Nonarteritic Ischemic Optic Neuropathy Research Articles

Nonarteritic Ischemic Optic Neuropathy

To describe the systemic and visual characteristics and prognosis in patients with nonarteritic ischemicoptic neuropathy (NAION) undergoing different treatments. Retrospective chart review was performed in Kaohsiung Veterans General Hospital patients from 1995-2005 with a clinical diagnosis of NAION, including nonarteritic anterior ischemic optic neuropathy and posterior ischemic optic neuropathy (PION). There were 14 PION patients out of a total of 103 cases. The average age at disease attack was 61 years old, and the ratio of males to females was 1.24:1. Comorbid systemic diseases and visual function were recorded at both initial presentation and the later follow-up period. The final results were recorded and compared by the different treatments they received in 4 groups. In all, NAION usually affected people > 50 years old, without any difference between sexes. Presenting visual acuity, age, and different treatment modes had no direct influence on the final visual outcome. The most significant associated factor was hypertension. NAION is a serious illness; the visual deficit persists even with aggressive treatment.

Intraocular Pressure Is Low in Eyes With Giant Cell Arteritis

Although ocular ischemia occurs in giant cell arteritis (GCA), intraocular pressure (IOP) has not been systematically evaluated as a diagnostic sign. We conducted a retrospective, case-controlled, observational study of IOP in patients with ocular manifestations of GCA (GCA patients), age-matched patients diagnosed with nonarteritic ischemic optic neuropathy (NAION patients), and age-matched patients with cataract (control patients). Medical records were examined for all consecutive patients with the diagnosis of GCA from 1995 to 2004 (n = 16) and NAION from 2002 to 2004 (n = 16) and for patient candidates for cataract extraction (n = 16). The eye intended for cataract extraction was chosen as the "affected eye" in the control patients. The mean IOP in the affected eye of 16 GCA patients was 11.9 mm Hg, significantly lower than the 15.1 mm Hg in affected eyes of age-matched NAION patients and 15.8 mm Hg in control patients (P = 0.002). At presentation, 5 GCA patients had IOP < 10 mm Hg (mean 6.8 mm Hg) without other signs of anterior segment ischemia. None of the NAION or control patients displayed such low IOPs. IOP was significantly lower in the patients with GCA than in patients with NAION or cataract. Hypotony occurred in one third of GCA patients without other signs of anterior ocular ischemia. These findings suggest that low IOP may be a distinguishing factor between GCA and NAION in patients with ischemic optic neuropathy, but evaluation of a larger group of patients is needed for confirmation.

Determining whether delayed nonarteritic ischemic optic neuropathy associated with cataract extraction is a true entity

To evaluate cases of delayed nonarteritic anterior and posterior ischemic optic neuropathy after cataract extraction and to evaluate the need for centralized prospective reporting of nonarteritic ischemic optic neuropathy after cataract extraction. Neuro-ophthalmology Clinics, University of Colorado Health Sciences Center and Denver Veterans Affairs Medical Center, Denver, Colorado, USA. A retrospective review of all patients referred to the Neuro-ophthalmology Divisions, University of Colorado Health Sciences Center and Denver Veterans Affairs Medical Center, from January 2001 to October 2005 was performed. All patients with a diagnosis of nonarteritic anterior or posterior ischemic optic neuropathy were identified. Patients with ischemic optic neuropathy that occurred between 2 months and 12 months after cataract extraction were selected for evaluation. Six eyes with nonarteritic ischemic optic neuropathy that occurred 2 to 6 months after cataract extraction in 4 patients (2 bilateral nonarteritic ischemic optic neuropathy) and 1 eye with nonarteritic ischemic optic neuropathy that occurred after 6 months in 1 patient were identified. One patient had nonarteritic ischemic optic neuropathy in 1 eye 3 months after cataract extraction and 4 years later had nonarteritic ischemic optic neuropathy in the fellow eye 5 months after cataract extraction. Follow-up after the last cataract extraction was 1 to 3 years for all patients. Although an association between cataract extraction and delayed nonarteritic anterior and posterior ischemic optic neuropathy has been suggested, current data do not support a causal relationship. In addition, the window of postoperative susceptibility for delayed ischemic optic neuropathy after cataract extraction is unclear.

