Hypercoagulable states in patients with retinal venous occlusion

Platelet and Thrombophilia-Related Risk Factors of Retinal Vein Occlusion

Retinal vein occlusion (RVO) is a heterogenous disorder in which the formation of a thrombus results in the retinal venous system narrowing and obstructing venous return from the retinal circulation. The pathogenesis of RVO remains uncertain, but it is believed to be multifactorial and to depend on both local and systemic factors, which can be divided into vascular, platelet, and hypercoagulable factors. The vascular factors include dyslipidaemia, high blood pressure, and diabetes mellitus. Regarding the platelet factors, platelet function, mean platelet volume (MPV), platelet distribution width (PDW), and platelet large cell ratio (PLCR) play key roles in the diagnosis of retinal vein occlusion and should be monitored. Nevertheless, the role of a hypercoagulable state in retinal vein occlusion remains unclear and requires further studies. Therefore, the following article will present the risk factors of RVO associated with coagulation disorders, as well as the acquired and genetic risk factors of thrombophilia. According to Virchow’s triad, all factors mentioned above lead to thrombus formation, which causes pathophysiological changes inside venous vessels in the fundus of the eye, which in turn results in the vessel occlusion. Therefore, a diagnosis of retinal vein occlusion should be based on both eye examination and general examination, including laboratory tests.

Cystotomy with or without fibrinogen clot removal for refractory cystoid macular edema secondary to branch retinal vein occlusion

To demonstrate the long-term effect of cystotomy with or without fibrinogen clot removal for treatment-resistant cystoid macular edema (CME) secondary to branch retinal vein occlusion (BRVO). Retrospective clinical study. We retrospectively analyzed medical records of 22 eyes of 22 patients with treatment-resistant CME secondary to BRVO with 12 months observation after cystotomy with or without fibrinogen clot removal. Patients included 11 women and 11 men. The mean ± SD age was 72.7 ± 10.2 years. LogMAR-converted best corrected visual acuity (BCVA) was statistically better at 12 months after surgery (0.30 ± 0.30) than preoperative BCVA (0.39 ± 0.27) (p = 0.01). The central sensitivity of microperimetry (dB) was maintained during follow-up (preoperative sensitivity: 25.4 ± 4.1, postoperative sensitivity at 12 months after the surgery: 25.9 ± 4.2, p = 0.69). Twelve months after surgery, there was a significant improvement in the central retinal thickness (CRT) on optical coherence tomography (OCT) (303.7 ± 80.1) (μm) compared with the preoperative CRT (524.2 ± 114.8) (p < 0.01). In 12 months, CME recurred in 3 of 22 eyes. The preoperative reflectivity in cystoid cavity on OCT was significantly higher in patients with fibrinogen clot removal (n = 5) than in patients without fibrinogen clot removal (n = 17) (p < 0.01). For treatment-resistant CME secondary to BRVO, Cystotomy with or without fibrinogen clot removal may be one of the treatment options.

Antiphospholipid antibody and risk of retinal vein occlusion: a systematic review and meta-analysis

BACKGROUND

Retinal vein occlusion (RVO) is a common retinal vascular disease and it is one of the most frequently reported causes of visual damage and blindness in the elderly. The current study investigated the potential association between antiphospholipid antibodies (APLA) and RVO risk by conducting a meta-analysis of case-control studies.

METHODS

A systematic literature search of Pubmed and Embase databases was conducted in August 1st, 2014. Odds ratios (ORs) were used to evaluate the associations between APLA and the incidence of RVO. A random-effects model was obtained for the quantitative synthesis.

RESULTS

A total of 11 studies were included in this meta-analysis. A meta-analysis of all studies assessing the risk of RVO revealed that APLA was associated with a statistically increased risk of RVO incidence (OR = 5.18, 95% CI = [3.37, 7.95]). The association between anticardiolipin antibodies (ACA) and the risk of RVO was significant (n =8, OR = 4.59, 95% CI = [2.75, 7.66]). However, the association between lupus anticoagulants (LA) and risk of RVO was non-significant (n = 5, OR = 3.90, 95% CI = [0.99, 15.37]). No significant publication bias was found in the 11 selected studies.

