Prevalence and associated factors of retinal vein occlusion in the Korean National Health and Nutritional Examination Survey, 2008-2012: A cross-sectional observational study

Influence of Smoking and Controlled Medical Conditions on the Risks of Branch Retinal Vein Occlusion in South Korea: A Population-Based Study

PURPOSE

To evaluate the effect of controlled medical conditions and risk of lifetime smoking history on the prevalence of branch retinal vein occlusion (BRVO) based on the Korea National Health and Nutrition Survey (KNHANES) database from 2017-2021.

METHODS

The study population consisted of individuals aged ≥ 40 years who had completed ophthalmological questionnaires, underwent comprehensive ophthalmological examinations, and had at least one good-quality readable fundus photograph. Age, sex, hypertension status, diabetes status, dyslipidemia status, body mass index status, a history of chronic kidney disease (CKD), a lifetime smoking history of ≥ 100 cigarettes, and glaucoma were subjected to univariate and multivariate logistic regression analyses.

RESULTS

The estimated prevalence (± standard error) of RVO was 0.5% (±0.1%). Significant risk factors were one-year increase in age, female sex, hypertension (stage 1, controlled, uncontrolled, and undiagnosed hypertension), underweight, pre-obesity, history of CKD, lifetime smoking history of ≥ 100 cigarettes, and glaucoma. Controlled diabetes decreased the risk of BRVO by 55% (odds ratio [OR] = 0.45, 95% confidence interval [CI] = 0.22-0.89, p = 0.022) and controlled hyper-high-density-lipoprotein (HDL)-cholesterolemia decreased the risk by 69% (OR = 0.31, 95% CI = 0.13-0.76, p = 0.010).

CONCLUSION

This study, for the first time, reported the association between lifetime smoking history of ≥ 100 cigarettes and BRVO in Korea. The risk of BRVO was lower in participants with controlled diabetes and hypo-HDL-cholesterolemia.

The Association between Vascular Abnormalities and Glaucoma-What Comes First?

Glaucoma is a leading cause of irreversible blindness worldwide. While intraocular pressure (IOP) presents a major risk factor, the underlying pathophysiology still remains largely unclear. The correlation between vascular abnormalities and glaucoma has been deliberated for decades. Evidence for a role played by vascular factors in the pathogenesis of glaucomatous neurodegeneration has already been postulated. In addition, the fact that glaucoma causes both structural and functional changes to retinal blood vessels has been described. This review aims to investigate the published evidence concerning the relationship between vascular abnormalities and glaucoma, and to provide an overview of the "chicken or egg" dilemma in glaucoma. In this study, several biomarkers of glaucoma progression from a vascular perspective, including endothelin-1 (ET-1), nitric oxide, vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMPs), were identified and subsequently assessed for their potential as pharmacological intervention targets.

Prevalence and systemic associations of retinal vascular occlusions in Sub-Saharan Africa

Background

Retinal vascular occlusions are a common cause of visual impairment. Studies on retinal vascular occlusions in sub-Saharan Africa (SSA) have primarily been retrospective and on retinal vein occlusion (RVO) only. The aim of this study, therefore, was to determine the prevalence and pattern of retinal vascular occlusions and their systemic associations in SSA.

Materials and Methods

This was a hospital-based, cross-sectional study involving all new patients presenting at the general ophthalmic and specialty retina clinics in four hospitals in Nigeria over a 1 year period. All the patients underwent a comprehensive eye examination. The demographic and clinical data of patients with retinal vascular occlusions were entered into an excel sheet and analyzed using the Statistical Package for the Social Sciences (SPSS) software version 22.0. Statistical significance was indicated by P < 0.05.

Results

A total of 8614 new patients were seen, and a diagnosis of retinal vascular occlusion was made in 90 eyes of 81 patients giving a disease prevalence of 0.9%. Eighty-one eyes of 72 (88.9%) patients had RVO, while 9 eyes of 9 (11.1%) patients had retinal artery occlusion (RAO). The mean age of patients with RVO and RAO was 59.5 years and 52.4 years, respectively. Increasing age, hypertension, and diabetes were the significant associations with retinal vascular occlusion with P < 0.0001.

