Prevalence of retinal vein occlusion in the Australian National Eye Health Survey

Estimating the rate of severe visual loss (wipe-out) following cataract surgery, a British Ophthalmological Surveillance Unit (BOSU) study

BACKGROUND

A sudden, irreversible reduction in visual acuity ('wipe-out') is a feared complication of cataract surgery. Current literature on wipe-out is limited in quantity and quality, and largely predates modern cataract surgery and imaging techniques. The objectives of our study were to estimate the incidence of wipe-out and to identify potential risk factors.

METHODS

We prospectively collated cases of wipe-out occurring in the UK during a 25-month study period using the British Ophthalmic Surveillance Unit reporting system. A total of 21 potential cases of wipe-out were reported, 5 of which met all inclusion and exclusion criteria.

RESULTS

The estimated incidence of wipe-out during the study period was 0.00000298, or approximately 3 cases per million cataract operations. All cases of wipe-out occurred exclusively in patients with advanced glaucoma (mean deviation -21.0 decibels or worse in the operated eye), with an over-representation of black people (40%) in our case series. A prior diagnosis of retinal vein occlusion (60%) and elevated post-operative IOP (40%) were more common among individuals suffering from wipe-out compared to the general population, suggesting these factors may contribute to the pathogenesis of wipe-out.

CONCLUSIONS

Our study shows that wipe-out is a rare complication, affecting approximately 3 per million undergoing cataract surgery. Patients with advanced glaucoma, black patients, and those with previous retinal vein occlusions may be at greater risk of wipe-out. We hope that the findings of our study will be used to help inform treatment decision-making and the cataract surgery consent process.

Proteome Analysis of Bevacizumab Intervention in Experimental Central Retinal Vein Occlusion

Bevacizumab is a frequently used inhibitor of vascular endothelial growth factor (VEGF) in the management of macular edema in central retinal vein occlusion (CRVO). Studying retinal protein changes in bevacizumab intervention may provide insights into mechanisms of action. In nine Danish Landrace pigs, experimental CRVO was induced in both eyes with argon laser. The right eyes received an intravitreal injection of 0.05 mL bevacizumab (n = 9), while the left control eyes received 0.05 mL saline water (NaCl). Retinal samples were collected 15 days after induced CRVO. Label-free quantification nano-liquid chromatography-tandem mass spectrometry identified 59 proteins that were regulated following bevacizumab treatment. Following bevacizumab intervention, altered levels of bevacizumab components, including the Ig gamma-1 chain C region and the Ig kappa chain C region, were observed. Changes in other significantly regulated proteins ranged between 0.58-1.73, including for the NADH-ubiquinone oxidoreductase chain (fold change = 1.73), protein-transport protein Sec24B (fold change = 1.71), glycerol kinase (fold change = 1.61), guanine-nucleotide-binding protein G(T) subunit-gamma-T1 (fold change = 0.67), and prefoldin subunit 6 (fold change = 0.58). A high retinal concentration of bevacizumab was achieved within 15 days. Changes in the additional proteins were limited, suggesting a narrow mechanism of action.

Management of macular oedema due to retinal vein occlusion: An evidence-based systematic review and meta-analysis

BACKGROUND

Central retinal vein occlusion and branch retinal vein occlusion are common causes of visual loss due to associated macular oedema. The aim of this review was to assess the effectiveness of interventions improving vision and treating macular oedema in central retinal vein occlusion and branch retinal vein occlusion.

METHODS

Medical search engines and clinical trial registries were systematically searched. Randomised clinical trials with ≥90 eyes and real-world outcome studies with ≥100 eyes each with ≥6 months follow-up were included.

RESULTS

There were 11 randomised controlled trials evaluating treatments for central retinal vein occlusion which met the inclusion criteria and 10 for branch retinal vein occlusion. There were 10 real world outcome studies of central retinal vein occlusion and 5 real world outcome studies of branch retinal vein occlusion. Meta-analysis was performed on studies that met the defined inclusion criteria. Main outcomes were change in visual acuity at 6-, 12-, 24- and 36 months by treatment.

