Global epidemiology of retinal vein occlusion: a systematic review and meta-analysis of prevalence, incidence, and risk factors

NONPERFUSION ASSESSMENT IN RETINAL VEIN OCCLUSION: Comparison Between Ultra-widefield Fluorescein Angiography and Widefield Optical Coherence Tomography Angiography

PURPOSE

To compare widefield optical coherence tomography angiography (OCTA) to ultra-widefield fluorescein angiography (UWFA) in the assessment of nonperfusion in retinal vein occlusion (RVO).

METHODS

A cross-sectional study of 43 eyes of 43 patients with RVO examined using both widefield OCTA (PLEX Elite, Carl Zeiss Meditec, Dublin, CA) with a panoramic montage of five 12 × 12-mm images and UWFA (Optos, 200°). Qualitative analysis was performed according to nonperfusion areas (cutoff: three disk areas) on widefield OCTA. The quantitative analysis assessed the vascular density on the widefield OCTA and ischemic index on UWFA.

RESULTS

The ischemic index on UWFA and vascular density in the superficial and deep plexus correlated significantly (P = 0.019, r = 0.357 and P < 0.013, r = 0.375, respectively). The qualitative classification on widefield OCTA and ischemic index on UWFA correlated significantly (P < 0.001, r = 0.618). For the detection of marked nonperfusion (ischemic index ≥ 25%), widefield OCTA had a sensitivity of 100% and a specificity of 64.9%.

CONCLUSION

The presence of nonperfusion on UWFA correlated with widefield OCTA. Optical coherence tomography angiography could help to identify high-risk RVO patients who might benefit from a further evaluation using fluorescein angiography.

Microvascular and functional changes according to the fundus location of the affected arteriovenous crossing in patients with branch retinal vein occlusion

Purpose:

The aim of this study was to evaluate the structural and functional changes occurring in patients with branch retinal vein occlusion (BRVO) according to the distance of the affected arteriovenous (AV) crossing to the centers of the fovea and optic disc by optic coherence tomography angiography (OCTA).

Methods:

Forty-five patients with unilateral BRVO and 45 age- and sex-matched healthy controls were included in this retrospective observational study. Images of the macula (3 mm × 3 mm) and affected AV crossing sites were obtained by OCTA. The fovea-AV crossing distance (FAVD), optic disc-AV crossing distance (DAVD), and optic disc-fovea distance (DFD) were measured.

Results:

The FAVD/DFD ratio was positively correlated with the vessel density in the superficial and deep affected hemifields (r = 0.430, P < 0.05 and r = 0.308, P < 0.05, respectively) and negatively correlated with the superficial foveal avascular zone and logarithm of the minimum angle of resolution (logMAR) visual acuity (r = –0.412, P < 0.05 and r = –0.356, P < 0.05, respectively). The DAVD/DFD ratio was not correlated with the logMAR visual acuity, superficial FAZ area or vessel densities in the affected hemifield (all P > 0.05).

Conclusion:

The affected AV crossing site that was further away from the fovea had better visual acuity and quantitative microvascular parameters in the affected hemifields. However, this correlation was not observed for the distance between the affected AV crossing site and the optic disc.

Prevalence of Retinal Vein Occlusions and Estimated Cerebrospinal Fluid Pressure: The Kailuan Eye Study

Purpose

To investigate the prevalence of retinal vein occlusions (RVOs) and associated factors in a Chinese population.

Patients and Methods

The cross-sectional community-based Kailuan Eye Study included individuals who participated in the Kailuan Study. RVOs were diagnosed on the fundus photographs. Estimated cerebrospinal fluid pressure (eCSFP) was calculated as “eCSFP=0.44*Body Mass Index+0.16*Diastolic Blood Pressure-0.18*Age”.

