Treatment Of Central Retinal Artery Occlusion Research Articles

Association between gut microbiota and central retinal artery occlusion: A two-sample Mendelian randomization study.

The gut microbiota might be closely related to central retinal artery occlusion (CRAO), but the causality has not been well defined. Two-sample Mendelian randomization (MR) study was used to reveal the potential causal effect between the gut microbiota and CRAO. Data for gut microbiota were obtained from the genome-wide association studies of the Dutch Microbiome Project (DMP) (n = 7738) and the MiBioGen consortium (n = 18,340), and data on CRAO were obtained from samples of FinnGen project (546 cases and 344,569 controls). Causalities of exposures and outcomes were explored mainly using the inverse variance weighted method. In addition, multiple sensitivity analyses including MR-Egger, weighted median (WM), simple mode, weighted mode, and MR Pleiotropy RESidual Sum and Outlier were simultaneously applied to validate the final results. We identified three microbial pathways (two risk factors/one protective factor) and seven microbial taxa (two risk factors/five protective factors) associated with CRAO in the DMP study. Based on the data from the MiBioGen consortium, we identified seven microbial taxa (two risk factors/five protective factors) associated with CRAO, including the Eubacterium genus, which was consistently identified as a risk factor in both the DMP and the MiBioGen consortium MR analyses. Our study implicates the potential causal effects of specific microbial taxa and pathways on CRAO, potentially providing new insights into the prevention and treatment of CRAO through specific gut microbial taxa and pathway. Since our conclusion is a hypothesis derived from secondary genome-wide association studies (GWAS) data analysis, further research is needed for confirmation.

Progress in central retinal artery occlusion: a narrative review.

Central retinal artery occlusion (CRAO) is a catastrophic ophthalmic emergency that severely impairs a patient's visual function, often reducing visual acuity to counting fingers or worse. Progress in CRAO research has provided new information regarding its epidemiological characteristics and led to useful assessments through various ophthalmic examinations. Additional insights about CRAO have been gained through studies of its pathophysiological mechanisms, improving intervention timing and enhancing patient prognosis. Treatment for CRAO has evolved, particularly with assistance from surgical instruments and surgical robots. Although surgical treatment is now possible, this option is not widely recognized by ophthalmologists. Conservative therapies have limited benefits compared with the natural course of disease. Recently, pars plana vitrectomy plus endovascular surgery has received considerable interest among ophthalmologists because of its potential efficacy in the treatment of CRAO. Considering the inconsistencies in rationale and efficacy of CRAO treatment modalities, it is important to distinguish between treatment effects and the natural courses of various CRAO subclasses. This narrative review explores progress in CRAO epidemiology, pathophysiology, ophthalmic examination, and treatment.

Central Retinal Artery Occlusion: A Review of Pathophysiological Features and Management

Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke that results in painless vision loss attributable to retinal infarction. A keen understanding of clinical presentation and underlying pathophysiological features is key to timely intervention and development of new treatment modalities. In CRAO, the time between initial insult to presentation is significant because, analogous to ischemic stroke, the duration of ischemia is inversely related to viable retinal tissue. A major challenge in CRAO is delayed presentation, which reduces the amount of salvageable retina. In addition, imaging techniques to effectively identify a retinal penumbra, or retinal tissue that is reversibly damaged, are not well established. To compile this narrative review, we conducted a systematic search of the PubMed database to identify relevant articles on the pathophysiological features and treatment of CRAO, including reviews, meta‐analyses, clinical studies, observational trials, and randomized trials. The search strategy included the following keywords: central retinal artery occlusion, CRAO, treatment, management, review, meta‐analysis, clinical study, observational trial, and randomized trial. We also searched for ongoing clinical trials related to CRAO on ClinicalTrials.gov. The identified articles and studies were then carefully evaluated for their relevance to the topic and used in compiling this review. Intravenous thrombolysis is a compelling therapeutic approach, with current limited data suggesting early intervention (4.5 hours of symptom onset) results in better patient outcomes. However, ongoing trials assessing and comparing different fibrinolytic agents, routes of administration (venous versus arterial), and timing of intervention will provide further insight on the efficacy of this treatment modality. In parallel, development and testing of imaging techniques aimed at quantifying retinal blood flow and assessing tissue viability could improve risk stratification to guide treatment. These can then be used in conjunction to guide use of conventional therapies, neuroprotectants, and thrombolytics for the management of various CRAO presentations that can be effectively deployed in emergency settings. This article provides a narrative review of pathophysiological features, risk factors, and current and emerging management techniques of CRAO.

