Trombofilia y factores de riesgo vascular en la obstrucción venosa retiniana

Deciphering the interplay of gut microbiota and metabolomics in retinal vein occlusion

This study aims to explore the link between retinal vein occlusion (RVO), a blinding ocular condition, and alterations in gut microbiota composition, to offer insights into the pathogenesis of RVO. Fecal samples from 25 RVO patients and 11 non-RVO individuals were analyzed using 16S rRNA sequencing and liquid chromatography-mass spectrometry (LC-MS). Significant differences in the abundance of gut microbial species were noted between RVO and non-RVO groups. At the phylum level, the RVO group showed an elevation in the ratio of Firmicutes to Bacteroidetes. At the genus level, the RVO group showed higher abundance in Escherichia_Shigella (P < 0.05) and less abundance in Parabacteroides (P < 0.01) than the non-RVO group. Functional predictions indicated reduced folate synthesis, biotin metabolism, and oxidative phosphorylation, with an increase in butyric acid metabolism in the RVO group. LC-MS analysis showed significant differences in purine metabolism, ABC transporters, and naphthalene degradation pathways, especially purine metabolism. Pearson correlation analysis revealed significant associations between bacterial genera and fecal metabolites. Enrichment analysis highlighted connections between specific metabolites and bacterial genera. The findings showed that the dysregulation of gut microbiota was observed in RVO patients, suggesting the gut microbiota as a potential therapeutic target. Modulating the gut microbiota could be a novel strategy for managing RVO and improving patient outcomes. Furthermore, the study findings suggest the involvement of gut microbial dysbiosis in RVO development, underscoring the significance of understanding its pathogenesis for effective treatment development.

IMPORTANCE

Retinal vein occlusion (RVO) is a blinding ocular condition, and understanding its pathogenesis is crucial for developing effective treatments. This study demonstrates significant differences in gut microbiota composition between RVO patients and non-RVO individuals, implicating the involvement of gut microbial dysbiosis in RVO development. Functional predictions and metabolic profiling provide insights into the underlying mechanisms, highlighting potential pathways for therapeutic intervention. These findings suggest that modulating the gut microbiota might be a promising strategy for managing RVO and improving patient outcomes.

Retinal vein occlusion in the general population after COVID-19 vaccination and infection

INTRODUCTION

Retinal vein occlusion (RVO) is mostly a consequence of vascular risk factors (VRF). COVID-19 vaccines have been related to vascular and thrombotic events (VTE).

OBJECTIVE

To assess the RVO incidence in the general population in our health area and the possible relation with COVID-19 infection and vaccination.

METHODS

Demographic features, classic VRF, thrombophilia data, COVID-19 status, and Framingham risk score were collected prospectively.

RESULTS

472 consecutive patients studied over 13 years with RVO were included (Valdecilla Cohort). Classic VRFs were present in 90%, antiphospholipid syndrome in 12.3%, and genetic thrombophilia in 13.5%. Ninety-one percent of RVO patients were vaccinated and 6.8% suffered COVID-19 infection. In the cohort, no patient had a new RVO after vaccination or infection. In the general population, 20 subjects had RVO after receiving the vaccine (0.006%). Overall, 8 cases occurred in the first-month post-vaccination and 12 after 30 days. In the early and late groups, there are 3 and 4 patients respectively, with a low-intermediate risk Framingham score. Twenty-nine patients in the cohort suffered SARS-CoV-2 infection, twenty-seven of them had RVO before infection. Two patients with low-risk Framingham scores had RVO after infection, one of them early (<1 month).

CONCLUSIONS

Vaccination and COVID-19 might be involved in the development of RVO in some cases, mainly in patients without VRF, thrombophilia, or chronic inflammatory conditions and with a lower Framingham score, especially in the first month after vaccination or infection.

Nonvalvular atrial fibrillation and retinal vein occlusion: The Valdecilla Cohort

INTRODUCTION AND OBJECTIVES

Retinal vein occlusion (RVO) and nonvalvular atrial fibrillation (NVAF) are associated with vascular risk factors (VRF) and aging. The aim of this study is to analyze differences in the prevalence of VRF, vascular events, glaucoma, and anticoagulant treatment in patients with NVAF and RVO compared to a control group of the general population from the same geographic area.

