Comparative Study of High Performance Low-Cost Optical Coherence Tomography (Stage 1B, 2 and 3)

There is some evidence that certain changes in retinal structures could be an indicator of Alzheimer's disease (AD). We are developing a new technology that combines optical coherence tomography (OCT) and angle-resolved low coherence interferometry (a/LCI) to make light scattering measurements of retinal tissue structure. The first objective of this study is to compare performance characteristics of our custom OCT instrument to a commercial OCT instrument. Once we have optimized our device, the second objective will be to use the custom OCT-a/LCI device to identify retinal structure changes that could be possible AD biomarkers.

For this study, the team will recruit volunteers to attend one study visit that is about 30 minutes long. For arm 1A (registered under NCT05530460), this visit will include examination with our custom OCT instrument, followed by examination with a commercial OCT system. For arms 1B and 2/3, the visit will include examination with the custom OCT-a/LCI instrument.

This study will recruit participants with Alzheimer's disease and healthy controls.

All Participants:

Inclusion criteria

• able to provide informed consent

Exclusion criteria

• potentially confounding ocular conditions, such as: glaucoma, current corneal injury, retinal damage, diabetes, corrected distance visual acuity worse than 20/40
• eyes that have had intraocular surgery or retinal surgery, other than cataract surgery

Participants with Alzheimer's Disease:

Inclusion:

• mild cognitive impairment (MCI) or dementia due to Alzheimer's disease, confirmed by A/T/N classification

Healthy Controls:

Exclusion:

• has a memory or other neurodegenerative diagnosis (including mild cognitive impairment, Parkinson's disease, Alzheimer's disease, traumatic brain injury, post-traumatic stress disorder)

If two eyes satisfy the inclusion / exclusion criteria, both eyes will be included in the study. If only one eye satisfies the criteria, only the qualifying eye will be included in the study.