administrative Coding for Nonarteritic Ischemic Optic Neuropathy.

Administrative claims have been used to study the incidence and outcomes of nonarteritic ischemic optic neuropathy (NAION), but the validity of International Classification of Diseases (ICD)-10 codes for identifying NAION has not been examined. We identified patients at 3 academic centers who received ≥1 ICD-10 code for NAION in 2018. We abstracted the final diagnosis from clinical documentation and recorded the number of visits with an NAION diagnosis code. We calculated positive predictive value (PPV) for the overall sample and stratified by subspecialty and the number of diagnosis codes. For patients with ophthalmology or neuro-ophthalmology visit data, we recorded presenting symptoms, examination findings, and laboratory data and calculated PPV relative to case definitions of NAION that incorporated sudden onset of symptoms, optic disc edema, afferent pupillary defect, and other characteristics. Among 161 patients, PPV for ≥1 ICD-10 code was 74.5% (95% CI: 67.2%-80.7%). PPV was similar when restricted to patients who had visited an ophthalmologist (75.8%, 95% CI: 68.4%-82.0%) but increased to 86.8% when restricted to those who had visited neuro-ophthalmologists (95% CI: 79.2%-91.9%). Of 113 patients with >1 ICD-10 code and complete examination data, 37 (32.7%) had documented sudden onset, optic disc swelling, and an afferent pupillary defect (95% CI: 24.7%-42.0%). Of the 76 patients who did not meet these criteria, 54 (71.0%) still received a final clinical diagnosis of NAION; for most (41/54, 75.9%), this discrepancy was due to lack of documented optic disc edema. The validity of ICD-10 codes for NAION in administrative claims data is high, particularly when combined with provider specialty.

Can Optical Coherence Tomography Angiography be a Useful Adjunctive Diagnostic Tool in Patient with Non Arteritic Ischaemic Optic Neuropathy?

Abstract
 Introduction : Perfusion deficiency of the optic nerve head is presumed to have an immense role in the pathogenesis of non-arteritic ischaemic optic neuropathy (NAION). Optical coherence tomography angiography (OCTA) is a non-invasive method that can assess posterior pole vasculature at multiple levels. Thus, these case series want to compare the OCTA in the acute (before four weeks) and chronic phases (after six weeks) of NAION with their fellow unaffected eyes to give an overview of vasculature changes in NAION.
 Case Illustration : This case series consists of four patients with NAION. Half of them came with a sudden painless blurry vision, and the remaining presented with an abrupt visual field defect. All of them have diabetes mellitus and hypertension. None of them have superimposed vascular pathology. The first OCTA was taken within seven days of the first symptoms, and the second OCTA was taken more than six weeks after.
 Discussion : The high percentage of systemic vascular risk factors and the acute onset supported the vascular occlusive hypothesis in the pathogenesis of NAION. Meanwhile, the OCTA provides an actual overview of the vasculature changes. Microvasculature is more likely to expand in the acute phase, and a more significant expansion was found in greater optic disc edema. On the other hand, microvascular tend to attenuate in the chronic phase, representing the pruning of capillaries. A swept-source OCTA with deeper penetration might give a better peripapillary choriocapillaris image in the acute phase.
 Conclusion : OCTA is a promising adjunctive tool for diagnosing and monitoring progression in patients with NAION.

Impact of flight and equivalent short-term high-altitude exposure on ocular structures and function.