METHODS

This is a prospective, single-center, case-control study. All patients diagnosed with RVO from December 2008 to March 2020 as well as a control group were included. Clinical, laboratory, electrocardiographic, and carotid ultrasound variables were analyzed.

RESULTS

A total of 386 patients with RVO and 343 controls were studied. Patients with RVO and NVAF were older and more of them had hypertension, a history of vascular events, and carotid atheromatosis than subjects with RVO without NVAF. In patients with NVAF who were on anticoagulants, those who had RVO differed from the controls with NVAF in that they had a higher prevalence of glaucoma (32 vs. 5.3%; p<0.034), with no significant differences regarding age, VRF, vascular events, or type of anticoagulant therapy (acenocumarol or direct-acting oral anticoagulants).

CONCLUSIONS

Patients with RVO and NVAF were older and had a higher prevalence of hypertension and carotid atheromatosis than subjects with RVO without NVAF. Patients with NVAF and RVO had higher prevalence of glaucoma than subjects with NVAF without RVO. In patients with NVAF, it is recommended to optimized VRF treatment and glaucoma control to prevent the development of RVO.

Retinal vein occlusion in patients under 50 years. Analysis of vascular risk factors, thrombophilia, carotid ultrasound findings and uncommon aetiologies

INTRODUTION

Retinal vein occlusion (RVO) has been related to vascular risk factors and thrombophilia.

METHODS

This is a prospective cohort study of all patients diagnosed with RVO and referred to an Internal Medicine clinic of a tertiary teaching hospital during a 10-year period. Clinical, laboratory and supra-aortic trunks ultrasound variables were analysed and compared according to age.

RESULTS

Some 309 patients diagnosed with RVO were included, 25 of them younger than 50 years. The prevalence of high blood pressure, dyslipidaemia, diabetes mellitus, hyperhomocysteinemia, and carotid plaque was significantly higher in patients >50 years than in those below. However, the prevalence of inherited thrombophilia was higher in the younger group (32.0% vs 11.4%; p = 0.005). Uncommon diseases related to RVO such as hepatitis C, thalassemia minor, Lyme disease, vasculitis, and periphlebitis were observed in young patients without vascular risk factors.

CONCLUSION

We suggest performing a genetic thrombophilia study in RVO patients younger than 50 years, while an exhaustive control of vascular risk factors is always recommended in all RVO patients. Moreover, we suggest bearing in mind uncommon diseases related to RVO, especially in young patients without vascular risk factors.

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.

Lipid profile and serum folate, vitamin B12 and homocysteine levels in patients with retinal vein occlusion

BACKGROUND

Retinal vein occlusion (RVO) is mainly related with vascular risk factors (VRF).

OBJECTIVES

To analyze the lipid profile and serum folate, vitamin B₁₂ and homocysteine levels, in patients with RVO and a population-based control group.

PATIENTS AND METHODS

Case-control study. Patients with RVO were assessed during an 11-year period.

RESULTS

We included 368 patients and 325 controls of similar age and sex. HDL cholesterol and folate levels were lower (52 [43-63] mg/dL vs. 55 [46-66]; p = 0.016 and 7 [5-10] ng/mL vs. 9 [7-13]; p < 0.0001, respectively) and non-HDL cholesterol and homocysteine levels higher (148.9 ± 37.3 mg/dL vs. 142.9 ± 34.5; p = 0.03 and 13.4 [11.2-18.2] μmol/L vs. 11.1 [9.0-14.4]; p < 0.001) in patients with RVO than controls. Although total cholesterol, LDL-C, and triglyceride levels were higher and serum vitamin B₁₂ levels were lower in RVO patients, these differences did not reach statistical significance.

CONCLUSIONS

RVO-patients have lower serum HDL-C and folate levels and higher non-HDL-C and serum homocysteine levels than population-based controls of similar age and sex. In patients with RVO, apart from the lipid profile, determination of serum homocysteine, folate and vitamin B₁₂ levels might be useful, as well as the treatment of their alterations.

