The premacular vitreous pocket (PVP), or vitreoschisis cavity, is a liquefied vitreous cavity in front of the posterior retina that is characteristic of various macular diseases, including macular holes and diabetic maculopathy.1 The reason for the development of PVPs is unknown because of the difficulty observing the formed vitreous in vivo. India ink and the fluorescein staining technique have delineated the structure of the PVP in the vitreous cavity in human eyes at autopsy2; however, the technique is limited because of the presence of artifacts during fixation of the fragile and mobile vitreous and postmortem changes. Optical coherence tomography has facilitated observation of the vitreous structures in vivo. Herein, we describe the development and fine details of PVPs in real time.
We retrospectively analyzed the posterior vitreous, retinas, and optic discs of 56 healthy eyes (39 patients; age range, 1-54 years) using swept-source optical coherence tomography (Topcon), which provides detailed images of the fine ocular structures. The scanning protocol used in this study was a single-line scan with 96 overlapping images and a radial scan with 32 overlapping images. Each line has a 12-mm transverse scanning length with 1024-pixel resolution. Eyes that appeared healthy were excluded if the patient had a family history of a hereditary vitreoretinal disease.
A PVP (Figure 1C-F) was detected in all eyes of patients older than 10 years and in no eyes of patients younger than 2 years (Figure 1A). A crack in the formed vitreous (Figure 1B), considered to be a primitive structure of the PVP, developed first in eyes around age 2 years. Between ages 3 and 9 years, a PVP was present in 16 eyes (49%) and a crack in 20 eyes (61%). Nine eyes (56%) with a PVP also had a crack. Among eyes with both a PVP and a crack, 16 eyes (86%) had cracks connected to the PVP. Twenty-eight eyes (80%) with PVPs had a liquefied connection between the PVP and the Cloquet canal (Figure 1C-F). The connection to the Cloquet canal was identified in both the PVP and the crack (Figure 1B). In younger eyes, the PVP was wider horizontally than vertically, and all detectable cracks were wider horizontally than vertically. During the early phase of PVP development, several eyes had multifocal PVPs and cracks (Figure 2A-C) in the premacular vitreous. A high-density structure, which appeared to be a remnant of regressed hyaloid vessels and was connected to the Bergmeister papilla, was present temporally along the crack and wall of the PVP in several eyes (Figure 2D).
A, No premacular vitreous pocket is seen in the eye of a 2-year-old boy. B, A premacular crack in the formed vitreous (arrowheads) is seen in the eye of a 3-year-old girl, and the Cloquet canal is connected to the crack. Premacular vitreous pockets are seen in the eyes of an 8-year-old boy (C), a 13-year-old boy (D), a 30-year-old man (E), and a 54-year-old woman (F), and they are all connected to the Cloquet canal. F, A partial posterior vitreous detachment is seen in the eye of a 54-year-old woman.
A-C, Sequential radial sections of the temporal premacular vitreous centered on the optic disc in the eye of a 6-year-old boy. Primitive PVPs are seen superotemporally (A) and inferotemporally (C) but no PVPs are seen temporally (B), indicating that these PVPs are multifocal in origin. D, A regressed hyaloid vessel within both the Cloquet canal and a PVP (arrows) is seen by swept-source optical coherence tomography in the eye of a 5-year-old boy.
Kishi and Shimizu3 originally identified PVPs in eyes at autopsy and implied that development began with slight separation of the vitreous at about age 2 years, although the PVPs might include postmortem changes. The current in vivo study showed that a PVP is often absent at birth and is often present by about age 3 years. Interestingly, the crack in the formed vitreous also was observed as an initial change around age 2 years.
The PVP and posterior Cloquet canal, which are separated by a dishlike wall of vitreous,4 were connected in most eyes of the current patients, even in eyes with a crack at an initial stage. Aqueous humor from the posterior Cloquet canal5 may play a role in formation of the crack and PVP.
Almost all primary PVPs and cracks that occasionally developed multifocally and coexisted with remnants of hyaloid vessels were wider horizontally than vertically. Because ocular movement is usually dominant horizontally, horizontal shear stress might generate cracks in horizontally layered premacular vitreous,6 in which remnants of hyaloid vessels may be related to the friability of the premacular vitreous. The vitreous and hyaloid vessels are symmetric along the anteroposterior axis during early development and become asymmetric after dominant growth of the temporoposterior region. Since the remnant, cracks, and PVPs were observed only temporally in the premacular vitreous, the asymmetric vitreous growth may contribute to the asymmetric location of these structures. Further study is needed to confirm our preliminary findings.
Corresponding Author: Dr Azuma, Department of Ophthalmology and Cell Biology, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan (email@example.com).
Published Online: June 13, 2013. doi:10.1001/jamaophthalmol.2013.240.
Conflict of Interest Disclosures: None reported.
Thank you for submitting a comment on this article. It will be reviewed by JAMA Ophthalmology editors. You will be notified when your comment has been published. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest*
Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 1
Customize your page view by dragging & repositioning the boxes below.
Enter your username and email address. We'll send you a link to reset your password.
Enter your username and email address. We'll send instructions on how to reset your password to the email address we have on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.