Sohan Singh Hayreh

University of Iowa, Iowa City, Iowa, United States

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Publications (252)835.76 Total impact

  • Sohan Singh Hayreh, M Bridget Zimmerman
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    ABSTRACT: To investigate systematically the retinal changes in branch retinal vein occlusion (BRVO) and their natural history. The study comprised 214 consecutive patients with BRVO (144 major BRVO and 72 macular BRVO eyes) seen within 3 months of onset. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. Initially, retinal hemorrhages were moderate to severe in the perifovea and macula in at least 65% in major and 52% in macular BRVO; at the fovea, it was 51% in major and 36% in macular BRVO. Initially, macular edema was more marked in major BRVO than in macular BRVO (P = 0.007). Major BRVO had a significantly higher rate of development of serous macular detachment (P = 0.002), epiretinal membrane (P = 0.008), serous retinal detachment (P = 0.002), perivenous sheathing (P < 0.0001), optic disk pallor (P < 0.0001), and lipid deposit (P < 0.0001) compared with macular BRVO. Retinal and disk neovascularization was seen only in major BRVO. The time to resolution of BRVO was significantly longer for major BRVO compared with macular BRVO (P = 0.0002). Major and macular BRVOs are two distinct clinical entities. Initial and final fundus findings in the two types differ markedly.
    Retina (Philadelphia, Pa.) 01/2015; DOI:10.1097/IAE.0000000000000418 · 2.93 Impact Factor
  • Sohan Singh Hayreh, M Bridget Zimmerman
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    ABSTRACT: To investigate systematically the retinal and optic disk changes in central retinal vein occlusion (CRVO) and their natural history.
    Retina (Philadelphia, Pa.) 07/2014; 35(1). DOI:10.1097/IAE.0000000000000256 · 2.93 Impact Factor
  • Sohan Singh Hayreh
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    ABSTRACT: Ocular vascular occlusive disorders collectively constitute the most common cause of visual disability. Before a disease can be managed, it is essential to understand its natural history, so as to be able to assess the likely effectiveness of any intervention. I investigated natural history of visual outcome in prospective studies of 386 eyes with non-arteritic anterior ischemic optic neuropathy (NA-AION), 16 eyes with non-arteritic posterior ischemic optic neuropathy, 697 eyes with central retinal vein occlusion (CRVO), 67 eyes with hemi-CRVO (HCRVO), 216 eyes with branch retinal vein occlusion (BRVO), 260 eyes with central retinal artery occlusion (CRAO), 151 eyes with branch retinal artery occlusion (BRAO) and 61 eyes with cilioretinal artery occlusion (CLRAO). My studies have shown that every one of these disorders consists of multiple distinct clinical sub-categories with different visual findings. When an ocular vascular occlusive disorder is caused by giant cell arteritis, which is an ophthalmic emergency, it would be unethical to do a natural history study of visual outcome in them, because in this case early diagnosis and immediate, intensive high-dose steroid therapy is essential to prevent any further visual loss, not only in the involved eye but also in the fellow, normal eye. In NA-AION in eyes seen <2 weeks after the onset, visual acuity (VA) improved in 41% of those with VA 20/70 or worse, and visual field (VF) improved in 26% of those with moderate to severe VF defect. In non-ischemia CRVO eyes with VA 20/70 or worse, VA improved in 47% and in ischemic CRVO in 23%; moderate to severe VF defect improved in 79% in non-ischemic CRVO and in 27% in ischemic CRVO. In HCRVO, overall findings demonstrated that initial VA and VF defect and the final visual outcome were different in non-ischemic from ischemic HCRVO - much better in the former than the latter. In major BRVO, in eyes with initial VA of 20/70 or worse, VA improved in 69%, and moderate to severe VF defect improved in 52%. In macular BRVO with 20/70 or worse initial VA, it improved in 53%, and initial minimal-mild VF defect was stable or improved in 85%. In various types of CRAO there are significant differences in both initial and final VA and VF defects. In CRAO eyes seen within 7 days of onset and initial VA of counting