Exposure to high-altitude conditions during flight or similar activities affects many aspects of visual function, which is critical not only for flight safety but for any altitude-related activity. We aimed to summarize the available literature pertaining to ocular changes during flight or equivalent short-term high-altitude exposure (e.g., hypobaric chamber, effortless ascent lasting ≤ 24 h) and to highlight future research priorities. Using the PubMed/MEDLINE and Web of Science/ISI Web of Knowledge databases with structured search syntax, we conducted a systematic review of the literature spanning a 40-year period (January 1, 1983, to October 10, 2023). Articles pertaining to ocular changes during flight or flight-equivalent exposure to altitude were retrieved. The reference lists of retrieved studies were also searched, and citations of these references were included in the results. Of 875 relevant PubMed and ISI publications, 122 qualified for inclusion and 20 more were retrieved from the reference lists of initially selected records, for a total of 142 articles. Reported anterior segment changes included deterioration in tear film stability and increased dry eye incidence, increased corneal thickness, discomfort and bubble formation in contact lens users, refraction changes in individuals with prior refractive surgery, decreased intraocular pressure, and alterations in pupillary reaction, contrast sensitivity, and visual fields. Photoreceptor-visual pathway changes included alterations in both photoreceptors and neuro-transduction, as evidenced in dark adaptation, macular recovery time, reduction in visual field sensitivity, and optic neuritis (likely an element of decompression sickness). Retinochoroidal changes included increases in retinal vessel caliber, retinal blood flow, and choroidal thickness; central serous chorioretinopathy; and retinal vascular events (non-arteritic ischemic optic neuropathy, high-altitude retinopathy, and retinal vein occlusion). The effect of short-term high-altitude exposure on the eye is, in itself, a difficult area to study. Although serious impairment of visual acuity appears to be rare, ocular changes, including tear film stability, contact lens wear, central corneal thickness, intraocular pressure, contrast sensitivity, stability of refractive surgeries, retinal vessels, visual fields, and macula recovery time, should be considered in civilian aviators. Our report provides guidance to climbers and lowlanders traveling to altitude if they have pre-existing ocular conditions or if they experience visual symptoms while at altitude. However, key outcomes have been contradictory and comprehensive studies are scarce, especially those pertaining to the choroid and retina. Such studies could not only deepen our understanding of high-altitude ocular pathophysiology, but could also offer valuable information and treatment possibilities for a constellation of other vision-threatening diseases.

Non-arteritic anterior ischemic optic neuropathy associated with ipsilateral hypoplastic internal carotid artery.

Vascular insufficiency of the optic nerve head is the cause of non-arteritic ischemic optic neuropathy (NAION). Carotid artery abnormalities are now considered as a predisposing factor for developing NAION. In this report, we present a case of NAION associated with ipsilateral internal carotid artery hypoplasia. A 69-year-old female was referred for evaluating the cause of vision loss in her left eye. The patient was diagnosed with left NAION, however, the magnetic resonance imaging (MRI) showed a considerably smaller left internal carotid artery (ICA) than the right side. The magnetic resonance angiography (MRA) confirmed the disparity as well as perfusion abnormalities of intracranial carotid arteries. The diagnosis of left ICA hypoplasia was made and verified by depicting a left side small carotid canal on the computed tomography (CT) scan. This report suggests that ICA hypoplasia could be associated with NAION.

Intravitreal allogeneic mesenchymal stem cells: a non-randomized phase II clinical trial for acute non-arteritic optic neuropathy

BackgroundAn effective treatment for acute non-arteritic ischemic optic neuropathy (NA-AION) has not been known or proven yet. Previous studies have suggested a neuroprotective effect of allogeneic bone marrow-derived mesenchymal stem cells. This study aims to report the results of a clinical trial on patients with acute non-arteritic optic neuropathy (NA-AION) treated with an intravitreal injection of allogeneic bone marrow-derived mesenchymal stem cells (BM-MSCs) (MSV®).MethodsWe conducted a prospective, non-randomized, clinical phase-II study (Eudra CT number 2016-003029-40; ClinicalTrials.gov Registry NCT03173638) that included 5 patients with acute unilateral NA-AION diagnosed within 2 weeks after symptom onset and who received an intravitreal injection of allogeneic BM-MSCs (0.05 ml; cell concentration: 1.5 × 106cells/mL). The patients underwent regular ophthalmological examinations and were followed for one year.ResultsIn this trial, allogeneic BM-MSCs appeared to be safe as no patients developed signs of acute nor chronic intraocular inflammation or a significant change in intraocular pressure, although an epiretinal membrane was developed in one patient. A retrolental aggregate formed shortly after the injection spontaneously disappeared within a few weeks in another phakic patient, leaving a subcapsular cataract. Visual improvement was noted in 4 patients, and amplitudes of P100 on the visually evoked potentials recordings increased in three patients. The retinal nerve fiber layer and macular ganglion cell layer thicknesses significantly decreased during the follow-up.ConclusionsBesides the development of an epiretinal membrane in one patient, the intravitreal application of allogeneic BM-MSCs appeared to be intraocularly well tolerated. Consequently, not only NA-AION but also BM-MSCs deserve more clinical investigational resources and a larger randomized multicenter trial that would provide stronger evidence both about safety and the potential therapeutic efficacy of intravitreally injected allogeneic BM-MSCs in acute NA-AION.Trial registration: Safety Assessment of Intravitreal Mesenchymal Stem Cells for Acute Non-Arteritic Anterior Ischemic Optic Neuropathy (NEUROSTEM). NCT03173638. Registered June 02, 2017 https://clinicaltrials.gov/ct2/show/NCT03173638.

