Abstract
Purpose :
In vivo methods to quantify macular pigments, such as heterochromatic flicker photometry, fundus reflectance, fundus autofluorescence, and resonance Raman spectroscopy, provide two-dimensional maps without depth information. Here we performed visible light OCT of macular pigments, employing SLD wavelengths tailored to sample MP absorption while minimizing photochemical hazards.
Methods :
We performed visible light OCT in 6 human subjects without evidence or history of ocular pathology (age 45.33 +/- 20.17 years, 2 female). Subjects were aligned using the red (centered at 650 nm) SLD. Data were acquired with red, blue-green (centered at 505 nm), and cyan (centered at 488 nm) SLDs at 40 kHz. Images were motion corrected and intensity averaged for display. A sub-band analysis of the blue-green and cyan channels was performed to provide more granular spectral information. Single-pass optical density (SPOD) was defined with respect to the red channel, with subtraction of a linear fit, excluding the foveal region with eccentricity +/- 0.5 mm (i.e. peripheral referencing).
Results :
Images of a 29 year-old female show clear attenuation of the cyan channel in the foveal outer retina [Fig. 1(A)]. SPODs in the foveola agree with published macular pigment (MP) absorption spectra [Fig. 1(B)]. Spatial variation of SPODs, shown along with co-registered retinal thickness [Fig. 1(C)], is consistent across sub-bands and channels. Interestingly, in this particular subject, all sub-bands depict an asymmetric MP distribution with respect to the foveal pit [Fig. 1(C)].
Conclusions :
Visible light OCT with tailored wavelengths yields SPOD measurements that are fully consistent with MP. These results suggest that careful choice of SLD wavelengths can provide reliable and safe MP measurements.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.