fingers or worse, VA improved in 82% with transient non-arteritic CRAO, 67% with non-arteritic CRAO with cilioretinal artery sparing, 22% with non-arteritic CRAO. Central VF improved in 39% of transient non-arteritic CRAO, 25% of non-arteritic CRAO with cilioretinal artery sparing and 21% of non-arteritic CRAO. Peripheral VF improved in non-arteritic CRAO in 39% and in transient non-arteritic CRAO in 39%. In transient CRAO, finally peripheral VFs were normal in 93%. In non-arteritic CRAO eyes initially 22% had normal peripheral VF and in the rest it improved in 39%. Final VA of 20/40 or better was seen in 89% of permanent BRAO, and in 100% of transient BRAO and nonarteritic CLRAO. In permanent BRAO eyes, among those seen within 7 days of onset, central VF defect improved in 47% and peripheral VF in 52%, and in transient BRAO central and peripheral VFs were normal at follow-up. My studies showed that AION, CRVO, BRVO, CRAO and BRAO, each consist of multiple distinct clinical sub-categories with different visual outcome. Contrary to the prevalent impression, these studies on the natural history of visual outcome have shown that there is a statistically significant spontaneous visual improvement in each category. The factors which influence the visual outcome in various ocular vascular occlusive disorders are discussed.
    Progress in Retinal and Eye Research 04/2014; DOI:10.1016/j.preteyeres.2014.04.001 · 9.90 Impact Factor
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    Sohan Singh Hayreh
    Expert Review of Ophthalmology 01/2014; 2(6). DOI:10.1586/17469899.2.6.889
  • Sohan Singh Hayreh, M. Bridget Zimmerman
    01/2014; 132(1):13. DOI:10.1001/jamaophthalmol.2013.5515
  • Sohan Singh Hayreh, M Bridget Zimmerman
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    ABSTRACT: In patients with bilateral sequential nonarteritic anterior ischemic optic neuropathy (NA-AION), previous studies have reported conflicting results on whether or not the visual outcome is similar in the 2 eyes. The authors investigated this issue in 174 consecutive patients with bilateral NA-AION. At the first visit, all patients had a detailed ophthalmic and medical history and comprehensive ophthalmic evaluation. Visual evaluation was performed by recording Snellen visual acuity and visual fields with kinetic perimetry. The same ophthalmic evaluation was performed at each follow-up visit. The data on the difference in visual acuity, which was converted to logarithm of the minimum angle of resolution (logMAR) form, and visual field defects between the first eye and the second eye of each patient at the initial visit and at the final follow-up were analyzed. A similar subgroup analysis was performed on patients treated with systemic corticosteroids. At presentation, both initial visual acuity and visual field defects were significantly better in the second eye than in the first eye (P < 0.0001). As a predictor of initial visual acuity in the second eye, the initial logMAR of the first eye only explained 7.0% (R) of the total variation in the initial logMAR of the second eye. Intraclass correlation (ICC) between the paired eyes was 0.19 (95% confidence interval [CI], 0.04-0.33), indicating poor agreement. The absolute difference in initial visual field grade between the 2 eyes was 0.5 or greater in 78%. The weighted kappa statistic for agreement between visual field defects of the 2 eyes was 0.27 (95% CI, 0.19-0.36), indicating poor agreement. At the final follow-up, a difference in logMAR of at least 0.3 between the paired eyes was found in 38% of the steroid-treated group and 45% of the untreated group. For visual field grade, there was a difference of at least 0.5 in 70% of those who were treated with steroid and in 76% of those not treated. The ICC for logMAR and weighted kappa for visual field grade for the paired eyes was below 0.60 for both the groups. The findings indicated poor agreement between the 2 eyes. The results show that in patients with bilateral sequential NA-AION, there are large differences between the visual acuity and visual field findings of paired eyes at initial and final visit, whether or not treated with steroids. It is not possible to predict the visual acuity and visual field grade in the second eye based solely on the first eye.
