A new study has opined that the retina in the eyes of patients suffering from cerebral malaria may help decipher why cerebral malarial infection is so deadly. To quote the words of the study, the retina serve as a "window into the brain".
It is the first study in which Malawi researchers showed that the build-up of infected blood cells in the narrow blood vessels of the brain leads to a potentially lethal lack of oxygen to the brain.
Malaria is one of the world's biggest killers and the majority of deaths occur as a result of cerebral malaria, where red blood cells infected by malaria parasites build up into the brain, leading to coma and convulsions and, if not treated swiftly, death.
For a long time, its known that cerebral malaria is accompanied by changes in the retina, known as malarial retinopathy which can be seen by examining the eye.
Because the retina can be considered as an extension of the central nervous system, it has been used previously as a "window into the brain", enabling swifter diagnosis of cerebral malaria.
But to date, it was not clearly understood why the disease should be so deadly.
In the new study led by Dr Nick Beare of the Royal Liverpool University Hospital, researchers examined the retinas of 34 children admitted to the hospital with cerebral malaria, by using a technique known as fluorescein angiography.
The technique involves injecting a special dye into the arm intravenously and photographing its passage through the blood vessels of the retina. It is used to identify fluid leakage or blockages in the small blood vessels at the back of the eye.
It was found that more than four in five of the children in the study had impaired blood flow in the blood vessels of their eyes.
Three-quarters had whitening to areas of the retina where blood did not appear to reach, implying that the parasites were disrupting the supply of oxygen and nutrients.
"We have previously used the retina to accurately diagnose severe malaria, but now this window into the brain has opened up our knowledge of what makes cerebral malaria so deadly," said Beare.
He added: "This is the first study to clearly show impaired blood flow in the eyes of patients with cerebral malaria. It has provided strong evidence to support what, until now, had been merely hypothesised: that cerebral malaria causes inadequate blood flow to the brain, depriving it of oxygen and causing potentially life-threatening damage."
According to Beare, the new findings point to new therapeutic measures for treating cerebral malaria more effectively, particularly in comatose children.
The study has been published in the Journal of Infectious Diseases.