Ischaemic papillopathy. Clinical and fluorescein aniographic review of forty cases

Exploring the contribution of carotid artery disease to the onset of non-arteritic ischemic optic neuropathies: A systematic review

PURPOSE

The role of carotid artery disease (CAD) in the development of various types of ocular arterial occlusive disorders has often been reported. This systematic review aims to evaluate and review the current evidence regarding the role of CAD and the subsequent carotid artery hemodynamic alterations in the development of non-arteritic anterior (NA-AION) and posterior (NA-PION) ischemic optic neuropathy.

METHODS

We systematically reviewed studies following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We systematically searched PubMed, Embase, and Scopus databases for relevant studies that clearly assessed the role of CAD and the subsequent carotid artery hemodynamic alterations in the development of NA-AION and NA-PION. All studies that examined the associations between CAD and the development of NA-AION and NA-PION in adults aged 18 years or older were synthesized. Quality assessment using the Newcastle-Ottawa Scale (NOS), and Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports and Case-Series were also conducted.

RESULTS

Our search identified 1933 manuscripts published in the English language. The number of participants with non-arteritic ischemic optic neuropathy (NA-ION) ranged from 1 to 191, with a total of 478 patients experiencing either NA-AION (410 out of 478), NA-PION (13 out of 478), or a combination of thereof (1 out of 478). The number of participants with NA-ION due to atherosclerosis ranged from 1 to 191, with a total of 376 patients.

CONCLUSIONS

Although carotid artery disease may rarely contribute to the development of NA-ION, it should be considered as a possible cause of NA-ION.

Impact of Lipid Parameters on Visual Acuity Change in Non-Arteritic Anterior Ischemic Optic Neuropathy

Purpose

To assess the potential influence of serum biochemical factors, specifically lipid profile parameters, on visual outcomes in patients with non-arteritic anterior ischemic optic neuropathy (NAION).

Patients and Methods

All patients diagnosed with NAION at Rajavithi Hospital between 1 January 2011 and 31 December 2020 were retrospectively reviewed. The primary outcome was defined as visual recovery, measured by an improvement of at least 0.2 logarithm of the minimal angle of resolution (logMAR) in their best-corrected visual acuity (BCVA) at the 12-weeks follow-up visit compared to the initial visit and determine whether those lipid profiles parameters are predictive of 12 weeks-visual outcomes. Factors of an initial poor VA were evaluated using logistic regression analysis.

Results

In this study, 84 patients with NAION were included to assess the impact of lipid parameters on visual outcomes. Majority of participants were male. The group with initial VA worse than 20/200 had significantly higher mean age of 58.3±7.6 years and levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL) (all p < 0.05 respectively). Throughout 12 weeks, a significant difference in change of BCVA between the two groups of initial VA was observed (p<0.001). Regarding lipid parameters on visual prognosis, lipid profile between the two groups of VA improvement of 0.2 logMAR was comparable different. The probability of VA improvement showed a weak association with TC levels. A gradual increase in probability slightly related to LDL parameter, while TG showed an inverse relationship. At elevated lipid levels, there was a greater degree of uncertainty in predicting visual outcomes.

Conclusion

While older age and elevated lipid levels, specifically TC, TGs, and LDL, were correlated with poorer initial visual acuity in NAION patients, no significant associations were identified between lipid parameters and long-term visual recovery. Early detection for individuals with dyslipidemia (DLP) and advanced age merit attention.

NAION or not NAION? A literature review of pathogenesis and differential diagnosis of anterior ischaemic optic neuropathies

PURPOSE

To offer a comprehensive review of the available data regarding non-arteritic anterior ischaemic optic neuropathy and its phenocopies, focusing on the current evidence to support the different existing aetiopathogenic hypotheses for the development of these conditions.

CONCLUSIONS AND IMPORTANCE

Due to the limited array of responses of the neural tissue and other retinal structures, different aetiopathogenic mechanisms may result in a similar clinical picture. Moreover, when the insult occurs within a confined space, such as the optic nerve or the optic nerve head, in which different tissues (neural, glial, vascular) are highly interconnected and packed together, determining the primary noxa can be challenging and may lead to misdiagnosis. Anterior ischaemic optic neuropathy is a condition most clinicians will face during their everyday work, and it is important to correctly differentiate among resembling pathologies affecting the optic nerve to avoid unnecessary diagnostic procedures. Combining a good clinical history and multimodal imaging can assist diagnosis in most cases. The key remains to combine demographic data (e.g. age), with ophthalmic data (e.g. refractive error), systemic data (e.g. comorbidities and medication), imaging data (e.g. retinal OCT) with topographic signs (e.g. focal neurology).

METHODOLOGY

Papers relevant for this work were obtained from the MEDLINE and Embase databases by using the PubMed search engine. One author (MPMG) performed the search and selected only publications with relevant information about the aetiology, pathogenic mechanisms, risk factors as well as clinical characteristics of phenocopies (such as vitreopapillary traction, intrapapillary haemorrhage with adjacent peripapillary subretinal haemorrhage or diabetic papillopathy) of non-arteritic anterior ischaemic optic neuropathy (NAION). The terms "non-arteritic ischaemic optic neuropathy/NAION", "vitreopapillary traction", "vitreopapillary traction AND non-arteritic ischaemic optic neuropathy/NAION", "posterior vitreous detachment AND non-arteritic ischaemic optic neuropathy/NAION", "central retinal vein occlusion AND non-arteritic ischaemic optic neuropathy/NAION", "disc oedema/disc oedema", "diabetes mellitus AND non-arteritic ischaemic optic neuropathy/NAION" and "diabetic papillopathy" were searched on PubMed. From each of these searches, publications were selected based on their title, obtaining a total of 115 papers. All papers not written in English were then excluded, and those whose abstracts were not deemed relevant for our review, according to the aforementioned criteria. Subsequent scrutiny of the main text of the remaining publications led us (MPMG, AP, ZS) to include references which had not been selected during our first search, as their titles did not contain the previously mentioned MeSH terms, due to their significantly relevant contents for our work. A total of 62 publications were finally consulted for our review. The literature review was last updated on 24-Aug-2022.