    Journal of neuro-ophthalmology: the official journal of the North American Neuro-Ophthalmology Society 07/2013; 33(4). DOI:10.1097/WNO.0b013e31829b5d03 · 1.09 Impact Factor
  • Sohan Singh Hayreh
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    ABSTRACT: Ischemic optic neuropathy is of two types: anterior and posterior. Non-arteritic anterior ischemic optic neuropathy (NA-AION) is the most common type of ischemic optic neuropathy. There are three major misconceptions about NA-AION: (1) that its pathogenesis is not known, (2) that NA-AION and ischemic cerebral stroke are similar in nature, pathogenetically and in management, and (3) that there is no treatment. All these misconceptions are based on lack of in-depth knowledge of the subject. They are discussed in the light of our current scientific knowledge. The pathogenesis of NA-AION is known but is highly complex. NA-AION and ischemic cerebral stroke are very different clinical entities, pathogenetically and in management. Aspirin has no beneficial effect. Corticosteroid therapy during the initial stages can be beneficial. To reduce the risk of development of NA-AION in the other eye or of further visual loss in the same eye, it is essential to reduce as many risk factors as possible. Management of arteritic anterior ischemic optic neuropathy and of posterior ischemic optic neuropathy is discussed.
    Albrecht von Graæes Archiv für Ophthalmologie 07/2013; DOI:10.1007/s00417-013-2399-z · 1.93 Impact Factor
  • Sohan S Hayreh, M Bridget Zimmerman
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    ABSTRACT: PURPOSE:: To investigate systematically the prevalence of amaurosis fugax (AF) in various ocular vascular occlusive disorders individually and to discuss the pathogeneses of each. METHODS:: The study comprised patients with central retinal artery occlusion (271 eyes), branch retinal artery occlusion (169 eyes), ocular ischemic syndrome (39 eyes), central retinal vein occlusion (864 eyes), hemi-central retinal vein occlusion (67 eyes), branch retinal vein occlusion (285 eyes), nonarteritic anterior ischemic optic neuropathy (946 eyes), and giant cell arteritis with visual loss (147 eyes). At first visit, all patients had a detailed ophthalmic and medical history and comprehensive ophthalmic evaluation and systemic evaluation. RESULTS:: Prevalence of AF was 12.18% in central retinal artery occlusion, 14.20% in branch retinal artery occlusion, 15.38% in ocular ischemic syndrome, 4.86% in central retinal vein occlusion, 37.84% in central retinal vein occlusion with cilioretinal artery occlusion, 13.43% in hemi-central retinal vein occlusion, 0.35% in branch retinal vein occlusion, and 2.54% in nonarteritic anterior ischemic optic neuropathy. In giant cell arteritis, 32.4% of patients with ocular involvement had a history of AF or 26.5% of the involved eyes. Amaurosis fugax in central retinal artery occlusion, branch retinal artery occlusion, and nonarteritic anterior ischemic optic neuropathy is mostly because of transient embolism. The pathogenesis of AF in each ocular vascular occlusive disorder is discussed. CONCLUSION:: Prevalence and pathogenesis of AF in various ocular vascular occlusive disorders varies widely. Amaurosis fugax may be the presenting symptom in these disorders and that always requires urgent evaluation.
    Retina (Philadelphia, Pa.) 04/2013; DOI:10.1097/IAE.0b013e31829234b5 · 2.93 Impact Factor
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    Jost B Jonas, Sohan S Hayreh, Yong Tao
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    ABSTRACT: Objective:To investigate the clinicopathological correlation of parapapillary atrophy.Materials and Methods:The study included 16 eyes of rhesus monkeys (Macaca mulatta) – 4 eyes with experimental glaucoma, 11 eyes after experimental temporary occlusion of the central retinal artery, and 1 normal eye. On histological sections, we measured zones with different histological characteristics. On fundus photographs, alpha zone and beta zone of parapapillary atrophy were measured and correlated with the histological data.Results:The size of the clinical alpha zone of parapapillary atrophy was significantly correlated with the size of the histological region with irregularities of the retinal pigment epithelium (P = 0.05; correlation coefficient r = 0.49) and with the size of the histological region with a decreased density of retinal photoreceptors (P = 0.01; r = 0.60). The size of clinical beta zone of parapapillary atrophy significantly correlated with the size of the histological region with complete loss of the retinal pigment epithelium (P <0.001; r = 0.91), with the size of the histological zone with a complete loss of photoreceptors (P <0.001; r = 0.81), and with the size of the histological zone with a closed choriocapillaris (P <0.001; r = 0.89).Conclusions:The clinically seen alpha zone of parapapillary atrophy correlates with histological parapapillary irregularities of the retinal pigment epithelium and decreased density of retinal photoreceptors. The clinically seen beta zone of parapapillary atrophy correlates with histological complete loss of the retinal pigment epithelium and of the photoreceptors, and a closure of the choriocapillaris.
