Seven Points That Explain the Lack of Effect from Reperfusion Therapy in Central Retinal Artery Occlusion

A Review of Current Literature on Central Retinal Artery Occlusion: Its Pathogenesis, Clinical Management, and Treatment

The ocular analogue of a cerebral stroke is central retinal artery occlusion (CRAO), a medical emergency concerning the eyes. Most patients experience substantial acute vision loss with a visual acuity of 20/400 or worse, resulting in decreased quality of life (QoL) and decreased functional ability. An impending cerebral stroke and ischemic heart disease are also more likely. The four distinct clinical entities that make up CRAO are non-arteritic CRAO, transitory non-arteritic CRAO, non-arteritic CRAO with cilioretinal artery sparing, and arteritic CRAO. Depending on the CRAO type, clinical traits, visual results, and treatment all vary greatly. Contrary to current belief, there is a spontaneous improvement in the optical field and vision, mainly in the first week. The likelihood of instinctive development in optical acuity in the first seven days varies greatly. The pathogenesis, epidemiology, and medical features of CRAO will be described in this review, along with present and potential management future options.

Neuroprotection for Nonarteritic Central Retinal Artery Occlusion: Lessons from Acute Ischemic Stroke

Nonarteritic central retinal artery occlusion (NA-CRAO) is a variant of acute ischemic stroke (AIS) and is a cause of sudden severe loss of vision. There are guidelines by the American Heart Association and the American Stroke Association for the care of CRAO patients. This review explores the basis of retinal neuroprotection for CRAO and its potential for improving the outcome of NA-CRAO. Recently, there have been significant advances in research into the use of neuroprotection to treat retinal diseases, including retinal detachment, age-related macular degeneration, and inherited retinal diseases. Also, neuroprotective research in AIS has been extensive, and newer drugs tested, including Uric acid, Nerinetide, and Otaplimastat, with promising results. Progress in cerebral neuroprotection after AIS offers hope for retinal neuroprotection after CRAO; and a possibility of extrapolating research findings from AIS into CRAO. Combining neuroprotection and thrombolysis can extend the therapeutic window for NA-CRAO treatment and potentially improve outcomes. Experimented neuroprotection for CRAO includes Angiopoietin (Comp Ang1), KUS 121, Gene therapy (XIAP), and hypothermia. Efforts in the field of neuroprotection for NA-CRAO should focus on better imaging to delineate the penumbra after an acute episode of NA-CRAO (using a combination of high-definition optical coherence angiography and electrophysiology). Also, research should explore details of pathophysiologic mechanisms involved in NA-CRAO, allowing for further neuroprotective intervention, and closing the gap between preclinical and clinical neuroprotection.

Intravenous thrombolysis in patients with central retinal artery occlusion: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

To investigate the efficacy and safety of intravenous thrombolysis (IVT) with alteplase in patients with central retinal artery occlusion (CRAO).

METHODS

We searched the database of PubMed and EMBASE for potentially eligible studies that reported IVT in CRAO patients from their dates of inception to May 19, 2021. The rate and odds ratios (OR) of best-corrected visual acuity (BCVA) improvement, mean difference (MD) of BCVA with 95% confidence interval (CI) were pooled with random effects model.

RESULTS

We included 8 studies enrolling 316 CRAO patients, among them, 157 patients received IVT with alteplase while 159 patients did not. The rate of best BCVA improvement was 47% (95% CI 33-62%) in the CRAO patients treated with IVT, which was higher than that of 12% (95% CI 1-23%) in those without IVT (OR 5.97, 95% CI [2.77-12.86]). In the setting of similar baseline BCVA (MD [logMAR] 0.16, 95% CI [- 0.15 to 0.46]), compared with those who did not receive IVT, the CRAO patients who received IVT had better best BCVA (MD [logMAR] - 0.23, 95% CI [- 0.44 to - 0.02]), but had no significant better final BCVA (MD [logMAR] - 0.10, 95% CI [- 0.32 to 0.12]). Two CRAO patients had complicated symptomatic intracranial hemorrhage after IVT.

CONCLUSIONS

IVT treatment might be effective and safe for CRAO patients, but ocular-specific complications which were not associated with thrombolysis could affect final visual acuity.

Risk of Stroke, Myocardial Infarction, and Death Among Patients With Retinal Artery Occlusion and the Effect of Antithrombotic Treatment

Purpose

To evaluate the risk of future stroke, myocardial infarction (MI), and death of patients with retinal artery occlusion (RAO) and the effect of various antithrombotic treatments as secondary prevention.