The Effects of Hyperbaric Oxygen Therapy in Patients with Central Retinal Artery Occlusion: A Retrospective Study, Systematic Review, and Meta-analysis.

PurposeCentral retinal artery occlusion (CRAO) is a vision-threatening condition with a potentially poor visual prognosis. Many different treatment modalities are suggested but controversy remains regarding effectiveness of these treatments. The purpose of this study is to perform a systematic review and meta-analysis in addition to analyzing retrospective data at our own tertiary care center regarding effectiveness of hyperbaric oxygen therapy (HBOT) in treatment of CRAO.MethodsThe PubMed, Scopus, and the Cochrane Library are searched from the date of database inception to September 2021 to conduct a review based on the PRISMA (preferred reporting items for systematic review and meta-analysis), evaluating the role of HBOT in visual recovery of CRAO patients. In addition, a retrospective chart review of patients clinically diagnosed with CRAO at our university-based hospital (University of Texas Health, San Antonio, TX, USA) from year 2011 to 2021 was conducted.ResultsAfter a review of 376 articles, three articles met the inclusion criteria for meta-analysis, where a total of 207 patients received HBOT versus 89 patients that did not receive any form of oxygen therapy. Analysis of these results demonstrate that HBOT in CRAO patients does not enhance the final visual outcome (p = 0.83). Similar conclusion was also drawn from retrospective analysis of 48 patients (15 HBOT versus 33 controls) at our tertiary care center, where no visual benefit was observed in the HBOT group.ConclusionsHBOT does not appear to improve final visual outcome and concerns remain regarding adverse reactions such as barotrauma and generalized seizures. Large, randomized studies are required for further understanding of the role of HBOT in treatment of CRAO.

Treatment outcomes on neovascularization after CRAO treated with hyperbaric oxygen

Central retinal artery occlusion (CRAO) is a condition that causes sudden vision loss due to obstruction of the retinal artery, typically from a thrombotic or embolic source. It is often associated with atherosclerotic risk factors, including cardiovascular disease, diabetes, hyperlipidemia, and a history of cerebrovascular disease. CRAO often leads to a poor visual outcome as well as neovascularization of the iris, retina, and optic disc, which can exacerbate vision loss and cause pain. While there are several treatment modalities for CRAO, few have been proven to be effective in decreasing the effects of neovascularization. The use of hyperbaric oxygen (HBO2) therapy is often used in the treatment of CRAO due to its ease of use and relatively benign side effect profile. This study aims to assess the degree of improvement in visual acuity (VA) and neovascularization following HBO2. Our data ultimately shows that 20% of patients developed neovascularization after HBO2 compared to 29.8% of those who did not undergo HBO2 (p<.05). Our findings suggest that HBO2 has a statistically significant protective effect against neovascularization and may improve long-term visual acuity.

Intravenous Recombinant Tissue-Type Plasminogen Activator Thrombolysis for Acute Central Retinal Artery Occlusion.

Central retinal artery occlusion (CRAO), an ocular stroke, causes severe and permanent visual impairment. Thrombolytic therapy is currently the main treatment option for CRAO. Intravenous thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) has been extensively applied in the treatment of CRAO with the proven advantages of effectiveness and safety. This meta-analysis aimed to assess the efficacy of intravenous rt-PA thrombolysis for the management of CRAO by evaluating the pooled evidence. A comprehensive literature search of electronic databases including PubMed, OVID, and Cochrane Library was conducted up to and including March 2019. All studies reporting visual outcomes after CRAO with thrombolytic therapy were collected. Data on visual acuity and adverse events were recorded and assessed in this analysis. Data were inputted into the statistical software of STATA. The studies were weighed by the inverse of the variance and merged in a random-effects model. The systematic review process yielded 7 eligible studies including 121 patients with CRAO who received the intravenous rt-PA treatment. Sixty-two patients showed improvement in visual acuity (52.0%; 95% CI, 34.0%-70.0%) following rt-PA intravenous thrombolytic therapy. The observed improvement rate in the intravenous rt-PA treatment group was significantly higher than the conservative treatment group (40.4% vs. 13.0%; OR = 5.16; 95% CI, 1.90-14.05). The incidence rate of complications was relatively low (11 out of the 121 patients). Hemorrhage (9/11) was the major reported complication. Mortality was zero. This meta-analysis indicated that intravenous rt-PA thrombolysis could be an effective and safe strategy for the management of CRAO. However, a more detailed large-scale clinical trial is warranted to strengthen the evidence-based therapeutic guidance.

