title: [The vitreous and the macula].
abstract: The macula is a site where various vitreoretinal disorders occur. In 1983 we started to observe the retinal surface of postmortem eyes with a scanning electron microscope (SEM). We investigated the anatomy of the vitreous in postmortem eyes by slit lamp biomicroscopy. The novel anatomy of the premacular vitreous led us to conduct a clinical study of vitreomacular interface diseases. In 1997, time domain optical coherence tomography(OCT) became available which facilitated visualization of the vitreoretinal interface. Swept source OCT which was introduced in 2012 can depict liquefied lacunae in the vitreous. It enabled us to elucidate the mechanism of vitreoretinal diseases. I. SEM revealed the remnants of vitreous cortex at fovea with high incidence (44%), which suggests strong vitreoretinal attachment at the fovea and vitreous cortex origin of the epiretinal membrane. II. We studied the anatomy of the vitreous in postmortem eyes. The vitreous of bisected eye balls was stained by fluorescein and immersed in water and observed by slit-lamp biomicroscopy. We discovered a "posterior precortical vitreous pocket (PPVP)" in adult eyes without posterior vitreous detachment (PVD). III. We performed clinical study in various vitreoretinal diseases based on the novel vitreous anatomy and explained their mechanism. 1. In diabetic retinopathy, ring shaped fibrovascular tissue surrounding the macula is formed along the outer margin of the PPVP. Although PVD progresses outside the PPVP, its posterior wall remains attached to the retina, which causes macular traction or cystoid macular edema. 2. In eyes with idiopathic epimacular membrane (IEM), detached vitreous cortex had an oval defect corresponding to the IEM. Posterior wall of the PPVP that is premacular vitreous cortex appeared to be the framework of IEM. 3. During vitrectomy for macular hole, premacular round defect appears when PVD is created. The residual cortex on the macula is fibrous membrane with elasticity. The tangential contraction of premacular cortex may generate anterior traction to the fovea, which leads to macular hole. IV. Using time domain OCT, we demonstrated the evolution of macular hole, myopic foveoschisis and lamellar macular hole. After 2007, we investigated age related changes of vitreoretinal interface by spectral domain OCT V. We demonstrated whole structure of the PPVP using swept source OCT. PPVP is a boat shaped premacular liquefied space which has a connecting channel to Cloquet's canal. PPVP develops during childhood. Visualization of vitreous structure proved that our previous assumptions are reasonable. Although the physiological function of the PPVP is unclear, we speculate that the aqueous flows into the PPVP though Cloquet's canal and the connecting channel.
authors: Shoji
authors: S
authors: Kishi
mesh_terms: D003930:Diabetic Retinopathy / Q000601:surgery; D006801:Humans; D008266:Macula Lutea / Q000473:pathology / Q000601:surgery* / Q000648:ultrastructure; D008854:Microscopy, Electron; D014796:Visual Perception; D014821:Vitrectomy / Q000379:methods; D014822:Vitreous Body / Q000473:pathology / Q000601:surgery* / Q000648:ultrastructure