Vascular supply of the optic nerve head: implications for optic disc ischaemia

The vascular supply of the optic nerve head is complex and remains incompletely delineated. Over the past 50 years, various investigators have attempted to clarify the relative contributions of the choroid, the short posterior ciliary arteries and the central retinal artery to the vascular beds of the inner retinal, prelaminar, laminar and retrolaminar segments of the nerve head. Conflicting theories have evolved, in no small part due to differing techniques of study, involving both flow parameters and anatomical constructs. These have included studies, both in normal subjects and in those with optic nerve ischaemia, of histopathology, electron microscopic corrosion casting, orbital colour Doppler flow studies, fluorescein angiography, indocyanine green angiography, laser Doppler flow studies, laser speckle flowgraphy, microperfusion and labelling studies and optical coherence tomography angiography. The nature of the optic disc, peripapillary retina and choroid microvasculature has implications for the pathophysiology of ischaemic optic neuropathy.

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

Background and objective

Non-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.

Methods

All 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.

Results

The 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).

Conclusions

None 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.

Choroidal involvement in systemic vasculitis: a systematic review

Systemic vasculitides are a large group of heterogeneous diseases characterized by inflammatory destruction of blood vessels targeting diverse organs and tissues including the eye. As the most vascularized layer of the eye, the choroid is expected to be affected in multiple systemic rheumatologic diseases with vascular involvement. While there are plenty of studies investigating retinal vascular involvement, choroidal vascular involvement in systemic vasculitides has not been investigated in isolation. However, choroidal manifestations including thickness changes, choroidal vasculitis and ischemia may be the earliest diagnostic features of systemic vasculitic diseases. Thus, multimodal imaging of the choroid may help early detection of choroidal involvement which may also have prognostic implications in these life-threatening diseases. This article aimed to review involvement of the choroid in systemic vasculitic diseases.

Clinical characteristics of progressive nonarteritic anterior ischemic optic neuropathy

AIM

To study whether patients with progressive nonarteritic anterior ischemic optic neuropathy (NAION) present earlier than patients with stable NAION and to describe their clinical characteristics and visual outcome.

METHODS

This was a retrospective chart review. All patients with NAION seen during the acute stage from January 2012 to December 2018 were reviewed. Patients were included if they had documented disc edema and follow up of at least 3mo. Patients with progressive NAION were identified if they worsened in 2 out of 3 parameters: visual acuity ≥3 Snellen lines; Color vision ≥4 Ishihara plates; the visual field defect involved a new quadrant. The clinical characteristics, time from symptom onset to presentation, systemic risk factors and visual outcome were compared to patients with stable NAION.

RESULTS

Totally 122 NAION cases met the inclusion criteria. Mean age was 58.1y (range 22-74), 70% were men. Twenty cases (16.4%) had progressive NAION. Patients with progressive NAION did not differ from stable NAION in their demographics, systemic risk factors or in their initial visual deficit. At last follow up, median visual acuity was 1.0 logMAR (IQR 0.64-1.55) in patients with progressive NAION, vs 0.18 (IQR 0.1-0.63) in stable NAION (P<0.001). Median color vision testing was 0 plates correct (IQR 0-2.5%) vs 92% plates correct (IQR 50%-100%) in the stable NAION group (P<0.001). Patients with progressive NAION differed in the time from symptom onset to presentation (median 2d vs 5d, P=0.011).

CONCLUSION

We find no identifiable risk factors associated with progressive NAION. Progressors arrive earlier for ophthalmological evaluation.

UNILATERAL OPTIC NEURITIS AND CENTRAL RETINAL VASCULITIS DUE TO OCULAR SYPHILIS

PURPOSE

Report a case of concurrent unilateral optic neuritis and central retinal artery occlusion as the presenting signs of syphilis.

METHODS

A case report of a 22-year-old man with progressive unilateral vision loss.

RESULTS

With no known previous history of syphilis, genital lesions, or other extraocular manifestations, the patient presented with pain with eye movements and decreased color vision. His vision dramatically worsened after a course of oral steroids. Examination was remarkable for severe right optic disk edema with a macular cherry-red spot and mild posterior uveitis. Magnetic resonance imaging of the orbits with contrast revealed enhancement and enlargement of the distal right optic nerve. Fluorescein angiography demonstrated delayed filling of the right central retinal artery, suggestive of impending central retinal artery occlusion. Syphilis serologies were positive from the serum, and cerebrospinal fluid Venereal Disease Research Laboratory test was reactive, consistent with neurosyphilis. Oral steroids were discontinued and vision improved with 2 weeks of intravenous penicillin.

CONCLUSION

This unusual case highlights one of the possible initial presentations of syphilis: unilateral optic neuritis and central retinal artery vasculitis with mild posterior uveitis. The worsening of vision after administration of oral steroids also highlights a potential complication of oral steroid use in the absence of a known etiology of vision loss. A thorough history and examination may be helpful in identifying risk factors for infectious causes, including syphilis, and should prompt additional evaluation.

Ischemic optic neuropathies and their models: disease comparisons, model strengths and weaknesses

Ischemic optic neuropathies (IONs) describe a group of diseases that specifically target the optic nerve and result in sudden vision loss. These include nonarteritic and arteritic anterior ischemic optic neuropathy (NAION and AAION) and posterior ischemic optic neuropathy (NPION, APION). Until recently, little was known of the mechanisms involved in ION damage, due to a lack of information about the mechanisms associated with these diseases. This review discusses the new models that closely mimic these diseases (rodent NAION, primate NAION, rodent PION). These models have enabled closer dissection of the mechanisms involved with the pathophysiology of these disorders and enable identification of relevant mechanisms and potential pathways for effective therapeutic intervention. Descriptions of the different models are included, and comparisons between the models, their relative similarities with the clinical disease, as well as differences are discussed.