Conclusion

Retinal vascular occlusions are an increasing cause of retinal disease in SSA and tend to occur at an earlier age. They are associated with hypertension, diabetes, and increasing age. Further studies will, however, be required to establish the demographic and clinical profile of patients with RAO in the region.

Novel superpixel method to visualize fundus blood flow resistivity in healthy adults

We aimed to perform superpixel segmentation of ocular blood flow maps obtained using laser speckle flowgraphy (LSFG) and investigate the effects of systemic parameters such as body weight, height, and sex on ocular blood flow resistivity. We studied 757 healthy participants (583 men, 174 women). We calculated the average beat strength over mean blur rate (BOM) as a LSFG resistivity index, as a function of age and sex using ordinary regions of interest (ROI) centered on the optic nerve head (ONH), the retinal vessels region and tissue around the ONH, and the choroid (CHD). We compared the ROI and superpixel-based methods, which are segmented based on image processing, for calculating the BOM. The sex differences in the BOM for the ONH, retinal-vessels region and tissue region of the ONH and CHD were significant for individuals aged ≤ 50 years (P < 0.01) but not those > 50 years old (P > 0.05). The average BOMs calculated using the ROI and superpixel methods were strongly correlated in the ONH (coefficient = 0.87, R² = 0.8, P < 0.0001, n = 5465). In summary, a superpixel-segmented BOM map is suitable for two-dimensional visualization of ocular blood flow resistivity.

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

Retinal vein occlusion (RVO) is the second most prevalent retinal disease. Despite this, the pathogenic mechanisms and risk factors are not entirely clear. In this article, we review recent publications on the classification, pathogenesis, risk factors, ischemic changes, cytokines, and vital complications of RVO. Risk factors and cytokines are important for exploring the mechanisms and new treatment targets. Furthermore, risk factors are interrelated, making RVO mechanisms more complex. Cytokines act as powerful mediators of pathological conditions, such as inflammation, neovascularization, and macular edema. This review aims to summarize the updated knowledge on risk factors, cytokines of RVO and signaling in order to provide valuable insight on managing the disease.

Clinical risk factors for retinal artery occlusions: a nationwide case-control study

PURPOSE

This study seeks to examine potential risk factors for the development of retinal artery occlusions (RAO).

METHODS

We used data obtained from Danish nationwide registries to evaluate potential risk factors for RAO present up to 5 years prior to the RAO diagnosis. The study included 5312 patients diagnosed with RAO registered in the Danish National Patient Register and 26,560 controls assessed from the general population matched on sex and age at index date. Adjusted conditional logistic regression was used to estimate the odds ratio of included risk factors for RAO diagnosis. We conducted supplementary analyses stratified on sex and age, and on RAO subtype. In addition, interaction analyses were performed between strata in the stratified analyses.

RESULTS

Risk factors associated with the development of RAO included diabetes, arterial hypertension, ischemic heart disease, peripheral artery disease, stroke, renal disease, cataract, and glaucoma, with ORs ranging from 1.33 to 4.94. Atrial fibrillation and sleep apnea yielded effect measures close to equivalence. The presence of a risk factor was generally associated with higher odds of RAO among the population ≤ 55 of age. Arterial hypertension was stronger associated with RAO in male patients than in female patients. The association with arterial hypertension was stronger for CRAO than for BRAO subtype.

CONCLUSION

The investigated risk factors suggest that atherosclerosis and conditions changing the intraocular pressure are involved in the pathophysiology of RAO.

The Quantification and Impact of Persistent Retinal Fluid Compartments on Best-Corrected Visual Acuity of Patients With Retinal Vein Occlusion

BACKGROUND AND OBJECTIVES

To evaluate the impact of persistent intraretinal fluid (IRF) and subretinal fluid (SRF) on best visual acuity (BVA) of patients with retinal vein occlusions (RVOs).

PATIENTS AND METHODS

This retrospective cohort study observed 92 treatment-naïve patients with RVO during 12 months of treatment with anti-vascular endothelial growth factor agents. Deep learning was used to quantify IRF and SRF volumes, and linear mixed effects regression modeled the impact on BVA.