Ischemic Optic Neuropathy in Male Veterans Prescribed Phosphodiesterase-5 Inhibitors

To determine the feasibility of a case-control study of phosphodiesterase (PDE)-5 inhibitors and nonarteritic ischemic optic neuropathy (NION). Retrospective cohort study using the National Veterans Health Administration's pharmacy and clinical databases. setting: National database. patient population: Male veterans 50 years of age and older with newly diagnosed NION or "possible" NION. interventional procedure: Dispensed prescription for a PDE-5 inhibitor. outcome measure: Incidence of NION and "possible" NION based on exposure to PDE-5 inhibitors. The relative risk of NION among men prescribed a PDE-5 inhibitor was 1.02 (95% confidence interval [CI]: 0.92 to 1.12). The relative risk of possible NION among men prescribed a PDE-5 inhibitor was 1.34 (95% CI: 1.17 to 1.55). The collective risk of NION and possible NION was marginally significant (relative risk [RR] 1.10 95% CI: 1.02 to 1.20). A case-control study, in which the dependent variable is NION and the effect size of the PDE-5 inhibitor is assumed small, is feasible.

Bilateral ischemic optic neuropathy after transurethral prostatic resection: a case report

BackgroundNonarteritic ischemic optic neuropathy affects the anterior portion of the optic nerve and is characterized by sudden, painless visual loss. The affected eye has a relative afferent pupillary defect. The typical funduscopic appearance includes optic disc edema, with associated nerve fiber layer hemorrhage. Risk factors include advanced age, systemic hypertension, nocturnal hypotension, diabetes mellitus, and a small cup-to-disc ratio. Bilateral presentation is rare. Postoperative optic neuropathy has been associated with nonocular surgery; risk factors include a combination of prolonged surgical times, acute systemic hypotension, anemia due to blood loss, or prone positioning. We report for the first time a patient with bilateral, simultaneous anterior ischemic optic neuropathy after elective transurethral prostatic resection.Case presentationA 66-year old man underwent surgery for benign prostatic hyperplasia. The preoperative blood pressure was 140/85 mmHg, hemoglobin 15.9 g/dL, and hematocrit 48.6%. Two hours postoperatively, the blood pressure, hemoglobin, and hematocrit dropped dramatically. One day later, transient horizontal diplopia developed. Funduscopy showed a congenitally small cup-to-disc ratio without papillary edema. Other ocular findings were unremarkable. By 4 days postoperatively, sudden and painless amaurosis bilaterally developed when the patient awoke with nausea and vomiting. Visual acuity was no light perception bilaterally. The optic discs were swollen with small hemorrhages. Scans of the head and orbits and electrolyte levels were normal. There were no responses on visual evoked potentials bilaterally. The blood pressure was 90/50 mm Hg, the hemoglobin 7.0 g/dL, and the hematocrit 22.9%, necessitating infusion of three units of packed red blood cells. The blood pressure, hematocrit, and hemoglobin increased to normal levels. Three months later the visual acuity remained no light perception. The pupils were unreactive and there was marked optic disc atrophy bilaterally.ConclusionBilateral and simultaneous acute ischemic optic neuropathy may be a rare but devastating surgical complication. The combination of anemia and hypotension may increase the risk of anterior ischemic optic neuropathy postoperatively after transurethral prostatic resection.

Is the Efficacy of LDL Apheresis in Ischemic Optic Neuropathy Linked to a Reduction in Endothelial Activation Markers?

Endothelial dysfunction of the optic microcirculation is considered to be the main pathogenetic mechanism in nonarteritic ischemic optic neuropathy. The aim of the present work was to assess whether a clinical improvement is correlated with a reduction in the endothelial activation markers by means of LDL apheresis (LDLA). Three weekly sessions of LDLA were administered in 23 patients affected by nonarteritic ischemic optic neuropathy. Statistically significant reductions were achieved in all parameters: total cholesterol (44.6%), LDL cholesterol (54.6%), fibrinogen (60.9%), von Willebrand factor (38.6%), sE-Selectin (22.6%), sICAM-1 (14%) and sVCAM-1 (15.5%), each of which was correlated with an improvement in the mean deviation of the visual field, although statistical significance for the single parameters was not reached. However, analysis of variance between the mean deviation improvement and the set of parameters taken together yielded highly significant results (p < 0.0001). LDLA was effective in reducing the values of all evaluated endothelial activation markers, and this trend was correlated with an improvement in the visual field.

