Cardiovascular and thrombophilic risk factors in patients with retinal artery occlusion

Studies on the Effects of Hypercholesterolemia on Mouse Ophthalmic Artery Reactivity

Atherogenic lipoproteins may impair vascular reactivity, leading to tissue damage in various organs, including the eye. This study aimed to investigate whether ophthalmic artery reactivity is affected in mice lacking the apolipoprotein E gene (ApoE-/-), a model for hypercholesterolemia and atherosclerosis. Twelve-month-old male ApoE-/- mice and age-matched wild-type controls were used to assess vascular reactivity using videomicroscopy. Moreover, the vascular mechanics, lipid content, levels of reactive oxygen species (ROS), and expression of pro-oxidant redox enzymes and the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) were determined in vascular tissue. Unlike the aorta, the ophthalmic artery of ApoE-/- mice developed no signs of endothelial dysfunction and no signs of excessive lipid deposition. Remarkably, the levels of ROS, nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), NOX2, NOX4, and LOX-1 were increased in the aorta but not in the ophthalmic artery of ApoE-/- mice. Our findings suggest that ApoE-/- mice develop endothelial dysfunction in the aorta by increased oxidative stress via the involvement of LOX-1, NOX1, and NOX2, whereas NOX4 may participate in media remodeling. In contrast, the ophthalmic artery appears to be resistant to chronic apolipoprotein E deficiency. A lack of LOX-1 expression/overexpression in response to increased oxidized low-density lipoprotein levels may be a possible mechanism of action.

High prevalence of thrombophilic risk factors in patients with central retinal artery occlusion

INTRODUCTION

Central retinal artery occlusion (CRAO) is a common cause of blindness and visual morbidity. In the majority of cases, it is related to thrombotic embolism. Nevertheless, the role of inherited or acquired thrombophilic risk factors in CRAO pathogenesis has not been comprehensively studied.

METHODS

In 126 CRAO patients (66 [52.4%] men, median age 55 [range: 18-80] years) and 107 matched controls (56 [52.3%] men, median age 53 [range: 34-78] years) we evaluated classical atherosclerotic risk factors, including serum lipid profile and glucose level, analyzed intima-media complex thickness (IMT) of external carotid arteries, and performed transthoracic echocardiography. Furthermore, we established the prevalence of inherited and acquired thrombophilic risk factors, such as factor V Leiden (FVL) and prothrombin 20210 G/A genetic variants, plasma activity of factor (F) VIII, protein C and antithrombin activity, and free protein S levels. We also assessed the presence of antiphospholipid antibodies (APLA) and evaluated blood homocysteine in all enrolled subjects. Additionally, we estimated the occurrence of Val34Leu polymorphism of the A subunit of coagulation factor XIII (FXIII-A) in both groups as a potential thrombosis-protecting factor.

RESULTS

Among traditional atherosclerotic risk components, obesity/overweight and hypercholesterolemia were the most common in the CRAO group and occurred in 103 (81.7%) and 85 (67.5%) patients, respectively. CRAO patients also had elevated IMT and altered echocardiographic parameters, indicating diastolic cardiac dysfunction. In thrombophilia investigations, at least one laboratory risk factor occurred in 72.2% (n = 91) of CRAO patients, with APLA as the most frequent, detected in 38.1% (n = 48) of them (almost seven times more frequent than in controls, p < 0.001). Deficiencies in protein C activity and free protein S levels were also common in the CRAO group, reported in 17.5% (n = 22) and 19.8% (n = 25) of patients, respectively. Interestingly, among two analyzed prothrombotic genetic variants, only the FVL was related to CRAO, with the allelic frequency 2.4 times more prevalent than in controls (p = 0.044). Finally, the CRAO group was characterized by hyperhomocysteinemia, almost twice as common as in controls (p = 0.026). Antithrombin deficiency, elevated FVIII, and FXIII-A Val34Leu polymorphism were not associated with CRAO.

CONCLUSIONS

Our findings suggest that thrombophilia plays a vital role in the pathogenesis of CRAO. Thus, proper laboratory screening should be considered in the primary and secondary prevention of those episodes, with implementing appropriate therapy as needed.

