Evaluation of Increase in Retinal Thickness as Diagnostic Marker in Central Artery Occlusion.

PURPOSE: To evaluate the increase in retinal thickness as a marker in predicting the onset of central retinal artery occlusions. METHODS: Retrospective clinical study conducted at one Swiss hospital. Electronic records were filtered for patients with artery occlusions. Optical coherence tomography data, including time between the imaging and ischemic event, were reviewed. Increase in relative retinal thickness was measured, defined as an increase in retinal thickness compared to the unaffected partner eye. This was correlated with the time from symptom onset. A cutoff value of relative increase of < 24.5% was applied, as suggested in previous studies. The results were compared to the time gathered from the electronic records, and sensitivity, specificity, positive predictive value as well as negative predictive value were calculated for predicting an ischemia time of < 4.5 h. RESULTS: Forty-two eyes from 41 patients with central artery occlusions were identified. Fourteen were female. Mean age was 66.4 ± 15.8 years. Initial corrected visual acuity was 2.41 ± 0.68 logMAR, and 2.13 ± 0.87 logMAR at the last follow-up (p > 0.05). Of eyes with a visual acuity of counting fingers (n = 38) or worse, 89.5% showed no improvement during follow-up, while eyes with logMAR 1 or better (n = 4) improved. Thirteen eyes (13 patients) presented within 4.5 h of the ischemic event. Four patients received i. v. thrombolysis, with visual recovery in one. In 12 eyes with an ischemia time of < 4.5 h, relative increase was below 24.5%. In the remaining 29 eyes with > 4.5 h, relative increase was below 24.5% in 4 eyes and above 24.5% in 25 eyes. This yielded a sensitivity of 92.3%, a specificity of 86.2%, with a positive predictive value of 75.0% and a negative predictive value of 96.2%. CONCLUSION: Central retinal artery occlusion is associated with severe vision loss. There is no current established therapy. Parameters that objectify the presence of a therapeutic window for thrombolysis are gaining in importance as patient history is often imprecise. Relative retinal thickness increase proved a noninvasive imaging parameter demonstrating adequate performance in detecting patients within the therapeutic window of thrombolysis. Further investigation of this parameter in central retinal occlusion is warranted.

Unusual case of retinal arterial branch occlusion: possible variant of Sneddon syndrome.

Sneddon's syndrome (SS) manifests through multiple strokes and livedo reticularis. Livedoid vasculopathy (VL) is characterized by a long history of foot and leg ulceration and histopathology indicating a thrombotic process. Arterial retinal branch occlusion is described in a 52-year-old male with VL. He did not present noticeable laboratory abnormalities, such as antiphospholipid antibodies, or a history of strokes. Retinal artery occlusion accompanied by VL could be a variant of Sneddon's syndrome. Optical coherence tomography angiography revealed a reduction in the macula's vascular layers in the asymptomatic eye, indicating localized microvascular changes as an evolving marker in the pathogenesis of SS.

A case series on treatment of central and branch retinal artery occlusion with intravenous tenecteplase: Tenecteplase for retinal artery occlusions.

OBJECTIVES: Central and branch retinal artery occlusions are disabling ischemic strokes of the retina for which established acute treatments are lacking. This is the first published report of the use of intravenous tenecteplase (TNK) for retinal artery occlusion, in which we describe the clinical course of four patients with central retinal artery occlusion (CRAO) and one patient with branch retinal artery occlusion (BRAO). MATERIALS AND METHODS: Patients were retrospectively recruited to the study from two stroke centers. Clinical course was determined from review of electronic medical records. The primary outcomes of interest were short and long term complications as well as visual acuity at presentation and at any subsequent follow up. RESULTS: There were no hemorrhagic complications. None of the four patients with CRAO experienced functional visual recovery (defined as improvement to 20/100 or better). The patient with BRAO had functional visual recovery. CONCLUSIONS: Intravenous TNK may be a safe and reasonable treatment for CRAO and BRAO.

Diffusion-weighted magnetic resonance imaging in early central retinal artery occlusion.

