ENDOTHELIN-1 AS A RISK FACTOR IN RETINAL VEIN OCCLUSION.

PURPOSE: Retinal vein occlusion (RVO) risk factors largely coincide with cardiovascular risk factors. Endothelin-1 (ET-1), the most potent vasoconstrictor with proinflammatory properties, is a known cardiovascular risk factor. In this study, we explore the role of serum ET-1 as a potential risk factor for RVO. METHODS: Endothelin-1 serum levels were measured in patients with RVO and control subjects. Samples were measured using the sandwich enzyme-linked immunosorbent assay for the quantitative determination of human big endothelin-1 (Biomedica Group, Austria). RESULTS: The study consisted of 147 RVO patients and 150 control subjects. Median serum ET-1 was significantly higher in RVO patients (0.26 pmol/L; range, 0.19-0.37 pmol/L) compared with control subjects (0.10 pmol/L; range, 0.05-0.22 pmol/L) (P < 0.0001) independent of the occlusion site. The difference remained significant after adjusting for arterial hypertension, diabetes mellitus, history of stroke, history of myocardial infarction, history of venous thromboembolism, glomerular filtration rate, and c-reactive protein. CONCLUSION: In conclusion, our results suggest that ET-1 is a potential risk factor for all types of RVO.

Role of the ABO blood groups as a risk factor for retinal vein occlusion.

Introduction A recent study suggested that non-O blood groups had an increased risk for the presence of RVO. In this study we investigated (i) an association between blood group and the presence of RVO and (ii) whether this association correlated to other RVO risk factors. Methods We included 485 RVO patients and 295 control subjects who were recruited in this case-control study. We determined ABO genotypes rs8176719 as a marker for the O allele and rs8176746 for the B allele by polymerase chain reaction. Results We did not find an association between ABO blood group and the presence of RVO. In detail, the proportion of ABO blood groups was similar among RVO patients and control subjects (p=0.527). In a logistic regression, non-O blood group was associated with 1.06-fold higher odds of being a RVO patient (95%CI: 0.78-1.45, p=0.693), and this lack of association prevailed upon multivariable adjustment for age, gender, history of stroke and venous thromboembolism and co-medication with lipid-lowering agents. Discussion Although non-O blood groups are a known risk factor for thrombotic and cardiovascular disease, they do not seem to be a major risk factor for the development of RVO.

SERUM LEVELS OF ANTIBODIES AGAINST OXIDATION-SPECIFIC EPITOPES ARE DECREASED IN PATIENTS WITH RETINAL VEIN OCCLUSION.

PURPOSE: Oxidative stress and inflammation have been implicated in the development of retinal vein occlusion (RVO). Oxidation-specific epitopes (OSEs) represent products of oxidative stress that can trigger vascular inflammation and thrombosis. Natural occurring antibodies have been shown to bind oxidation-specific epitopes thereby inhibiting their inflammatory potential and promoting their removal. METHODS: This prospective cross-sectional study included 270 patients with RVO and 81 in-hospital control patients. We measured three types of serum levels of oxidation-specific epitope-specific immunoglobulin M and immunoglobulin G antibodies (anti-copper-oxidized LDL [CuOx-LDL], antiphosphocholine [PC], anti-malondialdehyde-modified LDL [MDA-LDL]). History of arterial hypertension, hyperlipidemia, myocardial infarction, diabetes mellitus, stroke, smoking status, and several laboratory parameters were determined to control for potential confounders. RESULTS: Compared with controls, patients with RVO had significantly lower levels of immunoglobulin M and immunoglobulin G antibodies against CuOx-LDL and PC, and significantly lower levels of immunoglobulin G but not immunoglobulin M antibodies against MDA-LDL. The association between RVO patients and lower levels of these antibodies prevailed upon multivariable adjustment. CONCLUSION: These prospective data show that antibodies against oxidation-specific epitope are lower in patients with RVO compared with control patients and support the concept that oxidative stress and inflammation play key roles in the development and subsequent complications in RVO.

CHANGE OF CHOROIDAL VOLUME IN UNTREATED CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: Choroidal hyperpermeability plays a central role in the pathophysiology of central serous chorioretinopathy (CSC). In active CSC undergoing treatment, choroidal thickness decreases if subretinal fluid (SRF) resolves. This study aimed to investigate the change in choroidal thickness and volume in eyes with untreated CSC. METHODS: The authors retrospectively analyzed 27 eyes with treatment-naïve CSC (25 patients), who had a follow-up of 4 to 6 weeks. Retinal and choroidal volume and SRF were segmented manually and calculated using the Spectralis OCT built-in software (Spectralis; Heidelberg Engineering). RESULTS: In treatment-naïve eyes with CSC, an increase in SRF was significantly associated with an increase in choroidal thickness and volume (rho = 0.93, P < 0.01). Eyes with greater baseline choroidal volume showed a significantly greater decrease in SRF during follow-up (rho = -0.47, P = 0.03). CONCLUSION: In this study, an increase in SRF was associated with an increase in both choroidal thickness and volume in eyes with treatment-naïve CSC. Eyes with thicker baseline choroidal volume showed a greater reduction in SRF.