Age, Gender, and Laterality of Retinal Vascular Occlusion: A Retrospective Study from the IRIS® Registry

PURPOSE

Retinal vascular occlusion is a leading cause of profound irreversible visual loss, but the understanding of the disease is insufficient. We systematically investigated the age, gender, and laterality at the onset of retinal artery occlusion (RAO) and retinal vein occlusion (RVO) in the Intelligent Research in Sight (IRIS®) Registry.

DESIGN

Retrospective registry cohort.

PARTICIPANTS

Patients with retinal vascular occlusion participating in the IRIS® Registry.

METHODS

Patients who received a diagnosis of retinal vascular occlusion between 2013 and 2017 were included. Those with unspecified gender or laterality were excluded when conducting the relevant analyses. Patients were categorized into RAO, with subtypes transient retinal artery occlusion (TRAO), partial retinal artery occlusion (PRAO), branch retinal artery occlusion (BRAO), and central retinal artery occlusion (CRAO), and into RVO, with subtypes venous engorgement (VE), branch retinal vein occlusion (BRVO), and central retinal vein occlusion (CRVO). Age was evaluated as a categorical variable (5-year increments). We investigated the association of age, gender, and laterality with the onset frequency of retinal vascular occlusion subtypes.

MAIN OUTCOME MEASURES

The frequency of onset of RAO and RVO subtypes by age, gender and laterality.

RESULTS

A total of 1 251 476 patients with retinal vascular occlusion were included, 23.8% of whom had RAO, whereas 76.2% had RVO. Of these, 1 248 656 and 798 089 patients were selected for analyses relevant to gender and laterality, respectively. The onset frequency of all subtypes increased with age. PRAO, BRAO, CRAO, and CRVO presented more frequently in men (53.5%, 51.3%, 52.6%, and 50.4%, respectively), whereas TRAO, VE, and BRVO presented more frequently in women (54.9%, 56.0%, and 54.5% respectively). All RAO subtypes and BRVO showed a right-eye onset preference (TRAO, 51.7%; PRAO, 54.4%; BRAO, 53.5%; CRAO, 53.4%; and BRVO, 51.0%), whereas VE and CRVO exhibited a left-eye onset preference (53.3% and 50.9%, respectively).

CONCLUSIONS

Although retinal vascular occlusion incidence increases with age regardless of subtypes, we found various subtype-specific disease-onset differences related to gender and, in particular, ocular laterality. These findings may improve understanding of the specific cause of retinal vascular occlusions of different subtypes and their relationships with structural and anatomic asymmetries of the vascular system.

Apolipoprotein E Deficiency Causes Endothelial Dysfunction in the Mouse Retina

Objective

Atherogenic lipoproteins may impair vascular reactivity consecutively causing tissue damage in multiple organs via abnormal perfusion and excessive reactive oxygen species generation. We tested the hypothesis that chronic hypercholesterolemia causes endothelial dysfunction and cell loss in the retina.

Methods

Twelve-month-old apolipoprotein E-deficient (ApoE-/-) mice and age-matched wild-type controls were used in this study (n = 8 per genotype for each experiment). Intraocular pressure, blood pressure, and ocular perfusion pressure were determined. Retinal arteriole responses were studied in vitro, and reactive oxygen and nitrogen species were quantified in the retinal and optic nerve cryosections. The expression of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and the NADPH oxidase isoforms, NOX1, NOX2, and NOX4, were determined in retinal cryosections by immunofluorescence microscopy. Pro- and antioxidant redox genes were quantified in retinal explants by PCR. Moreover, cell number in the retinal ganglion cell layer and axon number in the optic nerve was calculated.