Methods

This cohort study was based on nationwide health registries and included the entire Danish population from 2000 to 2018. All patients with RAO were identified and their adjusted risks of stroke, MI, or death in time periods since RAO were compared with those of the Danish population. Furthermore, antithrombotic treatment of patients with RAO was determined by prescription claims, and the association with the risk of stroke, MI, or death was assessed using multivariate Poisson regression models and expressed as rate ratios (RR) with 95% confidence intervals (95% CIs).

Results

After inclusion, 6628 individuals experienced a first-time RAO, of whom 391 had a stroke, 66 had a MI, and 402 died within the first year after RAO. RAO was associated with an increased risk of stroke, MI, or death which persisted for more than 1 year for all three outcomes but was highest on days 3 to 14 after RAO for stroke, with an adjusted RR of 50.71 (95% CI, 41.55–61.87), and on days 14 to 90 after RAO for MI and death, with adjusted RRs of 1.98 (95% CI, 1.25–3.15) and 1.64 (95% CI, 1.28–189), respectively. Overall, antithrombotic treatment was not associated with any protective effect the first year.

Conclusions

Patients with RAO had an increased risk of stroke, MI, or death. No protective effect of antithrombotic treatment was shown.

Translational Relevance

These findings are relevant to the management of patients with RAO.

Safety and Efficacy of Selective Intra-arterial Thrombolysis for Central Retinal Artery Occlusion

PURPOSE

The purpose of this study was to determine the efficacy and safety of selective intra-arterial thrombolysis in patients with central retinal artery occlusion (CRAO).

METHODS

Medical records for 44 eyes of 44 patients diagnosed with acute non-arteritic CRAO and thrombolysis between October 2010 and February 2019 were analyzed retrospectively. Based on visual acuity, fundoscopic findings, and fluorescein angiography, the patients were classified into three stages: incomplete, subtotal, and total. The perfusion state using the best-corrected visual acuity (BCVA), arm to retina time, and arteriovenous passage times, after 1 month, 6 months, and at the final visit after the procedure, were compared with baseline readings.

RESULTS

Improvement of visual acuity was confirmed in 31 out of 44 patients (70.45%). The mean BCVA of 44 patients changed from 1.65 ± 0.78 logarithmic minimum angle of resolution (logMAR) at the first visit to 1.18 ± 0.91 logMAR at the last visit (p = 0.114). The BCVA according to CRAO stage was 0.08 ± 0.11 logMAR for the incomplete stage at the first visit, 0.06 ± 0.05 logMAR (p = 0.933) 1 month after the procedure, and 0.05 ± 0.07 logMAR (p = 0.933) at the last visit. In the subtotal stage, the results were 1.81 ± 0.54 logMAR at the first visit, 1.63 ± 0.76 logMAR (p = 0.035) 1 month after the procedure, and 1.36 ± 0.85 logMAR (p = 0.014) at the last visit. For the total stage of BCVA, the result at the first visit was 2.36 ± 0.25 logMAR, and it was 2.30 ± 0.30 logMAR (p = 0.510) 1 month after the procedure, and 2.42 ± 0.30 logMAR (p = 0.642) at the last visit. Reperfusion was observed in 40 patients out of the 44 (90.91%).

CONCLUSIONS

Selective intra-arterial thrombolysis can be helpful in patients with subtotal CRAO in terms of visual improvement and retinal arterial reperfusion.

Central retinal artery occlusion as a post-transfusion complication of red blood cells

A 32-year-old woman presented with a history of uterine myomatosis and repeated bleeding for 6 months. This produced a haemoglobin concentration of 6.5 g/dL, with a requirement for a red blood cell transfusion. One hour after the transfusion, she presented with a sudden and painless loss of vision in the right eye (RE). As she had no other symptoms, she was referred to the Neuro-Ophthalmology Department. On admission, her corrected visual acuity was hand movement in RE, and 0.6 in the left eye (LE). The anterior segment was unremarkable, except for a relative afferent pupillary defect in RE. In the fundus examination, the RE showed a diffuse pale retina with a cherry spot, consistent with occlusion of the central artery of the retina. Management was attempted but with no improvement. The studies corroborated retinal ischaemia in RE. During the systemic evaluation, the neuroimaging, autoimmune and haematology studies were negative, thus this complication was attributed to the red blood cell transfusion.