CONCLUSION

APLA was significantly associated with the risk of RVO. Advanced analyses showed that ACA rather than LA affected the risk of RVO. Additional well-designed and well-conducted epidemiological studies are required to further our understanding of the relationship between APLA and RVO risk.

Branch retinal vein occlusion in an asymptomatic adult with cystic fibrosis

PURPOSE

This article aims to describe a case of asymptomatic branch retinal vein occlusion (BRVO) in a patient with cystic fibrosis (CF) and discuss the possible link between the two.

CASE REPORT

A young adult (aged 35 years) with CF who presented for routine ocular examination was found to have a superior temporal BRVO in the left eye. Visual acuity was unaffected, measuring -0.06 LogMAR, and intraocular pressure was 10 mm Hg. Optical coherence tomography showed no macular involvement. Regarding the patient's general health, blood pressure was within the normal range, and there was no diabetes. Exploratory blood tests revealed elevated fibrinogen levels.

CONCLUSIONS

It is hypothesized that BRVO occurred secondary to raised fibrinogen levels, a common feature in CF resulting from chronic pulmonary infection and inflammation. Practitioners should be aware of the possible link between BRVO and CF.

Coronary artery disease, cerebral non-fatal ischemic stroke in retinal vein occlusion: an 8-yr follow-up

Forty-five consecutive subjects (26M, 19F; mean age 54 ± 14 yrs) with a diagnosed retinal vein occlusion (RVO), were followed-up for 8 yrs. As many as 145 sex-age- and blood pressure-matched individuals (78M, 67F; mean age 54.4 ± 13.5 yrs), that did not experience any vascular event, served as controls. At the time of the RVO, controls and subjects did not differ as to hypercholesterolemia, hypertrigliceridemia, diabetes mellitus, smoking habits, inherited/acquired thrombophilia. At the follow-up completion, they differed as to statin consumption (p = 0.016). During the 8-yrs follow-up, in the control population, 11 out of 145 (7.6%) subjects had experienced a major vascular event (8 coronary artery disease; 3 cerebral non-fatal ischemic stroke). In contrast, of the 45 subjects with a history of RVO, as many as 10 (22.2%) had experienced a major vascular event: 4 coronary artery disease; 4 cerebral non-fatal ischemic stroke; 2 cardiovascular + cerebrovascular event (p = 0.012). A prolonged antiplatelet treatment, prior to the major vascular event, was found in 5/45 cases (11.1%) vs 23/145 (15.9%) controls (p = 0.63). In contrast, a long-lasting administration of anti-hypertensive drugs, to achieve a control of blood pressure, was found in 83.4% of controls and only in 46.7% of cases (p < 0.0001). In conclusion, in a 8-yr follow-up, coronary artery disease and/or non-fatal ischemic stroke were more common in subjects with a history of RVO than in a large setting of subjects comparable for cardiovascular risk factors. These data also argue for RVO as a vascular disease in which aggressive anti-hypertensive therapy to prevent stroke and/or myocardial infarction is needed.

Antiphospholipid antibodies in ocular arterial and venous occlusive disease

PURPOSE

It was the aim of this study to evaluate antiphospholipid antibodies (APA), i.e. lupus anticoagulants (LA) and anticardiolipin (ACA) IgG and IgM, in ophthalmic occlusive disease.

METHODS

Over a 3.5-year period, APA were evaluated in 368 patients.