Results

Responses to the endothelium-dependent vasodilator, acetylcholine, were markedly impaired in retinal arterioles of ApoE-/- mice (P < 0.01). LOX-1 (P = 0.0007) and NOX2 (P = 0.0027) expressions as well as levels of reactive oxygen species (P = 0.0022) were increased in blood vessels but not in other retinal structures. In contrast, reactive nitrogen species were barely detectable in both mouse genotypes. Messenger RNA for HIF-1α, VEGF-A, NOX1, and NOX2, but also for various antioxidant redox genes was elevated in the retina of ApoE-/- mice. Total cell number in the retinal ganglion cell layer did not differ between ApoE-/- and wild-type mice (P = 0.2171). Also, axon number in the optic nerve did not differ between ApoE-/- and wild-type mice (P = 0.6435).

Conclusion

Apolipoprotein E deficiency induces oxidative stress and endothelial dysfunction in retinal arterioles, which may trigger hypoxia in the retinal tissue. Oxidative stress in nonvascular retinal tissue appears to be prevented by the upregulation of antioxidant redox enzymes, resulting in neuron preservation.

Risk of incident atrial fibrillation in patients presenting with retinal artery or vein occlusion: a nationwide cohort study

BACKGROUND

The inter-relationships of atrial fibrillation (AF) to retinal vascular occlusions (whether retinal artery occlusion (RAO) or retinal venous occlusion (RVO)) remain unclear. It is unknown if a presentation of retinal artery or venous occlusions may indicate a new onset cardiac arrhythmia. To shed light on this association, we investigated the risk of new onset AF in patients with known RAO and RVO.

METHODS

Patients with retinal occlusions from 1997 to 2011 were identified through Danish nationwide registries and matched 1:5 according to sex and age. Cumulative incidence and unadjusted rates of AF according to retinal vascular occlusions (i.e. RAO or RVO) were determined. Hazard ratios (HR) of AF according to retinal vascular occlusion were adjusted for hypertension, diabetes, vascular disease and prior stroke/systemic thromboembolism/transient ischemic attack.

RESULTS

One thousand three hundred sixty-eight cases with retinal vascular occlusions were identified (median age 71.4 (inter quartile range (IQR); 61.2-79.8), 47.3% male). RAO constituted 706 cases (51.6%) and RVO 529 (38.7%). The rate of incident AF amongst all cases with retinal vascular occlusion was 1.74 per 100 person-years (95% confidence interval (CI), 1.47-2.06) compared to 1.22 (95% CI, 1.12-1.33) in the matched control group. The rate of AF in RAO was 2.01 (95% CI, 1.6-2.52) and 1.52 (1.15-2.01) in RVO. HRs of incident AF adjusted for cardiovascular comorbidities were 1.26 (95% CI; 1.04-1.53, p = 0.019) for any retinal vascular occlusion, 1.45 (95% CI; 1.10-1.89, p = 0.015) for RAO, and 1.02 (95% CI; 0.74-1.39, p = 0.920) for RVO.

CONCLUSIONS

A new diagnosis of retinal vascular occlusion in patients without prior AF was associated with increased risk of incident AF, particularly amongst patients with RAO. Awareness of AF in patients with retinal vascular occlusions is advised.

Risk of recurrence in patients with pulmonary embolism: Predictive role of D-dimer and of residual perfusion defects on lung scintigraphy

The stratification of recurrence risk after a first episode of venous thromboembolism (VTE) is an important topic of research, especially in patients with pulmonary embolism (PE). Elevated D-dimer levels and residual vein obstruction (RVO) at compression ultrasonography have been studied as predictors of recurrence after withdrawing oral anticoagulant treatment (OAT). It is still unknown if residual perfusion defects (PD) on lung scintigraphy are related to recurrent PE. In the present study, we evaluated the association of PD with PE recurrence. The relationship between PD, elevated D-dimer levels, and RVO was also investigated. We prospectively followed 236 consecutive patients who survived a first episode of objectively confirmed PE, with or without deep-vein thrombosis. After at least three months of OAT, treatment was withdrawn in 139 patients. D-dimer levels were evaluated at one month of OAT withdrawal, RVO was measured, and perfusion lung scan (P-scan) was performed to evaluate PD. During follow-up, 20 patients experienced a recurrent episode of VTE. Elevated D-dimer levels were significantly associated with VTE recurrence, (p=0.003). RVO was present in 22% of the patients with recurrence and in 7.5% of those without (p=0.07). No significant association was found between PD >10% and VTE recurrence, D-dimer, or RVO. In conclusion, we confirmed the positive predictive value of elevated D-dimer levels for recurrent VTE. Residual PD on lung scintigraphy are neither predictive of recurrence nor related to D-dimer levels or RVO.

