In Vivo Study of Retinal Transmission Function in Different Sections of the Choroidal Structure Using Multispectral Imaging.

PURPOSE The confounding factors of retinal transmission function are unclear. This study aimed to investigate retinal transmission function by evaluating the morphologic features of the retina and choroid in different section layers using multispectral imaging (MSI) in healthy eyes. METHODS Multispectral imaging was performed on 122 healthy eyes. In each subject, 11 images at 550 to 850 nm were collected. The exposed region of choroidal vessels in the images was divided into three regions and evaluated by four grades. The relationships between the axial length (AL)/age/sex and exposure grade were analyzed. RESULTS The 122 subjects were 20- to 77-years old with AL ranging from 22.23 to 31.41 mm. The choroidal vessels of 56% of subjects were initially exposed in 590-nm wavelength imaging. The exposure grade of choroidal vessels was positively correlated with the AL (P < 0.05) in subjects who were 20 to 40 years old. Among the participants whose AL was between 22.00 and 25.00 mm, the exposure grade was positively correlated with age (P < 0.05). This correlation was most significant at the wavelength of 590 nm (P < 0.001). Additionally, the AL/age values at 590 nm were significantly different among grade groups (P < 0.05). No statistical relationship was found between sex and exposure grade (P > 0.05). CONCLUSIONS This study investigated the exposure grade of choroidal vessels as an indicator of the transmission function of the retina using MSI and provides reference exposure grades based on different AL/age groups of healthy subjects.