INTRODUCTION: Restricted retinal diffusion (RDR) has recently been recognized as a frequent finding on standard diffusion-weighted imaging (DWI) in central retinal artery occlusion (CRAO). However, data on early DWI signal evolution are missing. PATIENTS AND METHODS: Consecutive CRAO patients with DWI performed within 24 h after onset of visual impairment were included in a bicentric, retrospective cross-sectional study. Two blinded neuroradiologists assessed randomized DWI scans for the presence of retinal ischemia. RDR detection rates, false positive ratings, and interrater agreement were evaluated for predefined time groups. RESULTS: Sixty eight CRAO patients (68.4 ± 16.8 years; 25 female) with 72 DWI scans (76.4% 3 T, 23.6% 1.5 T) were included. Mean time-delay between onset of CRAO and DWI acquisition was 13.4 ± 7.0 h. Overall RDR detection rates ranged from 52.8% to 62.5% with false positive ratings in 4.2%-8.3% of cases. RDR detection rates were higher in DWI performed 12-24 h after onset, when compared with DWI acquired within the first 12 h (79.5%vs 39.3%, p < 0.001). The share of false positive ratings was highest for DWI performed within the first 6 h of symptom onset (up to 14.3%). Interrater reliability was "moderate" for DWI performed within the first 18 h (κ = 0.57-0.58), but improved for DWI acquired between 18 and 24 h (κ = 0.94). CONCLUSION: DWI-based detection of retinal ischemia in early CRAO is likely to be time-dependent with superior diagnostic accuracy for DWI performed 12-24 h after onset of visual impairment.

Macular vessel density in central retinal artery occlusion with retinal arterial cannulation.

To characterize and compare macular vessel density in central retinal artery occlusion (CRAO) eyes with retinal arterial cannulation and CRAO eyes with standard treatment. This study was Cross-sectional, observational study. Twenty-two eyes with nonarteric CRAO which underwent retinal arterial cannulation and 19 eyes with nonarteric CRAO with standard treatment were included. Optical coherent tomography angiography (OCTA)-based macular vessel density and visual acuity were examined. The dynamic ranged-based normalized rates of vessel density was compared within each group at the first visit to the clinic and 7 days after the onset. Macular vessel density in cannulation group was significantly better at 7 days after the onset than that at the first visit (3.73 ± 3.02 mm-1 vs. 7.89 ± 1.02 mm-1, P = 0.0001), while there wasn't significant improvement of macular vessel density in standard treatment group at 7 days after the onset (2.13 ± 1.62 mm-1 vs. 2.89 ± 0.22 mm-1, P = 0.067). At one month after the onset, mean LogMAR visual acuity in CRAO eyes with cannulation significantly improved compared with that at the first visit after the onset (1.678 vs. 0.979, P = 0.00012). Macular vessel density loss in CRAO eyes was improved by retinal arterial cannulation. Early intervention of retinal arterial cannulation is useful for minimizing visual impairment in CRAO eyes.

Presence of Embolic Source and Outcome in Central Retinal Artery Occlusion.

OBJECTIVES: The etiology of central retinal artery occlusion (CRAO) is unclear in approximately 50% of patients, suggesting pathomechanical heterogeneity; moreover, little is known about outcomes according to etiology. This study investigated whether the presence of an embolic source affects outcome in CRAO. METHODS: CRAO patients within 7 days of symptom onset were retrospectively enrolled. Clinical parameters, including initial and 1-month visual acuity, CRAO subtype, and brain images, were reviewed. CRAO etiology was categorized as CRAO with or without an embolic source (CRAO-E+ and CRAO-E-). Visual improvement was defined as a decrease in logarithm of the minimum angle of resolution ≥0.3 at 1 month. RESULTS: A total of 114 patients with CRAO were included. Visual improvement was noted in 40.4% of patients. Embolic sources were identified in 55.3% of patients, and visual improvement group rather than no improvement group was more commonly associated with the presence of an embolic source. In multivariable logistic regression analysis, CRAO-E+ independently predicted visual improvement (odds ratio 3.00, 95% CI 1.15-7.81, p = 0.025). DISCUSSION: CRAO-E+ was found to be associated with a better outcome. CRAO-E+ may be more prone to recanalization than that CRAO-E-.

Thrombolysis in central retinal artery occlusion: a retrospective observational study.

BACKGROUND: There is no evidence-based therapy for non-arteritic central retinal artery occlusion (NA-CRAO). Intravenous thrombolysis (IVT) with alteplase in a time window < 4.5 h may lead to a favorable outcome. Purpose of this study was to investigate the feasibility, efficacy and safety of IVT in patients classified as functionally blind. METHODS: We conducted a retrospective observational study of NA-CRAO-patients. All patients underwent an ophthalmological and neurological examination including cerebral magnetic resonance imaging (MRI) for assessment of additional stroke lesions. Patients were treated either conservatively or with IVT within 4.5 h. Visual acuity (VA) was evaluated in logMAR and a categorical analysis was performed. RESULTS: Thirty-seven patients were included in the study, 21 patients in the conservative treatment group (CTG) and 16 patients in the IVT group. The median logMAR visual acuity at admission and discharge was similar in both groups. The medium symptom to treatment time in the IVT group was 158.0 min. 3 patients (19%) of the IVT group showed a favorable outcome, all CTG patients remained at the level of functional blindness. No serious adverse events were observed after IVT. MRI showed additional acute stroke in over one-third of the patients (n = 14). CONCLUSIONS: Early intravenous thrombolysis therapy according to the current stroke protocol n a time window up to 4.5 h after the onset of symptoms was feasible and might be a potential treatment option for NA-CRAO. Patients with NA-CRAO are at very high risk of ischemic stroke and MRI should be done in all patients for optimized treatment and secondary stroke prevention. A prospective randomized study is required.

