Abstract
Purpose :
With recent technical advances, visible light OCT has revealed previously unseen retinal bands in the living human retina and enabled quantification of other bands for the first time. Here, we investigate outer retinal band 2, referred to as the ellipsoid zone or inner segment / outer segment (IS/OS) junction, with 1 micron axial resolution visible light OCT.
Methods :
Spectral/Fourier domain visible light OCT, with 1 micron axial resolution, was performed along the horizontal meridian from the fovea to the periphery in 2 male subjects aged 27 and 40. Data from a single subject (27 year-old Asian male with brown iris) is shown. A noise-corrected transverse cross-correlation matrix of the flattened volumetric OCT intensity data sets, displayed as an image, was employed to examine associations between various axial positions in the outer retina. The logarithm of the p value (not corrected for multiple comparisons) was also examined. All findings were confirmed qualitatively in the second subject (not shown).
Results :
Band 2 appeared as a single entity in the fovea, yet was clearly split into nominal bands 2a and 2b in the peripheral retina (Figure 1). The cross-correlation matrix showed that band 2a is associated with band 3 (Figure 2), referred to as the cone outer segment tips (COST) or cone interdigitzation zone (CIZ). On the other hand, band 2b was not associated with band 2a or band 3, though it was weakly associated with the rod IZ or rod OST in band 4 (Figure 2).
Conclusions :
Visible light OCT revealed a split band 2 in the human peripheral retina. The topography and transverse intensity variations of the outermost band 2b suggest an association with rods. Band 2b may relate to the rod IS/OS or ellipsoid zone which has been reported in various animal models.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.