MACULAR CHOROIDAL VOLUME CHANGES AFTER INTRAVITREAL BEVACIZUMAB FOR EXUDATIVE AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To evaluate the effect of intravitreal bevacizumab on the macular choroidal volume and the subfoveal choroidal thickness in treatment naïve eyes with exudative age-related macular degeneration. METHODS: The macular choroidal volume and the subfoveal choroidal thickness were measured using enhanced depth imaging optical coherence tomography. After a screening examination, each patient received 3 monthly intravitreal injections of 1.25 mg bevacizumab. One month after the third injection was a final assessment. RESULTS: Forty-seven patients with a mean age of 80 ± 6.4 years were included. The macular choroidal volume decreased significantly from median 4.1 mm (interquartile range 3.4-5.9) to median 3.9 mm (interquartile range 3.1-5.6) between the baseline and final examination (difference -0.46 mm, 95% confidence interval: -0.57 to 0.35, P < 0.001). Similarly, subfoveal choroidal thickness had decreased from 157.0 µm (interquartile range 116.0-244.5) at baseline to 139.0 µm (interquartile range 102.5-212.0) at the final examination (P < 0.001). Both parameters macular choroidal volume at baseline and subfoveal choroidal thickness at baseline were not associated with the response to treatment. CONCLUSION: The macular choroidal volume and the subfoveal choroidal thickness decreased significantly after 3 monthly bevacizumab injections for exudative age-related macular degeneration.

Heme oxygenase-1 gene rs2071746 polymorphism in retinal vein occlusion.

BACKGROUND: Heme oxygenase-1 (HO-1) is an important cytoprotective enzyme due to its ability to degrade pro-inflammatory heme. The common single nucleotide polymorphism (SNP) rs2071746 on the HMOX1 gene has been associated with HO-1 activity and a variety of cardiovascular diseases. This study was performed to investigate the association between the rs2071746 SNP and retinal vein occlusion (RVO). METHODS: We included 496 RVO patients and 297 control subjects in this case-control study. Genotypes of the rs2071746 polymorphism were determined by TaqMan assays. RESULTS: There was no association between the rs2071746 genotype and the presence of RVO (p = .443). The lack of association was found in all three logistic regression models, namely the dominant (p = .560), the recessive (p = .373) and the co-dominant model (p = .444). The distribution of the rs2071746 genotype was 30% (AA), 51% (AT), and 19% (TT). Baseline characteristics were similar between these genotypes, except for diabetes mellitus, which was less prevalent in the AA genotype (p < .001). CONCLUSION: The rs2071746 polymorphism does not seem to be a major risk factor for the presence of RVO.

Role of the tissue-type plasminogen activator -7351C > T and plasminogen activator inhibitor 1 4G/5G gene polymorphisms in central serous chorioretinopathy.

BACKGROUND: Central serous chorioretinopathy (CSC) is a common chorioretinal disease, characterized by choroidal hyperpermeability leading to neurosensory and/or retinal pigment epithelial detachments. Hypofibrinolysis due to higher plasma concentrations of plasminogen activator type 1 (PAI-1) or lower activity of tissue-type plasminogen activator (t-PA) has been implicated in the pathogenesis of CSC. Functional polymorphisms in the PAI-1 (SERPINE1) and t-Pa (PLAT) are thus potential risk factors for CSC. The aim of the present study was therefore to investigate a hypothesized association between the PAI-1 4G/5G and the t-PA -7351C > T gene variants and the presence of CSC. METHODS: The present study comprised 172 CSC patients and 313 control subjects. Genotypes of the PAI-1 4G/5G and the t-PA -7351C > T polymorphisms were determined by TaqManTM fluorogenic 5'-exonuclease assays. RESULTS: Allelic frequencies or genotype distributions of neither the PAI-1 4G/5G nor the t-PA -7531C > T polymorphisms were significantly different between patients with CSC and control subjects (PAI-1 4G/4G: 24.4% vs. 20.4, p = 0.36; t-PA -7351CC: 42.4% vs. 46.0%, p = 0.50). After adjusting for age and gender presence of the PAI-1 4G/4G genotype was associated with a non-significant odds ratio (OR) of 1.21 (95% confidence interval [95% CI]: 0.77-1.92, p = 0.41), while homozygosity for the t-PA -7351C allele yielded a non-significant OR of 0.91 (95% CI: 0.62-1.33, p = 0.62) for CSC. CONCLUSION: The present study suggests that both the t-PA -7351C > T and the PAI-1 4G/5G gene variants are unlikely major risk factors for CSC.

