anatomy of sclera

1.    Introduction Gross anatomy Layers  Blood supply, drainage and nerve supply
2. INTRODUCTION • Sclera forms posterior 5/6th of external tunic , connective tissue coat of eyeball. • it continues with duramater and cornea • Its whole surface covered by tenon’s capsule • Anteriorly covered by- bulbar conjunctiva • Inner surface lies in contact with choroid • With a potential suprachoroidal space in between
3. Equa THICKNESS OF SCLERA
4. • Thickness varies with individual, with age • Thinner- children, elder, F> M • Thickest posteriorly • Gradually becomes thinner when traced anteriorly • Thin at insertion of extraocular muscle

2. 


Introduction
Grossanatomy
Layers
Blood supply, drainage and nervesupply

4. INTRODUCTION
•Sclera forms posterior 5/6
th
of external tunic ,
connective tissue coat of eyeball.
•it continues with duramaterand cornea
•Its whole surface covered by tenon’scapsule
•Anteriorlycovered by-bulbar conjunctiva
•Inner surface lies in contact with choroid
•With a potential suprachoroidalspace in
between

5. Equa
THICKNESS OFSCLERA

6. •Thickness varies with individual, with age
•Thinner-children, elder, F> M
•Thickest posteriorly
•Gradually becomes thinner when traced
anteriorly
•Thin at insertion of extraocularmuscle

8. •Anterior scleralforamen
•Posterior scleralforamen
•Tenon’scapsule
•Duramater
•sclerotic ring
•Scleralspur
•Lamina cribrosa

9. •fascial sheath ofthe
eyeball
•Also known as fascial
bulbi, capsule of tenon,
bulbar sheath
•It’s a thin fibrous
membrane envelops the
eyeball from optic nerve to
the limbus

11. •Thescleralspuris an annular structure composed
of collagen in the human eye, a protrusion of
thescleraintothe anterior chamber.
•It is the origin of the longitudinal fibres of the
ciliarymuscle and is attached anteriorlyto the
trabecularmeshwork.
•It is a circular ridge of sclera present on the
innersideof corneoscleraljunction
•It is visible on gonioscopyabove the ciliarybody
band as a white line.

12. •It is mesh like structure present behind the
optic disc in the sclera
•It allows the fibres of the optic nerve to pass
through it and acts as pressure barrier
between the I.O space and retrobulbarspace
•The pores in the lamina cribrosaare visible as
lamellar dot sign in advanced glaucomatous
atrophy

14. APERTURE
•3 sets of aperture
1. Posterior aperture-situates around Optic N.
•Transmit long And short CiliaryN. & vessels
2. Middle aperture-4 in no.
•Are situated slightly posterior to the equator
•4 vertex veins passthroughthis
3. Anterior aperture-situates 3-4mm away from
limbus
•Ant.ciliaryvessels pass through this

15. Layers of
sclera
scle
r
a
episclera
Scleraproper
Lamina
fusca
thin, densevascularised
layer of connective tissue
fibroblasts, macrophages
and
lymphocytes
avascular structure
dense bundlesof
collagenfibres.
innermost blends with
suprachoroidal and supraciliary
laminae of the uvealtract.
brownish incolour
presence of pigmentedcells.

16. 1. EpiscleralTissue
•thin, dense, vascularised layer of connective tissue
•It covers sclera proper
•Fine fibroblasts, macrophages, lymphocytes are also
present in this layer
2. Sclera proper
•It is an avascularstructure
•Consist of bundle of collagen fibres
•The bands of collagen tissue cross each other in all
directions
3. Lamina fusca
•Innermost
•It blends of suprachoroidal&supraciliarylaminaeof
uvealtract
•It is brownish colour owing to presence of pigmented
cells

17. -Superficial aspect ofsclera
-bundles of collagen circumferentially arranged
-rich blood supplyanteriorly
-thin, dense, vascularised layer of connective tissue
-It covers sclera proper
-Fine fibroblasts, macrophages, lymphocytes are also
present in this layer
-thickest anterior to the rectus muscle insertions and
becomes progressively thinner toward the back of the
eye.

18. Lamina fusca
•Innermost
•It blends of suprachoroidal&supraciliary
laminaeof uvealtract
•It is brownish colour owing to presence of
pigmented cells
•grooves for the passage of ciliaryvessels and
nerves (emissarycanals)
•attached to the choroid by fine collagenfibers
•Brown colordue tomelanocytes

19. Sclera proper
•It is an avascularstructure
•Consist of bundle of collagen fibres
•The bands of collagen tissue cross each other
in all directions
•deficiency in water-binding substances
accounts for the scleraldull-whitecolor

20. 

Episclera-anterior and posterior ciliary arteries
Scleral stroma-relatively avasculaturestructure

22. 

Episcleral collecting veins
Vortex veins
Anterior ciliaryveins

23. 


Rich in nervesupply
Anterior sclera-long posterior ciliary nerves
which pierce it 2-4mm from the limbusto form a
plexus
Posterior sclera-short posterior ciliarynerves


24. 

FUNCTIONS
1.Protects intraocular components from trauma,
light, and mechanicaldisplacement
2.Withstands the considerable expansive force
generated by the intraocular pressure maintaining
the shape of theglobe
3.Provides attachment sites for the extraocularmuscles.

25. EMBRYOLOGY
•Sclera -> derived from mesenchyme-> derived
from neural crest