Results

The study included 12,499 participants with a mean age of 52.9±13.1 years. The overall prevalence of RVO was 120/12,499 or 0.96%, with branch RVOs observed in 116/12,499 individuals and central RVOs in 4/12,499 individuals. RVOs started at the optic disc in 19 participants (15.8% of all RVOs), and in 101 (84.2%) individuals arterio-venous crossings outside the optic disc. In multivariable analysis, a higher RVO prevalence was associated with older age (P<0.001), higher eCSFP (P<0.001), and higher fasting serum glucose concentration (P<0.001). Differentiating between RVOs at arterio-venous crossings and RVOs at the optic disc revealed that the prevalence of both RVO types was associated with higher eCSFP (P<0.001 and P=0.004, respectively) after adjusting for age and fasting serum glucose concentration.

Conclusion

In this adult Chinese population recruited on a community basis, the prevalence of any RVO (mean: 0.96) was associated with older age, higher eCSFP and higher fasting serum glucose concentration. Higher eCSFP may play an etiologic role in RVOs.

Vitamin B12 and Folate as Risk Factors for Retinal Vein Occlusion: A Meta-Analysis

PURPOSE

To evaluate the association between serum vitamin B12/folate and retinal vein occlusion (RVO).

METHODS

A comprehensive search of the PubMed database was performed, which identified 271 abstracts to be screened. Ten studies met our inclusion criteria and a meta-analysis of these comparative case-control studies was performed on the mean ± standard deviation serum vitamin B12 and folate levels, without language restrictions. Nine studies with 720 patients with RVO and 613 controls were included in the meta-analysis for vitamin B12, and 10 studies with 784 patients with RVO and 677 controls in the meta-analysis for folate.

RESULTS

There was no statistically significant difference between patients with RVO and controls in serum vitamin B12 levels (mean difference: - 40.25 pg/mL, p = 0.28), either central RVO (mean difference: - 18.24 pg/mL, p = 0.71) or branch RVO (mean difference: - 23.56 pg/mL, p = 0.48). On the contrary, the plasma folate level was significantly lower in RVO patients than in controls (mean difference: - 1.34 ng/mL, p = 0.001), as well as in patients with CRVO compared to controls (mean difference: - 1.48 ng/mL, p = 0.006), but not in BRVO patients (mean difference: - 0.72 ng/mL, p = 0.11).

CONCLUSIONS

RVO is associated with low serum folate levels, but not with serum vitamin B12 levels.

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.

Associations Between Retinal Artery/Vein Occlusions and Risk of Vascular Dementia

BACKGROUND

Vascular disease is a risk factor for Alzheimer's disease (AD) and related dementia in older adults. Retinal artery/vein occlusion (RAVO) is an ophthalmic complication of systemic vascular pathology. Whether there are associations between RAVO and dementia risk is unknown.

OBJECTIVE

To determine whether RAVOs are associated with an increased risk of developing vascular dementia or AD.

METHODS

Data from Adult Changes in Thought (ACT) study participants were analyzed. This prospective, population-based cohort study followed older adults (age ≥65 years) who were dementia-free at enrollment for development of vascular dementia or AD based on research criteria. RAVO diagnoses were extracted from electronic medical records. Cox-regression survival analyses were stratified by APOEɛ4 genotype and adjusted for demographic and clinical factors.

RESULTS

On review of 41,216 person-years (4,743 participants), 266 (5.6%) experienced RAVO. APOEɛ4 carriers who developed RAVO had greater than four-fold higher risk for developing vascular dementia (Hazard Ratio [HR] 4.54, 95% Confidence Interval [CI] 1.86, 11.10, p = 0.001). When including other cerebrovascular disease (history of carotid endarterectomy or transient ischemic attack) in the model, the risk was three-fold higher (HR 3.06, 95% CI 1.23, 7.62). No other conditions evaluated in the secondary analyses were found to confound this relationship. There was no effect in non-APOEɛ4 carriers (HR 1.03, 95% CI 0.37, 2.80). There were no significant associations between RAVO and AD in either APOE group.

CONCLUSION

Older dementia-free patients who present with RAVO and carry the APOEɛ4 allele appear to be at higher risk for vascular dementia.