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

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). 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. 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). 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.

Peripapillary Vitreous Traction Syndrome: Expanding the Spectrum of Anterior Optic Neuropathies.

Peripapillary vitreous traction (PVT) occurring without any underlying eye disease has been contemplated as a distinct entity from nonarteritic ischemic optic neuropathy (NAION) for many years and is sometimes difficult to differentiate from classical NAION. We report 6 new cases to analyze the clinical features of PVT syndrome that would expand the clinical spectrum of anterior optic neuropathies. Prospective case series. PVT syndrome seems to affect optic discs with a small area with a small cup-to-disc (C/D) ratio. The C/D ratio does not significantly increase in the chronic stage, as in NAION. Vitreous traction without detachment can either lead to mild retinal nerve fiber layer (RNFL) injury with attendant ganglion cell layer/inner plexiform layer (GCL/IPL) thinning in 29% or no injury at all in 71%. Eighty-six percent had good visual acuity (VA) and had no relative afferent pupillary defect (RAPD), whereas 14% had a transient RAPD; 71% had no color defect. Vitreous detachment after a period of severe and persistent traction can lead to more damage to the optic nerve head and RNFL that may look like NAION. Our hypothesized mechanically induced injury to the superficial optic nerve head may not lead to much visual impairment. In our study, no further therapeutic interventions were required. Based on our analysis of previously published cases and our own prospective case series of 6 patients, the PVT syndrome falls within the spectrum of anterior optic neuropathies, often affecting small optic discs with a small C/D ratio. Vitreous traction can lead to a partial or complete anterior optic neuropathy. The PVT syndrome may be a "more" anterior optic neuropathy distinct from classical NAION.

Non-arteritic anterior ischemic and glaucomatous optic neuropathy: Implications for neuroretinal rim remodeling with disease severity.

Post-acute non-arteritic ischemic optic neuropathy (NAION) and glaucomatous optic neuropathy (GON) can be difficult to differentiate clinically. Our objective was to identify optical coherence tomography (OCT) parameters to help differentiate these optic neuropathies. We compared 12 eyes of 8 patients with NAION and 12 eyes of 12 patients with GON, matched for age and visual field mean deviation (MD). All patients underwent clinical assessment, automated perimetry (Humphrey Field Analyzer II; Carl Zeiss Meditec, Dublin, CA, USA), and OCT imaging (Spectralis OCT2; Heidelberg Engineering, Heidelberg, Germany) of the optic nerve head and macula. We derived the neuroretinal minimum rim width (MRW), peripapillary retinal nerve fibre layer (RNFL) thickness, central anterior lamina cribrosa depth, and macular retinal thickness. MRW was markedly thicker, both globally and in all sectors, in the NAION group compared to the GON group. There was no significant group difference in RFNL thickness, globally or in any sector, with the exception of the temporal sector that was thinner in the NAION group. The group difference in MRW increased with increasing visual field loss. Other differences observed included lamina cribrosa depth significantly greater in the GON group and significantly thinner central macular retinal layers in the NAION group. The ganglion cell layer was not significantly different between the groups. The neuroretinal rim is altered in a dissimilar manner in NAION and GON and MRW is a clinically useful index for differentiating these two neuropathies. The fact that the difference in MRW between the two groups increased with disease severity suggests distinct remodelling patterns in response to differing insults with NAION and GON.

Vascular Changes in the Macula of Patients after Previous Episodes of Vision Loss Due to Leber Hereditary Optic Neuropathy and Non-Arteritic Ischemic Optic Neuropathy.

to assess the vasculature and thickness of the macula using OCT-A in patients who had experienced a previous episode of Leber hereditary optic neuropathy (LHON) or non-arteritic anterior ischemic optic neuropathy (NA-AION). twelve eyes with chronic LHON and ten eyes with chronic NA-AION and eight NA-AION fellow eyes were examined using OCT-A. The vessel density was measured in the superficial and deep plexus of the retina. Moreover, the full and inner thicknesses of the retina were assessed. There were significant differences in all sectors between the groups in regard to the superficial vessel density and the inner and full thicknesses of the retina. The nasal sector of the macular superficial vessel density was affected more in LHON than in NA-AION; the same with the temporal sector of the retinal thickness. There were no significant differences between the groups in the deep vessel plexus. There were no significant differences between the vasculature of the inferior and superior hemifields of the macula in all groups and no correlation with the visual function. The superficial perfusion and structure of the macula assessed with OCT-A are affected both in chronic LHON and NA-AION, but more in LHON eyes, especially in the nasal and temporal sectors.