Changes in Visual Function over Time in Koreans with Non-arteritic Anterior Ischaemic Optic Neuropathy

Non-arteritic anterior ischaemic optic neuropathy (NAION) causes severe visual loss in elderly patients. However, there are not much data of clinical course of NAION in Asian patients. To evaluate changes in visual acuity and visual field defects associated with non-arteritic anterior ischaemic optic neuropathy (NAION) among Korean patients, the medical records of 50 eyes from 43 patients with NAION patients seen from 1989 to 2011 were reviewed. A significant change in visual acuity was defined as a three-line change in Snellen acuity. Visual field defects were evaluated with Goldmann perimetry. Changes in the visual field were evaluated using the grid method. Thirty-eight percent of eyes showed improvement, 54% showed no change, and 8% showed deterioration of visual acuity at the last follow-up. Thirty-four percent of eyes showed improvement, 54% showed no change, and 12% showed deterioration of the visual field at the last follow-up. Most improvement in visual acuity occurred during the first month after the initial visit and in visual field between the first and third months of follow-up. The prognosis of visual acuity in association with NAION was worse in Korean patients as compared with Western studies. However, improved prognosis of visual field defects might come from the use of different methods for evaluation of the visual field.

Factors associated to temporal artery biopsy result in suspects of giant cell arteritis: a retrospective, multicenter, case-control study

PURPOSE

To evaluate the positivity rate of temporal artery biopsies (TAB) performed in suspects of giant cell arteritis (GCA) and to study the epidemiological and clinical factors associated to the biopsy result.

METHODS

A retrospective, multicenter, case-control study was performed, including three hundred and thirty-five patients who underwent TAB for a suspicion of GCA from 2001 to 2010. Clinical, epidemiological and pathology data were recovered from the patients' clinical records. Histologic diagnosis of GCA was made when active inflammation or giant cells were found in the arterial wall.

RESULTS

Eighty-one biopsies (24.2%) were considered positive for GCA. Clinical factors independently associated to TAB result in a logistic regression analysis were temporal cutaneous hyperalgesia (OR = 10.8; p < 0.001), jaw claudication (OR = 4.6; p = 0.001), recent-onset headache (OR = 4.4; p = 0.001), decreased temporal pulse (OR = 2.8; p = 0.02), pain and stiffness in neck and shoulders (OR = 2.3; p = 0.05), unintentional weight loss (OR = 1.33; p = 0.003) and age (OR = 1.085; p = 0.004). Other factors such as length of the surgical specimen (OR = 1.079; p = 0.028) and erythrocyte sedimentation rate (OR = 1.042; p < 0.001) were also statistically significant. The model was accurate (C-index = 0.921), reliable (pHosmer-Lemeshow = 0.733) and consistent in the bootstrap sensitivity analysis. No significant association was detected between TAB result and number of days of previous systemic corticosteroid treatment (p = 0.146). However, an association was observed between TAB result and the total accumulated dose of previous systemic corticotherapy (p = 0.043).

CONCLUSIONS

Exhaustive anamnesis and clinical examination remain of paramount importance in the diagnosis of GCA. To improve the yield of TAB, it should be performed specially in older patients with GCA-compatible clinic. TAB could be avoided in patients with an isolated elevation of acute phase reactants, without GCA-compatible clinic.

The spectrum of optic disc ischemia in patients younger than 50 years (an Amercian Ophthalmological Society thesis)

PURPOSE

To identify the spectrum of clinical and fluorescein angiographic features of optic disc ischemia in patients younger than 50 years.

METHODS

This retrospective comparative case series from a university consultative neuro-ophthalmology practice consisted of two phases. The first compared 108 cases of nonarteritic anterior ischemic optic neuropathy in patients younger than 50 years (NAIONy) to a cohort of 108 cases in patients 50 years or older (NAIONo). Predisposing risk factors, fluorescein angiographic features, and clinical course were compared. In the second phase, 12 cases of diabetic papillopathy under age 50 were assessed by fluorescein angiographic criteria for evidence of optic disc ischemia and compared to patients with NAIONy.

RESULTS

NAIONy comprised 108 (12.7%) of 848 NAION cases reviewed. Chronic renal failure with dialysis and migraine were more common in NAIONy. Fellow eye involvement rate was significantly higher for NAIONy patients (46/108, 42.6%) than for NAIONo patients (32/108, 29.6%). Fluorescein angiographic features of ischemia were documented in 44 (81.5%) of 54 eyes studied. In one case, these features were documented in pre-NAION edema. Diabetic papillopathy demonstrated delayed filling consistent with ischemia in 7 of 10 (70.0%), without significant visual field loss.

CONCLUSIONS

Ischemic optic neuropathy in patients younger than 50 years is not rare. Fellow eye involvement is more frequent in younger patients. Fluorescein angiography confirmation of impaired perfusion in multiple syndromes of optic neuropathy corroborates a spectrum of optic disc ischemia ranging from perfusion delay without visual loss to severely impaired perfusion and visual loss and incorporates optic neuropathies previously considered nonischemic.

Vasodilatory effects of antivascular endothelium growth factor (VEGF) antibody, corticosteroid, and nitric oxide on the posterior ciliary arteries

PURPOSE

The purpose of this study was to determine whether an antivascular endothelium growth factor (VEGF) antibody, a corticosteroid, and sodium nitroprusside (SNP) [a nitric oxide (NO) donor] are possible treatment agents for nonarteritic ischemic optic neuropathy (NAION) by clarifying their effects on high-K (potassium) solution-induced contraction in isolated rabbit and human posterior ciliary arteries (PCA).

METHODS

Vascular ring segments were cut from the distal section of the PCA and mounted in a double-myograph system. After obtaining the maximal contraction following the administration of high-K solution, bevacizumab as an anti-VEGF antibody, methylprednisolone as a corticosteroid, and SNP were administered separately. When a vasodilatory effect was observed, carboxy-PTIO (a NO scavenger) or L-NAME (a NO synthase inhibitor) was administered.

RESULTS

Bevacizumab did not relax either the rabbit or the human PCA, whereas methylprednisolone relaxed both. Neither carboxy-PTIO nor L-NAME inhibited methylprednisolone-induced relaxation. SNP relaxed the rabbit PCA. Carboxy-PTIO inhibited SNP-induced relaxation, but L-NAME did not. In the human PCA, the vasodilatory effect of SNP was present, but weaker than in the rabbit PCA.

