Anatomy of the sclera

1. BEVERLINE KHAVERE
LORNA JEPTUM
JOY MIRACLE
MARION KEMBOI
WYCLIFFE JUMA
GEORGE OKELLO

3.  The white part of the eye
 Forms the posterior five-sixth part of
external fibrous tunic
 Outer surface covered by Tenon’s capsules
 Anterior part covered by bulbar conjunctiva
 Inner surface lies in contact with a potential
suprachoroidal space in between
 In its anterior most part there is a furrow
which encloses the canal of schlemm
 The sclera is white due to the scattering of
light by dense irregular bundles of collagen

4.  Human sclera is thickest near the optic nerve
(approx 1mm) and thinnest at the insertion
of extra ocular muscles(approx 0.33mm)
 Merging with the tendons of extra ocular
muscles , the collective thickness of sclera
reaches 0.6mm
 It gradually thickens toward the cornea and
at the limbus the thickness is 0.83mm

6.  Episclera
 Scleral stroma
 Lamina Fusca

8.  Thin, dense vascularized layer of connective
tissue which covers the sclera proper
 It contains bundles of collagen , fine
fibroblast,macrophages and melanocytes
 Anteriorly,it blends with subconjunctival
tissue and Tenon’s capsule 1-3mm behind the
limbus
 It becomes very thin and indistinct posterior
to the equator
 It is supplied by anterior ciliary arteries
anteriorly and posterior ciliary arteries
posteriorly

9.  Also called sclera proper or subtantia propria
 Avascular structure which consists of dense
bundles of collagen fibres ,elastic
fibres,fibroblast and ground substances
 Ground substances are proteoglycans and
glycoproteins
 The scleral fibroblast play an important role
in synthesis and organisation of
collagen,proteoglycans and glycoprotein

10.  Innermost layer of sclera
 Characterized by abundance of pigmented
cells or melanocytes , mostly migrated from
choroid
 Connective tissue is loosely arranged than
the rest of the sclera
 Lamina fusca is separated from choroid by a
thin potential space known as suprachoroidal
or perichoroidal space
 Brownish in color owing to the presence of
pigmented cells

11.  Posterior aperture: structured around the
optic nerve and transmit long and short
ciliary nerves and vessels
 Middle aperture: four in number, situated
slightly posterior to the equator, through
these pass the four vertex veins (vena
verticosae)
 Anterior aperture: situated 3-4 mm away
from the limbus .Anterior ciliary arteries pass
through these apertures

12.  Scleral sulcus and scleral spur
 Sclerocorneal junction or limbus
 Canal of schlemm
 Lamina cibrosa

13.  The episclera receives its blood supply from
anterior and posterior ciliary arteries
 Scleral stroma is relatively avascular and
recieves nutrition mainly from episclera
vascular bed and to some extent underlying
choroidal vasculatures
 The sclera contains numerous channels and
passages through which the arteries ,veins
and nerves pass
 These channels or passages are known as
emissary canals

14.  Sclera is supplied by branches from the long
ciliary nerves which pierce it 2-4mm from
the limbus to form a plexus

15.  It provides protection and strength to the
eye
 Provides site for insertion of extra ocular
muscles
 Provides shape of the eyeball