    Indian Journal of Ophthalmology 04/2013; 62(2). DOI:10.4103/0301-4738.111216 · 0.93 Impact Factor
  • Sohan Singh Hayreh, Valérie Biousse
    Journal of neuro-ophthalmology: the official journal of the North American Neuro-Ophthalmology Society 09/2012; 32(3):278-87. DOI:10.1097/WNO.0b013e3182688218 · 1.09 Impact Factor
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    ABSTRACT: : To investigate the effect of cup to disk (C/D) ratio in various types of retinal vein occlusion (RVO) on the severity of retinopathy, visual outcome, and resolution of retinopathy and validity of the concept of the "compartment syndrome" in RVO. : The study comprised 1,222 consecutive eyes (768 central retinal vein occlusion [CRVO], 183 hemi-CRVO, and 271 branch retinal vein occlusion). Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. : Compared to sex-matched and age-matched normal eyes, C/D ratio ≥0.5 was significantly more common in all CRVOs and hemi-CRVO eyes but not in branch retinal vein occlusion. Retinal hemorrhages were significantly more severe in nonischemic CRVO with C/D ratio ≥0.5 compared to those with no or small cup, but no difference was found in hemi-CRVO and branch RVO. In ischemic CRVO, moderate hemorrhages were more with C/D ≥0.5 but severe hemorrhages were more with no cup. In various types of RVO, there was no significant association of C/D ratio with macular edema, retinopathy resolution, visual acuity, and visual field defect. : The findings of our study contradict the concept that the "compartment syndrome" plays any role in the prevalence of various types of RVO or in their severity, the resolution of retinopathy, or the visual outcome. This indicates that the advocated procedure of radial optic neurotomy, based on the compartment syndrome, is not a logical treatment for CRVO.
    Retina (Philadelphia, Pa.) 08/2012; 32(10):2108-18. DOI:10.1097/IAE.0b013e31825620f2 · 2.93 Impact Factor
  • Sohan Singh Hayreh
    Albrecht von Graæes Archiv für Ophthalmologie 05/2012; 251(3). DOI:10.1007/s00417-012-2062-0 · 1.93 Impact Factor
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    ABSTRACT: To evaluate changes in cup/disc (C/D) diameter ratios and parapapillary atrophy in patients with non-arteritic anterior ischemic optic neuropathy (NA-AION), using morphometric methods. The clinical non-interventional study included 157 patients with unilateral or bilateral NA-AION. Optic disc photographs taken from both eyes at the end of follow-up were morphometrically examined. Follow-up was 86.3±70.3 months. Horizontal and vertical disc diameters (P = 0.30;P = 0.61, respectively), horizontal and vertical C/D ratios (P = 0.47;P = 0.19,resp.), and size of alpha zone and beta zone of parapapillary atrophy (P = 0.27;P = 0.32,resp.) did not differ significantly between affected eyes and contralateral normal eyes in patients with unilateral NA-AION. Similarly, horizontal and vertical disc diameters, horizontal and vertical C/D ratios, and size of alpha zone and beta zone did not vary significantly (all P>0.05) between the unaffected eyes of patients with unilateral NA-AION and the eyes of patients with bilateral NA-AION. Optic disc diameters, C/D ratios, size of alpha zone or beta zone of parapapillary atrophy were not significantly associated with final visual outcome in the eyes affected with NA-AION (all P>0.20) nor with the difference in final visual acuity between affected eyes and unaffected eyes in patients with unilateral NA-AION (all P>0.25). NA-AION did not affect C/D ratios nor alpha zone and beta zone of parapapillary atrophy. Optic disc size was not related to the final visual acuity outcome in NA-AION.
