The Topographic Relationships and Geographic Distribution of Prevascular Vitreous Fissures and Cisterns Assessed by Ultrawidefield En Face Vitreous Images

Abstract

Purpose: To determine the topographic relationships and geographic distribution of prevascular vitreous fissures (PVFs) and cisterns across the entire posterior vitreous membrane in healthy subjects, using ultrawidefield en face and cross-sectional swept-source OCT (SS-OCT) images.

Design: Observational cross-sectional study.

Participants: Ninety-six eyes of 96 healthy participants (age range, 20-49 years) without posterior vitreous detachment.

Methods: For each eye, a 29 × 24-mm SS-OCT volume scan was obtained, along with standardized horizontal and vertical scans through the fovea.

Main outcome measures: Ultrawidefield en face and cross-sectional images were analyzed to assess the topographic relationships and geographic distribution of PVFs and cisterns in the posterior vitreous.

Results: En face imaging readily distinguished various preretinal liquefaction spaces throughout the posterior vitreous, extending to near the equator. Aside from the posterior precortical vitreous pocket (PPVP) and the area of Martegiani, all preretinal liquefied fissures and cisterns were distributed along superficial retinal vessels, suggesting they originated from prevascular vitreous liquefaction. In 96 eyes of healthy young and middle-aged adults, PVFs were identified in all participants, presenting a continuous course. Cisterns were detected in 79 eyes (82.3%) and were distributed as follows: superotemporal (91.1%), infratemporal (63.3%), supranasal (41.8%), and inferonasal (22.8%), respectively. The superotemporal cistern was most frequently observed (P < 0.001), and cisterns were more likely to involve multiple quadrants with age (P = 0.005). Additionally, all preretinal liquefaction spaces, including the PPVP, PVFs, and cisterns, were consistently located overlying the vitreoretinal tightly adhered regions.

Conclusions: Ultrawidefield en face vitreous imaging in healthy young and middle-aged adults revealed that (1) PVFs distributed along superficial retinal vessels with continuous course; (2) cisterns may develop from PVFs and are more common in the superotemporal quadrant; (3) cisterns appear early in life and become more widespread with age; (4) preretinal vitreous liquefaction follows a stereotypic pattern, aligning along regions of firm vitreoretinal adhesion.

Financial disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Cisterns; En face imaging; Prevascular vitreous fissures; Ultra-widefield; Vitreous.

Figure 1

Ultrawidefield dynamic en face assessment of posterior vitreous liquefaction in 2 subjects. (A1–A4) 29 × 24 mm dynamic en face scans at (A1) 0 μm, (A2) 100 μm, (A3) 250 μm, and (A4) 550 μm anterior to the retinal surface in a 27-year-old myopic (−4.25D) woman show a relatively homogenous vitreous gel structure, with continuous prevascular vitreous fissures (PVFs) overlying retinal blood vessels. Cisterns were not detected. (B1–B4) 29 × 24 mm dynamic en face scans at (B1) 0 μm, (B2) 100 μm, (B3) 200 μm, and (B4) 450 μm in a 32-year-old myopic (−0.75D) man demonstrate increasing vitreous syneresis with more established cisterns arranged radially and fewer PVFs. Note that cisterns, which are larger than PVFs, are found overlying the same retinal vessel locations. D = diopters.

Figure 2

UWF sectional and en face OCT images in a 48-year-old emmetropic man. Horizontal (A1) and vertical (A2) scans depict a boat-shaped posterior precortical vitreous pocket (PPVP), a conical-shaped area of Martegiani (M), a flat supramacular bursa (white asterisk), with 2 PVFs (black arrow) and a teardrop-shaped cistern (white arrow) overlying 3 retinal blood vessels. A thin layer of cortical vitreous fibers is visible at the posterior border of both PVFs and cisterns. (B1–B4) 29 × 24 mm dynamic en face scans at (B1) 0 μm, (B2) 100 μm, (B3) 250 μm, and (B4) 450 μm anterior to the retinal surface demonstrate the continuous course of PVFs and cisterns of various sizes along the superficial retinal vessels. White triangles indicate noteworthy cisterns expanding anteriorly. The white asterisk in (B4) indicates a degenerative supramacular bursa anterior to the PPVP, as shown in (A1). Both the PPVP and the area of M are visible in these en face scans. M = Martegiani; PVF = prevascular vitreous fissure; UWF = ultrawidefield.

Figure 3

Geographic distribution of cisterns. (A) In healthy young and middle aged adults, cisterns were observed most frequently in the superotemporal quadrant (91.1%), followed by the infratemporal (63.3%), superonasal (41.8%), and inferonasal (22.8%) quadrants, with the superotemporal quadrant having the highest incidence (P ＜ 0.001). (B) Quadrant involvement of cisterns across different age groups shows that cisterns appeared in one or more quadrants, with simultaneous involvement of all 4 quadrants predominantly observed in participants in their 40s (P = 0.005). ∗P ＜ 0.001; ∗∗P = 0.005.