Retinal vein occlusion in solid organ transplant recipients. Study of 4 cases and literature review

Although retinal venous obstruction (RVO) has been primarily related to vascular risk factors and glaucoma, there are a few studies of RVO in patients with solid organ transplants. An analysis was performed on total of 331 patients who presented with RVO (branch RVO in 226 cases and central RVO in 105 cases) over a 10 year period, and the characteristics were compared with the 4 patients with a history of solid organ transplant (liver, renal, or bipulmonary) who presented with RVO. In this series, the onset of RVO in transplant patients occurred at earlier ages than in other patients with RVO (58 vs. 68 years, respectively), affected the central vein of the retina (100% vs. 32%), and was associated with diabetes mellitus (75% vs. 25%), as well as with steroidal (100% vs. 1%) and immunosuppressive (tacrolimus 75% vs. 0%) treatments.

[Hypertension and Framingham general vascular risk score in retinal vein occlusion]

OBJECTIVES

To determine the prevalence of arterial hypertension (AHT), systolic blood pressure (SBP), the diastolic blood pressure (DPB), and the Framingham vascular risk score (FRS), in subjects with retinal vein occlusion (RVO), as well as in a control group.

PATIENTS AND METHOD

A prospective, cross-sectional case and control study was conducted on all patients with a diagnosis of RVO referred to the General Medicine Clinic, and comparing them with a control group. An analysis was performed on the clinical and laboratory variables.

RESULTS

A total of 253 patients with RVO were studied (132 males and 121 females) and 244 controls (112 males and 132 females) of similar age (67.9±12.3 vs. 68.1±9.2 años). The prevalence of AHT, and the SBP and DPB values in the clinic after the RVO were significantly higher in patients with RVO than in the controls (71.5% vs. 51.2%), SBP mmHg (148±22 vs. 138±18mmHg), DBP mmHg (83±10 vs. 77±10mmHg). The de novo diagnosis of AHT was made from the RVO in 23.8% of the cases. Significant differences were found in the FRS between the patients with RVO and the controls (11±8.3 vs. 8.25±6.3. There were no differences in any of the parameters studied between patients with peripheral or central RVO.

CONCLUSIONS

Hypertension is very prevalent as significantly more common in patients with RVO than in controls. Its diagnosis and treatment is often established from the RVO. The FRS is greater in patients with RVO. There were no differences in any of the parameters studied between patients with peripheral or central RVO. It is suggested that RVO should be considered a vascular event when defining therapeutic objectives.

Cardiovascular risk factors, nonvalvular atrial fibrillation and retinal vein occlusion

OBJECTIVES

To analyse the importance of cardiovascular risk factors, ultrasound findings in the supra-aortic trunk and the presence of anticoagulated nonvalvular atrial fibrillation (NVAF) in patients with retinal vein occlusion (RVO) and in a control group.

PATIENTS AND METHODS

A cross-sectional study was conducted of all patients with RVO consecutively referred to the office of internal medicine, comparing them with a control group. We analysed clinical, electrocardiographic and ultrasound variables.

RESULTS

We studied 212 patients (114 men and 98 women) with RVO and 212 controls (95 men and 117 women) of similar ages. Arterial hypertension, dyslipidaemia and diabetes mellitus were significantly more prevalent in the patients with RVO than in the controls (73.6 vs. 50%, 64.6 vs. 48.6% and 27.8 vs. 12.3%, respectively). We observed arteriosclerotic lesions in the supra-aortic trunk in 55% of the patients with RVO. The patients with RVO and NVAF had a greater burden of cardiovascular risk factors than the controls with NVAF. There were no differences in terms of the international normalised ratio or in the use of direct anticoagulants between the cases and controls with NVAF.

CONCLUSIONS

Cardiovascular risk factors (especially arterial hypertension) and arteriosclerotic involvement of the supra-aortic trunk are highly prevalent in RVO. Anticoagulation does not appear to be effective in preventing RVO.

