Posterior precortical vitreous pockets and connecting channels in children on swept-source optical coherence tomography

We observed the posterior vitreous in children using swept-source optical coherence tomography (SS-OCT). The normal right eyes of 73 children (ages, 3-11 years) were studied using SS-OCT with 12-mm horizontal and vertical scans in the posterior fundus. Posterior precortical vitreous pockets (PPVPs), narrow liquefied spaces along the vitreoretinal interface in the macula (mean, 165.4 ± 35.2 μm [depth] × 3327 ± 615.7 μm [width]), were observed at age 3 in horizontal scans. The PPVPs enlarged to 382.9 ± 51.8 × 4486.5 ± 342.3 from ages 4 to 6 (P < 0.01) and 524.9 ± 60.3 × 5485.9 ± 307.5 after age 7 (P < 0.01). In all subjects, the depth and width were means of 426.4 ± 38.2 and 4834.4 ± 228.1 μm, respectively. There were significant correlations between the PPVP size and age (PPVP depth, r = 0.42, P < 0.001; PPVP width, r = 0.42, P < 0.001), but not refractive error. The PPVP posterior wall was not visible in all eyes. The PPVP and Cloquet's canal appeared as separate spaces at ages 3 and 4 years. The connecting channel between the PPVPs and Cloquet's developed in 7.7%, 11.1%, 12.5%, 27.3%, 40%, 37.5%, and 50% at ages 5, 6, 7, 8, 9, 10, and 11, respectively. The PPVPs emerged in front of the macula as a solitary space in early childhood. They first were narrow liquefied spaces anterior to the macula at age 3 and evolved to small boat-shaped spaces that gradually enlarged with age. The channels connecting the PPVPs and Cloquet's canal begin to form after age 5. Their presence suggests a physiologic role of the PPVPs.