Optic disc structure in anterior ischemic optic neuropathy

The etiology of anterior ischemic optic neuropathy (AION), when not associated with giant cell arteritis, is usually unknown. Clinical, pathologic, and experimental studies have not determined a cause. The optic disc appearance in both the involved and normal fellow eye was studied in 51 patients with acute nonarteritic AION. The number of discs (both involved and fellow) without a physiologic cup was significantly greater than would be expected from normal population studies. The etiology of nonarteritic AION may be related to the anatomic configuration of the optic nerve.     

Optic disc edema in non-arteritic anterior ischemic optic neuropathy

We investigated the clinical characteristics, time to resolution and the factors that influence it, and evolutionary pattern of optic disc edema (ODE) in non-arteritic anterior ischemic optic neuropathy (NA-AION). Our study was conducted in 591 consecutive patients (749 eyes) with NA-AION who fulfilled our inclusion criteria. On their first visit to our clinic, all patients had a detailed ophthalmic and medical history, a comprehensive ophthalmic evaluation, and stereoscopic color fundus photography and fluorescein fundus angiography. On each follow-up visit, the same ophthalmic evaluation was performed, except for fluorescein fundus angiography. The effect of steroid therapy on ODE was evaluated in a “patient choice study” in 723 eyes, i.e., patients who voluntarily opted to have (343 eyes) or not have (380 eyes) this therapy. To identify the factors that influence time to ODE resolution, parametric regression models for interval-censored data were fitted by maximum likelihood estimation using an SAS procedure. Our results indicate that the overall median time (25–75th percentile) to spontaneous resolution of ODE from the onset of visual loss was 7.9 (5.8–11.4) weeks. The ODE resolution time was longer in diabetics than in non-diabetics (p = 0.003) in the single factor model. Multi-factor analysis showed that worse initial visual field defects (p < 0.0001) and worse visual acuity (p = 0.04) were associated with a faster resolution of ODE. Those treated with steroid therapy within 2 weeks after onset of NA-AION had significantly (p = 0.0006) faster ODE resolution than untreated cases. Severity of initial visual loss and systemic diseases were identical in steroid treated and untreated patients. A characteristic evolutionary pattern of ODE in NA-AION was observed. In conclusion, our study showed that in NA-AION the time course for resolution of ODE is shorter with greater severity of initial visual field and visual acuity loss, which may relate to the number of axons permanently damaged during the acute stage. Steroid therapy was associated with shorter time to resolution of ODE. Resolution of ODE goes through a characteristic evolutionary process. Supported by grant EY-1151 from the National Institutes of Health, Bethesda, Maryland, and in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York.     

Optic disc morphology after arteritic anterior ischemic optic neuropathy

OBJECTIVE: To evaluate the appearance of the nerve head in patients after giant cell arteritis-induced arteritic anterior ischemic optic neuropathy (A-AION). DESIGN: Noncomparative clinical case series. PATIENTS: The study comprised 29 patients who presented with unilateral A-AION and temporal artery biopsy-proven giant cell arteritis. Stereoscopic optic disc photographs, taken of both the affected and unaffected eyes at the onset of the disease and after a follow-up period of 20.10 +/- 25.36 months (median, 11 months; range, 2-102 months), were morphometrically evaluated. MAIN OUTCOME MEASURES: Size and shape of the optic disc, neuroretinal rim, optic cup, and alpha and beta zones of parapapillary atrophy. RESULTS: In the eyes after A-AION, at the end of the study, the neuroretinal rim was significantly (P = 0.002) smaller, and the optic disc cup area was significantly (P = 0.001) larger than those of the contralateral unaffected eyes. Alpha zone and beta zone of parapapillary atrophy did not vary significantly (P > 0.50). CONCLUSIONS: A-AION, like glaucomatous optic neuropathy, results in neuroretinal rim loss and optic disc cupping. However, in contrast to glaucoma, A-AION is not associated with an enlargement of parapapillary atrophy. The reasons and mechanisms responsible for these similarities and dissimilarities are discussed. Marked clinical, morphologic, and histopathologic similarities in optic disc cupping and loss of neuroretinal rim between A-AION and glaucomatous optic neuropathy are highly suggestive of a common mechanism for the development of the two diseases (i.e., ischemia of the optic nerve head). The subject is discussed at length.     

