Retinal Thickness Changes Over Time in a Murine AD Model APP .

Area of Science:

• Ophthalmology
• Neuroscience
• Genetics

Background:

• Alzheimer's disease (AD) may manifest retinal changes preceding brain pathology.
• The retina serves as a potential accessible biomarker for AD.
• Investigating retinal changes in AD models can offer insights into disease progression.

Purpose of the Study:

• To conduct a diachronic study of retinal thickness and retinal nerve fiber layer (RNFL) thickness.
• To compare these retinal parameters in an APP^NL-F/NL-F mouse model of AD with wild-type (WT) animals.
• To analyze changes over time from 6 to 20 months of age.

Main Methods:

• Utilized spectral domain optical coherence tomography (SD-OCT) for retinal imaging.
• Measured total retinal thickness across specific Early Treatment Diabetic Retinopathy Study (ETDRS) sectors.
• Assessed RNFL thickness in six sectors around the optic nerve.

Main Results:

• APP^NL-F/NL-F mice showed significant retinal thinning in various sectors at 6 and 20 months, and thickening in others at 17 months.
• RNFL analysis revealed significant thinning globally and in specific sectors at 6 and 20 months.
• Observed dynamic changes in retinal thickness, including thinning and thickening, throughout the study period.

Conclusions:

• Retinal thickness in the APP^NL-F/NL-F AD model exhibits dynamic changes, suggesting neurodegeneration, deposits, and neuroinflammation.
• These temporal retinal alterations mirror those seen in human AD retinas, supporting their role as potential biomarkers.
• The APP^NL-F/NL-F mouse model is valuable for understanding AD-related retinal pathology progression.