RESULTS

Eighty-six patients (23.4%), compared to 5% in the general population, tested positive for APA. APA did not differ significantly between patients with venous (20.6%) or arterial (25.5%) occlusive disease. This included 93 patients with central retinal vein occlusion (18% APA positive), 67 with retinal branch vein occlusion (24% APA positive), 41 with central retinal artery occlusion (22% APA positive), 53 with retinal branch artery occlusion (32% APA positive), 71 with anterior ischemic optic neuropathy (23% APA positive), 12 with posterior ischemic optic neuropathy (33% APA positive) and 31 patients with amaurosis fugax (23% APA positive). Excluding patients with accepted main risk factors, APA were positive in 15.3% of 85 patients.

CONCLUSION

The high APA prevalence confirms its relevance in ocular occlusive disorders.

CENTRAL RETINAL VEIN OCCLUSION IN PATIENTS TREATED WITH LONG-TERM WARFARIN SODIUM (COUMADIN) FOR ANTICOAGULATION

PURPOSE

To describe the clinical features of persons who developed central retinal vein occlusion (CVO) while being treated with Coumadin for chronic anticoagulation.

METHODS

In a retrospective, comparative, noninterventional case series of patients diagnosed with CVO while being treated with Coumadin as a systemic anticoagulant, visual and anatomical outcomes were compared with those for a cohort of patients diagnosed with CVO who were not treated with any systemic anticoagulation.

RESULTS

Fourteen eyes of 14 patients treated with Coumadin were identified. At presentation, the median international normalization ratio (INR) was 2.20 (range, 1.3-5.0). Eight patients (57%) had a therapeutic INR at the time of CVO. Their visual acuity and perfusion status were similar to those of patients with subtherapeutic INR. At the last follow-up (median, 16 months), visual acuity and perfusion status of the group of 14 eyes were similar to baseline findings (P = 0.62). Clinical features and outcomes were similar to those for a cohort of patients with CVO who were not being treated with systemic anticoagulation.

CONCLUSION

CVO can occur in patients being treated with Coumadin for systemic anticoagulation. Final visual acuity and perfusion status were similar to those in a cohort of patients with CVO who were not treated with Coumadin. Although visual acuity is unaffected, ensuring that the INR for these patients remains in the therapeutic range may be important to help prevent secondary systemic thrombotic and embolic disease.

Role of thrombophilic gene polymorphisms in branch retinal vein occlusion

OBJECTIVE

Branch retinal vein occlusion (BRVO) is a common cause of severe visual loss. Numerous risk factors, including arterial hypertension, diabetes mellitus, and arteriosclerosis, have been identified. Gene polymorphisms affecting hemostasis may also play a role in the pathogenesis of BRVO. The present study was therefore done to determine the prevalence of genetic polymorphisms in factors implicated in hypercoagulability among patients with BRVO.

DESIGN

Retrospective case-control study.

PARTICIPANTS

The study cohort consisted of 294 patients with BRVO and 294 control subjects, matched for age and gender.

METHODS

Determination of genotypes was done by allele-specific digestion of polymerase chain reaction products, or by 5' exonuclease assay (TaqMan).

MAIN OUTCOME PARAMETERS

Genotypes of factor V R506Q (factor V Leiden), prothrombin 20210G>A, fibrinogen beta -455G> A, factor XII (FXII) 46C>T, and ITGA2 807C>T (platelet glycoprotein Ia [GPIa] 807C>T) and ITGB3 L59P (platelet GPIIIa PlA1/PlA2) polymorphisms.

RESULTS

Genotype distributions of the investigated gene polymorphisms did not differ significantly between patients and control subjects. In contrast, significantly increased prevalences of arterial hypertension and hypercholesterolemia were found among patients with BRVO. In a logistic regression analysis, the presence of arterial hypertension was associated with an odds ratio (OR) of 2.32 (95% confidence interval [CI], 1.62-3.32), whereas hypercholesterolemia yielded an OR of 2.54 (95% CI, 1.74-3.70) for BRVO.

CONCLUSION

Our data indicate that the prevalences of the investigated gene polymorphisms do not differ significantly in patients with BRVO and control subjects. This suggests that these polymorphisms are not major risk factors for BRVO.