CONCLUSIONS

A corticosteroid has NO-independent vasodilatory effects. Exogenous NO has a weak dilating effect in the human PCA. Therefore, corticosteroid could be effective for the treatment of NAION.

Incidence of nonarteritic anterior ischemic optic neuropathy: increased risk among diabetic patients

OBJECTIVE

Previous studies have identified a higher prevalence of diabetes mellitus (DM) among patient cohorts with nonarteritic anterior ischemic optic neuropathy (NAION). We sought to determine the development of incident NAION among a group of newly diagnosed patients with DM and to estimate the incidence of NAION among the elderly.

DESIGN

Medicare 5% database study.

PARTICIPANTS

A total of 25 515 patients with DM and an equal number of age- and gender-matched nondiabetic patients.

METHODS

Query of Medicare 5% claims files identified patients with a new diagnosis of DM in 1994. A randomly selected control group was created using 1-to-1 propensity score matching. Patients with a diagnosis of giant cell arteritis, preexisting DM, and age 68 years or older or >95 years were excluded. Patients with DM and controls were followed for the development of NAION over the following 4745 days.

MAIN OUTCOME MEASURES

Incidence of NAION among patients with and without DM.

RESULTS

In each group, 85% were white, 11% were black, and 4% were other race. Patients were aged 76.4 years, and 40% were male. Mean follow-up was 7.6 years. In the diabetes group, 188 individuals developed NAION (0.7%) compared with 131 individuals (0.5%; P < 0.01) in the control group. In unadjusted Cox regression analysis, having DM was associated with a 43% increased risk (hazard ratio [HR]: 1.431; 95% confidence interval [CI], 1.145-1.789) of developing NAION. After adjusting for other covariates, the risk of developing NAION among individuals with DM was reduced to 40% (HR 1.397; 95% CI, 1.115-1.750). Male gender increased an individual's risk of developing NAION by 32% (HR 1.319; 95% CI, 1.052-1.654). No other covariate was statistically significantly associated with developing NAION. The annual incidence of NAION was 82 per 100 000 persons.

CONCLUSIONS

Diabetes mellitus significantly increased the risk of the diagnosis NAION. The incidence of NAION among patients aged more than 67 years may be higher than previously reported.

Giant cell arteritis: laboratory predictors of a positive temporal artery biopsy

PURPOSE

To identify laboratory predictors of a positive temporal artery biopsy.

DESIGN

Cross-sectional study using retrospective electronic data base review.

PARTICIPANTS

There were 3001 patients who had a temporal artery biopsy.

METHODS

The electronic database of a large health maintenance organization was searched for all patients who had a temporal artery biopsy performed from 1997 to 2006.

MAIN OUTCOME MEASURES

Odds ratios for erythrocyte sedimentation rate, C-reactive protein (CRP), and platelet count values associated with a positive temporal artery biopsy.

RESULTS

Four hundred fifty-nine cases of biopsy-proven giant cell arteritis were identified. The odds of a positive biopsy were 1.5 times greater with an erythrocyte sedimentation rate of 47 to 107 mm/hr, 5.3 times greater with a CRP >2.45 mg/dL, and 4.2 times greater with platelets >400,000/μL.

CONCLUSIONS

In this largest population-based giant cell arteritis study in the United States to date, we reaffirm Hayreh's finding of the significance of a CRP level >2.45 mg/dL in predicting a positive biopsy. Our findings support the literature suggesting that CRP and thrombocytosis may be stronger predictors of positive biopsy than erythrocyte sedimentation rate.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Nonarteritic anterior ischemic optic neuropathy: natural history of visual outcome

OBJECTIVE

To investigate systematically the natural history of visual outcome in nonarteritic anterior ischemic optic neuropathy (NAION).

DESIGN

Cohort study.

PARTICIPANTS

Three hundred forty consecutive untreated patients (386 eyes) with NAION, first seen in our clinic from 1973 to 2000.

METHODS

At first visit, all patients gave a detailed ophthalmic and medical history and underwent a comprehensive ophthalmic evaluation. Visual evaluation was done 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.

MAIN OUTCOME MEASURES

Natural history of visual acuity and visual field outcome in NAION.

RESULTS

Of the 386 eyes, 332 had 8 weeks or more of follow-up from the initial visit. At the initial visit, in eyes seen < or =2 weeks from onset of symptoms, 49% had visual acuity of > or =20/30 and 23% had < or =20/200; in these eyes, 38% had minimal to mild visual field defect and 43% marked to severe defect. In those who were first seen < or =2 weeks after onset with visual acuity < or =20/70, there was improvement in 41% at 6 months and in 42% at 1 year after the initial visit. Two years after the initial visit, there was deterioration in 9% of eyes with initial visual acuity of > or =20/60, and in 18% of those with initial visual acuity of < or =20/70. In those who were first seen < or =2 weeks of onset with moderate to severe visual field defect, there was improvement in 26% at 6 months and 27% at 1 year after the initial visit. Two years after the initial visit, 27% of eyes with initial minimal to mild field defects showed worsening, as did 19% of those with moderate to severe defects.

CONCLUSIONS

About half of the eyes with NAION presented with almost normal visual acuity (20/15 to 20/30) at the initial visit. Thus, the presence of normal visual acuity does not rule out NAION. Visual acuity and visual fields showed improvement or further deterioration mainly up to 6 months, with no significant change after that.