Quality of Life among Patients with Retinal Vein Occlusion: A Case-Control Study

Purpose: The purpose of this study was to evaluate health-related quality of life in patients with retinal vein occlusion (RVO) and investigate the possible risk factors for poor quality of life in patients with RVO.Methods: Participants in the study were 67 patients with RVO, 42 male and 25 female, mean-aged 73.1 ± 10.9 years, and 70 sex- and age-matched controls. Demographic data, lifestyle factors and medical history were recorded. All patients underwent best-corrected visual acuity measurement, dilated fundoscopy and optical coherence tomography. All participants completed two questionnaires assessing quality of life (EQ-5D, NEI VFQ-25). Risk factors for health-related quality of life in RVO patients were investigated.Results: Patients with RVO exhibited significantly lower composite score for VFQ-25 compared to controls (74.1 ± 3.8 vs. 91.7 ± 3.9 for patients and controls, respectively, p < .001). In addition, RVO patients had significantly lower EQ-5D Index score compared to controls (0.88 ± 0.15 vs. 0.92 ± 0.12 for patients and controls, respectively, p = .043). Risk factors associated with quality of life in patients with RVO were found the alcohol consumption, the presence of thyroidopathy, coagulation disorders, visual acuity in the eye with RVO, central retinal thickness, the type of edema, the presence of ischemia and the condition of external limiting membrane. In multivariate analysis, only alcohol consumption and visual acuity in the eye with RVO were found to be independent risk factors, affecting quality of life in RVO patients.Conclusions: Patients with RVO presented lower quality of life in comparison with controls. Potential risk factors should be taken into account and their early detection may improve quality of life in such patients and lead to targeted health policies.

Relative Retinal Blood Flow: A Novel and Informative Measure of Unilateral Retinal Vein Occlusion Severity

Purpose

This study quantifies retinal vascular blood flow affected by unilateral central or branch retinal vein occlusion (CRVO or BRVO). We created a new, unitless metric for the severity of these diseases—relative blood flow (RBF)—and contextualized it with subject demographics, ocular presentation, and systemic conditions. Finally, we explored its efficacy as a predictor of future outcomes.

Methods

Data were collected from 20 control subjects and 32 clinically diagnosed CRVO (n = 15) or BRVO (n = 17) patients. We used laser speckle flowgraphy to quantify blood flow as mean blur rate and present RBF as the ratio between the blood flow in a subject's diseased and undiseased eyes. Because of our demonstration that blood flow has high intrapatient (between eyes and over time) but low interpatient correlation in eyes of healthy subjects, any differences between eyes can be attributed to the disease. These data were correlated with subject demographics and disease characteristics.

Results

In CRVO and BRVO eyes, average blood flow decreased by 26% and 7%, respectively. In CRVO, occlusion duration, central macular thickness, intraocular pressure, diabetes, previous laser and injection treatments, and injection within three months after measurement were significantly associated with RBF. In BRVO, no significant associations with RBF were found.

Conclusions

Blood flow in CRVO and BRVO was reduced compared to the unaffected fellow eye in most patients. RBF was useful in determining the severity of RVOs and predicting future treatment needs.

Translational Relevance

RBF is a promising new and informative metric for quantifying the severity of unilateral RVOs.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.

Fatty acid-binding protein 4 is an independent factor in the pathogenesis of retinal vein occlusion

The main objective of current study was to identify the fatty acid-binding protein 4 (FABP4) expressed in both adipocytes and macrophages in vitreous fluid from patients with retinal vein occlusion (RVO). Patients with RVO (n = 14, CRVO; central RVO n = 5, BRVO; branch RVO n = 9) and non-RVO (macular hole or epiretinal membrane, n = 18) were surgically treated by a 25 or 27G vitrectomy. Undiluted vitreous fluid samples obtained as the result of surgery were subjected to enzyme-linked immunosorbent assays to measure the levels of FABP4 and vascular endothelial growth factor A (VEGFA).Data including ocular blood flow by laser speckle flow graphy (LSFG), height and weight, systemic blood pressures and several blood biochemistry values were collected. Among the LSFG mean blur rate (MBR) values of the optic nerve head (ONH) at baseline, MA (MBR of all area), MV (MBR of the vascular area), and MV-MT (MBR of the tissue area) were significantly decreased in patients with CRVO. The levels of V-FABP4 and V-VEGFA were relatively or significantly (P< 0.05) higher in the BRVO or CRVO patients compared to the non-RVO patients, respectively. A positive correlation (r = 0.36, P = 0.045) or a negative correlation (r = -0.51, P = 0.006) was observed between Log V-FABP4 and Log V-VEGF, or Log V-FABP4 and MV-MT at post-operative 1-week, respectively. Furthermore, neither of these factors were affected with respect to sex, body mass index and several clinical parameters that were collected, except that a positive correlation was observed for Log V-FABP4 with blood urea nitrogen. Stepwise multivariable regression analyses indicated that MV-MT at post-operative 1week was independently associated with Log V-FABP4 after adjustment for age and gender, and gender and Log V-FABP4 were independently associated with Log V-VEGFA after adjustment for age. The findings reported herein suggest that an independent factor, FABP4 may be synergistically involved in the pathogenesis of RVO with VEGFA.