Optic Disc Topography and Peripapillary Retinal Nerve Fiber Layer Thickness in Nonarteritic Ischemic Optic Neuropathy and Open-Angle Glaucoma

To evaluate the results of scanning laser tomography and scanning laser polarimetry (SLP) and the correlations with visual field damage (VFD) in eyes with nonarteritic ischemic optic neuropathy (n-AION) compared with eyes with open-angle glaucoma (OAG). Cross-sectional study. Thirty-three eyes of 33 patients with n-AION and 33 eyes with OAG whose age and VFD evaluated with the Humphrey field analyzer were matched to those of the n-AION eyes. The parameters of optic disc topography obtained with the Heidelberg Retina Tomograph II (HRT II) and retinal nerve fiber layer (RNFL) thickness with GDx with variable corneal compensation and the correlation to VFD. The cup area, cup-to-disc area ratio, and mean cup depth were significantly smaller, and the cup shape measure more negative, in the n-AION eyes than in the OAG eyes (P<0.001), whereas rim area was significantly greater (P<0.001). Multivariate analyses showed that none of disc area, rim area, and mean cup depth in the n-AION eyes and only rim area (P = 0.029) in the OAG eyes was significantly associated with mean deviation (MD). Ellipse average of RNFL thickness significantly correlated with MD in the n-AION eyes (P = 0.045) and in the OAG eyes (P = 0.022). Disc topography of eyes with n-AION was quantitatively characterized by small and shallow cupping and a relatively large rim area compared to eyes with OAG matched for age and VFD. In eyes with n-AION, significant correlation with VFD was found only for the RNFL thickness evaluated with SLP but not for the HRT II parameters.

Effect of Transcorneal Electrical Stimulation in Patients with Nonarteritic Ischemic Optic Neuropathy or Traumatic Optic Neuropathy

To determine whether transcorneal electrical stimulation (TES) can improve the visual function of patients with nonarteritic ischemic optic neuropathy (NAION) or traumatic optic neuropathy (TON). Eight consecutive patients at the Osaka University Hospital were studied. TES (600-800 microA, 20 Hz, 30 min) was applied once each to three eyes with NAION and to five eyes with TON, using a contact lens-type stimulating electrode. The primary outcome measurement was the change in visual acuity at 1 to 3 months after TES. An improvement in visual acuity was defined as a change of > or =0.3 log (minimum angle of resolution) (logMAR) units. The side effects of TES were also investigated. After TES application, the visual acuity improved in two patients with NAION and in four patients with TON. Visual acuity did not worsen in any of the eyes. Only a mild superficial punctuate keratopathy was observed in all eyes immediately after TES, and it healed by the next day. Visual acuity can be improved after TES without major complications in some patients with NAION or TON. These results suggest that TES should be considered as a new treatment for eyes with optic neuropathy.

Electrophysiological findings in patients with nonarteritic anterior ischemic optic neuropathy

Objective Nonarteritic ischemic optic neuropathy (NAION) is one of the most frequent causes of sudden visual loss in middle-aged or elderly patients. Although several electrophysiological methods are available for an objective evaluation of the visual deficits, these are not generally used in the assessment of the clinical condition of NAION patients. To evaluate the severity of the optic nerve and retinal damage, electrophysiological tests were performed on 8 patients with NAION. Methods Visual evoked potentials (VEPs), scotopic, photopic and flicker electroretinograms (ERGs), multifocal ERGs and pattern ERGs were recorded. Results The results demonstrated that the VEPs fairly reliably reflected the visual loss caused by NAION. The VEPs were extinguished in cases with a serious visual acuity loss, while a decrease in amplitude and a lengthening of the P100 latency were observed in cases with good visual acuity and a severe visual field loss and in the nonattacked fellow eye of the patients with monocular involvement. The pattern ERGs failed to show signs of retrograde degeneration. The photopic, scotopic and flicker ERGs, and the oscillatory potentials (OPs) were close to normal in these NAION patients. Conclusions Our observations permit the conclusion that electrophysiological methods can provide an objective indication of the clinical condition of these patients. The new data obtained promote an understanding of the pathomechanism of the disease. Significance Electrophysiological tests are suitable for monitoring of the progression of the disease in NAION patients.