Missing the 'window' might shut the light forever: Central retinal artery occlusion following spine surgery.

Missing the 'window' might shut the light forever: Central retinal artery occlusion following spine surgery.

Thrombolytic Treatment of Central Retinal Artery Occlusion(CRAO)

This review focuses on the literature available for the treatment of CRAO with thrombolysis including intra-arterial and intravenous approaches. Although CRAO is an ocular emergency that can lead to disabling blindness, no consensus treatment guidelines currently exist. Based on review of the current literature, further clinical trials are indicated to investigate the safety and efficacy of early thrombolytic therapy for CRAO.

Super-selective ophthalmic artery or selective carotid artery thrombolytic therapy for central retinal artery occlusion

Objective To observe the clinical effect of super-selective ophthalmic artery or selective carotid artery thrombolytic therapy for central retinal artery occlusion (CRAO).Methods Twelve CRAO patients (12 eyes) were enrolled in this study.The patients included 7 males and 5 females.The age was ranged from 19 to 68 years old,with an average of (50.0t3.5) years.The disease duration was from 8 to 72 hours,with a mean of 18 hours.All the patients were received the treatment of super-selective ophthalmic artery or selective carotid artery thrombolysis with urokinase (total 0.20-0.4 million U) and injection of papaverine 30 mg.Five patients received the treatment of super-selective ophthalmic artery thrombolytic therapy,7 patients received the treatment of selective carotid artery thrombolytic therapy (4patients because of the financial issues,3 patients because of thin ophthalmic artery).According to the visual acuity of post-treatment and pre-treatment,the therapeutic effects on vision were defined as effective markedly (improving three lines or more),effective (improving two lines) and no effect (no change or a decline).According to the arm-retinal circulation time (A-Rct) and filling time of retinal artery and its branches (FT) on fluorescence fundus angiography (FFA),the therapeutic effects on retinal circulation were defined as effective markedly (A-Rct 15 s,FT 2 s),effective (A-Rct was improved but in the range of 16-20 s,FT was in 3-8 s) and no effect (A-Rct was improved but 21 s,FT 9 s).Results The vision changes showed effective markedly in 5 eyes (41.7％),effective in 5 eyes (41.7％),no effect in 2 eyes (16.6 ％).The total therapeutic efficiency on vision was 83.4％.The retinal circulation was improved in all eyes after treatment,including effective markedly in 8 eyes (67.0％),effective in 4 eyes (33.0％).The total therapeutic efficiency on retinal circulation was 100.0％.No complications occurred in these 12 patients during the treatment or follow up,such as puncture site hematoma,intracranial hemorrhage,cerebral embolism,eye movement abnormalities,retinal and vitreous hemorrhage.Conclusion Super-selective ophthalmic artery and selective carotid artery thrombolytic therapy were effective in the treatment of CRAO. Key words: Retinal artery occlusion/drug therapy; Thrombolytic therapy; Urinary plasminogen activator/therapeutic use

Anterior chamber paracentesis after central retinal artery occlusion: a tenable therapy?