Homocysteine in retinal artery occlusive disease: A meta-analysis of cohort studies

Few studies have reported the relationship between retinal artery occlusion (RAO) and plasma homocysteine (Hcy) levels. Our goal was to evaluate the association between the plasma Hcy level and the risk of RAO disease. Several databases were searched for all published studies that involved Hcy and RAO. Six studies evaluated hyperhomocysteinemia (hHcy) in retinal artery occlusion patients and controls; the incidence of hHcy in patients with RAO was higher than the control and the pooled odds ratio (OR) was 6.64 (95% confidence interval (CI): 3.42, 12.89). Subgroup analyses showed that the ORs were 4.77 (95% CI: 2.69, 8.46) in Western countries, 22.19 (95% CI: 2.46, 200.37) in Asian countries, 9.70 (95% CI: 4.43, 21.20) in the age matched group, 11.41 (95% CI: 3.32, 39.18) in the sex matched group, 9.70 (95% CI: 4.37, 21.53) in the healthy control group, and 6.82 (95% CI: 4.19, 11.10) in the sample size >30. The mean plasma Hcy level from 5 case-control studies was higher than controls, and the weighted mean difference (WMD) was 6.54 (95% CI: 2.79, 10.29). Retinal artery occlusion is associated with elevated plasma Hcy levels. Our study results suggest that hHcy is probably an independent risk factor for RAO.

Retinal artery and vein thrombotic occlusion during pregnancy: markers for familial thrombophilia and adverse pregnancy outcomes

Background

Ocular vascular occlusion (OVO), first diagnosed during or immediately after giving birth, often reflects superposition of the physiologic thrombophilia of pregnancy on previously undiagnosed underlying familial or acquired thrombophilia associated with spontaneous abortion, eclampsia, or maternal thrombosis.

Specific aim

We describe OVO, first diagnosed during pregnancy or immediately postpartum, in three young females (ages 32, 35, 40) associated with previously undiagnosed familial thrombophilia.

Results

Branch retinal artery occlusion (BRAO) occurred at 9 and 13 weeks gestation in two females, aged 32 and 35. Central retinal vein occlusion occurred immediately postpartum in a 40-year-old. One of the two females with BRAO subsequently developed eclampsia, and one had a history of unexplained first trimester spontaneous abortion. All three females were found to have previously unexplained familial thrombophilia. The two females with BRAO had low first trimester free protein S 42 (41%), lower normal limit (50%), and one of these two had high factor VIII (165%, upper normal limit 150%). The woman with central retinal vein occlusion had high factor XI (169%, upper normal limit 150%). Enoxaparin (40–60 mg/day) was started and continued throughout pregnancy in both females with BRAO to prevent maternal–placental thrombosis, and of these two females, one had an uncomplicated pregnancy course and term delivery, and the second was at gestational week 22 without complications at the time of this manuscript. There were no further OVO events in the two females treated with enoxaparin or in the untreated patient with postpartum eclampsia.

Conclusion

OVO during pregnancy may be a marker for familial or acquired thrombophilia, which confers increased thrombotic risk to the mother and pregnancy, associated with spontaneous abortion or eclampsia. OVO during pregnancy, particularly when coupled with antecedent adverse pregnancy outcomes, should prompt urgent thrombophilia evaluation and institution of thromboprophylaxis to prevent adverse maternal and fetal–placental thrombotic events.