RESULTS

Average IRF volume declined -923.1 ± 2,382.5 nL from baseline to 12 months (P < .001). Average SRF volume declined -35.4 ± 223.4 nL from baseline to 12 months (P = .139). linear mixed effects regression modeling disclosed IRF≥ 1,616 nL at all time points predicted a -10.38 letter loss at 12 months (95% CI, -14.58 to -5.9 letters; P < .001). A similar relationship was not found for SRF.

CONCLUSION

Persistent IRF may be an important prognostic biomarker for BVA outcomes in real-world patients with RVO. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:139-147.].

Sudden Sensorineural Hearing Loss May Increase the Risk of Retinal Vein Occlusion: A Nationwide Cohort Study

Sudden sensorineural hearing loss (SSNHL) is thought to be a vascular disease. Retinal vein occlusion (RVO) is an also common ophthalmic vascular disease. Thus, we investigated the potential relationship between these using a retrospective nationwide cohort dataset. We compared 49,584 subjects in the SSNHL and the comparison (non-SSNHL) groups using patients randomly selected via propensity-score matching. We calculated the incidence, survival rate, and hazards ratio (HR) using log-rank test, and Cox proportional hazards regression models. This study examined a total of 375,490.4 person-years in the SSNHL group and 373,698.2 person-years in the comparison group. We found that 673 patients in the SSNHL group (1.8 cases per 1000 person-years) and 592 in the comparison group (1.6 cases per 1000 person-years) developed RVO during the 8-year follow-up period. The adjusted HR of RVO was 1.13 (95% confidence interval [CI] 1.01–1.26). The adjusted HR of developing RVO in SSNHL was the greatest in elderly patients (adjusted HR, 1.21; 95% CI, 1.01–1.46) and male patients (adjusted HR, 1.18; 95% CI, 1.03–1.34). Our findings suggest that clinicians should remain vigilant of the possibility of RVO development in SSNHL patients, specifically elderly male patients.

Analysis of postoperative intraocular pathologies in patients with mature cataracts

Purpose

To examine the prevalence and risk factors of intraocular pathologies after mature cataract surgery.

Methods

The medical records of 115 patients (115 eyes) diagnosed with brunescent or white cataracts, who underwent surgery at a single primary center between January 2018 and August 2021 were retrospectively reviewed. Dense cataracts precluded preoperative fundus examination in all eyes; however, patients with fundus examination results within 3 months after cataract surgery were included. Logistic regression analyses were performed to identify factors associated with intraocular pathologies.

Results

Intraocular pathologies were observed in 37 eyes (32.2%) 11.8 ± 13.9 days postoperatively. The most common abnormalities were drusen (6.1%), myopic degeneration (5.2%) and diabetic retinopathy (4.3%). Intraocular pathology in the fellow eye was associated with posterior segment pathology in mature cataract eyes (odds ratio, 47.72; P < 0.001).

Conclusions

The prevalence of each intraocular pathology found after mature cataract surgery was unremarkable. This study provides clinically useful evidence for clinicians to explain the risk of posterior segment pathology in patients with mature cataracts.

Effects of Antithrombotic Agents on Ophthalmological Outcomes, Cardiovascular Risk, and Mortality in Hypertensive Patients with Retinal Vein Occlusion: An Exploratory Retrospective Study

Background and objectives: Because few data are available, the aim of this study is to analyze the effects of antithrombotic agents (ATAs) on visual function and long-term risk of cardiovascular events and mortality in hypertensive patients with retinal vein occlusion (RVO). Materials and methods: Hypertensive patients with RVO were consecutively selected from 2008 to 2012 and followed for a median of 8.7 years. Ophthalmologists evaluated and treated RVO complications, and best-corrected visual acuity (BCVA) was checked at each visit during the first one year of follow-up. Survival analysis was conducted on the rate of the composite endpoint of all-cause deaths or non-fatal cardiovascular events. Results: Retrospectively, we collected data from 80 patients (age 68 ± 12 years, 39 males). Central and branch RVO was present in 41 and 39 patients, respectively, and 56 patients started ATAs (50 antiplatelet drugs, 6 warfarin, and 2 low-molecular weight heparin). Average BCVA of the cohort did not change significantly during one-year of follow-up. The only predictor of BCVA was the baseline BCVA value. There was a reduction in proportion and severity of macular edema and an increase in the cumulative proportion of retinal vein patency reestablishment during the follow-up, independent of treatment. ATAs had no effects on one-year BCVA, intraocular complications, or the composite endpoint rate. Conclusions: In this exploratory study, ATAs had no effect on BCVA during the first one year of follow-up and on the composite endpoint during the long-term follow-up. Further prospective studies need to be conducted with an accurate standardization of the intraocular and antithrombotic treatment to define the positive or negative role of ATAs in hypertensive patients with RVO.