Giant cell arteritis

Giant cell arteritis (GCA) is an immune-mediated vasculitis, affecting medium- to large-sized arteries, in individuals over the age of 50 years. Visual loss is a frequent complication of GCA, and once it occurs it tends to be both permanent and profound. Although major advances have been made in recent years in genetics, molecular biology and the description of the vessel wall morphology, the aetiology and pathogenesis of GCA are still incompletely understood. Over the years there has been much debate over whether polymyalgia rheumatica and GCA are separate or linked entities. Recent investigations support that polymyalgia rheumatica and GCA are two different expressions of the same underlying vasculitic disorder. A single cause or aetiological agent has not as yet been identified. Except for the histopathology of the arterial wall, there are no laboratory findings specific for GCA, and no particular signs or symptoms specific for the diagnosis. GCA typically causes vasculitis of the extracranial branches of the aorta and spares intracranial vessels. Transmural inflammation of the arteries induces luminal occlusion through intimal hyperplasia. Clinical symptoms reflect end-organ ischaemia. Branches of the external and internal carotid arteries are particularly susceptible. Corticosteroids remain the only proven treatment for GCA, the regimen initially involving high doses followed by a slow taper. However, early detection and treatment with high-dose corticosteroids is effective in preventing visual deterioration in most patients.

Retinal migraine

Retinal migraine is a primary headache disorder, clinically manifested by attacks of transient monocular visual loss associated with migraine headache. Although isolated reports suggest that retinal migraine is rare, it likely is under-recognized. Retinal migraine usually is reported in women of childbearing age who have a history of migraine with aura. It typically is characterized by negative monocular visual phenomena lasting less than 1 hour. More than half of reported cases with recurrent transient monocular visual loss subsequently experienced permanent monocular visual loss. Although the International Headache Society diagnostic criteria for retinal migraine require reversible visual loss, our findings suggest that irreversible visual loss is part of the retinal migraine spectrum, likely representing an ocular form of migrainous infarction.

Treatment of ischemic optic neuropathy

Ischemic damage of the optic nerve has no proven effective treatment. While ischemia related to vasculitis (arteritic) is treated with systemic corticosteroids, the primary goal is to prevent further damage, either in the affected or fellow eye. Thrombolytic or anticoagulation supplementive therapy may be considerations for the future. In the more common idiopathic (nonarteritic) form (NAION), multiple attempts at therapy, including systemic corticosteroids, anticoagulants and antiplatelet agents, diphenylhydantoin, hyperbaric oxygen, and optic nerve sheath decompression have been unsuccessful. The use of levodopa has been proposed but is unproven. Megadose intravenous corticosteroid therapy has not been studied in a systematic way. Neuroprotective strategies are under intense investigation for optic neuropathies including NAION, and clinical trials in humans are in progress. Optic nerve regeneration studies are ongoing in animals. Prophylaxis in NAION is unproven.

Computerized expert system for evaluation of automated visual fields from the Ischemic Optic Neuropathy Decompression Trial: methods, baseline fields, and six-month longitudinal follow-up

PURPOSE

To validate a computerized expert system evaluating visual fields in a prospective clinical trial, the Ischemic Optic Neuropathy Decompression Trial (IONDT). To identify the pattern and within-pattern severity of field defects for study eyes at baseline and 6-month follow-up.

DESIGN

Humphrey visual field (HVF) change was used as the outcome measure for a prospective, randomized, multicenter trial to test the null hypothesis that optic nerve sheath decompression was ineffective in treating nonarteritic anterior ischemic optic neuropathy and to ascertain the natural history of the disease.

METHODS

An expert panel established criteria for the type and severity of visual field defects. Using these criteria, a rule-based computerized expert system interpreted HVF from baseline and 6-month visits for patients randomized to surgery or careful follow-up and for patients who were not randomized.

RESULTS

A computerized expert system was devised and validated. The system was then used to analyze HVFs. The pattern of defects found at baseline for patients randomized to surgery did not differ from that of patients randomized to careful follow-up. The most common pattern of defect was a superior and inferior arcuate with central scotoma for randomized eyes (19.2%) and a superior and inferior arcuate for nonrandomized eyes (30.6%). Field patterns at 6 months and baseline were not different. For randomized study eyes, the superior altitudinal defects improved (P = .03), as did the inferior altitudinal defects (P = .01). For nonrandomized study eyes, only the inferior altitudinal defects improved (P = .02). No treatment effect was noted.

CONCLUSIONS

A novel rule-based expert system successfully interpreted visual field defects at baseline of eyes enrolled in the IONDT.

Correlation between optic disc atrophy and aetiology: anterior ischaemic optic neuropathy vs optic neuritis

BACKGROUND

The morphologic features of swollen disc in the acute stage of optic neuritis and anterior ischaemic optic neuropathy (AION) have been extensively investigated in contrast to the morphologic features of optic disc atrophy after these events.

OBJECTIVE

: A prospective study to evaluate the morphologic features of optic disc atrophy 6 months or more after optic neuritis and nonarteritic AION.

PATIENTS AND METHODS

A total of 35 optic discs after nonarteritic AION (n=27) and 24 after optic neuritis (n=19) in otherwise healthy subjects have been evaluated by direct fundoscopic examination with a +90 diopters lens and optic disc photography. The average age of patients at the onset of AION was 57.8 years (range: 38-80) and at the onset of optic neuritis was 32.6 (range: 19-46). The female:male ratio was 18 : 17 in the former and 15 : 9 in the latter. The evaluated parameters included: degree of rim pallor (0 to +3), location of rim pallor, height of rim above the retina, depth and width of cup, peripapillary retinal artery to vein (A : V) ratio, and peripapillary pigment epithelial atrophy. A comparison was made also with 17 age-matched normal discs of 17 patients. Statistical significance was calculated with chi(2) and Fisher's exact test.

RESULTS

Most of the discs after AION were paler (+2: 70%, +3: 26%) than after optic neuritis (normal colour: 8%, +1: 58%, P< or =0.007). Rim segmental involvement after AION was usually either superior 'altitudinal' (53%) or inferior 'altitudinal' (29%), whereas after optic neuritis, it was usually either temporal-central (papillomacular) (42%) or diffuse temporal (42%, P<0.0001). Discs had lower A : V ratio (1 : 3, 40%) after AION compared with optic neuritis (1 : 3, 8%) (P=0.007). There were no significant differences between the two groups in height of the rim, cupping, and peripapillary atrophy.

CONCLUSIONS

: A combination of the degree of rim pallor, location of rim pallor, and A : V ratio may be of value in assessing the aetiology of optic disc atrophy when no previous clinical data are available and a compressive lesion has been ruled out.