Optic disc evaluation by optical coherence tomography in nonarteritic anterior ischemic optic neuropathy

PURPOSE: To describe the characteristics of the optic nerve head (ONH) in patients with nonarteritic anterior ischemic optic neuropathy (NAION) and compare them with control subjects by using optical coherence tomography (OCT). METHODS: Patients with NAION underwent a complete ophthalmic examination, including OCT scanning of the ONH at diagnosis. The examination was repeated 1.5, 3, and 6 months later. Age- and sex-matched control subjects with no ocular disease underwent a similar evaluation. Data were obtained by using the ONH analysis protocol of the StratusOCT (Carl Zeiss Meditec, Dublin, CA). RESULTS: Twenty-three patients and 23 control subjects were included. In eyes with NAION, the vertical integrated rim area decreased significantly (P < 0.01) from the acute phase to the 6-month visit. The cup-to-disc (C/D) area ratio increased significantly (P = 0.002) from the acute examination to the 3-month visit. There was a significant difference between the NAION fellow eyes and the control eyes in C/D ratio, evaluated by slit lamp funduscopy (P < 0.001), and in the C/D area ratio (P = 0.001). The vertical integrated rim area was significantly (P = 0.001) greater in NAION fellow eyes than in control eyes. There was no significant difference in optic disc area or vertical disc diameter among the control eyes, NAION-affected eyes, and NAION fellow eyes. CONCLUSIONS: Although patients with NAION have lower C/D ratios than does the normal population, with a higher level of nerve fiber crowding, there was no difference in optic disc size between patients with NAION and control subjects. After the development of NAION, 47.8% of eyes had a C/D ratio that differed from that in the fellow eye by more than 0.1.     

非动脉炎性前部缺血性视神经病变视盘形态的Meta分析

目的 采用Meta分析的方法评价非动脉炎性前部缺血性视神经病变（Nonarteritic anterior ischemic optic neuropathy,NAION）患者视盘形态特点。设计 系统综述。研究对象 检索万方全文数据库、EMBASE和Pubmed 数据库中有关NAION 患者视盘定量测量的临床研究文献。方法 依据纳入和排除标准筛选文献,对纳入的研究进行数据提取并进行meta分析,统计学采用Stata软件进行异质性检验、合并WMD和敏感性分析。主要指标 视盘形态学参数。结果 共7篇文献符合纳入标准。NAION患者对侧健眼与正常对照比较,视盘面积（WMD=-0.20,95%CI：-0.37~-0.03）、视杯面积（WMD=-0.36,95%CI：-0.58~-0.14）、杯盘面积比（WMD=-0.15,95%CI：-0.23~-0.06）、视杯容积（WMD=-0.08,95%CI：-0.12~-0.05）、平均视杯深度（WMD=-0.10,95%CI：-0.13~-0.06）、视杯形态测量（WMD=-0.03,95%CI：-0.05~-0.02）均小于正常对照组,差异有统计学意义;而盘沿面积（WMD=0.05,95%CI：-0.15~0.25）、盘沿容积（WMD=0.05,95%CI：-0.07~0.16）两组间差异无统计学意义。NAION患者患眼与对侧健眼比较,盘沿容积（WMD=-0.08,95%CI：-0.14~-0.02）较健眼小,视杯形态测量（WMD=0.03,95%CI：0.00~0.06）较健眼大,差异有统计学意义;视盘面积（WMD=0.08,95%CI：-0.04~0.19）、视杯面积（WMD=0.08,95%CI：-0.01~0.17）、盘沿面积（WMD=-0.05,95%CI：-0.17~0.08）、杯盘面积比（WMD=0.02,95%CI：-0.02~0.06）、视杯容积（WMD=0.01,95%CI：-0.02~0.03）、平均视杯深度（WMD=0.00,95%CI：-0.02~0.03）差异两组间无统计学意义。结论NAION患者具有小视盘、小视杯的特点;NAION发生后,视杯有扩大趋势。（眼科,2014, 23： 235-239）     

非动脉炎性前部缺血性视神经病变视盘形态学定量研究

目的 研究非动脉炎性前部缺血性视神经病变(NAION)视盘形态结构特征,探讨 NAION 的发病机制.方法 应用海德堡视网膜断层扫描仪(HRT)对71例NAION患者对侧未发病眼及69名正常人随机选择一眼的视盘进行检测,对NAION患者和正常人的视盘参数进行比较分析.结果 NAION组视盘面积,视杯面积,杯盘面积比,平均视杯深度,最大视杯深度,视杯形态测量均小于正常对照组(P<0.05. NAION患者与正常组盘沿面积无差异(P>0.05. NAION组杯盘面积比小于等于0.2占91.5%,而对照组占40.6%,其中NAION组无视杯为14例,对照组仅为1例,NAION组无视杯的发生率明显高于对照组;两组杯盘面积比分布的差异具有统计学意义(P<0.05).结论 小视盘,小视杯及浅视杯是NAION患者视盘的形态学特点,也是导致NAION的解剖基础.     