Non-Arteritik İskemik Optik Nöropatili Olgulardaki Optik Koherens Tomografi Bulguları

Bu çalışmada; nonarteritik iskemik optik nöropatili olguların peripapiller retina sinir lifi tabakası kalınlığını ve optik diskin morfolojik değişiklerini optik koherens tomografi ile benzer yaş grubundan oluşan kontrol grubu ile karşılaştırmayı amaçladık. Çalışmaya Göz Hastalıkları Anabilim Dalı’nda nonarteritik iskemik optik nöropati tanısı almış 42 olgunun 50 gözü ve 50 normal olgunun 50 gözü dahil edildi. Nonarteritik iskemik optik nöropatili olgu grubunda %80.96’sı hipertansiyon hastasıyken, kontrol grubunun %52.00’sinde hipertansiyon mevcuttu. Nonarteritik iskemik optik nöropatili olgu grubunun, total, yarı alan ve sektöryel peripapiler retina sinir lifi tabakası kalınlığı kontrol grubuna göre anlamlı derecede ince bulundu. Sinir lifi tabakasındaki incelmenin en belirgin olduğu kadran %40.75 oranı ile üst kadrandı. Optik disk incelemesinde iki grup arasında ortalama cup/disk oranları birbirine benzerdi. Optik disk alanı nonarteritik iskemik optik nöropatili grupta 2.23±0.89 mm2 olup, kontrol grubunda 2.75±0.52 mm2 olarak bulundu. Nonarteritik iskemik optik nöropatili grubun optik disk alanı ortalaması istatistiksel olarak anlamlı şekilde daha küçük olarak saptandı (p=0.042). Nonarteritik iskemik optik nöropati geçirmiş olgularda optik koherens tomografi ile saptanan, özellikle üst kadranda lokalize belirgin peripapilller retina sinir lifi tabakası incelmesi ve optik disk alanının küçüklüğü nonarteritik iskemik optik nöropati tanısında yardımcı yöntem olarak kullanılabilir.

Is the clinical course of non-arteritic ischemic optic neuropathy associated with oxidative damage and the dynamics of the antioxidant response?

Oxidative stress is known to be a decisive factor in the wide etiopathogenesis of optic neuropathy. This study aimed to comprehensively evaluate the interaction of optic neuropathy's clinical course with systemic oxidative damage and antioxidant response dynamics in a large series. This case-controlled clinical study included 33 non-arteritic anterior ischemic optic neuropathy (NAION) patients and 32 healthy individuals. Extensive systemic oxidation profiles were statistically compared between the two groups, and correlations between the clinical and biochemical data in the study group were analyzed. Vitamin E and malondialdehyde (MDA) levels were significantly higher in the study group. Significant correlations were observed in the analyses between clinical findings and oxidative stress parameters. Correlations between vitamin E and intraocular pressure (IOP), between B12 and cup-to-disk ratio (c/d), between antioxidant glutathione and superoxide dismutase (SOD) enzyme systems, and between uric acid (UA) and age were found to be very significant. As significant correlations were found in either clinical and biochemical data or in oxidative stress parameters, correlations between vitamin E and cholesterol, MDA were found to be very significant. This study not only supplies significant information regarding oxidative damage and antioxidant response in NAION, but also points out the specific interactions of neuromodulators, like vitamin E, in intracellular signaling pathways and regulation mechanisms. A better reading of these connections may help improve diagnosis, follow-ups and treatment criteria and strategies.

The Use of Citicoline in Ophthalmology: An Educational Article

Objective: Citicoline is a safe form of the choline has been increasingly grouped with the water soluble B vitamins. It has been increasingly used with noticeable benefits in the treatment of several pediatric and neuro-psychiatric disorders including, cerebral palsy, cognitive impairment, autism disorders, Rett syndrome, and kernicterus. The aim of this paper is to provide an overview of citicoline research progress relevant to the field of ophthalmology. Conclusion: Citicoline is a safe agent that has the potential to have promising therapeutic applications in a variety of ophthalmological disorders including amblyopia, glaucoma, non-arteritic ischemic optic neuropathy, and diabetic retinopathy.

