Central Retinal Artery Occlusion Rates in Korea Decreased Over Time, Study Finds

Rates of central retinal artery occlusion (CRAO), which is associated with and shares common risk factors with cardiovascular diseases, have decreased over time in Korea, a recent cohort study of 50 million residents found.

Rates of central retinal artery occlusion (CRAO), which is associated with cardiovascular diseases and shares common risk factors with them, have decreased over time in Korea, a recent cohort study of 50 million residents found.1

CRAO occurs when the main artery delivering blood to nerve cells in the retina becomes blocked, most often by a blood clot or a small piece of cholesterol called an embolus, according to the American Society of Retina Specialists.2 Severe loss of vision is often a result of CRAO, which can be either temporary or permanent.

Given the rates of stroke and ischemic heart disease have dropped in high-income, industrialized countries over several decades, the new study, which was published in JAMA Ophthalmology, aimed to evaluate the trends regarding CRAO in Korea. Researchers utilized data from the Korean National Health Insurance Service from January 2002 to December 2015, identifying individuals who experienced CRAO based on the International Classification of Diseases, 10th Revision CRAO diagnostic code (H34.1).

The main outcomes analyzed in the study were: temporal trends in CRAO rates (measured as cases per 100,000 person-years), and age-standardized annual percentage changes (APCs) in incidence rates using joinpoint and birth cohort analyses.

Of the 50 million residents whose data were used for the study, 9892 people with incident CRAO were identified. Men made up 59.5% of the patients with CRAO, and the mean age at diagnosis in the overall cohort was 62.4 years.

The standard incidence rate in the overall population was a mean of 2 cases per 100,000 person-years (95% CI, 1.97-2.04). In men and women, the rates were 2.43 and 1.61 cases per 100,000 person-years, respectively. The incidence rate of CRAO decreased in the overall study population (APC, -3.46%; 95% CI, -4.3% to -2.6%), in men (APC, -2.90%; 95% CI, -3.9% to -1.9%), and even more so in women (APC, -4.56%; 95% CI, -5.7% to -3.4%) over time.

Patients younger than 65 years old saw a more significant decrease than those 65 years or older ([APC, -6.80%; 95% CI, -8.3% to -5.2%] and [APC, -0.57%; 95% CI, -1.5% to -0.4%], respectively.

Overall, the authors suggest that the decreased rate of CRAO between 2002 and 2015 in the 50 million residents included in the analysis may point to changes in the health care system on the whole. “This observed decrease may be associated with the development of a national health care system and the general improvement in chronic disease management,” they concluded.

References

1. Kim J, Byun SJ, Woo SJ, et al. Assessment of trends in the incidence rates of central retinal artery occlusion in Korea from 2002 to 2015. JAMA Ophthalmol. Published online February 11, 2021. doi:10.1001/jamaophthalmol.2020.6860

2. Retinal Artery Occlusion. American Society of Retina Specialists. 2017. Accessed February 19, 2021. https://www.asrs.org/patients/retinal-diseases/32/retinal-artery-occlusion