RETINAL VASCULAR OCCLUSION IN PATIENTS INFECTED WITH HUMAN IMMUNODEFICIENCY VIRUS

PURPOSE

To describe the clinical features of retinal vascular occlusions (macrovasculopathy) and the proportion of affected patients with human immunodeficiency virus (HIV) infection.

METHODS

Retrospective chart review of all HIV-infected individuals with retinal vascular occlusions seen at a single tertiary care clinic between November 1983 and May 1998.

RESULTS

Retinal vascular occlusion was found in 38 eyes of 33 (1.3%) of the 2,484 consecutive patients examined. Of the 33 patients, 16 (48.5%) had central retinal vein occlusion, 9 (27.3%) had branch retinal vein occlusion, 4 (12.1%) had hemiretinal vein occlusion, and 1 each (3.0%) had central retinal arterial occlusion, branch retinal arterial occlusion, and combined hemiretinal vein occlusion and branch retinal artery occlusion. One patient (3.0%) had Purtscher-like retinopathy in one eye. Multiple regression analysis revealed that macrovasculopathy was associated with the presence of noninfectious retinal microvasculopathy (odds ratio, 5.76; 95% confidence interval, 2.59-12.80). Vision at the time of diagnosis ranged between 20/20 and no light perception. Twenty-five (75.8%) of the 33 patients had follow-up examinations for a mean period of 9.1 months. Ocular findings during follow-up included capillary dropout in 3 patients (11.5%), posterior pole neovascularization in 4 (15.4%), vitreous hemorrhage in 4 (15.4%), and optic atrophy in 6 (23.1%). Vision at the last eye examination ranged between 20/20 and no light perception and was 20/200 or worse in 15 (39.5%) of 38 eyes.

CONCLUSIONS

Patients with HIV infection have a small risk of retinal vascular occlusion, but complications and visual loss are common in affected patients. There is a strong association between noninfectious retinal microvasculopathy and retinal vein occlusions.

Normal retinal vasculature despite familial protein C deficiency

PURPOSE

It is unclear whether protein C deficiency is associated with retinal venous occlusive disease.

DESIGN

We performed a cross-sectional study.

METHODS

Members of a protein C-deficient family, either deficient or nondeficient, with a history of nonocular venous thrombosis were included. All participants completed questionnaires regarding their medical and ophthalmic histories. Each subject underwent dilated direct ophthalmoscopic and binocular indirect ophthalmoscopic examinations by a single vitreoretinal specialist.

RESULTS

None of the 18 family members with a known history of nonocular thrombosis-12 with and 6 without protein C deficiency- manifested stigmas of recent or chronic retinal vascular occlusive disease.

CONCLUSIONS

This study showed no evidence of involvement of the retinal vascular bed in a family with an increased risk of nonocular venous thrombosis attributable to the deficiency of protein C.

Retinal periphlebitis resembling frosted branch angiitis with nonperfused central retinal vein occlusion

PURPOSE

To report the unusual association between severe retinal periphlebitis resembling frosted branch angiitis and nonperfused central retinal vein occlusion (CRVO).

METHODS

Observational case reports.

RESULTS

Patient 1 was a 28-year-old man who presented with extensive sheathing involving all retinal veins in one eye followed by nonperfused CRVO. Twenty-seven months after initial presentation, he developed perfused CRVO in the other eye followed by periphlebitis that progressed into nonperfused CRVO. Patient 2 was a 47-year-old man who presented with unilateral severe retinal periphlebitis associated with nonperfused CRVO. Despite systemic administration of corticosteroid therapy, rubeosis iridis developed in both patients and neovascular glaucoma developed in Patient 1 despite full panretinal photocoagulation. Extensive systemic workup and coagulation studies were unremarkable except for the presence of antiphospholipid antibodies in both patients and elevated plasma homocysteine level in Patient 2.

CONCLUSIONS

Severe retinal periphlebitis complicated by nonperfused CRVO is associated with poor visual outcome despite appropriate medical and surgical treatment.