High-Density Lipoprotein Function in Exudative Age-Related Macular Degeneration.

PURPOSE: High-density lipoproteins (HDL) have long been implicated in the pathogenesis of age-related macular degeneration (AMD). However, conflicting results have been reported with regard to the associations of AMD with HDL-cholesterol levels. The present study is the first to assess HDL composition and metrics of HDL function in patients with exudative AMD and control patients. METHODS: Blood samples were collected from 29 patients with exudative AMD and 26 age-matched control patients. Major HDL associated apolipoproteins were determined in apoB-depleted serum by immunoturbidimetry or ELISA, HDL-associated lipids were quantified enzymatically. To get an integrated measure of HDL quantity and quality, we assessed several metrics of HDL function, including cholesterol efflux capacity, anti-oxidative and anti-inflammatory activities using apoB-depleted serum from study participants. RESULTS: In our study, we observed that the HDL associated acute phase protein serum amyloid A (SAA) was significantly increased in AMD patients (p<0.01), whereas all other assessed apolipoproteins including ApoA-I, apoA-II, apoC-II, apoC-III and apoE as well as major HDL associated lipids were not altered. HDL efflux capacity, anti-oxidative capacity and arylesterase activity were not different in AMD patients when compared with the control group. The ability of apoB-depleted serum to inhibit monocyte NF-κB expression was significantly improved in AMD patients (mean difference (MD) -5.6, p<0.01). Moreover, lipoprotein-associated phospholipase A2 activity, a marker of vascular inflammation, was decreased in AMD subjects (MD -24.1, p<0.01). CONCLUSIONS: The investigated metrics of HDL composition and HDL function were not associated with exudative AMD in this study, despite an increased content of HDL associated SAA in AMD patients. Unexpectedly, anti-inflammatory activity of apoB-depleted serum was even increased in our study. Our data suggest that the investigated parameters of serum HDL function showed no significant association with exudative AMD. However, we cannot exclude that alterations in locally produced HDL may be part of the AMD pathogenesis.

Correction: High-Density Lipoprotein Function in Exudative Age-Related Macular Degeneration.

[This corrects the article DOI: 10.1371/journal.pone.0154397.].

Circadian macular volume changes in the healthy human choroid.

PURPOSE: To investigate a potential circadian fluctuation of the choroidal volume in healthy adults by enhanced depth imaging (EDI) via spectral-domain optical coherence tomography (SD OCT). DESIGN: Prospective observational case series. METHODS: Thirty healthy eyes of 15 healthy subjects with a median age of 26 years (range 22-55) underwent EDI SD OCT scans for macular choroidal volume measurement every 3 hours within a 24-hour period at a single tertiary center. The mean ocular perfusion pressure was calculated for each eye at each of the 8 time points as 2/3(mean arterial pressure-intraocular pressure [IOP]). The circadian fluctuation of the macular choroidal volume as well as the association with axial length, mean ocular perfusion pressure, or IOP was assessed using a linear mixed model. RESULTS: Macular choroidal volume showed a significant circadian fluctuation (P < .05) and was lowest at midday (mean ± SD, 10.14 ± 2.62 mm(3)) and highest at 3 AM (mean ± SD, 10.66 ± 2.70 mm(3)). Of all factors tested, only mean ocular perfusion pressure showed a significant association with macular choroidal volume fluctuation (P = .016). CONCLUSIONS: Macular choroidal volume shows a significant circadian pattern with higher values at night and lower values during the day in young adults. Besides time, mean ocular perfusion pressure is significantly associated with this fluctuation.

A Systematic Review and Meta-Analysis on the Safety of Vascular Endothelial Growth Factor (VEGF) Inhibitors for the Treatment of Retinopathy of Prematurity.

INTRODUCTION: Laser photocoagulation is the current gold standard treatment for proliferative retinopathy of prematurity (ROP). However, it permanently reduces the visual field and might induce myopia. Vascular endothelial growth factor (VEGF) inhibitors for the treatment of ROP may enable continuing vascularization of the retina, potentially allowing the preservation of the visual field. However, for their use in infants concern remains. This meta-analysis explores the safety of VEGF inhibitors. METHODS: The Ovid Interface was used to perform a systematic review of the literature in the databases PubMed, EMBASE and the Cochrane Library. RESULTS: This meta-analysis included 24 original reports (including 1.457 eyes) on VEGF inhibitor treatment for ROP. The trials were solely observational except for one randomized and two case-control studies. We estimated a 6-month risk of retreatment per eye of 2.8%, and a 6-month risk of ocular complication without the need of retreatment of 1.6% per eye. Systemic complications were only reported as isolated incidents. DISCUSSION: VEGF inhibitors seem to be associated with low recurrence rates and ocular complication rates. They may have the benefit of potentially allowing the preservation of visual field and lower rates of myopia. Due to the lack of data, the risk of systemic side effects cannot be assessed.