PON1, APOE and SDF-1 Gene Polymorphisms and Risk of Retinal Vein Occlusion: A Case-Control Study

Numerous studies have tried to evaluate the potential role of thrombophilia-related genes in retinal vein occlusion (RVO); however, there is limited research on genes related to different pathophysiological mechanisms involved in RVO. In view of the strong contribution of oxidative stress and inflammation to the pathogenesis of RVO, the purpose of the present study was to investigate the association of inflammation- and oxidative-stress-related polymorphisms from three different genes [apolipoprotein E (APOE), paraoxonase 1 (PON1) and stromal cell-derived factor 1 (SDF-1)] and the risk of RVO in a Greek population. Participants in this case-control study were 50 RVO patients (RVO group) and 50 healthy volunteers (control group). Blood samples were collected on EDTA tubes and genomic DNA was extracted. Genotyping of rs854560 (L55M) and rs662 (Q192R) for the PON1 gene, rs429358 and rs7412 for the APOE gene and rs1801157 [SDF1-3'G(801)A] for SDF-1 gene was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Multiple genetic models (codominant, dominant, recessive, overdominant and log-additive) and haplotype analyses were performed using the SNPStats web tool to assess the correlation between the genetic polymorphisms and the risk of RVO. Binary logistic regression analysis was used for the association analysis between APOE gene variants and RVO. Given the multifactorial nature of the disease, our statistical analysis was adjusted for the most important systemic risk factors (age, hypertension and diabetes mellitus). The dominant genetic model for the PON1 Q192R single nucleotide polymorphism (SNP) of the association analysis revealed that there was a statistically significant difference between the RVO group and the control group. Specifically, after adjusting for age and hypertension, the PON1 192 R allele (QR + RR) was found to be associated with a statistically significantly higher risk of RVO compared to the QQ genotype (OR = 2.51; 95% CI = 1.02-6.14, p = 0.04). The statistically significant results were maintained after including diabetes in the multivariate model in addition to age and hypertension (OR = 2.83; 95% CI = 1.01-7.97, p = 0.042). No statistically significant association was revealed between the other studied polymorphisms and the risk of RVO. Haplotype analysis for PON1 SNPs, L55M and Q192R, revealed no statistically significant correlation. In conclusion, PON1 192 R allele carriers (QR + RR) were associated with a statistically significantly increased risk of RVO compared to the QQ homozygotes. These findings suggest that the R allele of the PON1 Q192R is likely to play a role as a risk factor for retinal vein occlusion.

CENTRAL RETINAL VEIN OCCLUSION IN 12-YEAR-OLD GIRL WITH METHYLENETETRAHYDROFOLATE REDUCTASE MUTATION: A CASE REPORT AND REVIEW OF THE LITERATURE

PURPOSE

This case report describes a central retinal vein occlusion in a healthy 12-year-old girl who developed retinal neovascularization at 24 years of age. To the knowledge of the authors, this is the longest time between a reported pediatric central retinal vein occlusion event and neovascularization.

METHODS

The patient underwent a full history, physical examination, and laboratory workup to determine potential risk factors contributing to the vascular event. Fundus photographs, optical coherence tomography, and fluorescein angiography were performed throughout the patient's treatment course.

RESULTS

Family history was noncontributory, but laboratory testing revealed a mildly elevated homocysteine level and homozygous C677T mutation in methylenetetrahydrofolate reductase. As a result, she was started on folate supplementation. The patient has had no further ocular or systemic thrombotic events to date.

CONCLUSION

Pediatric patients presenting with central retinal vein occlusion should undergo a systemic workup and require long-term follow-up to avoid complications, such as intraocular hemorrhage, tractional retinal detachments, and neovascular glaucoma.

Ocular Phenotypes in Patients With Hemophagocytic Lymphohistiocytosis: A Retrospective Analysis in a Single Center Over 7 Years

PURPOSE

To investigate the presence and type of ocular abnormalities in patients with hemophagocytic lymphohistiocytosis (HLH).

DESIGN

A retrospective cross-sectional study.

