A potential pathway for managing diabetic patients with arterial emboli detected by retinal screening

Systematic review of the relationship between Hollenhorst plaques and cerebrovascular events

BACKGROUND

Few studies have evaluated the association between asymptomatic cholesterol emboli on fundoscopy (known as Hollenhorst plaque) and the subsequent risk of stroke or death.¹.

AIM

To evaluate the association between the presence of asymptomatic cholesterol retinal emboli and the risk of cerebrovascular events, with assessment of the need for carotid intervention.

METHODS

PubMed, Embase, and Cochrane Library databases were searched using appropriate terms. The systematic review was conducted according to PRISMA guidelines.

RESULTS

Initial search revealed 43 in Medline and 46 in Embase databases. Twenty-four potentially eligible studies were included after duplicate and non-related studies were excluded based on title and abstract. Three more studies were identified from reference lists. Seventeen studies were included in the final analysis. Asymptomatic cholesterol emboli were present in 1343 patients. Approximately 17.8% (n = 181) had history of either cerebro-vascular Accident (CVA) or transient ischaemic attacks (TIAs) at presentation (more than 6 months). Nine studies mentioned the incidence of cerebrovascular events during follow-up. Of 780 patients, 93 evolved to stroke, TIAs, or death from a major carotid event during the follow-up period (6-86 m), an incidence of about 12%. Death due to stroke was documented in 3 studies (n = 12).

CONCLUSION

The presence of asymptomatic retinal emboli indicates a risk of a cerebrovascular event when compared to patients with no plaques seen on fundoscopy. The evidence suggests that these patients warrant referral for medical optimization of cardiovascular risk factors. Currently, there is no recommendation to support carotid endarterectomy in patients with Hollenhorst plaques, or retinal emboli, and further studies are needed to assess this.

Asymptomatic retinal emboli and current practice guidelines: a review

Asymptomatic retinal emboli are found in 1-3% of patients on routine fundus examination. As the use of teleretinal imaging for diabetic patients and ocular photography continues to increase, the number of asymptomatic retinal emboli found will also increase. This article will discuss the different aetiologies of retinal emboli and will present an overview of the recommended referrals for further systemic testing and treatment. It is important to communicate well with the primary care physician when asymptomatic retinal emboli are detected to ensure the appropriate investigations are undertaken.

Arterial Occlusions to the Eye: From Retinal Emboli to Ocular Ischemic Syndrome

: Abstract: A loss or lack of blood supply to the eye can result in acute loss of vision. The site of ischemia may be at the level of the retinal arterioles, the central retinal artery, or further back at the ophthalmic and internal carotid artery. Recognizing the symptoms and signs are important to help prevent permanent ischemic and irreversible blindness. The objective of this review article is to provide the general ophthalmologists with information on how to recognize the symptoms and to best manage these patients. The management is to investigate for the cause of the transient monocular visual loss and to apply secondary prevention to address atherosclerotic risk factors to prevent further ischemic events like a stroke.

Prevalence of Retinal Emboli and Acute Retinal Artery Occlusion in Acute Ischemic Stroke

OBJECTIVE

In population-based studies asymptomatic retinal emboli occur in .32%-2.9% of people. Retinal artery occlusion (RAO) may occur concurrently with cerebral stroke but the frequency is unknown. No study has examined how commonly retinal emboli occur in the acute stroke population. We aimed to assess the prevalence of retinal emboli and RAO at the time of carotid territory ischemic stroke.

METHODS

Patients were enrolled prospectively after onset of symptoms consistent with the diagnosis of carotid territory ischemic stroke. Every participant underwent pharmacologic dilation of both pupils and bedside funduscopic examination. Emboli were classified as cholesterol, calcific, platelet/fibrin, or other and categorized by the side of occurrence. Stroke was classified as atheroembolic, cardioembolic, embolic stroke of undetermined source, lacunar, or other. Acute RAO was diagnosed by direct visualization of ischemic retinal whitening.

RESULTS

Sixty-five patients were enrolled with a mean age of 59.2 years; 23 were female (35.4%). Eleven of 65 subjects (16.9%) had retinal emboli visible on funduscopy; all were cholesterol emboli except a single platelet/fibrin embolus in a patient with atheroembolic source. Six patients (9%) had acute RAO and no RAO was seen in the lacunar or undetermined source subgroups.

CONCLUSIONS

Retinal emboli occurred more than 10 times more frequently in the acute stroke patient than in large population-based studies. RAOs also occurred concurrently with ischemic stroke. Although emboli were seen in patients with atheroembolic and cardioembolic sources, all patients with carotid disease had emboli in the ipsilateral eye. Future studies are required to determine if the presence of retinal emboli or RAO may help elucidate an etiology in patients suffering from embolic stroke of undetermined source.

Prevalence and Associations of Retinal Emboli With Ethnicity, Stroke, and Renal Disease in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Disease Study

Importance

To our knowledge, population-based data on retinal emboli are limited in Asia. Besides its associations with traditional cardiovascular risk factors and stroke, associations between retinal emboli and renal disease and function remain unclear.

Objective

To examine the prevalence of and risk factors for retinal emboli in a large, contemporary, multiethnic Asian population.

Design, Setting, and Participants

This population-based cross-sectional study was conducted from 2004 to 2011 and included a total of 10 033 Chinese, Malay, and Indian persons aged 40 to 80 years residing in the general communities of Singapore. Analyses were performed from November 2016 to February 2017.