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.

ASSOCIATION OF RETINAL VEIN OCCLUSION WITH CARDIOVASCULAR EVENTS AND MORTALITY: A Systematic Review and Meta-analysis

PURPOSE

Previous studies examining the association of retinal vein occlusion (RVO) and cardiovascular events have been inconsistent and have mostly focused on stroke and myocardial infarction. The goal of this study is to use meta-analysis to examine the available evidence examining the association of RVO with incident cardiovascular events and mortality.

METHODS

Systematic review and meta-analysis of all longitudinal cohort studies published in PubMed, Embase, and the Cochrane Library from inception to April 7, 2018, that evaluated the association of baseline RVO and incident cardiovascular events and/or mortality, that provided multivariate-adjusted risk estimates with 95% confidence intervals (95% CIs), and that had average follow-up ≥1 year. The Newcastle-Ottawa scale was used to assess study quality. Multivariate-adjusted risk estimates with 95% CI along with study characteristics were extracted from each study, and pooled risk ratios (RRs) with 95% CI were generated using a random-effects model with inverse-variance weighting to account for heterogeneity. Main outcomes were incident stroke (fatal or nonfatal), myocardial infarction, heart failure, peripheral arterial disease, all-cause mortality, and cardiovascular mortality.

RESULTS

Fifteen cohort studies with a total of 474,466 patients (60,069 with RVO and 414,397 without RVO) were included. Each study had Newcastle-Ottawa scale score ≥6, indicating moderate-to-high quality. Retinal vein occlusion was associated with increased risk of stroke (RR = 1.45; 95% CI, 1.31-1.60), myocardial infarction (RR = 1.26; 95% CI, 1.17-1.37), heart failure (RR = 1.53; 95% CI, 1.22-1.92), peripheral arterial disease (RR = 1.26; 95% CI, 1.09-1.46), and all-cause mortality (RR = 1.36; 95% CI, 1.02-1.81), but was not associated with increased risk of cardiovascular mortality (RR = 1.78; 95% CI, 0.70-4.48).

CONCLUSION

This review suggests patients with RVO have an increased risk of cardiovascular events and all-cause mortality. More studies are needed to determine the highest risk periods for cardiovascular events and mortality after RVO and whether immediate cardiovascular evaluation and intervention will improve outcomes.

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.

Changes in the Retinal Microvasculature Measured Using Optical Coherence Tomography Angiography According to Age

In this cross-sectional study, we examined age-related changes in the retinal vessels of 100 healthy participants, aged from 5 to 80 years, and divided into four groups (G1, under 20 years of age; G2, from 20 to 39 years of age; G3, from 40 to 59 years of age; G4, age 60 years or older). All subjects underwent swept-source optical coherence tomography (SS-OCT) and OCT angiography (OCTA). The vascular density (VD) of the superficial (SCP) and deep capillary plexus (DCP), and choriocapillaris (CCP) were measured using OCTA. The vascular density of each capillary layer, foveal avascular zone (FAZ) area, ganglion cell-inner plexiform layer (GC-IPL) thickness, retinal thickness (RT), and choroidal thickness (CT) were compared between age groups. Most OCT variables were correlated with OCTA variables. The FAZ area; VD of the SCP, DCP, and CCP; GC-IPL thickness; RT; and CT showed significant difference (p < 0.001) between G1 + G2 and G3 + G4, except for central GC-IPL thickness (p = 0.14) and central RT (p = 0.25). Density of the retinal capillary vasculature reduced and FAZ area increased after age 40, which represents the onset of middle age.