Retinal vein thrombosis: The Internist's role in the etiologic and therapeutic management

Retinal vein occlusion is a common and important cause of vision loss. In general, knowledge about this condition is scant within an internist's practice but the condition is relevant because of its association with other chronic ailments. A diagnosis of RVO should prompt the investigation of conditions needing chronic management in these patients. In this review we summarize the clinical presentation of RVO, its classification, associated risk factors, and treatment focused in the internist's scope of practice.

Polymorphic markers of the G1639A form of VKORC1 involved in the development of retinal vessel occlusion

Background. Retinal vessel occlusion (RVO) is an eye disease that leads to decreased visual acuity, ultimately resulting in blindness. RVO is observed in 1%–2% of individuals older than 40 years. The etiology of RVO remains unclear. However, the most widely recognized risk factors include age, hypertension, hyperlipidemia, atherosclerosis, cardiovascular diseases, and diabetes. The number of patients with RVO among the young population has increased in recent years, and owing to this increased incidence, more attention is paid to genetic factors. Polymorphisms in the genes encoding proteins involved in the vitamin K cycle are one of these genetic factors that might influence RVO. According to literature, the G1639A polymorphism in the vitamin K epoxide reductase complex subunit 1 (VKORC1) is a possible risk factor for RVO.  The purpose of the study. To estimate the association between carriers of the G1639A form of VKORC1 and the development of venous RVO (VRVO) and arterial RVO (ARVO). Materials and methods. The study included 126 patients aged between 40 and 80 years, with a mean age of 61.5 years. Genotyping for the presence of the G1639A polymorphism of VKORC1 was performed using polymerase chain reaction (PCR). Statistical analysis was performed using the program Instat. Results. The GG genotype was found to be significantly more frequently in patients with VRVOthan in those without pathology of retinal vessels (42.6 vs 32%, p = 0.0449). The GG genotype was observed at a higher frequency in patients with ARVO than in those without pathology of retinal vessels (60 versus 32%, p = 0.0925). However, having the AA form of G1639A was significantly less frequent in patients with VRVO compared with those without vascular pathology of the retina (9.8 vs 28%, p = 0.0238, RR 2.015, 95% confidence interval 1.011–4.16). The AA genotype was observed at a lower frequency in patients with ARVO than the control group (6.7 vs 28%,  p = 0.1593). Conclusions. Our study demonstrates that having the GG form of the G1639A polymorphism of VKORC1 is associated with the development of VRVO and possibly ARVO. However, having the AA form of this polymorphism is associated with a lower risk of developing VRVO and may also be associated with a lower risk of developing ARVO.

EFFECT OF PEGAPTANIB AND RANIBIZUMAB ON PLASMA AND VITREOUS HOMOCYSTEINE IN PATIENTS WITH EXUDATIVE AGE-RELATED MACULAR DEGENERATION

PURPOSE

To investigate homocysteine (Hcy) concentration in the blood plasma and the vitreous in patients with exudative age-related macular degeneration receiving intravitreal anti-vascular endothelial growth factor therapy.

METHODS

Plasma Hcy and vitreous Hcy levels were analyzed in 73 exudative age-related macular degeneration patients (50.7% received pegaptanib 0.3 mg and 50.3% received ranibizumab 0.5 mg) and compared with 80 controls and 40 patients with idiopathic epiretinal membranes, respectively. Homocysteine concentration was measured by immunonephelometric particle test, and it was determined before and after antiangiogenic therapy.

RESULTS

The mean Hcy concentrations (± SD) of blood plasma and vitreous were 13.0 ± 4.2 μmol/L and 1.00 ± 0.3 μmol/L in patients treated with pegaptanib; in ranibizumab group, they were 12.8 ± 2.5 μmol/L and 1.4 ± 0.6 μmol/L, respectively. The results of plasma and vitreous Hcy indicated statistically significant differences between exudative age-related macular degeneration patients and control groups (P = 0.03 and P = 0.02). After 6 months with both intravitreal therapies, the plasma and vitreous Hcy concentrations did not change significantly (P = 0.1).

CONCLUSION

Pegaptanib and ranibizumab did not increase the plasma or vitreous Hcy concentrations.

The role of coagulation disorders in patients with retinal vein occlusion

BACKGROUND

The role of a hypercoagulable state in the pathogenesis of retinal vein occlusion (RVO) has not been conclusively established.