Selective Thrombophilia Screening in Young Patients with Retinal Artery Occlusion

Purpose: To investigate the prevalence of various thrombophilic disorders among young patients with retinal artery occlusion (RAO). Procedures: We retrospectively reviewed thrombophilia screening data of young patients ≤60 years of age with RAO and healthy controls matched for gender and age. Results: Thrombophilia screening data of 25 young patients and 62 healthy controls were analyzed. Mean patient age by the time of the RAO was 43.3 ± 10.8 years. Overall, thrombophilic defects were found to be present in 17 patients (68%) compared with 11 of 62 controls (17.7%; p < 0.0001). Multivariate logistic regression analysis confirmed a statistically significant association between the development of RAO and increased levels of lipoprotein(a) (odds ratio: 9.48; p = 0.001) and factor VIII (odds ratio: 6.41; p = 0.024). There was a strong association between the presence of thrombophilic disorders and a personal or family history of thromboembolism (p = 0.01). Conclusions: Our results indicate that screening for thrombophilic disorders among selected young patients with RAO yields positive results in a high percentage of cases.

Prevalence of thrombophilic genetic factors among patients with retinitis pigmentosa

PURPOSE

To determine the prevalence of thrombophilic factors in patients with retinitis pigmentosa (RP).

METHODS

Fifty consecutive patients with RP and 50 controls matched by age and gender were tested for the presence of the following mutations: factor II (GA20210), factor V Leiden (GA1691), methylenetetrahydrofolate reductase (CT677), factor XIIIa (Val→Leu), β-fibrinogen (GA455), tumor necrosis factor receptor (TNFRII) (M196R), plasminogen activator inhibitor-1 (PAI-1) (4 G/5 G), and plasminogen activator inhibitor-1 (PAI-1) (GA844).

RESULTS

The following heterozygous mutations were found in patients/controls: factor V Leiden (12/14), factor XIIIa (20/30), methylenetetrahydrofolate reductase 677 TT (48/52), β-fibrinogen GA455 (36/36), TNFRII (M196R) (40/42), PAI-1 4 G/5 G (40/48), and PAI-1 GA844 (50/52). The difference between patients with RP and the control group was not statistically significant for the prevalence of any of the studied factors (P > 0.05).

CONCLUSION

In this study, thrombophilic mutations were not increased in patients with RP. Thrombophilic mutations do not seem to be risk factors for RP. Routine investigation of hereditary thrombophilia in these patients is not justified.

Co-occurrence of acute retinal artery occlusion and acute ischemic stroke: diffusion-weighted magnetic resonance imaging study

PURPOSE

To evaluate the co-occurrence of acute ischemic stroke and acute retinal artery occlusion (RAO).

DESIGN

Retrospective observational case series.

METHODS

We included 33 consecutive patients with acute RAO who underwent diffusion-weighted magnetic resonance imaging within 7 days of the onset of visual symptoms. The causes of RAO were classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria, which are based on clinical features and the results of etiological evaluations for atherosclerosis, cardioembolism and other prothrombotic conditions. We evaluated the prevalence of accompanying acute ischemic stroke in subjects with acute RAO and examined the relationships with etiological parameters.

RESULTS

Acute ischemic stroke was detected in 8 (24.2%) subjects with RAO. Among these subjects, 3 (37.5%) patients did not exhibit any neurologic symptoms or signs. Most of the infarction patterns were small, multiple and scattered. All of the subjects with RAO who were positive for lesions on diffusion-weighted imaging had identifiable causes, whereas only 36% of the subjects who were negative for lesions had identifiable etiologies (P = .003). Carotid stenosis or cardioembolic sources were found more commonly in cases of central retinal artery occlusion (CRAO; 7/18, 38.9%) than in cases of branch retinal artery occlusion (BRAO; 1/15 6.7%, P = .046).

CONCLUSIONS

Acute cerebral infarctions frequently accompany RAO. We recommend diffusion-weighted imaging for patients with RAO because the presence of lesions on diffusion-weighted imaging is accompanied by a significantly increased probability of identifying the cause.

Retinal vein and artery occlusions: a risk factor for stroke in atrial fibrillation

BACKGROUND

Retinal vascular occlusions may constitute an independent risk factor for stroke in patients with atrial fibrillation.