METHODS

Observational report of ocular findings and their associations with age, sex, underlying disease, and hematologic parameters. HLH was defined according to the 2004 criteria, and the patients were enrolled from March 2013 to December 2021. Analysis began in July 2022 and ended in January 2023. The main outcome measures were ocular abnormalities associated with HLH and their potential risk factors.

RESULTS

Of 1525 HLH patients, 341 had ocular examinations, and 133 (133 of 341, 39.00%) had ocular abnormalities. Mean age at presentation was 30.21 ± 14.42 years. The multivariate analysis indicated that old age, autoimmune disorders, decreasing red blood cell count, decreasing platelet count, and increasing fibrinogen level were independent risk factors of ocular involvement in HLH patients. The most common presenting ocular findings were posterior segment abnormalities (66 patients, 49.62%), including retinal and vitreous hemorrhage, serous retinal detachment, cytomegalovirus retinitis, and optic disc swelling. Other HLH-associated ocular abnormalities included ocular surface infection (conjunctivitis, 34 patients, 25.56%; keratitis, 16 patients, 12.03%), subconjunctival hemorrhage (11 patients, 8.27%), chemosis (5 patients, 3.76%), anterior uveitis (11 patients, 8.27%), glucocorticoid-induced glaucoma (5 patients, 3.76%), radiation cataract (1 patient, 0.75%), dacryoadenitis (2 patients, 1.50%), dacryocystitis (1 patients, 0.75%), orbital cellulitis (2 patients, 1.50%), orbital pseudotumor (2 patients, 1.50%), and strabismus (2 patients, 1.50%).

CONCLUSIONS

Eye involvement is not uncommon in HLH. Better awareness among both ophthalmologists and hematologists is necessary for prompt diagnosis and institution of appropriate management strategies with potential to save sight and life.

A Narrative Review of the Complex Relationship between Pregnancy and Eye Changes

Pregnancy is a condition often characterized by changes that occur in different parts of the body. Generally, the eyes suffer several changes during pregnancy that are usually transient but may become permanent at times. This may occur due to the release of placental hormones and those of maternal endocrine glands and fetal adrenal glands. Due to hormonal influences, physiological ocular changes during pregnancy have been shown in Caucasian women, so corneal sensitivity, refractive status, intraocular pressure, and visual acuity may change during pregnancy. Within this review, all studies that referred to physiological aspects and to changes of ocular pathology of pregnancy, the effect of the pregnancy on pre-existing (diabetic retinopathy, neuro-ophthalmic disorders) eye disorders, postpartum ocular changes, the intraocular pressure and the effect of hypotensive ophthalmic medicine during pregnancy, the connection between pregnancy and the neuro-ophthalmic pathology, as well as the role of anesthesia were analyzed.

Methylenetetrahydrofolate reductase polymorphisms as risk factors for retinal venous occlusive disease: A literature review

The role of polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene in retinal vein occlusion (RVO) is a theme of discussion since the first reports of RVO in patients with MTHFR C677T mutation and without classic acquired risk factors for retinal vascular disease. The association between MTHFR polymorphisms and RVO has been studied over the last 20 years producing conflicting results. This review aims to summarize the literature concerning the role MTHFR polymorphisms as risk factors for RVO.

Genetic correlation between Prothrombin G20210A polymorphism and retinal vein occlusion risk

The aim of this study was to perform an updated meta-analysis to quantitatively investigate the association between G20210A polymorphism of Prothrombin gene and the risk of retinal vein occlusion (RVO), based on the available publications with inconsistent results. We utilized the Stata software to perform the heterogeneity test, association test, Begg's and Egger's tests, and sensitivity analysis. We searched three on-line databases (PubMed, Embase, and WOS) and obtained a total of 422 articles. Based on our selection criteria, 24 case-control studies were finally enrolled in this overall meta-analysis; a subgroup analysis by the factors ethnicity, control source, and RVO type was done. Through the association test of overall meta-analysis, we did not observe a significant difference between RVO cases and controls under the A vs G (allele) (z=1.49, P=0.137), A vs G (carrier) (z=1.42, P =0.155), GA vs GG (z=1.50, P=0.135), and GA+AA vs GG (z=1.50, P=0.135). Furthermore, we observed similar negative results in the association test of subgroup analysis (all P>0.05). Heterogeneity, Begg's, and Egger's tests excluded the presence of high heterogeneity and publication bias. Statistically stable results were observed in the sensitivity analyses. Based on integrated analysis of the current evidence, Prothrombin gene G20210A polymorphism is likely unrelated to the risk of RVO.