    PLoS ONE 05/2012; 7(5):e37499. DOI:10.1371/journal.pone.0037499 · 3.53 Impact Factor
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    Sohan Singh Hayreh
    Albrecht von Graæes Archiv für Ophthalmologie 04/2012; 250(9):1255-60. DOI:10.1007/s00417-012-2026-4 · 1.93 Impact Factor
  • Sohan Singh Hayreh, M Bridget Zimmerman
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    ABSTRACT: To investigate the incidence of ocular neovascularization (NV) in central and hemicentral retinal vein occlusion. The study comprised consecutive 912 (673 nonischemic and 239 ischemic) central retinal vein occlusion and 190 (147 nonischemic, 43 ischemic) hemicentral retinal vein occlusion eyes. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. In ischemic central retinal vein occlusion, within 6 months from time of onset, the cumulative probability of development of iris NV was 49%, angle NV 37%, NV glaucoma 29%, retinal NV 9%, and disk NV 6%. More severe peripheral retinal hemorrhages were significantly associated with iris NV (P = 0.005), angle NV (P = 0.0004), and NV glaucoma (P = 0.012). Eyes that developed disk NV had more cotton wool spots (P = 0.058) than those without. In ischemic hemicentral retinal vein occlusion, within 12 months of onset, the cumulative probability of development of retinal NV was 29%, disk NV 12%, and iris NV 12%; within 6 months of onset, angle NV was found in 10% and NV glaucoma in 5%. Anterior chamber flare was associated with anterior segment NV and may precede the development of NV. Patients who developed NV were significantly younger, and there was a greater prevalence of NV glaucoma in patients with primary open angle glaucoma. In ischemic central retinal vein occlusion, anterior segment NV is much more common than posterior segment NV, and the cumulative chance of developing anterior segment NV is maximum during the first 6 months. In ischemic hemicentral retinal vein occlusion, posterior segment NV is much more common than anterior segment NV.
    Retina (Philadelphia, Pa.) 04/2012; 32(8):1553-65. DOI:10.1097/IAE.0b013e318246912c · 2.93 Impact Factor
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    Sohan Singh Hayreh
    The British journal of ophthalmology 09/2011; 95(11):1617-8. DOI:10.1136/bjophthalmol-2011-300799 · 2.92 Impact Factor
  • Sohan Singh Hayreh, M Bridget Zimmerman
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    ABSTRACT: To investigate the natural history of visual outcome in hemicentral retinal vein occlusion (HCRVO). The study comprised 65 consecutive HCRVO patients (67 eyes) seen within 3 months of onset. At first visit, all patients had a detailed ophthalmic and medical history and comprehensive ophthalmic evaluation. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity using the Snellen visual acuity chart, and visual fields with a Goldmann perimeter. Hemicentral retinal vein occlusion was classified into nonischemic (57 eyes) and ischemic (10 eyes) at initial visit. Nonischemic HCRVO involved superior and inferior half of the retina in 39% and 56%, respectively, and in ischemic HCRVO in 50% and 40%, respectively. In nonischemic HCRVO, initial visual acuity was 20/60 or better in 73.7% and minimal to mild visual field loss in 96% and in ischemic HCRVO in 40% and 55.5%, respectively. After resolution of macular edema, in nonischemic HCRVO eyes, cumulative chance of improvement was 50% with 20/70 or worse initial visual acuity, and deterioration in only 6% with 20/60 or better initial visual acuity, and in 5% with minimal to mild visual initial field loss. This study suggests a good prognosis in the natural history of visual outcome in nonischemic HCRVO.