Wide-Field Fluorescein Angiography in the Diagnosis and Management of Retinal Vein Occlusion: A Retrospective Single-Center Study

Background

The aim of this retrospective study was to evaluate the role of wide-field fluorescein angiography (WF-FA) in the diagnosis and management of retinal vein occlusion (RVO) at a single center in Poland.

Material/Methods

This study included 106 patients (112 eyes) diagnosed with RVO (102 eyes) or impending RVO (10 eyes) (54% women and 46% men, aged 26 to 86 years). The medical records of the participants were reviewed in search of documentation on ocular and systemic diseases. Results of FA of central and peripheral retina and optical coherence tomography (OCT) scans, which had been used to establish treatment indications, were analyzed. WF-FA was performed with Spectralis HRA+OCT or Optos Tx200.

Results

Actual RVO was found in 102 eyes. Of those cases, 46.1% were CRVO (central retinal vein occlusion), 40.2% branch retinal vein occlusion, 11.8% small tributary vein occlusion, and 1.9% hemispheric retinal vein occlusion. Neovascularization on an optic disc, neovascularization elsewhere, and veno-venous collateral vessels were observed in 32.3%, 17.4%, and 41.2% of the eyes, respectively. Peripheral ischemic zones were present in 59.8% of the eyes, in 20.6% of which, ischemia was not observed in the posterior pole. Dye leaks limited to peripheral vessels, peripheral vascular amputations, and central macular edema in OCT were observed in 17.6%, 43.1%, and 63.7% of the eyes, respectively. Retinal laser photocoagulation was conducted on 73.5% of the eyes.

Conclusions

Decision-making about management of patients with RVO should be done after physical examination and analysis of central and peripheral retina FA. In 20.6% of patients, assessment of the peripheral retina resulted in a change in treatment. The first changes suggestive of progression of thrombotic disease to the ischemic form appeared on the periphery in images from WF-FA.

Intravitreal ketamine promotes neuroprotection in rat eyes after experimental ischemia

Retinal ischemia, one of the most common cause of visual loss, is associated with blood flow inadequacy and subsequent tissue injury. In this setting, some treatments that can counteract glutamate increase, arouse interest in ischemic pathogenesis. Ketamine, a potent N-methyl-d-aspartate (NMDA) receptor antagonist, provides a neuroprotective pathway via decreasing the excitotoxicity triggered by excess glutamatergic. Thus, the goal of this study was to evaluate the safety of intravitreal use of ketamine and their potential protective effects on retinal cells in retinal ischemia/reperfusion model. Initially, ketamine toxicity was evaluated by cytotoxicity assay and Hen's egg chorioallantoic membrane (HET-CAM) method. Afterward, some ketamine concentrations were tested in rat's eyes to verify the safety of the intravitreal use. To investigate the neuroprotective effect on retinal, a single intravitreal injection of ketamine in concentrations of 0.059 mmol.L-1 and 0.118 mmol.L-1 was performed one day before the retinal injury by ischemia/reperfusion model. After 7 and 15 days, the retina activity was evaluated by electroretinogram (ERG) records and, lastly, by morphological analyzes. Cytotoxicity assay reveals that the maximum ketamine concentration that could reach retinal pigmented epithelium cells is 0.353 mmol.L-1. HET-CAM assay showed that concentrations above 0.237 mmol.L-1 are irritants to the eye. Thus, Ketamine in concentrations of 0.0237 mmol.L-1, 0.118 mmol.L-1, and 0.059 mmol.L-1 were selected for in vivo toxicity test. ERG records reveal a tendency of b-wave amplitude to decrease as the luminous intensity increased, in the group receiving ketamine at 0.237 mmol.L-1. Therefore, ketamine in concentrations at 0.059 mmol.L-1 and 0.118 mmol.L-1 were chosen for the following tests. In the ischemia retinal degeneration model, pretreatment with ketamine was capable to promote a recovery of retinal electrophysiological function minimizing the ischemic effects. In histological analysis, the groups that received intravitreal ketamine showed a number of retinal cells significantly higher than the vehicle group. In TUNEL assay a reduction on TUNEL-positive cells was observed in all the layers for both concentrations which allow to affirm that ketamine contributes to reducing cell death in the retina. Transmission electron microscopy (TEM) reaffirms this finding. Ketamine intravitreal pretreatment showed reduced ultrastructural changes. Our findings demonstrate that ketamine is safe for intravitreal use in doses up to 0.118 mmol.L-1. They seem to be particularly efficient to protect the retina from ischemic injury.