CONCLUSIONS

Intravitreal anti-vascular endothelial derived growth factor is recommended as first line treatment over intravitreal corticosteroid due to its effectiveness and lower rate of ocular adverse events. Best outcomes are achieved when intravitreal treatment is started early. Macular laser may have an adjunctive role in branch retina vein occlusion but not central retinal vein occlusion.

Retinal vein occlusion. Audit of a specialized care program

BACKGROUND AND OBJECTIVES

Retinal vein occlusion (RVO) is the second most frequent cause of retinal vascular disease and is related to classic cardiovascular risk factors. A specific program was designed to detect and treat risk factors in patients with RVO. The aim of this study is to audit the results of this program.

PATIENTS AND METHODS

The program consisted of a multidisciplinary clinical evaluation by the Ophthalmology and Internal Medicine Departments. All patients with RVO were screened, at minimum, for hypertension, diabetes, dyslipidemia, smoking, overweight, and antiphospholipid syndrome. New risk factors or poor control of known risk factors were expected to be found in at least one-third of the patients. Among them, therapeutic measures were expected to be taken in at least two-thirds. A dissociated automated search of the data of all patients who entered the program between April 2021 and April 2022 was performed.

RESULTS

Fifty-six patients were included for analysis. Of these, 39 (69.6%) had at least one new or poorly controlled risk factor and 43 (76.8%) had their treatment modified in some way. Antiphospholipid syndrome was detected in five (8.9%). Only one patient had low-risk hereditary thrombophilia. After an exhaustive examination, no risk factors were found in 11 patients.

CONCLUSION

This specific program has been effective in detecting new or poorly controlled risk factors and improving their treatment.

Effect of Conbercept Treatment on Macular Edema and Microvascular Structure in Eyes with Retinal Vein Occlusions

Objective

Methods

Results

Conclusion

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.

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.

Aqueous humor inflammatory cytokine levels and choroidal thickness in patients with macular edema associated with branch retinal vein occlusion

PURPOSE

We aimed to investigate the association between subfoveal choroidal thickness (SCT) and the level of aqueous humor (AH) inflammatory cytokines in patients with macular edema (ME) associated with branch retinal vein occlusion (BRVO).

METHODS

Twenty-eight eyes of 28 BRVO ME patients who underwent intravitreal injection treatment (ranibizumab, bevacizumab, or dexamethasone implant) were prospectively recruited. The concentrations of vascular endothelial growth factor (VEGF)-A and inflammatory cytokines were measured from AH samples. We analyzed clinical factors associated with visual gain or the degree of central macular thickness (CMT) decrease and the association between SCT and inflammatory cytokine levels.

RESULTS

On multiple linear regression analysis, the AH interleukin (IL)-8 level was significantly associated with visual gain and CMT reduction at 6 months. Age, systemic hypertension, and AH monocyte chemo-attractant protein 1 level showed a significant association with baseline SCT, and VEGF-A showed a significant association with baseline SCT ratio (BRVO eye SCT/fellow eye SCT). Those with thick SCT showed a higher level of AH soluble VEGF receptors 2 and IL-8 and showed better visual gain and greater CMT reduction at 2 and 6 months compared to the thin SCT group.

CONCLUSIONS

The level of AH inflammatory cytokines was significantly associated with the ischemic status of the retina, treatment outcomes, and SCT in BRVO ME patients. Thick baseline SCT might be a predictive sign for better treatment outcomes in BRVO ME patients which are thought to be related to a higher level of intraocular inflammatory cytokines in these patients.

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.

Retinal vascular occlusions

Acute retinal vascular occlusions are common causes of visual impairment. Although both retinal artery occlusions and retinal vein occlusions are associated with increased age and cardiovascular risk factors, their pathophysiology, systemic implications, and management differ substantially. Acute management of retinal artery occlusions involves a multidisciplinary approach including neurologists with stroke expertise, whereas treatment of retinal vein occlusions is provided by ophthalmologists. Optimisation of systemic risk factors by patients' primary care providers is an important component of the management of these two disorders.

Prevalence and associations of non-retinopathy ocular conditions among older Australians with self-reported diabetes: The National Eye Health Survey

AIM

To determine the prevalence and associations of non-retinopathy ocular conditions among older Australian adults with diabetes.