METHODS

We performed a retrospective study on a nationwide cohort with atrial fibrillation from 1997 to 2008. The rate of stroke/systemic thromboembolism (TE)/transitory ischemic attack (TIA) was determined for atrial fibrillation patients with and without a history of retinal vascular occlusion. A Cox regression analysis, adjusted for risk factors and medications, was performed to determine the independent predictive value of retinal arterial or venous occlusion for the risk of ischemic stroke, TE or TIA in atrial fibrillation patients.

RESULTS

We included 87 202 patients with non-valvular atrial fibrillation. At baseline, a history of retinal arterial occlusion was diagnosed in 224 patients (0.26%) and a history of retinal venous occlusion in 361 (0.41%). Patients without retinal occlusion had a rate of stroke/TE/TIA of 4.52 (95% confidence interval [CI] 4.44-4.60). For patients with retinal arterial occlusion, the rate of stroke/TE/TIA was 8.16 (95% CI 6.35-10.49) per 100 person-years, and for patients with retinal venous occlusion it was 7.28 (95% CI 5.93-8.94) per 100 person-years. In multivariate analysis, both retinal arterial occlusions (hazard ratio [HR] 1.39, 95% CI 1.08-1.79) and retinal venous occlusions (HR 1.26, 95% CI 1.02-1.54) were associated with an increased risk of future stroke/TE/TIA.

CONCLUSIONS

A history of retinal arterial or retinal venous occlusion is associated with an increased risk of stroke/TE/TIA in patients with atrial fibrillation. Thus, prior retinal vascular occlusion may be considered as a previous thromboembolic event when evaluating stroke risk in patients with atrial fibrillation.

Thrombophilia and retinal vascular occlusion

Purpose

The purpose of this research was to assess associations of thrombophilia with central retinal vein occlusion (CRVO), central retinal artery occlusion (CRAO), and amaurosis fugax (AF); to evaluate outcomes of normalizing high homocysteine; and to study CRVO, CRAO, and AF developing in estrogens/estrogen agonists in women subsequently shown to have thrombophilia.

Methods

Measures of thrombophilia–hypofibrinolysis were obtained in 132 CRVO cases, 15 CRAO cases, and 17 AF cases. Cases were compared to 105 healthy control subjects who did not differ by race or sex and were free of any ophthalmologic disorders. All cardiovascular disease (CVD) risk factors were compared to healthy general populations.

Main outcome measures

The main outcome measure of this study was thrombophilia.

Results

CRVO cases were more likely than controls to have high homocysteine (odds ratio [OR] 8.64, 95% confidence intervals [CI]: 1.96–38), high anticardiolipin immunoglobulin M (IgM; OR 6.26, 95% CI: 1.4–28.2), and high Factor VIII (OR 2.47, 95% CI: 1.31–7.9). CRAO-AF cases were more likely than controls to have high homocysteine (OR 14, 95% CI: 2.7–71.6) or the lupus anticoagulant (OR 4.1, 95% CI: 1.3–13.2). In four of 77 women with CRVO (two found to have high homocysteine, two with inherited high Factor XI), CRVO occurred after starting estrogen–progestins, estrogen–testosterone, or estrogen agonists. In one of eight women with CRAO found to have high anticardiolipin antibody IgG, CRAO occurred after starting conjugated estrogens, and AF occurred after starting conjugated estrogens in one of eleven women with AF (inherited protein S deficiency). Therapy for medians of 21 months (CRVO) and 6 months (CRAO-AF) was 5 mg folic acid, 100 mg B6, and 2000 mcg/day B12 normalized homocysteine in 13 of 16 (81%) CRVO cases and all five CRAO-AF cases with pretreatment hyperhomocysteinemia. The CRVO cases had an excess of hypertension; CRAO-AF cases had an excess of type 2 diabetes and hypertension.

Conclusion

Treatable thrombophilia, hyperhomocysteinemia in particular, is more common in RVO cases than in normal controls. RVO occurs after estrogens or estrogen agonists were administered in women subsequently shown to have thrombophilia.