The visual morbidity of optic nerve head drusen: a longitudinal review

The ophthalmologic complications of optic nerve head drusen (ONHD) in adults have been documented, whereas data on the degree of visual morbidity from OHND in children are limited. The medical records of all patients diagnosed with ONHD at a single, tertiary care ophthalmology department from January 1, 2010, until July 1, 2018, were reviewed retrospectively. Patients were identified using ICD-9 and ICD-10 codes. Inclusion criteria were age ≤18 years of age and formal documentation of ONHD by ancillary testing. A total of 213 patients (386 eyes with ONHD) met inclusion criteria. Mean age at diagnosis was 10.13 ± 4.09 years, and mean follow-up was 2.76 ± 2.91 years. Formal visual fields were available for 208 eyes. Repeatable visual field defects were noted in 24 eyes (11.5%). The most common defect was a nasal step, which occurred in 11 eyes (45.8%). Fifteen eyes had visual field defects at presentation, and 9 eyes developed field loss within 1.39 ± 0.55 years of diagnosis. There was no correlation found between intraocular pressure and degree of visual field loss. Choroidal neovascular membranes were clinically apparent in 5 eyes and treatment was required in 3 eyes. Nonarteritic ischemic optic neuropathy developed in 2 eyes. Visual morbidity associated with ONHD in children is common and may develop in a short period of time after initial diagnosis. There was no correlation found with intraocular pressure.

MACULAR EDEMA AS UNUSUAL PRESENTATION OF NON-ARTERITIC ISCHEMIC OPTIC NEUROPATHY (NAION)

Introduction: Non-arteritic Ischemic Optic Neuropathy is the most common type of ischemic optic neuropathy. Nearly half of NAION patients presented with 20/30 or better visual acuity. Central vision is often preserved relative to the visual field loss.Macular edema in NAION patient is rare, and its occurrence may confuse to other disease and lead to unnecessary treatment. Case Report: We identified a NAION patient presented with macular edema. The patient age was above 40 and had diabetes mellitus (DM). He had clinical findings consistent with NAION with poor visual acuity at the early presentation. Optical coherence tomography examination was performed, and the patient had prominent subretinal fluid. Intravitreal antiVEGF injection was done on our patient and he showed a significant improvement of macular edema. Discussion: Macular edema is a rare clinical manifestation that may contribute a visual deterioration in NAION. The incidence of macular edema in NAION patients is difficult to measure since OCT of macula is not routinely performed. In our report, we encountered a case of NAION complicated by macular edema that underwent a different approach in therapy. Spontaneous regression of subretinal fluid was seen during observation without any treatment given. Our patient achieved a stable visual acuity and visual field defect. This finding is under the literature that spontaneous recovery will be observed during the natural course of acute NAION. Conclusion: Macular edema is an unusual but self-limiting presentation of NAION. Therefore, a comprehensive examination is needed to prevent any unnecessary treatment.

The Risk of Non-arteritic Ischemic Optic Neuropathy Post-intravitreal Bevacizumab Injection.

To report the incidence of non-arteritic ischemic optic neuropathy in diabetic patients treated with intravitreal bevacizumab injection. A prospective comparative analytic study was done in the King Hussein Medical Center during the period between June 2020 and June 2021. Inclusion criteria included diabetic patients who attended a retina clinic. Exclusion criteria included patients with pre-existing ischemic optic neuropathy. Patients were divided into two groups. The first group included diabetic patients who did not require bevacizumab injection and were treated either with follow-up visits or pan-retinal photocoagulation, and the second group included patients who were treated with intravitreal bevacizumab. Patients were followed up for a period of one year. Data collected in two groups included the total number of patients and the number of patients with non-arteritic ischemic optic neuropathy. Results were compared in both groups. A P-value was used to study the statistical significance and was considered to be statistically significant if ≤0.05. The mean age for patients in group 1 was 64.3 years, with a male to female ratio of 1.1 to 1. In group 2, the mean age was 66.2 years, with a male to female ratio of 1.2 to 1. The total number of patients in group 1 was 7375, among whom 68 patients had non-arteritic ischemic optic neuropathy. While in group 2, the total number was 2468 and 49 of them had non-arteritic ischemic optic neuropathy. Most cases of non-arteritic ischemic optic neuropathy were seen in patients who had received three or more injections. Conclusion: Intravitreal bevacizumab in diabetic patients is considered a risk factor for the development of non-arteritic ischemic optic neuropathy, especially in patients receiving more than three injections.