AIM

To analyse the prevalence of thrombophilia in RVO.

DESIGN

Prospective case-control study.

METHODS

All the patients diagnosed with RVO were referred to an Internal Medicine clinic and compared with sex- and age-matched individuals from a population-based cohort. Demographic, clinical and laboratory variables (including a thrombophilia panel) were analysed.

RESULTS

One hundred and seventy patients (93 men and 77 women; 68 ± 11 years) and 170 controls (80 men and 90 women; 67 ± 10 years) were included. RVO was peripheral in 113 cases. Genetic thrombophilia was detected in 13% of patients. Acquired thrombophilia was observed in 10% of cases and 4.7 % of controls (P < 0.01). Sixty-three percent of cases and 24.6% of controls had serum hyperhomocysteinemia (odds ratio [OR] 5.2, IC 95% 2.7-10.1; P < 0.0001) : In RVO patients aged <50 years (n = 11), 36.4% had genetic thrombophilia (P = 0.04), as well as 50% of those without vascular risk factors (n = 18; P = 0.01). Forty-one (24%) patients with RVO received antiplatelet agents and 13 (7.6%) were on anticoagulants due to preexistent atrial fibrillation.

CONCLUSIONS

We suggest that, in patients with RVO, hyperhomocysteinemia and antiphospholipid syndrome should be ruled out. Moreover, a study of genetic thrombophilia should only be considered in those aged <50 years or without cardiovascular risk factors. Antiplatelet therapy with aspirin is probably the treatment of choice of RVO, to reduce the overall vascular risk. Anticoagulation should only be considered in patients with high-risk thrombophilia.

Retinal venous pressure in the non-affected eye of patients with retinal vein occlusions

BACKGROUND

To measure the retinal venous pressure (RVP) in both eyes of patients with unilateral central retinal vein occlusions and to compare these values to controls.

METHODS

The study included 31 patients with unilateral central retinal vein occlusions (CRVO) and 31 controls who were matched by age, sex, and systemic disease. RVP was measured in all patients bilaterally by means of contact lens ophthalmodynamometry, and the RVP measurements of the affected and unaffected eyes of patients were compared to the RVPs of controls. Ophthalmodynamometry is done by applying an increasing pressure on the eye via a contact lens. The minimum force required to induce a venous pulsation is called ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) [RVP = ODF + IOP].

RESULTS

The RVP group means ± SD were as follows: patient's affected eyes (45.0 ± 11.6 mmHg), patient's unaffected eyes (38.0 ± 11.1 mmHg) ,and (17.7 ± 6.7 mmHg) in the eyes of controls. The values of RVP, even in the patients unaffected eyes, were significantly higher than in the eyes of controls (P < 0.001).

CONCLUSIONS

In patients with CRVO, the RVP is increased in both the affected as well as in the unaffected contralateral eye.

Risk Factors and Treatment Strategies in Patients With Retinal Vascular Occlusions

Retinal vein occlusion (RVO) and retinal artery occlusion (RAO) cause significant visual impairment. The role of thrombophilia and cardiovascular testing is uncertain, and optimal treatment strategies have not been determined. We reviewed medical records of 39 patients with RVO and RAO (23 women and 16 men). Thrombophilia and cardiovascular evaluations were performed and outcomes were reviewed. In all, 24 (61.5%) patients had at least 1 thrombophilia. Elevated factor VIII levels were found in RVO (n = 5) but not in RAO. There are no other significant differences in thrombophilias in RVO compared to those in RAO. Most patients had hypertension(41.2% RAO and 55% RVO) and hyperlipidemia (35.5% RAO and 81.8% RVO). In all, 4 women were using oral contraceptives, 2 were pregnant or postpartum. Follow-up data was available for 28 patients (13 RAO, 15 RVO). Nineteen were treated with aspirin, four with warfarin, and one with low molecular weight heparin. Eight patients reported improvement in vision at time of follow-up (5 RAO, 3 RVO). Multiple risk factors are associated with RVO and RAO, and a complete assessment should include thrombophilia and cardiovascular studies.