Pathogenesis of nonarteritic anterior ischemic optic neuropathy

Based on histopathology, electron microscopic corrosion cast studies, optic nerve blood flow studies, and clinical data, the pathogenesis of idiopathic nonarteritic ischemic optic neuropathy includes the following features: (1) structurally crowded optic discs are predisposed; (2) laminar and retrolaminar regions are the most common locations for infarction; (3) there is flow impairment in the prelaminar optic disc during the acute phase; (4) lack of consistent choroidal flow impairment and the retrolaminar location of infarcts suggest vasculopathy within or distal to the paraoptic branches of the posterior choroidal arteries; (5) diabetes is the most consistently identified vasculopathic risk factor; (6) impaired autoregulation of the disc circulation by atherosclerosis, with a possible contribution from serotonin and endothelin-mediated vasospasm, may play a role; and (7) progression may be caused by secondary cell death after the initial ischemic insult or compression from cavernous degeneration and mechanical axonal distortion.

Non-Arteritic Anterior Ischaemic Optic Neuropathy: A New Indication for Carotid Endarterectomy

We present a case of non-arteritic anterior ischaemic optic neuropathy (NAION) associated with ipsilateral internal carotid artery stenosis, in a patient who presented with sudden loss of vision. This patient underwent a carotid endarterectomy and reported both subjective and objective improvement in vision in the immediate postoperative period and a complete resolution of symptoms at 6 weeks follow-up. This case raises the question of a new indication for carotid endarter-ectomy in selected cases of NAION.

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

PURPOSE

To examine the prevalence and incidence of second eye nonarteritic anterior ischemic optic neuropathy (NAION) and associated patient characteristics in patients enrolled in the Ischemic Optic Neuropathy Decompression Trial (IONDT) Follow-up Study.

DESIGN

Randomized clinical trial with observational cohort.

METHODS

Patients randomized to optic nerve sheath decompression surgery or careful follow-up had a diagnosis of acute unilateral NAION, visual acuity between 20/64 and light perception, and were aged 50 years or older. Eligible patients who declined randomization or whose visual acuity was better than 20/64 were not randomized but followed as part of an observational cohort. Follow-up examinations took place at 3, 6, 12, 18, and 24 months and annually thereafter.

RESULTS

Four hundred eighteen patients were enrolled; 258 randomized and 160 observed. Previous NAION or other optic neuropathy was present in the fellow eye of 21.1% (88/418) of patients at baseline. Four patients developed optic neuropathy in the fellow eye at follow up that could not be conclusively diagnosed as NAION. New NAION in the fellow eye occurred in 14.7% (48/326) of patients at risk during a median follow up of 5.1 years. Randomized patients experienced a higher incidence (35/201; 17.4%) than nonrandomized patients (13/125; 10.4%). A history of diabetes and baseline visual acuity of 20/200 or worse in the study eye, but not age, sex, aspirin use, or smoking were significantly associated with new NAION in the fellow eye. Final fellow eye visual acuity was significantly worse in those patients with new fellow eye NAION whose baseline study eye visual acuity was 20/200 or worse.

CONCLUSIONS

Follow-up data from the IONDT cohort provide evidence that the incidence of fellow eye NAION is lower than expected: new NAION was diagnosed in 14.7% of IONDT patients over approximately 5 years. Increased incidence is associated with poor baseline visual acuity in the study eye and diabetes, but not age, sex, smoking history, or aspirin use.

Indocyanine green and fluorescein angiography in nonarteritic anterior ischemic optic neuropathy

PURPOSE

To assess the value of indocyanine green angiography (ICGA) for demonstrating choroidal vascular abnormalities in patients with nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

The authors compared the ICGA and fluorescein fundus angiography characteristics of peripapillary circulation in 11 patients with acute NAION. There were 7 men and 4 women; the age range for the patients was 36 years to 72 years (mean +/- SD, 47.7 +/- 10.76 years). The angiographic factors considered significant were delay of peripapillary choroidal filling in the vertical watershed zone, leakage from the optic disk, and absolute filling defects on the disk. The authors compared the incidence of a vertical peripapillary watershed zone in the eyes of the 11 patients with that in the normal eyes of 50 controls (age range, 44-79 years) who had unilateral age-related macular degeneration.

RESULTS

Indocyanine green angiography revealed a peripapillary watershed zone in 8 of 11 patient eyes and 23 of 50 control eyes. There was no statistical difference in the number of eyes affected in each group (chi2 = 0.53; P = 0.47). Fluorescein fundus angiography showed leakage from the disk in 10 of 11 patients, whereas ICGA highlighted this problem in only 7 of the patients. The choroidal filling time of the watershed zones was significantly longer with ICGA (t = 3.13; P = 0.011).

CONCLUSION

Although ICGA allows better visualization of the choroidal watershed zones associated with NAION, it did not reveal any significantly different incidence of vertical choroidal watershed zone encompassing the optic disk for patients with NAION and controls. Fluorescein fundus angiography better visualized leakage from the disk in the patient group. These findings indicate that ICGA offers no significant advantage in terms of clinical diagnosis and management of NAION.

Acute bilateral optic disk edema with a macular star figure in a 12-year-old girl

A 12-year-old girl developed headaches and bilateral optic disk edema due to malignant hypertension. Optic disk edema in most of these cases is probably on the spectrum of ischemic optic neuropathy rather than increased intracranial pressure.

Visual manifestations of temporal arteritis

Visual difficulties are common in patients with temporal arteritis. They may be the presenting manifestation of the disease or may occur at any time during its course. The visual deficits that occur in patients with temporal arteritis are most often loss of visual acuity or visual field; however, some patients develop double vision or other symptoms of ocular motor dysfunction. Knowledge of the visual deficits associated with temporal arteritis can aid in the diagnosis of the disorder, and early diagnosis of temporal arteritis can often prevent such deficits from developing.

The prevalence of cupping in end-stage arteritic and nonarteritic anterior ischemic optic neuropathy

OBJECTIVE

To evaluate the prevalence of cupping in arteritic anterior ischemic optic neuropathy (AAION) and nonarteritic anterior ischemic optic neuropathy (NAION).

