Abstract
Purpose :
To evaluate choroidal melanin distribution in healthy subjects by polarization-sensitive optical coherence tomography (PS-OCT).
Methods :
This study involved 57 eyes of 57 healthy Japanese subjects. The presence of melanin in the choroid was determined by using the degree of polarization uniformity (DOPU) obtained by 1 μm Jones-matrix PS-OCT. Choroidal melanin thickness was evaluated for 5 mm circular region from the foveal center, and compared with age (26 – 84 years), axial length (22.0 – 28.5 mm), choroidal thickness, and choroidal luminal/stromal ratio. To evaluate the distribution of choroidal melanin thickness, circular region was divided into five sectors (center, upper, lower, nasal, and temporal) by modified ETDRS layout.
Results :
The mean choroidal thickness and choroidal melanin thickness (mean ± SD) at 5 mm circular region were 202.5 ± 80.8 μm and 68.3 ± 24.2 μm, respectively. Mean choroidal thickness showed significant negative correlation with age (β = -0.30, P = 0.004) and axial length (b = -0.21, P = 0.03), and significant positive correlation with luminal/stromal ratio (β = 0.62, P < 0.001). Mean choroidal melanin thickness showed significant negative correlation with axial length (β = -0.26, P = 0.045) and luminal/stromal ratio (β = -0.60, P = 0.001), and significant positive correlation with choroidal thickness (β = 0.85, P < 0.001). The mean choroidal thickness and choroidal melanin thickness of the nasal sector were significantly thinner than that of all other sectors (P < 0.001).
Conclusions :
PS-OCT provides an in vivo objective choroidal melanin distribution. Choroidal melanin thickness varies significantly with location, axial length, and choroidal morphology.
This is a 2021 ARVO Annual Meeting abstract.