Are there specific retinal changes seen in frontotemporal dementia patients?

Frontotemporal dementia (FTD) is a brain disorder that damages the frontal and temporal lobes, causing changes in behavior, personality, and language. Because the eye and the brain grow from the same early tissue, researchers have looked at whether the retina (the light-sensing layer at the back of the eye) shows measurable changes in people with FTD. The short answer is yes: several studies find that certain retinal layers are thinner in FTD, and these changes can be seen with non-invasive eye scans. However, the same changes also appear in other brain diseases, so they are not yet a stand-alone test for FTD.

What the research says

A systematic review and meta-analysis pooled data from ten studies and found that people with FTD had significantly thinner retinal nerve fiber layer (RNFL) than people with Alzheimer disease ³. RNFL is a layer of nerve fibers that carry signals from the eye to the brain. Compared with healthy controls, people with FTD also had a significantly thinner ganglion cell layer-inner plexiform layer (GCL-IPL), a deeper retinal layer that contains the cell bodies of those nerve fibers ³. When researchers combined several retinal measures into one pooled analysis, the overall difference was not statistically significant, which suggests that some retinal layers are more informative than others ³.

A separate literature overview reached a similar conclusion: using a scan called optical coherence tomography angiography (OCT-A), researchers saw reduced RNFL and ganglion cell layer (GCL) thickness in FTD, as well as in Alzheimer disease, vascular dementia, amyotrophic lateral sclerosis, multiple sclerosis, and Parkinson disease ⁶. That same review noted an enlarged foveal avascular zone (the small central area of the retina that lacks blood vessels) in these conditions ⁶. Importantly, the review concluded that so far these retinal changes could not be specifically assigned to one particular form of dementia ⁶. In other words, the retina changes in FTD, but it also changes in other neurodegenerative diseases.

Laboratory work supports the idea that FTD-related proteins affect the retina. In a mouse model carrying a mutant form of TDP-43, a protein that builds up in most FTD cases, researchers found impaired retinal electrical responses in young female mice at 3 to 4 months of age, well before brain symptoms appeared at 8 months ⁸. The same study found changes in mitochondrial regulators only in the retinas of the affected mice ⁸. This is animal research, so it does not prove the same timing happens in people, but it points to the retina as an early site of FTD-related damage.

Other research has looked at blood proteins rather than the eye. A plasma proteomics study found 370 proteins with different expression levels in people with FTD compared with controls, reflecting processes like gliosis (scarring by support cells in the brain), synaptic dysfunction, immune activation, and metabolism ⁴. This is not a retinal finding, but it shows that FTD leaves measurable biological traces outside the brain. A broader review on diabetes and neurological disorders also lists FTD among conditions where metabolic factors may modify risk and phenotype, though it does not report retinal data ².

What to ask your doctor

• Would an optical coherence tomography (OCT) or OCT angiography scan be useful in my situation, and what would it add to my current evaluation?
• If my retinal scan shows thinning of the nerve fiber layer or ganglion cell layer, how specific is that finding for FTD versus other conditions?
• Are there any retinal findings that could help distinguish FTD from Alzheimer disease or other dementias in my case?
• Should I see an eye specialist (ophthalmologist or neuro-ophthalmologist) as part of my dementia workup?
• How often should retinal imaging be repeated, if at all, to track changes over time?