Transvitreal channel related to an intravitreal developmental anomaly. Slitlamp and electron-microscopical study.

Description of an intravitreal glia particle connected to an atypical transvitreal channel, which was found incidentally during the autopsy of an unfixed sheep vitreous. The anomaly is interpreted as an avulsion of retinal tissue during prenatal development, resulting in a decreased density of the vitreous framework (transvitreal channel) above the retinal defect. In analogy to other observations of transvitreal channels, which occur at all sites where the inner retinal surface is altered, the analysis of the anomaly sustains the hypothesis that framework of the vitreous is formed by elements of the retinal surface. The cells within the particle were examined with electronmicroscopy. They show immature collagen fibrils between glia cells, which may be precursors of vitreous collagen, immigrating through intercellular lacunae into the vitreous.