The eyes as a window to the brain – ophthalmology in the early diagnosis of neurodegenerative diseases

For years, we have been saying that “the eyes are the mirror of the soul.” In 2025, we can say something more—the eyes are the mirror of the brain.
 
Modern ophthalmology is beginning to play an important role in the detection of diseases such as Alzheimer's, Parkinson's, multiple sclerosis, and diabetic neuropathy.

What exactly can be seen in the eye?

  • Changes in the thickness of the retinal ganglion cell layer (OCT) may suggest neurodegenerative changes in the brain before the first clinical symptoms appear.
  • Imaging studies of blood vessels in the retina (OCT-A) show microcirculation that strongly correlates with cerebral microcirculation.
  • Eye movement disorders or delays in tracking movement may be an early sign of neurological disorders.

 Alzheimer's “diagnosed” in the retina?

More and more studies confirm that the accumulation of beta-amyloid proteins—characteristic of Alzheimer's disease—can be seen in the structures of the retina even several years before the onset of memory loss symptoms.

What does this mean for the patient?

A single OCT or OCT-A examination is enough to obtain an initial indication that something is happening in the nervous system.

It is a non-invasive, quick, and widely available test that can help a family doctor or neurologist decide on further diagnostics.

Ophthalmologists and optometrists – new partners in neurology?

Yes. In the coming years, the role of eye care specialists will grow not only in the context of correcting vision defects, but also in the prevention of brain diseases.

This is a great opportunity, but also a responsibility – we must educate both doctors and patients that an eye exam is more than just selecting lenses.

Conclusion?

Vision is not just about the eyes. It is an extension of the brain. That is why every eye exam should be treated as an opportunity for early health intervention.

 Does your practice offer OCT as standard? Do you inform patients that when we look into their eyes, we are also looking at their nervous system?

Share your opinion — maybe together we can push the boundaries of prevention.

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