Three-month change in cerebral glucose metabolism in patients with nonarteritic ischemic optic neuropathy

No specific therapy is available for non-arteritic ischemic optic neuropathy (NAION), a blinding disease, which is related to microvascular insufficiency of the optic disc and white matter lesions in brain MRI representing ischemia. We hypothesize that pentoxifylline, traditionally used for treatment of peripheral vascular disease due to its ability to decrease viscosity and increase erythrocyte flexibility, may be useful to improve blood flow in patients with NAION. Positron emission tomography (PET) to determine the change in glucose metabolic rate in the visual cortex of patients with NAION versus age-matched controls was performed after 3 months' administration of pentoxifylline. Eight patients clinically diagnosed with NAION underwent clinical and laboratory evaluation, brain MRI and PET with fluoride-18 fluorodeoxyglucose (FDG). All patients were treated with oral pentoxifylline 400 mg three times a day for a period of at least 3 months. Three patients were included in the final PET data analysis. At baseline, PET revealed bilateral metabolic decreases especially in the ventral visual stream in all patients compared with 56 age- and gender-normalized controls. Metabolic changes were seen in the dorsal stream areas 17, 18, and 19, cerebellar region, dorsolateral prefrontal cortex, medial temporal lobe, and frontal eye fields 8 and 6. At 3 months following pentoxifylline, all three patients included in the final PET data analysis showed partial normalization from the baseline metabolism. Metabolic imaging with FDG-PET in NAION provides functional information not attainable with conventional brain MRI. The exact relevance of these results, and the role of pentoxifylline in these metabolic changes, should be determined by means of a larger randomized and controlled trial.

Neuro-Ophthalmic Emergencies for the Neurologist

A variety of acute neurologic disorders present with visual signs and symptoms. In this review the authors focus on those disorders in which the clinical outcome is dependent on timely and accurate diagnosis. The first section deals with acute visual loss, specifically optic neuritis, ischemic optic neuropathy (ION), retinal artery occlusion, and homonymous hemianopia. The authors include a discussion of those clinical features that are helpful in distinguishing between inflammatory and ischemic optic nerve disease and between arteritic and nonarteritic ION. The second section concerns disc edema with an emphasis on the prevention of visual loss in patients with increased intracranial pressure. The third section deals with abnormal ocular motility, and includes orbital inflammatory disease, carotid-cavernous fistulas, painful ophthalmoplegia, conjugate gaze palsies, and neuromuscular junction disorders. The final section concerns pupillary abnormalities, with a particular emphasis on the dilated pupil and on carotid artery dissection. Throughout there are specific guidelines for the management of these disorders, and areas are highlighted in which there is ongoing controversy.

Non-arteritic ischemic optic neuropathy developing soon after use of sildenafil (Viagra): a report of seven new cases

Non-arteritic ischemic optic neuropathy developing soon after use of sildenafil (Viagra): a report of seven new cases

Non‐arteritic ischaemic optic neuropathy (NAION) in patients under 50 years of age

The goal of our study was to compare the case histories and clinical findings in three young patients (aged<50 years) who had undergone their first attack of non-arteritic ischaemic optic neuropathy (NAION). We intended to consider whether NAION at a relatively young age might comprise a separate pathological and diagnostic entity. All three cases revealed some common characteristics. All of them experienced recurrent attacks with bilateral manifestations that led to severe loss of vision and visual field defects. The patients had also suffered from diabetes mellitus for a long time, but none of them had diabetic retinopathy. The case histories of these relatively young patients showed some differences, including recurrences and more severe loss of vision, to those of elderly patients. However, all the signs we found had been reported previously, although much less frequently, in NAION cases among elderly patients. The clinical and laboratory findings definitely exclude the possibility of an alternative diagnosis. Hence, our results do not support the notion of a different pathomechanism of NAION at a young age and its existence as a separate disease entity.