Inherited and acquired thrombophilia in adults with retinal vascular occlusion: A systematic review and meta-analysis

BACKGROUND

Retinal vascular occlusion is a leading cause of sight loss. Both retinal artery occlusion (RAO) and retinal vein occlusion (RVO) have been associated with hypercoagulable states; however, the burden of thrombophilia in these patients is unclear.

OBJECTIVES

This study aims at estimating the prevalence of inherited and acquired thrombophilias in adults with RAO or RVO through a systematic review and meta-analysis of the literature.

PATIENTS/METHODS

PubMed and EMBASE were systematically searched from inception to 29 February 2020. All studies reporting prevalences of factor V Leiden (FVL) and prothrombin (F-II) G20210A mutations, methylenetetrahydrofolate reductase (MTHFR) C677T and plasminogen activator inhibitor (PAI) 4G polymorphisms, antithrombin III (AT-III), protein C (PC) and protein S (PS) activity deficiencies, hyperhomocysteinemia, and antiphospholipid (APL) antibodies in adults with RAO or RVO were included. Pooled prevalences and 95% confidence intervals (CI) were calculated.

RESULTS

Ninety-five studies were included; FVL and F-II mutations were found in 6% (95% CI: 5-8) and 3% (95% CI: 2-4) of individuals with RVO, respectively, whereas AT-III, PC, and PS activity deficiencies were found in <2%. The MTHFR C677T and PAI 4G homozygous polymorphism were observed in 13% (95% CI: 10-17) and 23% (95% CI: 16-31) of RVO, respectively; 8% presented APL antibodies. Similar findings were observed in individuals with RAO.

CONCLUSIONS

Compared with healthy subjects, patients with retinal vascular occlusion showed similar prevalences of inherited and acquired thrombophilias. These findings do not support routine thrombophilia screening in individuals with RAO or RVO.

Age-related differences in presentation and outcomes of anti-VEGF treatment of retinal vein occlusion

OBJECTIVE

To assess age-related differences at baseline and treatment outcomes in patients with retinal vein occlusion (RVO) and macular edema treated with anti-vascular endothelial growth factor (VEGF) therapy DESIGN: Single-centre retrospective chart review.

PARTICIPANTS

295 treatment-naïve RVO patients.

METHODS

295 RVO patients included were separated into age quartiles: group A (22-61 years), group B (62-70 years), group C (71-79 years), and group D (80-95 years). Outcomes including central subfield thickness (CST), cubic volume, cubic average thickness, and visual acuity (VA) were collected at baseline and at 6 and 12 months after treatment. The primary outcome of the study was the CST at 12 months after anti-VEGF therapy.