Role of Optical Coherence Tomography Angiography in Non-Arteritic Ischemic Optic Neuropathy: A Case Report

Introduction: Non-arteritic ischemic optic neuropathy (NAION) is the second most common optic neuropathy in adults. Since circulatory insufficiency is presumed to have a role in pathogenesis of NAION, optical coherence tomography angiography (OCTA) is suggested as a tool in assessing NAION patients, while optical coherence tomography (OCT) can detect structural changes. This case report aims to describe the congruity of visual field defect with OCT and OCTA result in a case of bilateral NAION, highlighting the role of both OCT and OCTA in NAION. Case Report: A 52-years-old male came due to painless, progressive blurry vision in both eyes, especially in lower visual field, for the past 7 months. Humphrey visual field examination revealed inferior visual field defects in both eyes. OCTA showed reduced retinal perfusion in the superior part bilaterally. OCT revealed ganglion cell loss in the superior part of his right eye and almost all parts of his left eye. Retinal nerve fiber layer (RNFL) thinning was found in the superior part bilaterally. Discussion: In this case, the congruity of visual field defect, reduced perfusion, ganglion cell-inner plexiform layer (GCIPL), and RNFL thinning portrayed the connection of hypoperfusion as the presumed underlying mechanism of NAION, neuron loss as the result of the hypoperfusion, and the visual field loss as the presenting symptom in NAION. Conclusion: This finding demonstrates the role of OCT-A and OCT in diagnosing and monitoring progression in patients with NAION.OCT-A is a useful tool to evaluate microvascular changes, while OCT can be used to evaluate RNFL and GCIPL thinning.

Nonarteritic Anterior Ischemic Optic Neuropathy: Cystic Change in the Inner Nuclear Layer Caused by Edema and Retrograde Maculopathy

Microcystic macular edema (MME), also known as retrograde maculopathy (RM), is associated with severe optic atrophy because of a range of causes. However, similar changes have also been described in primary retinal pathology and the pathogenesis of MME is debated. A retrospective observational case series. Patients with nonarteritic ischemic optic neuropathy. A retrospective observational case series was performed at the University Hospital of Liège, Belgium. The medical records of patients who were referred to our Neuro-ophthalmology department with a diagnosis of nonarteritic anterior ischemic optic neuropathy (NA-AION), between 2014 and 2021, were reviewed. Ganglion cell complex thickness, acute and chronic inner nuclear change. In a cohort of 34 patients (mean age: 60 ± 12.5 years; 65.6% men) with NA-AION, we identified a transient microcystic change in the inner nuclear layer (INL) associated with optic disc swelling in 19 eyes at presentation. This early change was associated with a transudate of intraretinal and subretinal fluid originating from the optic disc. Among patients who had shown this transient change 3 subsequently developed MME, which remained fixed during the period of observation (range, 12-34 months). No MME was observed in patients without an early INL transient change. Microcystic macular edema was observed in patients with severe ganglion cell complex thinning at 6 months: mean (± SD) loss in superior hemimacula(-28.2 ± 5.2 μm [-33.3%, range,-22.3 to-30.3 μm]) and in inferior hemimacula(-30.7 ± 5.6 μm [-31.0%, range,-24.3 to 34.8 μm]). Our study has revealed 2 causes of INL cystic change in the same patients experiencing NA-AION, 1 reversible and the other likely permanent. This finding highlights the distinction between genuine edema related to transudation of fluid (in this case secondary to ischemic optic disc swelling) and the phenomenon observed in RM that is related to the degree of retinal nerve fiber layer/ganglion cell complex thinning. Cystic change in the INL is associated with severe optic atrophy (MME). However, similar changes have been described inretinalpathology and the pathogenesis of MME is debated.