A Comparison of Risk Factors for Postoperative and Spontaneous Nonarteritic Anterior Ischemic Optic Neuropathy

: Whether postoperative non-arteritic ischemic optic neuropathy (NAION) is caused by surgery is unsettled. To provide further evidence on this issue, it is useful to compare the characteristics of patients who develop NAION following intraocular surgery to those who develop NAION spontaneously. : In a retrospective review of patients diagnosed with NAION between January 1, 1993 and December 31, 1999, 12 cases of NAION in 11 subjects were identified as occurring within 30 days of cataract extraction or intraocular lens exchange (postoperative NAION group). Using Fisher exact test, the prevalence of NAION risk factors (hypertension, diabetes mellitus, hypercholesterolemia, smoking, small cup-to-disc ratios) was compared with that of a similarly aged control group of 37 subjects diagnosed with spontaneous NAION (spontaneous NAION group). : Patients with postoperative NAION had a lower prevalence of hypertension than did those with spontaneous NAION (27% versus 68%, P = 0.034) and a lower prevalence of cup-to-disc ratios of less than or equal to 0.2 (55% vs. 94%, P = 0.006). The prevalence of elevated cholesterol, diabetes mellitus, and tobacco use was similar in the two groups. : The prevalence of hypertension and low cup-to-disc ratios is significantly lower in subjects with NAION following lens-related intraocular surgery than in those with spontaneous NAION, indicating that risk factors for NAION in these settings may be different.

Impairment of homocysteine metabolism in patients with retinal vascular occlusion and non-arteritic ischemic optic neuropathy

Mild hyperhomocysteinemia is established as an independent risk factor for atherothrombotic disease, including ocular pathologies such as retinal vascular occlusion and non-arteritic ischemic optic neuropathy (NAION). Low intake or low status of B-vitamins explains elevated total homocysteine (tHcy) concentrations only in part. The underlying cause for disturbed homocysteine metabolism requires further insight. We investigated whether the combined determinations of plasma tHcy, methylmalonic acid (MMA) and cystathionine provide more information on the causes of impaired homocysteine metabolism as compared with vitamin B12, vitamin B6 and folate in patients with ocular ischemic vascular disease. A total of 51 hyperhomocysteinemic (>12 micromol/L) patients with retinal vascular occlusion (n=42) and NAION (n=9) were included. Mild renal dysfunction was an important determinant of tHcy, indicated by the positive correlation between creatinine and tHcy (r=0.47, p=0.001). The assessment of MMA in addition to tHcy identified at least 12 out of 51 patients (23%) who were most likely to have a functional vitamin B12 deficiency. An additional 14 patients (27%) with elevated MMA and cystathionine levels also had slightly elevated concentrations of creatinine, pointing to the need for discrimination between renal dysfunction and vitamin B12 deficiency in this group. In contrast, measurement of cystathionine is very sensitive for renal dysfunction and this marker was strongly related to serum creatinine (r=0.56, p<0.001) and to tHcy (r=0.50, p<0.001). Measurement of the vitamins folate, vitamin B12 and vitamin B6 in plasma did not provide sufficient information on intracellular disturbances in homocysteine metabolism. In conclusion, the metabolites homocysteine, cystathionine and MMA are sensitive indicators and valuable for discrimination of the underlying cause of mild to moderate hyperhomocysteinemia, with implications for therapeutic targeting.

Mitochondrial T9957C Mutation in Association with NAION and Seizures but not MELAS

Purpose: To assess the functional significance of the mitochondrial nt-9957 mutation in a man with non-arteritic ischemic optic neuropathy (NAION). This nt-9957 mutation has been previously reported in association with mitochondrial encephalopathy, lactic acidosis, and stroke-like events (MELAS). Methods: The patient was examined clinically and with magnetic resonance imaging and spectroscopy. The entire coding region of the mitochondrial genome was sequenced, and mitochondrial function was assessed by flow cytometry after staining with fluorescent dihydroethidium. Results: This 76-year-old man had optic nerve disease bilaterally and seizures, but no clinical or radiological evidence of MELAS. He had no mitochondrial DNA mutation other than the 9957. Functional testing revealed a severe defect in mitochondrial complex III activity. Conclusions: This patient had a mitochondrial functional deficit consistent with his 9957 mutation. It seems quite likely that this mutation may be responsible for optic nerve and brain injuries.