Interventions or Exposures

Retinal emboli were ascertained from retinal photographs obtained from both eyes of all participants according to a standardized protocol. Age-standardized prevalence of retinal emboli was calculated using the 2010 Singapore adult population. Risk factors were assessed from comprehensive systemic and ophthalmic examinations, interviews, and laboratory investigations.

Main Outcomes and Measures

Retinal emboli.

Results

Of the 10 033 participants, 9978 (99.5%) had gradable retinal photographs. Of these, 5057 (50.7%) were female, and 3375 (33.8%) were Indian. We identified 88 individuals (0.9%) with retinal emboli; the overall person-specific, age-standardized prevalence of retinal emboli was 0.75% (95% CI, 0.60-0.95), with the highest prevalence seen in the Indian cohort (0.98%), followed by the Chinese (0.73%) and Malay (0.44%) cohorts (P = .03). In multivariable-adjusted analysis, factors associated with prevalent retinal emboli included older age (per 5-year increase; odds ratio [OR], 1.22; 95% CI, 1.05-1.41), Indian ethnicity (compared with Malay ethnicity; OR, 3.58; 95% CI, 1.95-6.60), hypertension (OR, 1.95; 95% CI, 1.03-3.70), chronic kidney disease (OR, 2.05; 95% CI, 1.15-3.64), creatinine level (per SD increase; OR, 1.13; 95% CI, 1.05-1.21), glomerular filtration rate (per SD increase; OR, 0.67; 95% CI, 0.51-0.86), and history of stroke (OR, 3.45; 95% CI, 1.70-6.99).

Conclusions and Relevance

Based on 88 individuals among 9978 participants of 3 major Asian ethnic populations, retinal emboli were most commonly seen in Indian persons and associated with conventional cardiovascular risk factors, stroke, and chronic kidney disease. Therefore, its presence may signal vascular embolic event and damage not only in the brain but also in the kidneys. If these data are confirmed in longitudinal studies, they would suggest that persons with retinal emboli may require both general cardiovascular and renal assessment.

Assessing Patients with Asymptomatic Retinal Emboli Detected at Retinal Screening

Introduction

Asymptomatic retinal emboli have been associated with diabetes, the presence of significant carotid artery stenosis (≥70%) and an increased risk of stroke. However, there is no clear guidance on how best to investigate and manage patients found to have asymptomatic retinal emboli. Therefore, this study aimed to assess the incidence of significant carotid artery stenosis in patients found to have asymptomatic retinal emboli at diabetic retinopathy screening, and to examine disease management approaches among these patients.

Methods

Patients with new retinal emboli visible at diabetic retinopathy screening were referred to a medical retinopathy clinic and underwent examinations according to a standardized protocol, including carotid Doppler ultrasound and echocardiography. Case notes of patients referred between January 2013 and April 2014 were reviewed. Results of investigations, medication changes and the number of patients who underwent relevant surgical interventions were noted.

Results

Retinal emboli were present in 44 of 13,643 people screened (0.32%). Full data were available for 39 patients. Twenty-two patients (56%) had relevant medication changes. Nine (23%) patients had significant carotid artery stenosis. One underwent carotid endarterectomy, and eight received maximal medical therapy.

Conclusion

Significant carotid artery stenosis was not uncommon in patients with incident retinal emboli at retinal screening. The referral and investigation protocols identified individuals at risk of cerebrovascular events and led to optimized management. Pathways utilizing Doppler ultrasound and physician referral should be more widely implemented.

Retinal emboli

Retinal emboli are opacities identified in retinal arterioles and are often incidental findings on ophthalmic examination. They are generally composed of cholesterol, platelet-fibrin, or calcium and are thought to arise from carotid arteries, coronary arteries, or cardiac valves. In the general population, the estimated prevalence is 0.2% to 1.3%, and the estimated incidence is 0.9% to 2.9%. The transient nature of retinal emboli likely explains the variations between and within these reported figures. The strongest risk factor for retinal emboli is smoking, which has been reported consistently across many studies. Other likely risk factors include older age, hypertension, male sex, total cholesterol, coronary artery disease, and history of coronary artery bypass grafting. The presence of multiple risk factors, as is common in many patients, confers a higher risk for retinal emboli. Several studies suggest that retinal emboli predict an increase in stroke-related, all-cause, and possibly cardiovascular mortality. Due to these sequelae, patients often undergo further workup, most commonly carotid ultrasonography. However, given the low prevalence of significant carotid disease in patients with retinal emboli, further workup, such as carotid ultrasound, should be reserved for those with risk factors for carotid disease. All patients would benefit from medical optimization and coordinated care with the primary care physician.

Screening for diabetic retinopathy and diabetic macular edema in the United Kingdom

Despite advances in screening for and treatment of diabetes, diabetic retinopathy and maculopathy are still major causes of visual loss around the world. Systematic screening programs for diabetic eye disease have been developed in many countries. The main aim of these services is to reduce diabetes-related blindness and ease the burden of illness on the patients and their families. In the United Kingdom (UK), the NHS Diabetic Eye Screening Program offers annual digital fundus photography for all patients with diabetes over the age of 12 years regardless of their socio-economic status or ethnicity. In 2010-2011 a nationwide uptake of 79% was achieved. If disease is identified, referral to a specialized eye unit for further assessment and treatment are organized to take place within a pre-specified time frame. Internal and external quality assurance ensures efficacy and safety. This paper aims to summarize the current situation of diabetic retinopathy screening in the UK and outlines the challenges ahead.