Characteristics of posterior precortical vitreous pockets visualized by swept-source OCT and en face OCT

To determine the characteristics of posterior precortical vitreous pockets (PPVPs) and to observe vitreous changes in myopic eyes by swept-source optical coherence tomography (SS-OCT) and en face imaging in a cohort of the Chinese Han population. This was a cross-sectional study. Volunteers (235 participants, 374 eyes) received an SS-OCT examination. The heights and widths of the PPVPs were measured by SS-OCT. The area of the PPVPs was measured on en face images. The relationships between PPVP size and sex, age, axial length (AL) and spherical equivalent (SE) were evaluated. The mean width and height were 6711.64 +/- 1241.87 mu m and 662.47 +/- 326.39 mu m, respectively. The area of the PPVPs was 30.296 +/- 9.114 mm2. Boat-shaped, oval, and hook-shaped PPVPs were observed in 73.26%, 21.12%, and 5.62% of all eyes, respectively; 73.53% of all PPVPs had channels communicating with Cloquet's tubes. There was a significant difference in the PPVP width among the participates over and under 50 years old (t = -2.508, P = 0.031). Age had a positive correlation with the PPVP width (r = 0.53, P = 0.001). The PPVP height showed significant differences among the different myopia groups (F = 3.618, P = 0.013). SE had a negative correlation with the PPVP height (r = -0.176, P = 0.001). However, there were no correlations between the AL and the width, height or area of the PPVPs (P = 0.117; P = 0.334; P = 0.057, respectively). Age and myopia affect the size of PPVPs. SS-OCT greatly facilitates visualization of the complex structure of the vitreous.