Factor XII deficiency: a thrombophilic risk factor for retinal vein occlusion

PURPOSE

Factor XII deficiency is among the coagulation disorders that have been implicated in major thromboembolic events. However, little is known about an association of this coagulation disorder and retinal vessel occlusion. In the current study, we investigated the prevalence of factor XII deficiency in patients with retinal vein occlusion (RVO) with reference to age and cardiovascular risk factors.

DESIGN

Cross-sectional study.

METHODS

A cohort of 150 consecutive patients with central or branch retinal vein occlusion and 135 subjects matched for age and gender were prospectively screened for factor XII deficiency. Both cohorts were divided into two subgroups (<= 45 or >45 years), depending on the patients' age at the time of the RVO or a previous thromboembolic event.

RESULTS

Overall, factor XII deficiency was found to be present in 14 (9.3%) of 150 patients and in 1 (0.7%) of 135 controls (P =.0009). Patient age <= 45 years at the time of the RVO or a previous thromboembolic event was associated with a high prevalence of factor XII deficiency (18%). By contrast, only 5 (5%) of 100 patients >45 years (P =.016) and none of the young controls (P =.0001) tested positive for factor XII deficiency. The prevalence among patients >45 years was similar to that found in age-matched controls (2%; P =.66).

CONCLUSIONS

Our results indicate that factor XII deficiency is highly prevalent in RVO patients <= 45 years of age. By contrast, the prevalence of factor XII deficiency in RVO patients older than 45 years appears to be similar to that seen in healthy individuals.

Anticardiolipin antibodies in patients with retinal vein occlusion and no risk factors: a prospective study

BACKGROUND

Several reports have described the association between antiphospholipid antibodies (APAs) and retinal venous occlusive (RVO) disease. The purpose of this study was to look at the prevalence of these antibodies in patients with RVO disease and no conventional risk factors. We specifically examined how APAs may affect the course of this disease.

METHODS

Twenty-four patients with the diagnosis of RVO disease were screened prospectively for APAs. All were free from risk factors for retinal vein thrombosis and other immunologic conditions. Patients were observed for a period of 3 to 12 months.

RESULTS

Lupus anticoagulant was negative in all 24 patients. Ten (43%) of 24 patients had anticardiolipin antibodies (ACAs). All patients with ACAs were younger than 45 years of age, with an average age of 33 years. The average age of patients with no ACAs was 66 years. Comparison of the average age of the two groups showed a statistically significant difference. There was no statistical significance between the two groups for development of neovascular disease. Seropositive patients who developed neovascularization had elevated titers for an average of 11.8 weeks versus 3.3 weeks for those who did not have neovascularization. Neovascular complications generally began several weeks after the titers became negative.

CONCLUSION

There was a significant prevalence of ACAs in young patients with RVO disease and no associated systemic risk factors. Seropositive patients who developed neovascular disease had elevated titers for more than 6 weeks. However, the role of these transient ACAs in retinal vein occlusion is still not clear and merits further study.

Central retinal vein occlusion risk profile: a case-control study

PURPOSE

To identify risk factors for central retinal vein occlusion (CRVO).

METHODS

This clinic-based case-control study included 408 patients with CRVO aged 21 years and older and 566 controls who were seen between January 1, 1990, and December 31, 2001. Multivariate logistic regression analysis was used to adjust for various factors and test potential interactions between the different variables.

RESULTS

An increased risk of CRVO was found in persons with systemic hypertension, but odds ratios were greater for older patients. Risk of CRVO increases with age and also in association with hypercoagulability. Diabetes mellitus, kidney disease, and glaucoma were associated with increased risk for CRVO. A significantly greater prevalence of higher erythrocyte sedimentation rate was present in young adults compared with older patients.

CONCLUSIONS

The results suggest a relationship between CRVO and certain risk factors (systemic hypertension, diabetes mellitus, kidney disease, glaucoma, older age) and support the possibility of an association between CRVO and urban location. The findings also support the potential value of medical treatment of underlying medical conditions in preventing occurrence of CRVO.

