Quantifying the influence of optical coherence tomography beam tilt in the normal adult mouse retina

Parallel microstructures within the retina – like retinal nerve fiber layer (RNFL) axons – differentially reflect light depending on its angle. This effect has previously been observed with optical coherence tomography (OCT), but it is under-studied. Quantification of this effect might provide useful information about retinal microstructures, and therefore the broader health of the retina. Our goal was to quantify the influence OCT beam tilt on reflectivity of each layer of the normal adult mouse retina., Using a Bioptigen Envisu UHR2200 system, we collected OCT images of twenty-seven healthy control mouse retinas (from fifteen mice). Images included the optic nerve head, the temporal retina, and the nasal retina. We converted signal intensities to estimated attenuation coefficients (eAC) for further processing.  Each retina was imaged multiple times with various beam tilts. eAC was measured at beam tilts in the range of ±30° (where 0° would be the most standard acquisition, where the beam is perpendicular to the surface of the retina). Images had a nominal resolution of 1.4 µm × 1.4 µm. Retinas were digitally linearized and spatially normalized to facilitate averaging and data aggregation across mice. This repository includes all retinal images processed for the associated publication. For three of the retinas, we also provide R code (r-project.org) and images from intermediate processing steps., , # Quantifying the influence of optical coherence tomography beam tilt in the normal adult mouse retina.

[https://doi.org/10.5061/dryad.95x69p8th](https://doi.org/10.5061/dryad.95x69p8th)

## Description of the data and file structure

In optical coherence tomography (OCT), the angle of the beam influences the apparent reflectivity of the retina. The relationship between beam tilt and reflectivity has been characterized in some layers of the mouse retina. We sought to characterize that relationship for all layers of the retina. To this end, we collected multiple OCT images at varying beam tilts from fifteen (15) adult wild-type C57 mice (Jackson Labs, Bar Harbor, ME, age ~3 mo).

References:

Meleppat RK, Zhang P, Ju MJ, Manna SK, Jian Y, Pugh EN, Zawadzki RJ, 2019. Directional optical coherence tomography reveals melanin concentration-dependent scattering properties of retinal pigment epithelium. J Biomed Opt 24(6):1-10.

### Files and variables

#### File: beam\_tilt\_data\_for\_Dryad...