RESULTS

Mean baseline CST for groups A, B, C, and D was 406.3 ± 161.2 μm, 463.4 ± 165.5 μm, 470.6 ± 187 μm, and 427.3 ± 187.2 μm, respectively. No significant differences in CST were observed between groups at baseline, 6 months, or 12 months (p ≥ 0.08). Mean baseline VA for groups A, B, C, and D was 55.8 ± 19.5, 54.4 ± 19.8, 54.7 ± 19, and 51.4 ± 20.4 Early Treatment Diabetic Retinopathy letters, respectively. VA did not differ significantly between age groups at baseline, 6 months, or 12 months (p ≥ 0.06).

CONCLUSIONS

The presentation of RVO and the visual outcomes of anti-VEGF therapy do not vary based on age.

Correlations between choroidal thickness and renal function in patients with retinal vein occlusion

The purpose of this study was to analyze the correlation of renal function indices with sub-foveal choroidal thickness (SFChT) in treatment-naïve (naïve) eyes with retinal vein occlusion (RVO) using swept-source optical coherence tomography (SS-OCT) and systemic workup. Retrospective chart review was performed from Dec 2016 to Sep 2019 in patients newly diagnosed with treatment-naïve unilateral RVO. Ocular parameters, including SFChT, and systemic profiles, including renal function indices, were reviewed. Simple and multiple linear regression analyses were performed to check if there was a correlation between renal profiles and SFChT. A total of 56 patients were included in the study; 34 of them were branch RVO and 22 were central RVO patients. Multiple linear regression analysis revealed that SFChT was positively correlated with estimated glomerular filtration rate (eGFR) (P < 0.001). SFChT showed significant correlation with renal function indices. In addition, choroidal thickness may be considered as systemic biomarkers for renal function.

Retinal vein occlusion and chronic kidney disease: A meta-analysis

OBJECTIVES

We performed this meta-analysis to assess the correlation of retinal vein occlusion (RVO) and chronic kidney disease (CKD).

METHODS

We searched PubMed, Embase, Web of Science and Cochrane Library for population-based studies reporting the CKD as associated factor to RVO, central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO). Then we pooled the data for analysis.

RESULTS

After screening potential literature, 12 eligible studies with 23,656,214 individuals were finally included in quantitative synthesis. The pooled prevalence (95% confidence interval [CI]) of CKD in RVO group was 10.9% (95% CI: 6.6%, 15.1%). The pooled prevalence of any RVO in end stage renal disease (ESRD) group was 1.8% (95% CI: 1.6%, 2.1%). The prevalence of CKD was significantly higher in subjects diagnosed with RVO than non-RVO participants (odds ratio [OR]: 3.30; 95% CI: 2.28, 4.76; p < 0.001). CRVO subjects had a higher prevalence of CKD than BRVO patients (OR: 2.17; 95% CI: 1.28, 4.66; p = 0.004). In a similar manner, compared to non-ESRD subjects, ESRD patients had significantly higher prevalence of RVO (OR: 2.19; 95% CI: 1.97, 2.43; p < 0.001), CRVO (OR: 2.61; 95% CI: 2.17, 3.15; p < 0.001) and BRVO (OR: 2.01; 95% CI: 1.76, 2.30; p < 0.001).

CONCLUSION

The prevalence of CKD increases in RVO patients, especially in CRVO. And in turn, the prevalence of RVO also increases in ESRD patients. The data support a correlation of RVO and CKD.

Real-world outcomes with ranibizumab in branch retinal vein occlusion: The prospective, global, LUMINOUS study

Objective

To evaluate the effectiveness, safety, and treatment patterns of ranibizumab 0.5 mg in treatment-naïve patients with branch retinal vein occlusion (BRVO) enrolled in the LUMINOUS^™ study.

Study design

A 5-year, global, prospective, multicenter, observational, open-label study conducted in a clinical practice (real-world) setting at outpatient ophthalmology clinics that recruited 30,138 consenting adult patients from all approved indications for ranibizumab across 42 countries. Patients with BRVO were treated according to the local ranibizumab label of the participating countries. Mean change in visual acuity (VA) in Early Treatment Diabetic Retinopathy Study letters from baseline to Year 1, treatment exposure during Year 1, and adverse events (AEs) over 5 years were assessed.

