Quantitative evaluations of vortex vein ampullae by adjusted 3D reverse projection model of ultra-widefield fundus images

Abstract

The purpose of this study was to determine the number and location of vortex vein ampullae (VVA) in normal eyes. This was an observational retrospective study. Montage images of one on-axis and two off-axis ultra-widefield images of 74 healthy eyes were enhanced, and reverse projected onto a 3D model eye. The number and distance between the optic disc to each VVA in the four sectors were compared. The significance of correlations between these values and age, sex, visual acuity, refractive error, and axial length was determined. The mean number of VVA was 8.10/eye with 1.84, 2.12, 2.19 and 1.95 in upper lateral, lower lateral, upper nasal, and lower nasal sectors, respectively. The mean number of VVA/eye was significantly greater in men at 8.43 than women at 7.76 (P = 0.025). The mean distance between the optic disc and VVA was 14.15 mm, and it was 14.04, 15.55, 13.29 and 13.66 mm in the upper lateral, lower lateral, upper nasal and lower nasal sectors, respectively (all P < 0.05). The number and location of VVA can be obtained non-invasively, and the number was significantly higher in men than women. This technique can be used to determine whether these values are altered in a retinochoroidal disease.

Sex Differences in Choroidal Vessels Using Novel Wide-Field Choroidal En-Face Images from Optical Coherence Tomography

“…Introducing new parameters, en-face p-CVD, and p-CVS, our study uncovered signi cant sex differences in choroidal structure, posteriorly and peripherally, surpassing CCT in distinguishing between sexes even after adjusting for confounders. These results align with our previous research indicating a greater number of vortex vein ampullas in men 25 and higher fundus tessellation, suggesting larger choroidal vessels in males. 26 Our study further supports the notion that quantitative measurements from wide-angle choroidal en-face images effectively capture sex differences in the choroid.…”

Sex- and Age-Dependent Wide-Field Choroidal Thickness Differences in Healthy Eyes

“…Men reportedly have significantly thicker choroids than women [ 13 , 19 ], and reports exist on the sex differences in the lumen/interstitial ratio [ 13 ]. We examined the number of vortex vein ampullae from montage fundus images and reported that the mean number of vortex veins was significantly higher in men than in women, which was more pronounced in the superior quadrant [ 20 ]. The lower number of vortex veins in women could result in a higher blood return volume per each Haller vessel in women.…”

Vortex Veins in Eyes With Pachychoroid Spectrum Disorders Evaluated by the Adjusted Reverse 3-Dimensional Projection Model

“… 19 Therefore, the information on peripheral choroidal vessels collected by ICGA is limited, and it is practically challenging to compare pachychoroidal images with normal ones, which have many variations. 20 , 21 , 22 Furthermore, when examining the location of peripheral choroidal vessels, it is difficult to capture the entire fundus even with an ultrawide-field fundus image. Distortion makes strict quantitative evaluation difficult even if a montage image is created.…”

“…Distortion makes strict quantitative evaluation difficult even if a montage image is created. 20 , 21 …”

“…To solve these problems, we developed an adjusted 3-dimensional (3D) reverse projection model method to noninvasively quantify the peripheral choroid without dye by extracting choroidal vascular enhancement images from undistorted montaged ultrawide-field fundus images and reported the distribution of VVA in healthy subjects. 20 , 23 This technique enables an accurate and noninvasive analysis of VV locations. We hypothesized that choroidal vascular pathology in eyes with PSD is characteristic of VVA.…”