Optic disc edema with aphakic cystoid maculopathy masquerading as ischemic optic neuropathy

Two patients with visual loss after cataract extraction were found to have prominent pallid optic disc edema, peripapillary hemorrhage, and cystoid maculopathy. A diagnosis of anterior ischemic optic neuropathy, with coincidental aphakic cystoid macular edema, was initially considered. The clinical course, however, favored a diagnosis of visual loss secondary to maculopathy. In both cases, fluorescein angiography disclosed leakage of fluorescein dye from macula, optic disc, and peripapillary foci. Fluorescein angiography and stereo color photographs of 51 patients with aphakic cystoid maculopathy were reviewed to determine the incidence of optic disc edema. Although optic disc swelling was rarely recognized on fundus photography, optic disc hyperfluorescence was observed in 75% of cases.     

Embolic anterior ischemic optic neuropathy

The presumed cause of anterior ischemic optic neuropathy is atherosclerotic vascular changes. Small-vessel occlusive vascular disease most likely causes occlusion of one or more posterior ciliary arteries, compromising blood flow to the optic nerve head and choroid. We present the case of a 59-year-old black man with cholesterol emboli within the retinal vasculature combined with a clinical picture of anterior ischemic optic neuropathy and choroidal nonperfusion demonstrated by i.v. fluorescein angiography. We believe this is evidence that, in a rare case, embolic phenomena may be the cause of anterior ischemic optic neuropathy.     

Nonarteritic anterior ischemic optic neuropathy

PURPOSE OF REVIEW: Nonarteritic anterior ischemic optic neuropathy remains a disease that is poorly understood in many aspects. The clinical presentation may diverge significantly from the classic unilateral, painless, sudden vision loss affecting patients over the age of 50 years. This variability might make nonarteritic anterior ischemic optic neuropathy hard to differentiate from optic neuritis and arteritic ischemic optic neuropathy. The course of nonarteritic anterior ischemic optic neuropathy is also variable, often sequentially affecting the other eye. RECENT FINDINGS: Visual recovery has been reported, but it is not the rule. Multiple risk factors have been proposed, including crowded disc, atherosclerosis, diabetes, hyperlipidemia, hypertension, hypotension, hemoconcentration, hemodilution, and hypercoagulable states. The optic nerve damage in nonarteritic anterior ischemic optic neuropathy appears to result from a perfusion insufficiency in the short posterior ciliary arteries leading to infarction of the retrolaminar portion of the optic disc. The underlying mechanisms are still unclear, however. Multiple medical and surgical treatment options have been investigated, including optic nerve sheath decompression, standard and megadose corticosteroids, levodopa, carbidopa, hyperbaric oxygen, and neuroprotective agents, but no proven effective treatment is currently available. SUMMARY: Intense investigations in humans and animals are under way. Hopefully these studies will enhance our understanding of the risk factors and pathophysiology of nonarteritic anterior ischemic optic neuropathy and aid in developing new strategies for prevention and treatment.     

Nonarteritic anterior ischemic optic neuropathy

Nonarteritic anterior ischemic optic neuropathy refers to an idiopathic ischemic process of the anterior portion of the optic nerve. The typical presentation is sudden and painless visual loss with examination features of an optic neuropathy. Among the various associated risk factors are optic disc morphology, advanced age, systemic arterial hypertension, diabetes mellitus, and nocturnal hypotension. Currently, there is no proven effective long-term treatment for this disorder.     

Optical coherence tomography angiography of optic disc perfusion in non-arteritic anterior ischemic optic neuropathy

AIM: To compare the optic disc blood flow of non-arteritic ischemic optic neuropathy (NAION) eyes with normal eyes. METHODS: The optic disc blood flow densities of diagnosed non-acute phase NAION eyes (21 eyes, 14 individuals) and normal eyes (19 eyes, 12 individuals) were detected via Optovue optical coherence tomography angiography (OCTA). The optic disc blood flow was measured via Image J software. Correlations between optic disc perfusion and visual function variables were assessed by linear regression analysis. RESULTS: The average percentage of the optic disc non-perfusion areas in the non-acute phase NAION patients (17.84%±6.18%) was increased, when compared to the normal control eyes (8.61%±1.65%), and the difference was statistically significant (P<0.01). Moreover, there was a proportional correlation between the visual field mean defect (MD) and the optic disc non-perfusion area percentage, and the relationship was statistically significant (t=3.65, P<0.01, R2=0.4118). In addition, the critical correlation between the best corrected visual acuity (BCVA) and the optic disc non-perfusion area percentage was statistically significant (t=4.32, P<0.01, R2=0.4957). CONCLUSION: The optic disc non-perfusion area percentages detected via OCTA in NAION eyes were significantly increased when compared with the normal eyes. Both the BCVA and MD were correlated with the optic disc flow detected, revealing that OCTA may be valuable in the diagnosis and estimation of NAION.     

