Retinal Artery Occlusion

  • General Information:
    • Considered to be a form of a stroke with similar clinical approach and management
    • Incidence is low with less than 10 in 100,00
    • Average age is 60-65 with men more commonly affected and RF of HTN, smoking and diabetes
    • Most common etiology is carotid artery atherosclerosis, especially in older patients. Other etiologies common in the elderly include cardioembolic disease, carotid artery dissections, hypercoagulable states and vascultitis
  • Clinical Manifestations:
    • Central retinal artery occlusion and branch retinal artery occlusion present with acute, painless loss of monocular vision
    • Central retinal artery occlusion: acute and profound loss of vision in one eye, often painless, can be preceded by transient monocular blindness or a stuttering, fluctutaing course
    • Branch retinal artery occlusion: acute monocular vision loss that may be restricted to part of the visual field, with less than half of patients having impaired visual acuity
  • Diagnosis:
    • On funduscopic exam with CRAO you will see a “cherry red spot” in the macula with ischemic retinal whitening due to the occlusion +/- retinal emboli.
    • For BRAO there is a sectoral pattern to the retinal opacification +/- retinal emboli.
    • Definitive diagnosis is rarely needed, but can be confirmed with fluorescein angiography
  • Treatment: OCULAR EMERGENCY
    • Can attempt occular massage, anterior chamber paracentesis, mannitol or acetazolamide can reduce IOP, vasodilator medications or hyperbaric oxygen
    • In selected patients, ophtho can do intra-arterial thrombolysis or surgical revascularization

“Hold the burger, pass me the cornmeal and beans…”

In a recent article from Nature Communications published on April 28, 2015, Dr. Stephen J. D. O’keefe and his colleagues conducted an interesting study looking at how diet affects mucosal biomarkers of colon cancer risk. They performed 2-week food exchanges in which African-Americans were fed a traditional African diet of high fiber and low fat and Africans were fed western style diet (high fat and low fiber). Colonoscopies were done and biopsies showed less inflammation of the colon and increased production of butyrate, a fatty acid that is thought to protect from colon cancer, in those who ate the traditional African style diet compared to western. Although no direct correlation of diet and colon cancer risk is stated by the authors, the results suggest that diet can have a profound and rapid effect on mucosa which may affect development of colon cancer. Check out the NY Times article below as well as the abstract and original article from Nature Communications and thanks to Dr. Bedimo for the reference!

African Diet May Lead Away from Colon Cancer (NY Times)

Fat, fibre, and cancer risk in African Americans and rural Africans (Nature Communications)

Abstract

Rates of colon cancer are much higher in African Americans (65:100,000) than in rural South Africans (5:100,000). The higher rates are associated with higher animal protein and fat, and lower fibre consumption, higher colonic secondary bile acids, lower colonic short-chain fatty acid quantities and higher mucosal proliferative biomarkers of cancer risk in otherwise healthy middle-aged volunteers. Here we investigate further the role of fat and fibre in this association. We performed 2-week food exchanges in subjects from the same populations, where African Americans were fed a high-fibre, low-fat African-style diet and rural Africans a high-fat, low-fibre western-style diet, under close supervision. In comparison with their usual diets, the food changes resulted in remarkable reciprocal changes in mucosal biomarkers of cancer risk and in aspects of the microbiota and metabolome known to affect cancer risk, best illustrated by increased saccharolytic fermentation and butyrogenesis, and suppressed secondary bile acid synthesis in the African Americans.

Liberia is declared Ebola free

The World Health Organization announces the end of Ebola in Liberia, but the epidemic continues in nearby Sierra Leone and Guinea.

By Declan Butler & Erika Check Hayden

Liberia is the first of three main countries affected by Ebola to be free of the disease, the World Health Organization said today, marking the end of the 15-month-long epidemic in the country. But the epidemic continues in nearby Sierra Leone and Guinea, and the WHO is warning against complacency, highlighting the risk of further flare ups and geographical spread.

The last person in Liberia known to be infected with the disease died on 27 March and was buried the following day. That means that as of today, 42 days have elapsed since the burial — the delay that the WHO uses to declare a country Ebola-free and twice the maximum incubation period for the disease.

Data suggest that an end to the epidemic across West Africa is also in sight. In the week up to 3 May, Guinea and Sierra Leone each reported just nine new cases — a far cry from the later months of last year, when the epidemic was peaking and hundreds of cases were being reported every week.

Ebola is also more geographically contained now. Back then it was a widespread disease that raged like a forest fire. Now it consists a few burning embers confined to the Forécariah prefecture in western Guinea, the neighbouring district of Kambia in Sierra Leone, and a region around Sierra Leone’s capital, Freetown.

But there are reasons for caution. Forécariah itself is a large district, and borders between countries in the region are porous, meaning that there is always a risk that an infected person might travel and spark new outbreaks elsewhere. With the rainy season underway, outbreaks in more remote regions could prove difficult to control as dirt tracks — often the only means of access — are transformed into muddy swamps.

There is an urgent need to learn from the mistakes and weaknesses that Ebola exposed. Bruce Aylward, who leads the WHO’s Ebola response, recently remarked: “Ebola was not an exception. Ebola is a precedent.” Panjabi, for example, highlights the need to remove “blindspots” in rural healthcare. If professionally trained and supported healthcare workers had been stationed in remote villages throughout Guinea, Liberia and Sierra Leone, he says, when the first patients grew sick, they could have sounded the alarm before a small outbreak became a global crisis. “We may have stopped the hotspots,” he says, “but the blind spots – remote villages with little or no access to healthcare – still exist.”

Nature | doi:10.1038/nature.2015.17513