    Retina (Philadelphia, Pa.) 08/2011; 32(1):68-76. DOI:10.1097/IAE.0b013e31821801f5 · 2.93 Impact Factor
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    ABSTRACT: To investigate systematically the role of anti-platelet-aggregating drugs or anticoagulants in central retinal vein occlusion (CRVO) and hemi-CRVO. Cohort study. Six hundred eighty-six consecutive patients with CRVO (567 patients, 585 eyes) and nonischemic hemi-CRVO (119 patients, 122 eyes). At first visit, all patients had a detailed ophthalmic and medical history (including the use of anti-platelet aggregating drugs or anticoagulants), and comprehensive ophthalmic and retinal evaluation. Visual evaluation was carried out by recording visual acuity, using the Snellen visual acuity chart, and visual fields with a Goldmann perimeter. The same ophthalmic evaluation was performed at each follow-up visit. At the initial visit, CRVO and hemi-CRVO were classified as nonischemic and ischemic. Visual acuity, visual fields, and severity of retinal hemorrhages. All 3 types of CRVO, showed a significantly greater severity of retinal hemorrhages among aspirin users than nonusers (P<0.001). Initial visual acuity and visual fields were significantly worse in aspirin users than nonusers in nonischemic CRVO and hemi-CRVO, but did not differ for ischemic CRVO. Among patients with nonischemic CRVO who initially had 20/60 or better visual acuity, there was a significant association of aspirin use with visual acuity deterioration. The odds ratio of visual acuity deterioration, adjusting for age, diabetes, ischemic heart disease, and hypertension, for aspirin users relative to nonusers was 2.24 (95% confidence interval [CI], 1.14-4.41; P = 0.020). Of those whose macular edema resolved, overall cumulative visual acuity outcome also suggested a higher percentage with deterioration among aspirin users, odds ratio for deterioration of 3.62 (95% CI, 0.97-13.54; P = 0.05) for aspirin users relative to nonusers. For the nonischemic CRVO patients with 20/70 or worse visual acuity at the initial visit, after resolution of macular edema, improvement in visual acuity was less likely in the aspirin users than in nonusers (odds ratio, 0.18; 95% CI, 0.04-0.72; P = 0.016). Findings of this study indicate that, for patients with CRVO and hemi-CRVO, the use of aspirin, other anti-platelet aggregating agents, or anticoagulants was associated with a worse visual outcome and no apparent benefit. The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 06/2011; 118(8):1603-11. DOI:10.1016/j.ophtha.2011.04.036 · 5.56 Impact Factor
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    Sohan Singh Hayreh
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    ABSTRACT: The initial section deals with basic sciences; among the various topics briefly discussed are the anatomical features of ophthalmic, central retinal and cilioretinal arteries which may play a role in acute retinal arterial ischemic disorders. Crucial information required in the management of central retinal artery occlusion (CRAO) is the length of time the retina can survive following that. An experimental study shows that CRAO for 97min produces no detectable permanent retinal damage but there is a progressive ischemic damage thereafter, and by 4h the retina has suffered irreversible damage. In the clinical section, I discuss at length various controversies on acute retinal arterial ischemic disorders. Classification of acute retinal arterial ischemic disorders: These are of 4 types: CRAO, branch retinal artery occlusion (BRAO), cotton wool spots and amaurosis fugax. Both CRAO and BRAO further comprise multiple clinical entities. Contrary to the universal belief, pathogenetically, clinically and for management, CRAO is not one clinical entity but 4 distinct clinical entities - non-arteritic CRAO, non-arteritic CRAO with cilioretinal artery sparing, arteritic CRAO associated with giant cell arteritis (GCA) and transient non-arteritic CRAO. Similarly, BRAO comprises permanent BRAO, transient BRAO and cilioretinal artery occlusion (CLRAO), and the latter further consists of 3 distinct clinical entities - non-arteritic CLRAO alone, non-arteritic CLRAO associated with central retinal vein occlusion and arteritic CLRAO associated with GCA. Understanding these classifications is essential to comprehend fully various aspects of these disorders. Central retinal artery occlusion: The