Chlamydia in anterior ischemic optic neuropathy

There is an increasing body of evidence linking the common respiratory human pathogen Chlamydia pneumoniae with atherosclerosis and other vascular disorders. Our research was designed to investigate the association of this organism with anterior ischemic optic neuropathy (AION), representing an acute ischemic disorder of the optic nerve head. Sera were examined of 14 consecutive patients with AION and of 14 age- and sex-matched control subjects with noncardiovascular, nonpulmonary disorders. Antibodies against chlamydial lipopolysaccharide (LPS) and outer membrane proteins of C. pneumoniae were determined by ELISA. Further, nucleic acid amplification tests were done in order to detect C. pneumoniae-specific nucleotide sequences. Four patients (29%) were IgA positive, 11 (79%) were IgG positive and 1 (7%) was IgM positive for chlamydial LPS antibodies. In the control group, 36, 79 and 7% were IgA, IgG and IgM positive and showed no significant difference. IgA, IgG and IgM antibodies to C. pneumoniae were found in 43, 79 and 0% and did not differ from matched controls. By the nucleic acid amplification test, specific C. pneumo niae sequences were neither detected in the AION patients nor in the control group. These data do not support the association of AION with previous C. pneumoniae infection. However, it remains unclear whether Chlamydia actually initiates atherosclerotic injury, facilitates its progression or plays another role in other vascular disorders.     

Familial non-arteritic anterior ischemic optic neuropathy

PURPOSE: Primary objective was to investigate clinical characteristics of nonarteritic anterior ischemic optic neuropathy (NA-AION) in three families; secondarily, to test these families for a previously detected mitochondrial mutation in a pedigree with familial NA-AION. METHODS: Study comprised three families where more than one member developed NA-AION. All patients with NA-AION had a detailed ophthalmic, medical and family history, and comprehensive ophthalmic evaluation at initial visit and on follow-up. One patient from family 1, one from family 2, 41 non-familial NA-AION patients, 97 control subjects and 1,488 patients with suspected Leber hereditary optic neuropathy (LHON) were tested for the presence of mitochondrial mutation (G4132A) in a previously reported genetic study of family 3. RESULTS: Familial NA-AION was found in seven individuals of family 1, four of family 2 and six of family 3. Symptoms, signs and clinical findings of familial NA-AION were similar to classical NA-AION, with two exceptions: familial NA-AION had an earlier onset (47.3 + 8.6 years versus 60.1 + 13.6 years) and a higher frequency of bilateral disease. The G4132A mitochondrial variant was not detected outside family 3. None of the three major mutations associated with LHON (G3460A, G11778A, T14484C) was found among Familial NA-AION patients. CONCLUSIONS: The only difference in clinical features between familial NA-AION and classical NA-AION is that the former has an earlier onset and a higher frequency of bilateral disease. The G4132A mutation is not commonly associated with familial NA-AION, and was not detected in patients with non-familial NA-AION. The role of hereditary factors in familial NA-AION remains largely unknown.     

Bilateral arteritic anterior ischemic optic neuropathy

Background

Arteritic anterior ischemic optic neuropathy (AION) is a disease of the optic nerve head seen in patients over the age of 50 and more commonly over the age of 70. With few exceptions, arteritic AION is caused by giant cell arteritis. Early diagnosis and prompt treatment with corticosteroids are essential for preventing potentially devastating visual loss from this disease.

Case Report

A 63-year-old white man presented with the complaints of blurred vision of the right eye and visual field loss of the left eye. Ocular examination found bilateral swollen optic nerve heads. Visual field testing showed altitudinal defects in each eye. Laboratory testing was significant for elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels. The patient was treated with oral prednisone for arteritic AION and referred to a rheumatologist. At follow-up, the patient’s ESR and CRP levels showed significant improvement. The optic nerve head of the left eye showed a reduction in swelling, and the visual field finding was stable.

Conclusion

Arteritic AION is an ocular emergency. Optometrists need to be able to recognize and diagnose this condition quickly to initiate critical corticosteroid treatment.