This story is part of a series on the current progression in Regenerative Medicine. This piece is part of a series dedicated to the eye and improvements in restoring vision.
In 1999, I defined regenerative medicine as the collection of interventions that restore tissues and organs damaged by disease, injured by trauma, or worn by time to normal function. I include a full spectrum of chemical, gene, and protein-based medicines, cell-based therapies, and biomechanical interventions that achieve that goal.
A new study published in the journal Headache sheds light on the link between migraines and the eye, revealing new potential biomarkers for this complex condition. If you are one of the more than one billion people who suffer from migraines, you know they can come with a variety of sensations and pains. If you don’t live with migraines, imagine this.
You’re sitting at your desk, your eyes glued to the computer screen, and you feel a strange sensation creeping up on you. Suddenly, your vision becomes fuzzy and distorted, and despite your best efforts, the sensation persists.
In disbelief, you watch flashing lights and zigzag patterns dance before your eyes, accompanied by a tingling sensation that spreads across your face and hands. The aura envelopes you, making it hard to focus on your work. You realize this is a migraine aura, a warning sign that an overwhelming headache may be coming.
Migraines can be debilitating, affecting approximately 12% of the population globally. Intense headaches often characterize them but can cause visual disturbances, such as flashing lights or blurry vision. A lesser-known aspect of migraines is their potential impact on the retina, the thin layer of tissue that lines the back of the eye.
Exploring Migraine Mechanisms
Over the years, multiple theories have been proposed to explain the mechanisms underlying this debilitating condition. One of the most well-accepted hypotheses is the neurovascular theory, which proposes that both neural and vascular components interact to trigger a migraine attack. The theory suggests that an initial neuronal event within the brain leads to a cascade of events culminating in a neurovascular headache.
Another theory that holds considerable clout is the neurogenic theory, which maintains that migraines are primarily a neurogenic process with secondary changes in cerebral perfusion. This robust theory suggests that neuronal hyperexcitability, neurogenic inflammation, and neurovascular disorders all play a role in the development and maintenance of migraines.
While still theoretical, emerging research investigating the molecular and genetic bases of migraines may, in time, provide us with even more insights into the complex physiological mechanisms underlying this enigmatic and enervating condition. For now, it’s essential to explore the types of migraine and how we can “see” them in the retina.
Types of Migraines
Migraines are a type of headache that can be debilitating and affect people’s quality of life. They are classified into two main types: migraines with and without aura. An aura is a sensory experience that precedes or accompanies a migraine episode and can manifest differently in different people.
Visual auras are the most common type of aura experienced by people with migraines. These can include seeing flashing lights, zigzag patterns, or blind spots in their vision. Some people may see bright lines or spots that move across their field of vision. Visual auras can last for several minutes to an hour and can be followed by a headache.
Types of Migraine Auras
Various types of auras can cause sensory disturbances such as tingling or numbness in the face or hands. This sensation can be similar to pins and needles or an electric shock. During an aura, some individuals may experience difficulty speaking or expressing themselves. They may also have trouble remembering words or names. Migraines associated with these symptoms are commonly referred to as hemiplegic migraines.
It’s important to note that not everyone with migraines experiences auras. However, for those who do, they can be a helpful warning sign that a headache is on its way.
Migraines and the Retina
The relationship between migraines and the retina has been a research topic for several years, with evidence pointing to reduced blood flow and abnormal vascular function in the retina during migraine episodes. However, the traditional methods for studying the retina are limited in their ability to capture these phenomena, leading researchers to explore new imaging technologies such as optical coherence tomography angiography (OCTA).
The study published in Headache used technology called OCTA to look at the tiny blood vessels in the eyes of people who get migraines. They compared people with migraines during and between attacks, as well as healthy people. The study found less blood flow to the retina during migraine attacks. This was true for both migraines, with or without an “aura.”
A Headache-free Comparison
The interictal analysis, performed when the patient is not experiencing a migraine episode, revealed a significant difference in the blood perfusion of the foveal region between patients with migraines with aura and those without aura. The fovea is a small, central retina area that provides sharp and detailed vision.
Visualization of the interictal foveal vessel flux index (VFI) in a representative healthy control (HC), migraine with aura (MA) and migraine without aura (MO) participant.
The study suggests that distinct retinal vascular signatures might be potential biomarkers for migraines. The finding of lower blood perfusion in the foveal region in patients with migraines with aura compared to those without aura suggests that there might be a correlation between this particular region of the retina and the occurrence of migraines with aura.
These findings have important implications for diagnosing and treating migraines, as they suggest that different types of migraines may have distinct physiological characteristics that can be identified through retinal imaging. This could lead to more accurate diagnoses and personalized treatment plans for migraine patients.
Limitations and Significance of the Research
The study’s sample size is small, including only 37 patients with migraines with aura, 30 with migraines without aura, and 20 healthy controls. Regardless of this limitation, the study’s findings are significant, and they have the potential to lead to better diagnosis, treatment, and prevention strategies for migraines. Finding biomarkers to distinguish between migraines and track their progression over time could be a breakthrough. It’s essential to continue research in this direction.
The researchers acknowledge that the mechanisms underlying migraines and their relationship with the retina are not fully understood. However, their study provides new clues and evidence for further exploration. In the future, doctors and researchers can use OCTA to track changes in the retina and adjust treatment plans accordingly. This could lead to a brighter future for those affected by migraines, offering new hope for relief and a better quality of life.
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