Macular Edema as Unusual Presentation of Non-Arteritic Ischemic Optic Neuropathy (NAION)

Introduction: Non-arteritic Ischemic Optic Neuropathy is the most common type of ischemic optic neuropathy. Nearly half of NAION patients presented with 20/30 or better visual acuity. Central vision is often preserved relative to the visual field loss. Macular edema in NAION patient is rare, and its occurrence may confuse to other disease and lead to unnecessary treatment.
 Case Report: We identified three NAION patients presented with macular edema. The patients' age was above 40 and had diabetes mellitus (DM). Our patients had clinical findings consistent with NAION with poor visual acuity at the early presentation. Optical coherence tomography examination was performed, and all patients had prominent subretinal fluid. Intravitreal anti-VEGF injection was done on our first patient and no treatment was given to our second and third patient. All patients showed a significant improvement of macular edema.
 Discussion: Macular edema is a rare clinical manifestation that may contribute a visual deterioration in NAION. The incidence of macular edema in NAION patients is difficult to measure since OCT of macula is not routinely performed. In our report, we encountered three cases of NAION complicated by macular edema that underwent a different approach in therapy. Spontaneous regression of subretinal fluid was seen during observation without any treatment given. Our patients achieved a stable visual acuity and visual field defect. This finding is under the literature that spontaneous recovery will be observed during the natural course of acute NAION.
 Conclusion: Macular edema is an unusual but self-limiting presentation of NAION. Therefore, a comprehensive examination is needed to prevent any unnecessary treatment.

Factors Associated With Visual Acuity in Non-arteritic Ischemic Optic Neuropathy Patients: A Five-Year Cross-Sectional Study.

Background and objectiveNon-arteritic ischemic optic neuropathy (NAION) is a common cause of optic neuropathy in elderly patients. Currently, there is no definitive treatment for this condition, and the factors influencing visual outcomes have not yet been conclusively identified. In this study, we aimed to evaluate factors that affect visual outcomes and those that are predictors of the development of NAION in a Thai population.MethodsAll patients diagnosed with NAION at the Rajavithi Hospital between January 1, 2016, and December 31, 2020, were retrospectively reviewed to evaluate the improvement in their best-corrected visual acuity (BCVA) and determine the factors that are predictive of visual outcomes.ResultsThe 80 patients reviewed were predominantly male (55%) with a mean age of 55.8 ±9.89 years. Their most common comorbidities were dyslipidemia (DLP) (67.5%), diabetes mellitus (DM) (61.3%), and hypertension (HT) (48.8%). At the 12-week follow-up visit, there was a significant improvement of at least 0.2 logarithm of the minimum angle of resolution (logMAR) in BCVA (p=0.001). A significantly greater percentage of patients with higher age, DM, and HT was observed in the unfavorable visual recovery (UVR) group (p=0.002, p=0.001, and p=0.005 respectively). In contrast, neither baseline visual acuity nor cup-to-disc ratio (CDR) affected the result of visual recovery (p=0.275 and p=0.076, respectively). In multivariate logistic analysis, older age increased the odds of worse visual recovery [odds ratio (OR): 4.014; 95% CI: 1.038-15.515; p=0.044], as did having DM (OR: 3.809; 95% CI: 1.168-12.421; p=0.027), and HT (OR: 4.577; 95% CI: 1.491-14.049; p=0.008).ConclusionsNone of the baseline visual status parameters (visual acuity, CDR, or visual field defect) was able to determine the outcome of visual recovery at 12 weeks in our NAION patients. Regarding systemic vascular diseases, diabetes and HT are significant risk factors and also predictors of poor visual improvement in Thai populations. NAION patients who are elderly or have vascular diseases such as DM or HT should be closely followed up and advised about the likelihood of having inferior visual recovery.

Clinical and Mechanistic Review of Amiodarone-Associated Optic Neuropathy.

Amiodarone-associated optic neuropathy (AAON) is a complex clinical diagnosis, requiring distinction from non-arteritic ischemic optic neuropathy (NAION) due to a shared at-risk patient population. Diagnosis of AAON is complicated by a varied clinical presentation and incomplete pathophysiologic mechanisms. This article reviews pertinent literature for describing and clinically delineating AAON from NAION, as well as newly reported protective mechanisms of insulin-like growth factor 1 (IGF-1) and PI3K/Akt against amiodarone-induced oxidative and apoptotic injury in retinal ganglion and pigment epithelial cells. These studies offer a basis for exploring mechanisms of amiodarone toxicity in the optic nerve.