This document discusses the anatomy and development of the vitreous humor in the eye. It begins by describing the embryological origin of vitreous cells from surface ectoderm, neuroectoderm, and mesodermal tissues. During the primary vitreous stage, the vitreous body begins forming before closure of the choroidal fissure and appears as a fibrillated secretion filling the vitreous space. The document then covers the general features, structure including hyaloid layers, cortical and medullary regions, attachments, composition and transport processes of the mature vitreous humor. It concludes by describing the physicochemical properties and factors affecting expansion and contraction of the vitreous gel.

1. ANATOMY OF VITREOUS
DR RAKESH JAISWAL

2. Embryology of vitreous
Cells of origin of the vitreous gel
include
•Cell of the surface ectoderm(lens
anlage)
•Cell of the neuroectoderm(retina
and ciliary epithelium )
•Mesodermal cells b/w the surface
and neural ectoderm at the
anterior rim of the developing
optic cup
•Mesodermal cells migrating into
optic cup via fetal fissure with
hyaloid system

4. PRIMARY VITREOUS STAGE
•primary vitreous body begins its
formation before the closure of
the chorioidal fissure
• Primary vitreous appears at the
time of formation of the optic
cup, is a fibrillated secretion of
the retinal cells, and fills in the
vitreous space with a feltwork of
fine fibrils
•Primary cellular vitreous
formation
•Vascularization of primary
vitreous
•Its mixed ectodermal and
mesenchymal origin

7. Congenital and
development
abnormalities
•Mittendorf dot
•Muscae volitantes
•Persistent hyloid
system
•Vitreous cyst

9. Failure of secondary vitreous
•COLOBOMA
•Vitreous tracts ,Transvitrous channel

12. GENERAL FEATURES
• Vitreous humour is an inert,transparent,coloursless,jelly-
like structure
• Hydrophilic gel serves as optical functions and act as
important supporting structure for eyeball
• Anteriorly-by post surface lens and ciliary body
• Posteriorly-by retina

13. • wt-4g
• Vol-4cc (2/3vol of entire globe)
 approximately 99 % water
1 % solid
• 0.9% salts
• 0.08% protein
• 0.02% mucopolysaccharide

14. STRUCTURE
• The vitreous is the largest and simplest
connective tissuse present as a single piece in
the human body
• Divided in 3 parts
1. Hyaloid layer or membrane
2. Cortical vitreous
3. Medullary vitreous

15. Hyaloid layer
• It is not a true membrane but outermost
surface of vitreous
1. Ant hyaloid membrane (ant limiting
membrane layer)
2. Post hyaloid membrane (post limiting
membrane layer)

17. Ant hyaloid membrane
• It covers vitreous body ant 1.5mm from the ora serrata
• Lies in contact with pars plana,ciliary processes,ciliary zonules and
post lens capsule(form ring about 9mm in diameter called as
hyaloido-capsular ligament of wieger in center of it space called
Berger’s space
• It connect with other intraocular structures by
following fine ligaments
Hyalociliary zonules-AHM to valley b/w ciliary
processes

18. • Retrolental ligament-AHM to lens
• Coronary ligament- its fibres extend AHM to
inner face of the post third of ciliary processes
circumferentially
• Median ligament-it also runs circumferentially
from AHM at the level of mid zone of pars plana

19. Posterior hyaloid membrane
• It extends back from the vitreous base up to
the optic disc
• It lie in contact with the internal limiting
membrane of the retina

20. Cortical vitreous
• It lie in peripheral zone appox 100 micron in width
• It is more condensed fibrillar vitreous
• It contain Type 2 collagen fibrils interspersed with
the sodium hyaluronate ,mucopolysaccharide
molecules which provide viscosity ,elasticity and
tensile strenght to it
• 2 percent of the total vitreous vol
• It is the metabolic centre of the vitreous
body(vitreous cells –hyalocytes)
• Vitreos cells synthesize the hyaluronic acid

21. Medullary vitreous
• Majority of vitreous body is form by central
medullary vitreous
• Similar to cortical vitreous except it is less
fibrillar structure and cell free

22. Vitreous tracts
• Vitreous tracts are fine sheet like condensations of vitreous tissue which
radiate into the virteous space from ciliary body and ant retina
•

23. Topographic subdivisions of vitreous
space

24. ATTACHMENTS OF THE VITREOUS
• OPTIC DISC
• BACK OF LENS
• FOVEAL REGION
• ORA SERRATA

26. BIOCHEMICAL COMPOSITION
• Composed of 3 major structural components
1. Water
2. Collagen-like fibres
3. Hyaluronic acid a glycosaminoglycans(GAGs)

27. TRANSPORT PROCESSES
• The active pump mechanisms located at level
of ciliary body ,pigment epithelium and
possible retinal vessels are concerned with
active transport of materials across the
vitreous

28. PHYSICOCHEMICAL PROPERTIES
• Wt -4g
• Vol-4cc
• Refractive index-1.3349 it transmit almost 90%
of light b/w 300-1400 nm
• Plasticity-provided by 3D collagen fibres which
is electrostatically neutral bec they are not cross
linked and allow vitreous vol to expand
• Viscoelasticity-provided by network of
hyaluronic acid molecular chain

29. VITREOUS EXPANSION AND CONTRACTION
Its is a funtion of ionic charge of the vitreous
structure
POSITIVE CHARGE NEGATIVE CHARGE
Na Hyaluronic acid
Nacl
Protien mol
TEMP AND PH –cause shrinkage of vitreous
FREEZES –expansion of vitreous

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