BackgroundThe goal of this study was to investigate the visual outcome of acute central retinal artery occlusion (CRAO) after current standard therapy with and without paracentesis. In addition, we investigated whether there was a dependence of the resulting visual acuity on the time between first symptoms and implementation of paracentesis. Finally, we analysed risk factors for CRAO.MethodsWe performed a retrospective analysis of data from patients with CRAO who received standard in-patient therapy with and without paracentesis at the Dr. Horst Schmidt Clinics in Wiesbaden, Germany between 2000 and 2012. The primary endpoint was the change of visual acuity 3 days after the initiation of intervention.ResultsData from 74 patients with CRAO were included in the study. Fifteen patients were treated conservatively and 59 patients received additional paracentesis. Clinically significant improvement of BCVA (logMAR ≥ 0.3) after 3 days was observed in 26.7% of patients without paracentesis, 36.4% of patients with paracentesis within 6 hours, 20% of patients with paracentesis within 7–24 hours, and 23.1% of patients with paracentesis more than 24 hours after the onset of symptoms. There was no significant difference in the outcome between patients with (BCVA 1.9 ± 0.31) and without paracentesis (BCVA 1.75 ± 0.32) (p = 0.9), nor among the groups with paracentesis (p = 0.8). One patient suffered a lens injury due to the paracentesis, with subsequent need for cataract surgery.ConclusionsThere was no added gain in visual acuity by performing a paracentesis, independent of the time elapsed between first symptoms and the implementation of paracentesis. In the absence of any tangible effectiveness of paracentesis and the inherent risks of paracentesis such as intraocular infection and injury, paracentesis does not appear to be warranted as a treatment of CRAO.

Reply: ‘Central retinal artery occlusion and cerebral stroke’

Sir, We are grateful to Dr McLeod1 for the interest that he has shown in our paper.2 Rather, then there being a conspiracy to increase the confusion within central retinal artery occlusion (CRAO), our study demonstrates that the disease is incompletely understood. In particular, we disagree with Dr McLeod that the retinal penumbra lasts for more than 24 h. Retinal and cerebrovascular ischaemia share a number of common pathophysiological features and is reflected by the recent extended definition of stroke involving retinal as well as cerebral ischaemia.3 In vitro experiments show that when neuronal cells are deprived of oxygen, that within 5 s, there is evidence of neuronal dysfunction. Within 10 s, cell death occurs. The elegant experiment of Astrup et al4 demonstrated that the penumbra is a function of collateral perfusion and that if there was no resolution of the occlusion, then eventually the penumbra would fail, and infarction would be permanent. In cerebral stroke using perfusion imaging, various groups have demonstrated that the ischaemic penumbra may persist beyond 24 h. However, randomised controlled trials of reperfusion therapy in acute stroke have demonstrated on that in the majority of individuals, the ischaemic penumbra only extends out to 4.5 h and at maximum, 6 h.5, 6 The misperceptions that the retinal penumbra persists for 24 h, initially backed up by observational data, led to the design of two randomised controlled trials that recruited individual with central retinal artery occlusion of beyond 6 h. The EAGLE study recruited subjects up to 19 h of symptom onset,7 while our group conducted a randomised controlled trial of intravenous tPA given to individuals within 24 h of symptom onset.8 Both of these randomised controlled trials were negative studies, however, a signal was seen in individuals who receive tPA within 6 h of symptom onset.8 This mirrors the retinal tolerance time demonstrated in Hayreh's animal experiments of 4 h.9 Conversely, if the thrombus that initially caused a retinal artery occlusion resolves such that retinal perfusion is restored, then the symptoms will be invariably improved leading to a transient central retinal artery occlusion. Nevertheless, we agree with Dr McLeod that the classical clinical features of central retinal artery occlusion remain more or less the same, but that various findings may give a clue as to the time of the onset or alternatively the presence of partial occlusion. These are important points given that for randomised controlled trials on the treatment of CRAO are to succeed, then individuals need to be recruited within the shortest time possible.

Intravenous thrombolysis with urokinase for central retinal artery occlusion in 115 patients