Results

Of the 1366 recruited BRVO patients, 405 were treatment-naïve at baseline with a mean (standard deviation [SD]) age of 67.9 (12.5) years, 57.5% were female, and 71.8% were White. At Year 1 (n = 189), the mean (SD) VA gain was 11.9 (17.66) letters from a baseline of 49.2 (±20.32) letters with a mean (SD) of 5.0 (2.34) injections. VA gains were higher in patients (n = 83) who received 6–9 injections (13.6 [20.16] letters) than in those who received 2–5 injections (n = 92, 11.7 [15.43] letters), or 1 injection (n = 14, 3.6 [13.72] letters). Patients with baseline VA <23 letters had numerically highest VA gains (n = 20, 31.1 [24.48] letters). Over 5 years, the rate of ocular/non-ocular AEs was 7.4%/9.1% and serious AEs was 0.3%/4.4% in treatment-naïve BRVO patients (n = 405).

Conclusions

One year results from the LUMINOUS real-world study showed a clinically meaningful VA improvement with ranibizumab in treatment-naïve patients with BRVO; numerically higher VA gains were achieved in patients who received more injections and those with poor baseline VA. No new safety signals were observed.

Quantitative analysis of metabolites in glucose metabolism in the aqueous humor of patients with central retinal vein occlusion

Quantitative analysis of aqueous humor (AH) was performed to investigate glucose metabolism in patients with central retinal vein occlusion (CRVO), and to explore metabolic changes after anti-vascular endothelial growth factor (VEGF) treatment. AH samples were collected from 35 patients. Participants diagnosed with CRVO (n = 15) were compared to participants who underwent cataract surgery (n = 20). Thirteen of the participants with CRVO received second-round anti-VEGF treatments. Ultra-high performance liquid chromatography tandem-mass spectrometry (UHPLC-MS/MS) was used to quantify metabolites of the AH. Central macular thickness (CMT) and retinal ganglion cell layer (RGC) thickness were measured using spectral-domain optical coherence tomography. Thirteen metabolites involved in glucose metabolism were identified. Among these metabolites, succinate, glutamate, and glutamine were significantly decreased for the CRVO group (p = 0.028, 0.009, and 0.017, respectively). The α-ketoglutarate/citrate (K/C) ratio had a significant positive correlation with glutamine levels for both control (r = 0.922, p < 0.001) and CRVO groups (r = 0.674, p = 0.006). A significant increase in lactate was observed after intravitreal anti-VEGF administration (t = 2.273, p = 0.045); the change in CMT was negatively correlated with this increase (r = -0.745, p = 0.003). The alteration of RGC thickness was negatively correlated with increases in both glutamine (r = -0.619, p = 0.024) and glucose (r = -0.754, p = 0.003). These results indicate that, compared to glucose metabolism, glutamine was significantly decreased in the AH of patients with CRVO, and may therefore serve as a potential target for CRVO therapy. The glycolytic pathway might be enhanced after intravitreal anti-VEGF injection, which is an important insight into CRVO pathophysiology.

Incidence of retinal vein occlusion with long-term exposure to ambient air pollution

This study aimed to investigate whether long-term exposure to airborne hydrocarbons, including volatile organic compounds, increases the risk of developing retinal vein occlusion (RVO) among the population of Taiwan. A retrospective cohort study involving 855,297 people was conducted. Cox proportional hazards regression analysis fitted the multiple pollutant models for two targeted pollutants, including total hydrocarbons (THC), nonmethane hydrocarbons (NMHC) were used, and the risk of RVO was estimated. The chi-squared test and one-way analysis of variance were used to test differences in demographics and comorbidity distribution among tertiles of the targeted pollutants. Before controlling for multiple pollutants, hazard ratios for the overall population were 19.88 (95% CI: 17.56-22.50) at 0.51-ppm increases in THC and 4.33 (95% CI: 3.97-4.73) at 0.27-ppm increases in NMHC. The highest adjusted hazard ratios for different multiple pollutant models of each targeted pollutant were statistically significant (all p values were ≤0.05) for all patients at 29.67 (95% CI: 25.57-34.42) for THC and 16.24 (95% CI: 14.14-18.65) for NMHC. Our findings suggest that long-term exposure to THC and NMHC contribute to RVO development.