Influence of age and gender on the pulse waveform in optic nerve head circulation in healthy men and women

The influences of age and gender differences on the pulse waveform in the optic nerve head (ONH) in healthy adults, using laser speckle flowgraphy (LSFG) were evaluated. We studied 908 healthy subjects (men = 701, age: 50.0 ± 9.1, women = 208, age: 49.8 ± 9.5, p = 0.76), evaluating these pulse waveform parameters: the blowout score (BOS), blowout time (BOT), acceleration time index (ATI), and the rising and falling rates. The parameters were analyzed separately for the tissue, vessels, and throughout the optic nerve head (All). All parameters were compared between genders. We investigated which independent factors for the pulse waveform in the ONH is most strongly correlated with age. All sections of the BOS, BOT, ATI, and falling rate showed a significant gender difference. A univariate regression analysis revealed that BOT-Tissue showed the strongest correlation with age (r = −0.51). The factors contributing independently to the BOT-Tissue were gender, age, heart rate, mean arterial blood pressure, pulse pressure, spherical refraction, and estimated glomerular filtration rate. Among the subjects aged >41 years, the chronological changes of BOT-Tissue in the women were significantly lower than those in the men. We concluded that the pulse waveform in the ONH has clear differences between the genders and shows chronological changes.

Association of glaucoma with risk of retinal vein occlusion: A meta-analysis

To summarize epidemiological evidences on the association between glaucoma and the risk of retinal vein occlusion (RVO). Relevant studies were identified by searching in PubMed, EMBASE and Cochrane until February 2018. Fifteen eligible observational studies were aggregated in this analysis. All results were analysed and pooled using random effects models with 95% confidence intervals (CI). In all studies, the odds ratio (OR) of glaucoma as a risk factor for RVO was 4.01 (95% CI: 3.28-4.91). In RVO subtype-differentiated subgroup analyses (six studies), the pooled OR showed that glaucoma was associated with central retinal vein occlusion (CRVO) (OR: 6.21; 95% CI: 4.64-8.31), branch retinal vein occlusion (BRVO) (OR: 2.38; 95% CI: 1.77-3.19) and hemiretinal vein occlusion (HRVO) (OR: 4.60; 95% CI: 2.26-9.35). In glaucoma-classified subgroup analyses (five studies), primary open-angle glaucoma (POAG) (OR: 5.03; 95% CI: 3.97-6.37) and chronic open-angle glaucoma (COAG) (OR: 2.36; 95% CI: 1.39-4.02) were significant risk factors for RVO development. There was a plausible relationship between primary angle closure glaucoma (PACG) and RVO risk (OR: 1.85; 95% CI: 0.41-8.35); to be precise, the OR was 5.3 in PACG and CRVO risk (95% CI: 1.04-26.95; p = 0.045), while the OR was 0.65 in PACG and BRVO risk (95% CI: 0.07-6.27; p = 0.707). To sum up, this meta-analysis shows that glaucoma is associated with the risk of RVO. Glaucoma should be kept in mind when investigating patients with RVO in the clinic.

The influences of gender and aging on optic nerve head microcirculation in healthy adults

Potential differences in the nature of the influences of aging and gender on the optic nerve head (ONH) microcirculation, using laser speckle flowgraphy (LSFG) were evaluated. We studied 908 healthy subjects (men = 701, age: 50.0 ± 9.1 yrs, women = 208, 49.8 ± 9.5 yrs, p = 0.76). The average, maximum (Max), and minimum (Min) mean blur rate (MBR) in a heartbeat were evaluated. The parameters were analyzed separately for the tissue, vessels, and throughout the ONH (All). We investigated which MBR sections are correlated with gender and age by univariate and multivariate regression analyses. The Max MBR-All (r = −0.31) was most strongly correlated with gender (men = 1, women = 0). The Min MBR-All (r = −0.24) was most strongly correlated with age, followed by Min MBR-All (r = −0.20). The factors contributing independently to the Max MBR-All were gender (β = −0.15), pulse pressure, spherical refraction, ocular perfusion pressure, and red blood cell (RBC) count. The factors contributing independently to the Min MBR-Vessel were gender (β = −0.09), age (β = −0.25), body mass index, heart rate, and spherical refraction. The factors contributing independently to the Min-MBR-All were age (β = −0.22), heart rate, and RBC count. Our results revealed that gender differences influence the Max MBR, and aging influences the Min MBR. These correlations were stronger than that of average MBR.