Intracranial and orbital doppler in cerebrovascular disease

Color doppler imaging (CDI) is a diagnostic tool that allows non-invasive evaluation of the orbital and intra-cranial structures. It operates by the doppler principle, which is detecting changes in the frequency of sound that is reflected from flowing blood, allowing estimation of flow velocity. CDI has been used in the diagnosis and follow up of ophthalmic conditions such as central retinal artery occlusion, central retinal vein occlusion, arteritic and non-arteritic ischemic optic neuropathy and the ocular ischemic syndrome. In addition, orbital conditions like varices can be evaluated. Transcranial doppler has been used to assess strokes and arteriovascular malformations of the brain. The main limitation of CDI is that it provides information about velocity and not flow. Despite this, it remains a valuable tool to diagnose ocular and intracranial conditions characterized by ischemia or abnormal blood flow.

Bilateral sequential non-arteritic anterior ischemic optic neuropathy in incomplete Reiter's syndrome

A 35-year-old man with a history of incomplete Reiter's syndrome presented with bilateral sequential non-arteritic ischemic optic neuropathy (NAION), which was associated with an elevated IgG titer to Chlamydia pneumoniae. Previous reports have shown that optic disc edema as part of posterior segment inflammation may be seen in patients with incomplete Reiter's syndrome. This is the first case report demonstrating NAION occurring in incomplete Reiter's syndrome. C. pneumoniae and small optic discs could have predisposed him to develop both this syndrome and NAION.

Ischemic optic neuropathy as the first manifestation of elevated cholesterol levels in young patients

Purpose To investigate the relationship between idiopathic nonarteritic ischemic optic neuropathy (NAION) and serum lipid levels in patients ≤ 50 years of age. Design Case-control study. Participants Thirty-seven consecutive patients with NAION and 74 age- and gender-matched comparison patients. Methods and main outcome measures Serum lipid levels and the presence of several historical diseases and exposures were abstracted from the medical records in cases and controls. Results The mean total cholesterol level was significantly increased in patients with NAION compared with controls (235.4 vs. 204.0 mg/dl, P < 0.001). The odds ratio of having high blood cholesterol (≥ 240 mg/dl) with NAION was 3.3 (95% confidence interval, 1.4–7.8), and the likelihood increased when the comparison was restricted to nondiabetic patients. Diabetes mellitus was more common in cases than controls ( P = 0.027), but systemic hypertension was not significantly different ( P = 0.63). No patient (0 of 24) had a magnetic resonance imaging study consistent with optic neuritis or central nervous system demyelination. Visual improvement was uncommon. Conclusions This study demonstrates that hypercholesterolemia is associated with NAION in younger patients. NAION may be the first manifestation of a lipid disorder, a previously unrecognized syndrome. These patients have experienced a focal, microvascular central nervous system ischemic event at a relatively young age. Aggressive treatment of lipid abnormalities in these patients may be warranted.

Comparison of information obtained by operative note abstraction with that recorded on a standardized data collection form

Background. The Ischemic Optic Neuropathy Decompression Trial compared optic nerve decompression surgery with careful follow-up for treatment of patients with nonarteritic ischemic optic neuropathy. Surgeons submitted a standardized data collection form and operative notes for 123 patients randomized to and undergoing surgery. The purpose of this study was to see whether operative notes have sufficient and reliable data to avoid development of a surgery data collection form in future trials. Methods. We abstracted data from Ischemic Optic Neuropathy Decompression Trial patient operative notes, calculated the proportion of completed responses, and compared abstracted responses with those originally recorded on corresponding case report forms. Results. Variables used to identify persons, dates, or eye (left/right) were reported 100% of the time on operative notes and with excellent agreement with those recorded on the case report form (median agreement, 100%; range, 95% to 100%). Categoric variables, used to establish the characteristics of surgical steps, were also reported reliably on operative notes (median agreement, 84%; range, 0 to 100%). Open-ended variables tended to be reported more frequently on operative notes (exact agreement, 57% and 34%, respectively, for complications and postoperative medications). Quantitative variables were infrequently reported but correlated well with values reported on the data collection forms (Pearson correlation coefficients, 0.78, 0.79, 0.94, 0.96). For many variables, disagreements were minor and often were related to interpretation of the operative notes by the abstractor. Conclusion. In our trial, operative note abstraction adequately documented surgery date and surgeon and provided more complete information than the standardized report form with respect to complications but did not provide complete information for other variables. (Surgery 2003;133:324-30.)