METHODS

Multistage random-cluster sampling was used to select 3098 non-indigenous Australians aged 50y or older (46.4% male) and 1738 indigenous Australians aged 40y or older (41.1% male) from all levels of geographic remoteness in Australia. Participants underwent a standardised questionnaire to ascertain diabetes history, and a clinical examination to identify eye disease. We determined the prevalence of uncorrected refractive error, visually significant cataract, cataract surgery, age-related macular degeneration, glaucoma, ocular hypertension, retinal vein occlusion and epiretinal membrane among those with and without self-reported diabetes.

RESULTS

Participants with self-reported diabetes had a higher prevalence of cataract surgery than those without diabetes (28.8% vs 16.9%, OR 1.78, 95%CI: 1.35-2.34 among non-indigenous Australians, and 11.3% vs 5.2%, OR 1.62, 95%CI: 1.22-2.14 among indigenous Australians). Diabetic retinopathy (DR) increased the odds of cataract surgery among self-reported diabetic indigenous and non-indigenous Australians (OR 1.89, P=0.004 and OR 2.33, P<0.001 respectively). Having diabetes for ≥20y and having vision-threatening DR increased the odds of cataract surgery among indigenous Australians with diabetes (OR 3.73, P=0.001 and 7.58, P<0.001, respectively).

CONCLUSION

Most non-retinopathy ocular conditions are not associated with self-reported diabetes. However, to account for Australia's worsening diabetes epidemic, interventions to reduce the impact of diabetes-related blindness should include increased cataract surgery services.

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

Background

Retinal vein occlusion (RVO) is the second most common retinal vascular disorder that affected 16.4 million people worldwide in 2008. The last decade has seen new epidemiological data on RVO, enabling us to provide a contemporary estimation of RVO epidemiology.

Methods

We searched PubMed, Medline, Embase, GLOBAL HEALTH, World Health Organization Global Health Library, China National Knowledge Infrastructure for studies that reported prevalence or incidence of RVO in the general population. The age- and sex-specific prevalence of RVO was estimated by a multilevel mixed-effects logistic regression, the incidence of RVO and potential risk factors for RVO were respectively pooled by a random-effects meta-analysis.

Results

The prevalence of any RVO, branch RVO (BRVO) and central RVO (CRVO) all increased with advanced age, but didn’t differ significantly between sexes. In 2015, the global prevalence of any RVO, BRVO and CRVO in people aged 30-89 years was 0.77% (95% confidence interval CI = 0.55-1.08), 0.64% (95% CI = 0.47-0.87) and 0.13% (95% CI = 0.08-0.21), equivalent to an overall of 28.06 million, 23.38 million and 4.67 million affected people. For any RVO, the pooled five-year cumulative incidence was 0.86% (95% CI = 0.70-1.07) and the pooled ten-year cumulative incidence was 1.63% (95% CI = 1.38-1.92). Hypertension was the strongest risk factor for any RVO, with a meta- odds ratio (OR) of 2.82 (95% CI = 2.12-3.75).

Conclusions

This study provides an updated summary of RVO epidemiology in the general population. More epidemiological studies worldwide are still needed to better understand the global disease burden of RVO.

Short-term effect of intravitreal conbercept injection on major and macular branch retinal vein occlusion

OBJECTIVE

To evaluate the effectiveness of intravitreal conbercept injection on major and macular branch retinal vein occlusion (BRVO).

METHODS

This retrospective analysis involved 43 patients with BRVO (major BRVO n = 24; macular BRVO, n = 19) who were diagnosed by fluorescein fundus angiography (FFA) and injected with intravitreal conbercept. The following outcomes were measured at baseline and follow-up (1-6 months): best-corrected visual acuity (BCVA), central foveal thickness (CFT), total retinal volume in a 6-mm diameter section of the macula, choroidal thickness under the central fovea of the macula, relative area of retinal hemorrhage, complications, and times when repeated injection was performed.

RESULTS

There were significant differences between the two groups in terms of BCVA, CFT, and total retinal volume in a 6-mm diameter section of the macula at 6 months after treatment. Choroidal thickness under the central fovea of the macula and relative area of retinal hemorrhage showed no significant differences between the two groups at 6 months after treatment; however, they significantly differed from baseline measurements.

CONCLUSION

In general, intravitreal injection of conbercept may have a better short-term effect in patients with macular BRVO than in patients with major BRVO.