DESIGN

Retrospective, observational case series.

PARTICIPANTS

Three hundred one patients.

METHODS

Review of clinical records and color fundus photographs.

MAIN OUTCOME MEASURES

Photographic and clinical interpretation of optic nerve appearance.

RESULTS

Ninety-two patients with AAION and 102 with NAION were included in the study. Disc photographs of 42 patients (48%) with AAION and 32 patients (31%) with NAION were available for reassessment. These were presented in a masked fashion along with a random sample of 27 disc pairs considered to be 'normal' and 27 disc pairs with 'established glaucoma' according to two examiners. Cupping was present in 92% of eyes with AAION secondary to giant cell arteritis and in 2% of eyes with NAION (kappa = 0.96; P < 0.001).

CONCLUSIONS

The end-stage optic disc appearance in AAION secondary to giant cell arteritis is cupping, whereas segmental or diffuse pallor without cupping is the typical disc appearance after NAION.

Temporal arteritis: a clinical approach

OBJECTIVE

To develop a clinical guide to the evaluation of temporal arteritis.

DESIGN

A Medline English-language search of the literature from 1966 to 1998, including more than 300 articles about temporal arteritis, was performed to develop a guide to the evaluation of temporal arteritis.

RESULTS

A user-friendly guide to the evaluation of temporal arteritis was developed based on the following criteria: (1) clinical suspicion, (2) laboratory testing, and (3) temporal artery biopsy.

CONCLUSION

A clinical guide to the evaluation of temporal arteritis may assist clinicians in the care of patients with this condition.

Current concepts in giant cell (temporal) arteritis

Giant cell (temporal) arteritis continues to be a sight-threatening, systemic vasculitis with a poorly understood pathogenesis. The characteristic granulomatous inflammation of the vessel wall commonly leads to local ischemia. Recent advances in immunological investigations have characterized the cellular components of the disease process, but the etiology has so far remained unresolved. A reappraisal of the clinical features of giant cell (temporal) arteritis demonstrates the heterogeneity of the manifestations of the disease, including ischemic optic neuropathy. A range of new laboratory investigations and blood flow studies with color Doppler imaging have demonstrated promising roles, with respect to diagnosis and long-term follow-up. Prompt diagnosis and expeditious treatment require a high index of clinical suspicion, particularly for atypical cases. Corticosteroids remain the treatment of choice, other immuno-suppressive agents being used as second line steroid-sparing agents. Giant cell (temporal) arteritis leads to increased vascular and visual morbidity and, if untreated, may prove fatal. To maintain high standards of management of this enigmatic disorder, ophthalmologists need to be aware of the clinical spectrum of giant cell (temporal) arteritis and currently available diagnostic tests and treatment strategies.

Giant cell arteritis: validity and reliability of various diagnostic criteria

PURPOSE

To ascertain the validity, reliability, sensitivity, and specificity of various signs and symptoms of and diagnostic tests for early diagnosis of giant cell arteritis.

METHODS

From 1973 to 1994, we studied 363 patients who had temporal artery biopsy for suspected giant cell arteritis. All patients underwent detailed clinical evaluation and had erythrocyte sedimentation rates determined; since 1985, 223 patients had their C-reactive protein values estimated. Erythrocyte sedimentation rate and C-reactive protein levels were also estimated in 749 and 138 control subjects, respectively. Signs and symptoms of giant cell arteritis, erythrocyte sedimentation rate, and C-reactive protein levels among patients with positive and negative biopsies were compared.

RESULTS

Of the 363 patients, temporal artery biopsy was positive in 106 and negative in 257. The odds of a positive biopsy were 9.0 times greater with jaw claudication (P < .0001), 3.4 times greater with neck pain (P = .0085), 2.0 times greater with an erythrocyte sedimentation rate of 47 to 107 mm/hour (P = .0454), 3.2 times greater with C-reactive protein above 2.45 mg/dl (P = .0208), and 2.0 times greater for age 75 years or more (P = .0105).

CONCLUSIONS

Clinical criteria most strongly suggestive of giant cell arteritis include jaw claudication, C-reactive protein above 2.45 mg/dl, neck pain, and an erythrocyte sedimentation rate of 47 mm/hour or more, in that order. C-reactive protein was more sensitive (100%) than erythrocyte sedimentation rate (92%) for detection of giant cell arteritis; erythrocyte sedimentation rate combined with C-reactive protein gave the best specificity (97%).

Hyperbaric oxygen therapy for nonarteritic anterior ischemic optic neuropathy

PURPOSE

To evaluate the effectiveness of hyperbaric oxygen therapy in reducing optic nerve damage in acute nonarteritic anterior ischemic optic neuropathy.

METHODS

Twenty-two eyes in 20 patients with acute nonarteritic anterior ischemic optic neuropathy were treated with hyperbaric oxygen (100% oxygen, 2.0 absolute atmospheres of pressure) in two 90-minute inhalation sessions per day for ten days. Changes in mean visual acuity and mean sensitivity loss were compared with those of 27 untreated control patients with acute nonarteritic anterior ischemic optic neuropathy, and proportions of patients with a change in acuity or mean sensitivity loss were compared with controls. Similar analysis was performed on subgroups based on time delay from symptom onset to therapy.

RESULTS

Mean values for visual acuity were increased at final examination in both groups; although the increase was greater in controls, the difference was not statistically significant. Mean visual field sensitivity loss was minimally increased; although the increase was smaller in controls, the difference between groups was not significant. There was no significant difference between groups in proportions of patients with change in acuity score or mean sensitivity loss. Stratification by time delay to therapy did not suggest that treatment within nine days produced better visual results than that for either controls or those treated later.

CONCLUSIONS

Hyperbaric oxygen therapy using 100% oxygen and 2.0 absolute atmospheres of pressure did not produce a significant improvement in visual acuity or visual field for patients with acute nonarteritic anterior ischemic optic neuropathy.

Anterior ischemic optic neuropathy

AION is the most common acute optic neuropathy in patients over 50 and, although the diagnosis is often straightforward, our methods for managing the associated visual loss are inadequate. Analysis of the wealth of information gained from recent clinical studies may move us closer to an effective therapy.