Acute retinal vein occlusion and cystic fibrosis

Background

The ocular manifestations of cystic fibrosis typically present with surface irritation or nyctalopia due to Vitamin A deficiency, however, there have been two previous reports of patients with cystic fibrosis that developed retinal vein occlusions. These reports hypothesized that either elevated fibrinogen levels due to chronic infections or elevated homocysteine levels have predisposed patients with cystic fibrosis to develop retinal vein occlusions.

Case presentation

We present a case of a 35-year-old male with cystic fibrosis complicated by chronic sinusitis with no history of organ transplantation or chronic pulmonary infections who presented with an acute branch retinal vein occlusion in his left eye with associated macular edema. Evaluation revealed an elevated fibrinogen level, while the rest of his workup was relatively unremarkable including a normal homocysteine level. His vision remained 20/20 throughout his care and he did not require treatment of his macular edema.

Conclusions

Patients with cystic fibrosis are at an increased risk of developing retinal vein occlusions likely due to a variety of systemic thrombogenic factors rather than a single risk factor which had been reported previously. Elevated fibrinogen levels in these patients may not be due to chronic infections, but inherent to the cystic fibrosis.

Factor V G1691A is associated with an increased risk of retinal vein occlusion: a meta-analysis

We performed a meta-analysis to investigate the association between the Factor V G1691A polymorphism and the risk of retinal vein occlusion (RVO). This analysis included 37 studies involving 2,510 cases and 3,466 controls. Factor V G1691A was associated with an increased risk of RVO in the allele, heterozygote, dominant, and carrier models (PA < 0.001, odds ratios >1), but not the homozygote or recessive models (PA > 0.05). Similar results were observed in a meta-analysis of central retinal vein occlusion (CRVO) and when comparing Caucasian subgroups to population-based controls. These data demonstrate that the G/A genotype of Factor V G1691A is associated with an increased risk of RVO/CRVO in a Caucasian population.

No evidence for thrombophilia in patients with retinal venous occlusion: a systematic GRADE-based review

Retinal venous occlusion represents a common retinal disorder that untreated often leads to severely reduced vision. While general risk factors for vascular disease are known to increase the risk of an event, the role of thrombophilia is controversial. The purpose of this systematic review was to evaluate the evidence for thrombophilia investigation in patients presenting with retinal venous occlusion. Eligible studies were identified by a MESH-based search in PubMed 11-13 of March 2015. The level of evidence was stated according to the guidelines published by the GRADE working group using three levels for quality of evidence: high, moderate and low. A total of 118 studies relating to the study question were identified. After excluding case stories, commentaries, cross-sectional studies and reviews/expert opinions, 28 original papers and two meta-analyses were included in the final qualitative synthesis. The majority of studies were small case-control studies, and only one large cohort study was identified. No randomized controlled trials were retrieved. All the studies were categorized as low quality of evidence. Systematic thrombophilia screening in patients presenting with retinal venous occlusion cannot be recommended.

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.

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.

Preservation of retinal structure and function after cilioretinal artery occlusion: a case report

Cilioretinal artery occlusion is a cause of sudden, often catastrophic loss of central vision. There are no established effective treatments. Recently, a patient presented 24 hours after a cilioretinal artery occlusion, following a cardiac catheterization prior to which her blood thinners had been discontinued. Lacking an effective way to address the severe retinal ischemic oxidative stress, she was offered, under compassionate use, a multivitamin complex designed to address retinal ischemia and oxidative stress. Significant components of this product are L-methylfolate and n-acetyl cysteine. The patient experienced a rapid unexpected improvement in vision and preservation of retinal structure, suggesting that marked improvement in retinal artery occlusions outcomes may be possible as late as 24 hours postocclusion. This is the third reported case of cilioretinal artery occlusion associated with cardiac catheterization.

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.