Oclusión de la arteria central de la retina como complicación oftalmológica luego de un accidente ofídico / Central retinal artery occlusion as an ophthalmic complication after snakebite

La mordedura de serpiente causa entre 421.000-1.200.000 envenenamientos anuales con múltiples trastornos sistémicos secundarios a hematotoxicidad, neurotoxicidad y vasculotoxicidad siendo raras las manifestaciones oftalmológicas secundarias a mordedura de serpiente. La familia de serpientes Viperidae, causa más frecuentemente manifestaciones oftalmológicas como el infarto macular, el glaucoma crónico de ángulo abierto y la hemorragia retiniana o vítrea. La oclusión de la arteria central de la retina es una complicación ocular extremadamente rara. Reportamos el caso de una paciente de 30 años de edad, que consultó por mala visión del ojo izquierdo semanas después de sufrir una mordedura de serpiente (Bothrops atrox) en el miembro inferior izquierdo. Se diagnosticó de una oclusión de la arteria central de la retina con hallazgos anormales en el examen físico oftalmológico y en pruebas complementarias retinianas y neurooftalmológicas (AU)

Snakebite causes 421,000 - 1,200,000 poisonings per year due to hematotoxicity, neurotoxicity and vasculotoxicity. Ophthalmological manifestations secondary to snake bites are rare. If the snake belongs to the Viperidae family, the most frequent ophthalmologic manifestations are macular infarction, chronic open-angle glaucoma, and retinal or vitreous hemorrhage. Central retinal artery occlusion is an extremely rare ocular complication. We report the case of a 30-year-old patient, who consulted due to poor vision in her left eye weeks after suffering a snake bite (Bothrops atrox) in her left lower limb. The diagnosis was a central retinal artery occlusion in the left eye with abnormal findings in the ophthalmological physical examination and in complementary retinal and neuro-ophthalmological tests (AU)

Retinal and optic nerve magnetic resonance diffusion-weighted imaging in acute non-arteritic central retinal artery occlusion.

OBJECTIVES: Diffusion weighted imaging hyperintensity (DWI-H) has been described in the retina and optic nerve during acute central retinal artery occlusion (CRAO). We aimed to determine whether DWI-H can be accurately identified on standard brain magnetic resonance imaging (MRI) in non-arteritic CRAO patients at two tertiary academic centers. MATERIALS AND METHODS: Retrospective cross-sectional study that included all consecutive adult patients with confirmed acute non-arteritic CRAO and brain MRI performed within 14 days of CRAO. At each center, two neuroradiologists masked to patient clinical data reviewed each MRI for DWI-H in the retina and optic nerve, first independently then together. Statistical analysis for inter-rater reliability and correlation with clinical data was performed. RESULTS: We included 204 patients [mean age 67.9±14.6 years; 47.5% females; median time from CRAO to MRI 1 day (IQR 1-4.3); 1.5 T in 127/204 (62.3%) and 3.0 T in 77/204 (37.7%)]. Inter-rater reliability varied between centers (κ = 0.27 vs. κ = 0.65) and was better for retinal DWI-H. Miss and error rates significantly differed between neuroradiologists at each center. After consensus review, DWI-H was identified in 87/204 (42.6%) patients [miss rate 117/204 (57.4%) and error rate 11/87 (12.6%)]. Significantly more patients without DWI-H had good visual acuity at follow-up (p = 0.038). CONCLUSIONS: In this real-world case series, differences in agreement and interpretation accuracy among neuroradiologists limited the role of DWI-H in diagnosing acute CRAO on standard MRI. DWI-H was identified in 42.6% of patients and was more accurately detected in the retina than in the optic nerve. Further studies are needed with standardized novel MRI protocols.

Difference in topographic morphology of optic nerve head and neuroretinal rim between normal tension glaucoma and central retinal artery occlusion.