Fibrinogen, cholesterol and smoking as risk factors for non-arteritic anterior ischaemic optic neuropathy

Non-arteritic anterior ischaemic optic neuropathy (AION) is thought to be due to occlusion of the posterior ciliary circulation. Raised lipid and fibrinogen concentrations are recognised risk factors for vessel occlusion in cardiovascular disease and stroke but, although suspected as risk factors in non-arteritic AION, they have not been studied in this condition. We therefore performed a case-control study on 41 patients with non-arteritic AION, looking at these and other atherosclerotic risk factors. The odds ratio of cholesterol being > 6.5 mmol/l in non-arteritic AION was 2.7 (95% confidence interval 1.09 to 6.65; p < 0.05) and of fibrinogen being > 3.6 g/l was 5 (2.66 to 9.39; p < 0.05). Smoking was also found to be significantly associated with non-arteritic AION, the odds ratio being 16 (3.23 to 79.23; p < 0.001). These were the only risk factors found to be significantly associated with non-arteritic AION. This raises the possibility that appropriate medical management of these factors could be given to prevent recurrence in the fellow eye.

Systemic diseases associated with nonarteritic anterior ischemic optic neuropathy

PURPOSE

We investigated, in nonarteritic anterior ischemic optic neuropathy, the prevalence of various systemic diseases before or at its onset and the incidence of subsequent morbidity and mortality.

METHODS

We investigated prospectively the presence of systemic diseases before or at the onset of nonarteritic anterior ischemic optic neuropathy in 406 patients. The information was obtained by complete medical history and physical examination. The prevalence rates of systemic diseases in young, middle-aged, and elderly groups were compared with those in the general population. We also analyzed the influence of systemic diseases on subsequent morbidity and mortality.

RESULTS

Compared with the prevalences reported in the general population, our patients in each of the three age groups showed a significantly higher prevalence of arterial hypertension (P < or = .02), diabetes mellitus (P < .01), and gastrointestinal ulcer (P < or = .02). Also, middle-aged and elderly patients showed a significantly higher prevalence of ischemic heart disease (P < .01) and thyroid disease (P < .01). Middle-aged patients had significantly higher rates of chronic obstructive pulmonary disease and cerebrovascular disease (P < or = .01). After onset of anterior ischemic optic neuropathy, patients with both arterial hypertension and diabetes mellitus had a significantly higher incidence of cerebrovascular disease (P < .01).

CONCLUSIONS

Nonarteritic anterior ischemic optic neuropathy is a multifactorial disease in which some systemic diseases may act as predisposing factors and others as precipitating factors. Patients with anterior ischemic optic neuropathy show no significant increase in mortality, but those with both arterial hypertension and diabetes mellitus have significantly (P < .01) increased incidence of cerebrovascular disease.

[The arteritic type of anterior ischemic optic neuropathy. Study of 25 cases]

The clinical, laboratorial perimetric and fluorescein angiographic features of the arteritic type of the anterior ischemic optic neuropathy (A-AION) was studied in 25 patients (40 eyes) in order to characterize the profile of the disease and to allow the differential diagnosis with the non-arteritic anterior ischemic optic neuropathy (NA-AION) and other disorders of the optic nerve. The A-AION occurred in patients 60 to 88 years old (mean 74 years) and was highly predominant in females (64 per cent). Fifteen patients had both eyes involved, either simultaneously or usually within few days or weeks after the initial involvement. Headache and eye pain were the most commonly observed prodromic complaints whereas systemic symptoms of giant cell arteritis (GCA) were seen in all patients. The laboratorial abnormalities most commonly found were high values of reactive C protein, plasmatic fibrinogen and erythrocyte sedimentation rate. In the great majority of the patients visual acuity was severely affected. The optic disc was always abnormal, usually showing a pale edema. In addition to that retinal changes were commonly found. Goldmann perimetry disclosed a wide variety of visual fields abnormalities, the most common of them being inferior altitudinal defects. Fluorescein fundus angiography revealed delayed or absent disc fluorescence, or sectorial or diffuse hypofluorescence or hyperfluorescence of the optic disc. Choroidal filling delay was the most characteristic and frequent angiographic finding in the arteritc type of the disease.

Fluorescein angiography in acute nonarteritic anterior ischemic optic neuropathy

Fundus fluorescein angiograms from 41 patients with nonarteritic anterior ischemic optic neuropathy of less than three weeks' duration were compared with those from 43 age-matched control subjects. Patients with disease showed statistically significant delay in both the onset and the time to completion of prelaminar optic disk filling. Neither onset nor completion of peripapillary choroidal filling were markedly delayed when compared with control subjects. Frequency of occurrence of delayed filling within peripapillary choroidal watershed zones was not increased in patients with disease. There was no consistent correlation by quadrant between optic disk filling delay, choroidal filling delay, optic disk swelling or hyperfluorescence, and visual field deficit. No trend for change in characteristics was found with increasing time interval from onset of symptoms to performance of angiography. Fluorescein angiography in nonarteritic anterior ischemic optic neuropathy demonstrates delayed optic disk filling without consistent relation to adjacent peripapillary choroidal filling delay or other disease findings.

Coagulation abnormalities in ischaemic optic neuropathy

The aetiology of non-arteritic ischaemic optic neuropathy (ION) is multifactorial with local anatomical and systemic haemodynamic abnormalities both playing a role. A careful search for treatable vascular disease risk factors is required to allow rational therapy, to optimise the visual prognosis and to allow new insights into pathogenesis. We describe 7 cases in which there was an associated thrombophilic (prothrombotic) state; 4 had deficiencies of the physiological anticoagulants proteins C and S and antithrombin III and 2 had anti-phospholipid antibody (lupus anticoagulant) syndromes. A further patient had reduced levels of the physiological fibrinolytic agent tissue plasminogen activator (t-PA). In 5 patients other risk factors for small vessel occlusive disease were also present, and 4 had recurrent episodes of ION in the same eye. The visual prognosis in these patients may be improved by anticoagulation with warfarin.