Objective To observe the effects of intravenous thrombolysis with urokinase for centralretinal artery occlusion (CRAO).Methods A total of 115 CRAO patients diagnosed by fluorescence fundus angiography (FFA) were enrolled in this study.The patients included 61 males and 54 females,with a mean age of (56.7±15.2) years (from 41 to 75 years).The duration ranged from 1 to 30 days.All the patients were affected unilaterally.All the patients were received the treatment of intravenous thrombolysis with urokinase (3000 U/kg,two times per day,continuous treatment for six to seven days) and retrobulbar injection of dexamethasonc 2.5 mg (one time per day,continuous treatment for 14 days).Following that,1.2 mg/kg brain protein hydrolysate (nerve nutrition) and 360 mg troxerutin (vasodilator) were given by intravenous drip (one time per day,continuous treatment for 14 days).Effectiveness of the thrombolytic and subsequent treatments including the recovery of vision and retinal arterial filling time before and after treatment were observed.Comparing the visual acuity of post treatment and pre-treatment,improving three lines or more is considered as effective markedly,improving two lines as effective,no change or a decline as no effect.With FFA as the retinal circulation recovery index,the arm-retinal circulation time (A-Rct) ≤ 15s and all branches of central retinal artery were filled with fluorescence within 2s filling (normal) as effective markedly; A-Rct improved but was in 15～20s range,all branches of central retinal artery were filled with fluorescence within 3～ 8s as effective; A Rct improved but was still ≥ 21s,all branches of central retinal artery were filled with fluorescence within ≥9s as no effect.The relationship between age,gender,the disease course,subsequent treat time and curative effectiveness were analyzed.Results There were 79 patients were examined for FFA again after thromholysis treatment which including 11 patients with complete obstruction and 68 patients with incomplete obstruction.In 11 patients with complete obstruction,eight patients showed that optic disc vascular retrograde filling disappeared,A Rct was 28-54s,and the filling time from retinal artery to tip was18-55s; three patients showed persistent optic disc vascular retrograde filling within 3-4 minutes of FFA.In 68 patients with incomplete obstruction,A-Ret returned to normal in 35 patients (51.4％),effective in 18 patients (26.5％) and no effect in 15 patients (22.1％).Retinal circulation time was shorter than that before thrombolysis treatment (x2 =11.4,P＜0.05).Comparison of distribution of visual acuity before and after thrombolysis treatment,the difference was statistically significant (x2=12.1,P＜0.05).Comparison of distribution of final visual acuity after subsequent treatment with that of after thrombolysis treatment,48 eyes improved two lines or more,the efficiency was 41.7％,the difference was statistically significant (x2 =14.6,P＜0.05).Comparison to that of before treatment,vision changes showed effect markedly in 58 patients (50.4％),effective in 35 patients (30.4％),no effect in 22 patients (19.2％),the difference was statistically significant (x2 =44.5,P＜0.05).Comparison the average age to that of effective,valid and invalid patients,the difference was not statistically significant (t=0.98,1.17,0.55; P＞0.05).There was no relationship between effectiveness and gender (x2=2.6,P＞0.05).In 76 patients with duration within seven days,43 patients were effective markedly and 22 patients were effective,the efficiency was 85.5％.In 25 patients with duration of 8-15 days,11 patients were effective markedly and eight patients were effective,the efficiency was 76.0％.In 34 patients who received subsequent treatment 8-14 days,18 patients were effective markedly and nine patients were effective,the efficiency was 79.4％.In 51 patients who received subsequent treatment 15-21 days,27 patients were effective markedly and 18 patients were effective,the efficiency was 88.2％.Conclusion Intravenous thrombolysis with urokinase was effective in the treatment of CRAO. Key words: Retinal artery occlusion/drug therapy; Urinary plasminogen activator/therapeutic use; Urinary plasminogen activator/administration & dosage

Multicenter study of the European Assessment Group for Lysis in the Eye (EAGLE) for the treatment of central retinal artery occlusion: design issues and implications. EAGLE Study Report No. 1

None of the “classic” conservative therapies used for the treatment of acute central retinal artery occlusion (CRAO) has proven effective in retrospective studies. Over the past 10 years, local intra-arterial thrombolysis (administered in situ, directly in the ophthalmic artery via catheter angiogram) has been used increasingly in various centers, particularly in Germany. Small case series and retrospective studies have suggested improvement of the visual function in about 25% of treated patients; however, the use of in situ thrombolysis for the treatment of acute CRAO is debated, and remains limited to pilot centers. In 2002, a German group initiated a randomized prospective multicenter study evaluating the therapeutic efficacy of in situ thrombolysis in acute CRAO [The European Assessment Group for Lysis in the Eye (EAGLE)]. Inclusion criteria were age between 18 and 75 years, CRAO not older than 20 hours, with a visual acuity less than 0.32. Exclusion criteria were branch retinal artery occlusion (BRAO), cilioretinal arteries supplying the macula, and severe systemic disorder. Each included patient was randomized to conservative or local intra-arterial thrombolysis therapy. The conservative regime included bulbus massage, lowering intraocular pressure with topical beta-blocker and acetazolamide, acetylsalicylic acid, heparin, and isovolemic hemodilution. Local intra-arterial thrombolysis was performed using a maximum of 50 mg rtPA injected directly into the ophthalmic artery by an experienced interventional neuroradiologist. During the following five days, all patients received heparin. Primary study end point was visual acuity one month after therapy (in comparison with visual acuity before therapy). The authors calculated that they would need 100 patients per group (a total of 200 patients). Participating centers were located in Germany, Switzerland, and Austria. Between June 2002 and April 2005, only 47 patients were included. The study is therefore being continued. The authors emphasize that, to this date, treatment of CRAO with in situ thrombolysis should only be performed as part of a research study and not routinely. They welcome new study centers to join them in order to increase the inclusion rate.—Valérie Biousse

