In a study reported in the American Heart Association journal Hypertension, researchers said retinal imaging may someday help assess if you’re more likely to develop a stroke.”The retina provides information on the status of blood vessels in the brain,”. Worldwide, high blood pressure is the single most important risk factor for stroke. However, it’s still not possible to predict which high blood pressure patients are most likely to develop a stroke.Even in patients on medication and achieving good blood pressure control, the risk of a blood clot was 96 percent higher in those with mild hypertensive retinopathy and 198 percent higher in those with moderate or severe hypertensive retinopathy.
Visual symptoms and abnormalities occur at high rates in people with traumatic brain injury (TBI).
Vision-related symptoms, including difficulty reading, light sensitivity, more likely to have problems related to eye movement (saccadic dysfunction), blurred vision caused by focusing problems (accommodative dysfunction) and problems moving the eyes together to focus on near objects (convergence insufficiency).The high rate of visual problems occurred even though most patients had normal visual acuity.
Retina thinning may reveal how rapidly multiple sclerosis is progressing, researchers from Johns Hopkins MS Center reported in the journalNeurology. The scientists explained that they referred to the thinning of “a layer of the retina in the eyes”.
Sticky plaques of proteins called amyloids mark several different, though related degenerative brain diseases including Alzheimer’s, Parkinson’s and Creutzfeld-Jacobs. The symptoms of these disorders overlap and methods to diagnose and monitor them are not very advanced.
To solve this problem, scientists at the University of California, San Diego, have devised several new fluorescent probes that change color depending on what type of amyloid they encounter. Because amyloids accumulate in the eye as well as the brain, their discovery offers hope that one day neurodegenerative diseases could be differentially diagnosed with simple eye drops or ointment and an eye exam.
Visual impairment in extremely preterm children is mainly due to Retinopathy Of Prematurity (ROP), although cerebral damage, often referred to as cerebral visual impairment, can also be a cause amongst those born extremely premature.
Our brains process many more stimuli than we become aware of. Often images enter our brain without being noticed: visual information is being processed, but does not reach consciousness, that is, we do not have an impression of it. Then, what is the difference between conscious and unconscious perception, and can both forms of perception be changed through practice? These questions are important not only for basic research, but also for the treatment of patients with perceptual deficits due to brain lesions e.g. following a stroke. Scientists at the MPI for Brain Research in Frankfurt/Main could now show that seeing can be trained. Today, we know that the processing of stimuli in the cortex remains extremely plastic, or malleable, even in adults
Experiments have shown that the neuronal processes that underlie conscious perception are very flexible,” Schwiedrzik concludes. The findings provide important insights for medical applications, in particular for the rehabilitation of people suffering from perceptual deficits caused by brain lesions.
It has long been thought that blindness after brain lesions is irreversible and that damage to the optic nerves leads to permanent impairments in everyday activities such as reading, driving, and spatial orientation. A new study published in Elsevier’sBrain Stimulation suggests that treating such patients with low levels of non-invasive, repetitive, transorbital alternating current stimulation (rtACS) for 10 days (30-40 min per day) significantly reduces visual impairment and markedly improves vision-related quality of life.
The authors reported eye exam findings in seven astronauts as well as an analysis of post-flight questionnaires regarding in-flight vision changes in approximately 300 additional astronauts. The seven astronauts with ocular anomalies had returned from long-duration space missions to the International Space Station (ISS) and all seven subjects had undergone complete eye examinations, including dilated exams and photographs of the back of the eye. Several had MRI scans, spinal taps, and computerized analysis of their optic nerve. After 6 months of space flight, all 7 astronauts had eye findings, including swollen optic nerves, distortion of the shape of the eyeball, and retinal changes. Most became more farsighted, and had blurred vision, especially at near. The spinal taps showed either top normal or slightly elevated pressures in the spinal fluid surrounding the brain and optic nerves.
The 300 post-flight questionnaires documented that approximately 29% and 60% of astronauts on short and long-duration missions, respectively, experienced a worsening of distance or near visual acuity. Some of these vision changes remain unresolved years after flight. The authors theorized that changes may have resulted from fluid shifts brought about by prolonged exposure to low gravity. The findings might represent parts of a spectrum of ocular and brain responses to extended exposure to low gravity. Future research is ongoing for astronauts entering new missions.
When we gaze at a shape and then the shape disappears, a strange thing happens: We see an afterimage in the complementary color. Now a Japanese study has observed for the first time an equally strange illusion: The afterimage appears in a “complementary” shape – circles as hexagons, and vice-versa.
“The finding suggests that the afterimage is formed in the brain, not in the eye,” the author, Hiroyuki Ito of Kyushu University, wrote in an email. More specifically, the illusion is produced in the brain’s shape-processing visual cortex, not the eye’s light-receiving, message-sending retina. The findings appear in an upcoming issue ofPsychological Science, a journal published by the Association for Psychological Science.