OCT En Face Analysis of the Posterior Vitreous Reveals Topographic Relationships among Premacular Bursa, Prevascular Fissures, and Cisterns

Purpose: To characterize the topographic relationships among vitreous structures, including the premacular bursa, prevascular vitreous fissures, cisterns, and lacunae, in healthy participants using en face and cross-sectional swept-source (SS) OCT. Design: Prospective, comparative study. Participants: Sixty eyes of 60 healthy participants (age range, 4–35 years). Eyes of individuals younger than 20 years (n = 29) were compared with eyes of individuals 20 years of age or older (n = 31). Methods: From each study eye, 12 × 12-mm SS OCT volume scans comprising 1024 × 1024 A-scans centered at the fovea were acquired. Main Outcome Measures: En face and cross-sectional data were analyzed to characterize topographic relationships between hyperreflective spaces anterior to the vitreoretinal interface. Results: Prevascular vitreous fissures are an almost universal feature of human eyes. Cisterns became more prevalent over the course of the first 20 years (r = 0.49; P = 0.002). In 97% of eyes in individuals older than 20 years, en face and cross-sectional SS OCT showed the premacular bursa and prepapillary gap merge at a distance superior to the optic nerve and then follow a superonasal course anteriorly. However, only 69% of individuals younger than 20 years demonstrated such a connection (P = 0.01). A close topographic relationship of vitreous fissures and cisterns to the underlying vasculature of the posterior pole was visible on en face projections. En face imaging readily distinguished these spaces. Degenerative, eyewall-parallel fissure planes and their course were described for the first time in a 3-dimensional manner. The fissure planes were rare in younger eyes (12%) and significantly more common in older eyes (42%; P < 0.001). Conclusions: En face SS OCT demonstrated that (1) premacular bursa and Cloquet's canal are not connected in younger patients, but are connected in older patients; (2) prevascular vitreous fissures overly the retinal vessels; and (3) cisterns are continuous with prevascular fissures.