Bilateral central retinal artery occlusions in an infant with hyperhomocysteinemia

A previously healthy 7-week-old boy developed bilateral central retinal artery occlusions in the presence of hyperhomocysteinemia and elevated serum methylmalonic acid and was found to have a transcobalamin receptor mutation. Retinal arterial occlusion is uncommon in young patients and typically prompts a systemic workup. In cases of atypical retinal arterial occlusion, hyperhomocysteinemia should be investigated.

The incidence of central retinal artery occlusion in Olmsted County, Minnesota

PURPOSE

To determine the incidence of central retinal artery occlusion in Olmsted County, Minnesota.

DESIGN

Retrospective chart review.

METHODS

Medical records of all patients living in Olmsted County, Minnesota between 1976 and 2005 diagnosed with central retinal artery occlusion were identified using the Rochester Epidemiology Project medical records linkage system.

RESULTS

Forty-three cases were identified for an unadjusted annual incidence in the female population of 1.02 per 100,000 and 1.67 per 100,000 in the male population, with a combined incidence of 1.33. Incidence rates were also age- and/or sex-adjusted to the 2000 census figures for the US white population using direct standardization. Age-adjusted annual incidence per 100,000 for the female population was 1.15 (95% confidence interval [CI], 0.60-1.71), for the male population was 2.78 (95% CI, 1.69-3.86), and combined was 1.87 (95% CI, 1.31-2.43). When adjusted for age and sex, the incidence was 1.90 per 100,000 (95% CI, 1.33-2.47).

CONCLUSION

Central retinal artery occlusion is a rare event. The incidence is 1.3 per 100,000 in Olmsted County, Minnesota, or 1.90 per 100,000 when age- and sex-adjusted for the United States white population.

Ocular artery thrombosis as an initial presentation of a prothrombin G20210A mutation

The G20210A mutation in the prothrombin gene is an established risk factor for venous thrombosis. There is controversy as to the role played by this mutation in arterial thrombotic disease. We present the case of a 56-year-old man who presented with a central retinal artery occlusion of the left eye. Evaluation revealed hypercholesterolemia, smoking, and heterozygosity for the prothrombin G20210A mutation. The literature concerning hereditary thrombophilia and retinal artery occlusion was reviewed. The synergistic effect of multiple risk factors is emphasized. Screening for hereditary thrombophilia should be considered, regardless of patient age. The prothrombin G20210A mutation may be associated with central retinal artery occlusion.

Ocular disorders as the prevailing manifestations of antiphospholipid syndrome: a case series

Introduction

Antiphospholipid syndrome is an autoimmune disorder characterized by either a history of vascular thrombosis (one or more clinical episodes of arterial, venous, or small vessel thrombosis in any tissue or organ) or pregnancy morbidity in association with the presence of antiphospholipid antibodies. The systemic features of the syndrome are characterized by large variability depending on the affected organ(s). Among them, neurological and behavioural disturbances, dermatological features as livedo reticularis and renal, ocular, liver or valvular heart manifestations have been reported in antiphospholipid syndrome patients. However, studies on the frequency and clinical presentation of the ocular manifestations as the prevailing (first) sign of antiphospholipid syndrome in patients suffering from "unexplained" ocular disease are missing. Herein, we present three cases suffering from unexplained ocular disease as first manifestation of antiphospholipid syndrome.

Case presentation

All the three patients were referred to our department because of unexplained ocular features from the anterior or posterior segment and unexplained neuro-ophthalmologic symptoms. The first patient had bilateral retinal occlusive disease, the second and the third patient had unilateral nonarteritic anterior ischemic optic neuropathy with macular oedema. Moderate to high levels of antiphospholipid antibodies were detected in all of them at baseline as well as 6 to 12 weeks after initial testing confirming the presence of antiphospholipid antibodies. Anticoagulant treatment with acenocoumarol was instituted resulting in stabilization and/or improvement of ocular signs in all of them.

Conclusion

Due to the important diagnostic and therapeutic implications of antiphospholipid syndrome, the possibility of ocular features as the first clinical manifestation of antiphospholipid syndrome should be kept in mind of the physicians particularly in patients with no evident risk factors for ocular disease. In this case, prompt anticoagulant treatment and close follow-up seem to be essential for vision salvation and stabilization.