Primary anti-phospholipid antibody syndrome (APS): current concepts

Primary anti-phospholipid syndrome (APS) is a thrombophilic state characterized by recurrent arterial and venous thrombosis, recurrent pregnancy loss, and the presence of circulating anti-phospholipid antibodies that may be responsible for thrombophilia and pregnancy morbidity. Ophthalmologic features are present in 15-88% of the patients with primary APS, thus ophthalmologists are one of the first physicians to whom the patient will present. An accurate diagnosis may save the patient from recurrent, potentially life-threatening thrombosis. In the U.S.A., an estimated 35,000 new cases of APS-related venous thrombosis occur each year in a population that is several decades younger than the patient population typically affected by thrombosis. Clinical features, such as chorea, transverse myelitis, cardiac valvular lesions, and accelerated atherosclerosis, are hypothesized to be due to a direct tissue-antibody interaction and cannot be explained purely by thrombosis. The use of recently proposed, well-defined diagnostic criteria, and better standardization of laboratory assays for the anti-phospholipid antibodies should help enable epidemiological surveys to establish the prevalence of these antibodies in patients with thrombosis and in the general population. Diagnosis of APS should be considered in all patients with recurrent systemic or ocular thrombosis in the absence of known risk factors. Several well-designed prospective studies show an increased risk of thrombosis in the presence of medium to high antibody level. With ocular involvement in as many as 88% of APS patients, an ophthalmic assessment should be an integral part of the clinical work-up of any patient with suspected or confirmed APS. The presence of isolated ocular thrombophilia with persistently elevated anti-phospholipid antibodies or lupus coagulant should confirm the diagnosis of APS. Management of these patients must be a multi-disciplinary effort with either a rheumatologist or a hematologist having the overall responsibility for coordinating treatment and monitoring the patient's immune status and anticoagulation. Treatment of isolated ocular thrombophilia in the presence of moderate to high titers of antiphospholipid antibodies should be on the same principles as patients with APS to prevent recurrent ocular or cerebral thrombosis.

Central retinal vein occlusion and thrombophilia

Central retinal vein occlusion is one of the commonest vascular diseases of the eye. The pathogenesis is multifactorial with both local factors and systemic diseases being aetiologically important. Many thrombophilic conditions have recently been identified and studies looking at their potential role in CRVO have been undertaken. The aim of this review is to critically appraise these studies as to date many have given conflicting results, making it far from clear what role thrombophilic conditions play in CRVO. It appears that hyperhomocysteinaemia and antiphospholipid syndrome are causes of CRVO and there is evidence that disorders causing hypofibrinolysis may also be important. The common hereditary thrombophilic conditions however do not appear to be strong risk factors but larger studies are needed for a definitive answer.

Anterior ischaemic optic neuropathy associated with central retinal vein occlusion

PURPOSE

To report the unusual association between non-arteritic anterior ischaemic optic neuropathy (NAION) and non-ischaemic central retinal vein occlusion (CRVO) in two patients.

METHODS

Case reports are presented.

RESULTS

Non-ischaemic CRVO was manifested by dilated, tortuous retinal veins with flame-shape retinal haemorrhages. Fluorescein angiography showed prolonged arteriovenous transit time and normal retinal capillary perfusion without macular oedema. The presence of colour vision abnormalities, relative afferent pupillary defects, pale disc swelling and visual field deficits indicated that the visual loss was attributable entirely to NAION. Laboratory investigations disclosed impaired fibrinolytic function in case 1 and the presence of antiphospholipid antibodies in case 2.

CONCLUSIONS

Compression of the central retinal vein by the swollen optic nerve could have predisposed to CRVO. The presence of thrombophilic abnormalities may have contributed to the concomitant occlusion of posterior ciliary arteries and central retinal vein. Ischaemic optic neuropathy needs to be considered in patients with CRVO when the visual acuity is not consistent with the retinal pathology.