Visual Functions Following Recovery From Non-Arteritic Central Retinal Artery Occlusion

Visual acuity and other visual functions may improve following treatment of central retinal artery occlusion (CRAO). A prospective, noncomparative case series study was conducted to investigate patients' visual functions after treatment of non-arteritic CRAO. Eight consecutive patients whose visual acuity improved following successful systematic treatment protocol for non-arteritic CRAO of less than 48 hours (one of them with patent cilioretinal artery) were evaluated for visual functions. The visual acuity in seven patients ranged from no light perception to counting fingers at 3 feet on presentation and improved to 20/100 to 20/20 following treatment. The visual tests included: blue-yellow (Farnsworth D-15) and green-red (pseudoisochromatic Ishihara color plates) color discrimination, contrast sensitivity, and visual fields. The patients were also evaluated for subjective daily function following treatment. All tests were also performed in the fellow uninvolved eye as a control. The visual acuity following treatment improved from no light perception to counting fingers at 3 feet to an average of 20/65 (range, 20/20 to 20/100). Despite this improvement, six patients had dyschromatopsia to blue, green, or red whereas only two patients with a final visual acuity of 20/20 preserved their full color discrimination. All patients had decreased contrast sensitivity at mid-spatial frequency (6 cycles/min) or a more generalized decrease and visual field defects. All of the patients except one were satisfied with the visual outcome and daily function after treatment. Despite improvement in visual acuity after treatment for CRAO, all patients had residual visual function abnormalities. These abnormalities may be attributed to partial recanalization, conversion of CRAO to multiple branch retinal artery occlusions, or different retinal susceptibility for ischemia.

Aggressive systematic treatment for central retinal artery occlusion

PURPOSE: To report the efficacy of an aggressive systematic regimen for the treatment of acute nonarteritic central retinal artery occlusion (CRAO). METHODS: Eleven patients who had unilateral CRAO with symptoms of fewer than 48 hours’ duration were treated with an aggressive stepwise systematic regimen until retinal circulation improved or until all the treatment steps were performed. Five patients with unilateral CRAO and symptoms of fewer than 48 hours’ duration were treated in the same institution in an arbitrary nonsystematic manner. The therapeutic steps of the aggressive treatment included ocular massage, sublingual isosorbide dinitrate, intravenous acetazolamide, intravenous mannitol or oral glycerol, anterior chamber paracentesis, intravenous methylprednisolone followed by streptokinase, and retrobulbar tolazoline. After each step, retinal flow was evaluated by three-mirror contact lens. The nonsystematic treatment was arbitrary and included one or several of the above. Visual acuity and complete eye examination data were recorded before and after treatment. RESULTS: Visual acuity and retinal arterial supply were improved in eight (73%) of the 11 patients treated in the stepwise systematic manner. All eight patients in whom visual acuity improved had symptoms for fewer than 12 hours, and the presumed cause was either platelet-derived or cholesterol embolus from atheroma or the patients had glaucoma. Patients in whom visual acuity did not improve had CRAO that was attributed to calcified emboli or primary antiphospholipid antibody syndrome and had symptoms more than 12 hours before treatment. Visual acuity did not improve in all five patients with the nonsystematic treatment regardless of the presumed cause or duration of the occlusion. The success of the treatment in the systematic treatment group was statistically significantly better compared with the outcome of the nonsystematic treated group (Fischer exact test, P = .01). CONCLUSIONS: In the treatment of CRAO, an aggressive systematic regimen including medical and mechanical means may reestablish retinal circulation and improve visual outcome. The cause of arterial occlusion, the nature of occlusive emboli, and the duration of retinal ischemia may determine the visual outcome, but a larger series is warranted to verify the effectiveness of the treatment and the prognostic factors.