pathogeneses, clinical features and management of the various types of CRAO are discussed in detail. Contrary to the prevalent belief, spontaneous improvement in both visual acuity and visual fields does occur, mainly during the first 7 days. The incidence of spontaneous visual acuity improvement during the first 7 days differs significantly (p<0.001) among the 4 types of CRAO; among them, in eyes with initial visual acuity of counting finger or worse, visual acuity improved, remained stable or deteriorated in non-arteritic CRAO in 22%, 66% and 12% respectively; in non-arteritic CRAO with cilioretinal artery sparing in 67%, 33% and none respectively; and in transient non-arteritic CRAO in 82%, 18% and none respectively. Arteritic CRAO shows no change. Recent studies have shown that administration of local intra-arterial thrombolytic agent not only has no beneficial effect but also can be harmful. Prevalent multiple misconceptions on CRAO are discussed. Branch retinal artery occlusion: Pathogeneses, clinical features and management of various types of BRAO are discussed at length. The natural history of visual acuity outcome shows a final visual acuity of 20/40 or better in 89% of permanent BRAO cases, 100% of transient BRAO and 100% of non-arteritic CLRAO alone. Cotton wools spots: These are common, non-specific acute focal retinal ischemic lesions, seen in many retinopathies. Their pathogenesis and clinical features are discussed in detail. Amaurosis fugax: Its pathogenesis, clinical features and management are described.
    Progress in Retinal and Eye Research 05/2011; 30(5):359-94. DOI:10.1016/j.preteyeres.2011.05.001 · 9.90 Impact Factor
  • Sohan Singh Hayreh
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    ABSTRACT: Ischemic optic neuropathies (IONs) consist primarily of two types: anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). AION comprises arteritic AION (A-AION: due to giant cell arteritis) and non-arteritic AION (NA-AION: due to other causes). PION consists of arteritic PION (A-PION: due to giant cell arteritis), non-arteritic PION (NA-PION: due to other causes), and surgical PION (a complication of several systemic surgical procedures). These five types of ION are distinct clinical entities etiologically, pathogenetically, clinically and from the management point of view. In the management of AION, the first crucial step with patients aged 50 and over is to identify immediately whether it is arteritic or not because A-AION is an ophthalmic emergency and requires urgent treatment with high-dose steroid therapy to prevent any further visual loss in one or both eyes. Patients with NA-AION, when treated with systemic corticosteroid therapy within first 2 weeks of onset, had significantly better visual outcome than untreated ones. Systemic risk factors, particularly nocturnal arterial hypotension, play major roles in the development of NA-AION; management of them is essential in its prevention and management. NA-PION patients, when treated with high-dose systemic steroid therapy during the very early stages of the disease, showed significant improvement in visual acuity and visual fields, compared to untreated eyes. A-PION, like A-AION, requires urgent treatment with high-dose steroid therapy to prevent any further visual loss in one or both eyes. There is no satisfactory treatment for surgical PION, except to take prophylactic measures to prevent its development.
    Indian Journal of Ophthalmology 03/2011; 59(2):123-36. DOI:10.4103/0301-4738.77024 · 0.93 Impact Factor

Publication Stats

9k Citations
835.76 Total Impact Points

Institutions

  • 1974–2015
    • University of Iowa
      • • Department of Ophthalmology and Visual Sciences
      • • Department of Pediatrics
      • • Department of Biostatistics
      Iowa City, Iowa, United States
  • 2009–2012
    • University of Iowa Children's Hospital
      Iowa City, Iowa, United States
  • 1999–2000
    • Friedrich-Alexander Universität Erlangen-Nürnberg
      • Department of Ophthalmology
      Erlangen, Bavaria, Germany
    • University of Lausanne
      Lausanne, Vaud, Switzerland
  • 1989
    • University of Illinois at Chicago
      • Department of Ophthalmology and Visual Sciences (Chicago)
      Chicago, Illinois, United States
  • 1987
    • University of Michigan
      Ann Arbor, Michigan, United States
  • 1972
    • The University of Edinburgh
      Edinburgh, Scotland, United Kingdom