Although central retinal artery occlusion (CRAO) has its own defining pathomechanism and clinical characteristics, morphologic feature of the optic nerve head (ONH) during its later stage is not diagnostic, which makes it difficult to differentiate CRAO from other optic neuropathies. This cross-sectional study was performed to investigate the differences in the topographic morphology of the ONH in eyes with normal-tension glaucoma (NTG) and CRAO. Thirty-one eyes with NTG; 31 eyes with CRAO; and 31 healthy fellow eyes of the subjects with CRAO were included. ONH morphology was evaluated by measuring horizontal rim width (HRW), minimal rim width in the selected horizontal image (MRW), and lamina cribrosa curvature index (LCCI) in horizontal B-scan images obtained using enhanced depth-imaging optical coherence tomography. HRW was smaller and LCCI was larger in NTG eyes than in both CRAO and healthy fellow eyes (both P < 0.001), while both were comparable between CRAO and healthy fellow eyes. MRW differed significantly among the three groups, being smallest in NTG eyes followed by CRAO and healthy fellow eyes (P < 0.001). NTG and CRAO eyes with a similar degree of RNFL loss differed in ONH morphology, indicating that mechanisms of ONH damage differ between these two conditions.

Detectability of Retinal Diffusion Restriction in Central Retinal Artery Occlusion is Linked to Inner Retinal Layer Thickness.

PURPOSE: To investigate retinal microstructure differences in central retinal artery occlusion (CRAO) patients with and without visible retinal diffusion restriction (RDR) on diffusion-weighted magnetic resonance imaging (DWI). METHODS: Consecutive CRAO patients with available optical coherence tomography (OCT) and DWI, both performed within 7 days after symptom onset, were included in a retrospective cohort study. The OCT scans were reviewed to assess retinal layer thickness, optical intensity and structural integrity. The OCT findings were compared between patients with and without visible RDR on DWI using Mann-Whitney U or Pearson's Χ2 test. RESULTS: A total of 56 patients (mean age 70.8 ± 12.8 years) were included. RDR was observed in 38 subjects (67.9%) with visually correlating low ADC map in 26 of 38 cases (68.4%). Superior and inferior parafoveal macular thickness measurements (SMT, IMT) of RDR negative patients were significantly lower when compared to RDR+ patients (370.5 ± 43.8 µm vs. 418.2 ± 76.0 µm, p = 0.016; 374.4 ± 42.9 µm vs. 428.8 ± 63.2 µm, p = 0.004) due to differences in inner retinal layer thickness (IRLT, 188.8 ± 34.4 µm vs. 234.7 ± 49.0 µm, p = 0.002). IRLT values of RDR negative patients were higher in 1.5T compared to 3T the DWI (205.0 ± 26.0 µm vs. 168.6 ± 32.8 µm, p = 0.026). CONCLUSIONS: Detectability of RDR is likely contingent upon the degree of ischemic retinal swelling in CRAO. Technical adjustments to the DWI protocol, such as increased field strength, may improve visibility of RDR.

Retinal vascular occlusion in pregnancy: three case reports and a review of the literature.

BACKGROUND: Retinal arterial occlusive events in young patients are rare. However, because of physiological multifactorial adaptations during pregnancy, retinal vascular occlusive disease may occur spontaneously. In addition, a patent foramen ovale is a risk factor for an ischemic thromboembolic event. Since fluorescein angiography, a central tool in the evaluation of these occlusions, should be avoided during pregnancy, optical coherence tomography angiography, a novel technique, offers a good opportunity for visualizing vascular perfusion of retinal tissue. CASE PRESENTATION: Here we present a case series of three patients (Caucasian, nonsmoker) who visited our clinic owing to acute visual impairment and central scotoma. Using regular optical coherence tomography and optical coherence tomography angiography, retinal vascular occlusions were detected, thus initiating the evaluation of systemic risk factors. We report two patients (30 and 32 years old) who developed cilioretinal artery occlusion but whose etiology differed: one was of thromboembolic origin associated with patent foramen ovale, while the other was caused by hemodynamic blockade secondary to central retinal vein occlusion. In both cases, optical coherence tomography angiography revealed reperfusion of the cilioretinal artery occlusion. However, transient ischemia led to retinal atrophy after a few weeks. In the third patient (32 years old), 8 weeks after onset of scotoma, optical coherence tomography angiography revealed atrophy of the middle layers and impaired perfusion in the deep capillary plexus, and thus a paracentral acute middle maculopathy was diagnosed. All patients regained normal visual acuity and had otherwise uncomplicated pregnancies, and laboratory blood tests did not reveal any defects or alterations. CONCLUSIONS: As shown here, optical coherence tomography angiography enables risk-free imaging of retinal vessel perfusion during pregnancy. Together with regular optical coherence tomography, it allows one to predict functional outcome according to the existing retinal occlusion-related atrophy.