The document summarizes the microstructure of the sclera. It has three layers - the episcleral tissue, sclera proper, and lamina fusca. The sclera proper is the main layer, consisting of dense bundles of collagen fibers crossing in all directions, making it opaque. It has anterior, middle, and posterior apertures that transmit nerves and vessels. The sclera provides tough, protective covering for the eyeball and is supplied by nerves.

1. GEORGE COLLEGE OF
MANAGEMENT AND SCIENCE
NAME: ALMAAZ AHMED
STREAM: B.OPTM
SEM.: 2nd SEM
ROLL: 16401719005
SUBJECT CODE: BO-203
SUBJECT NAME: ANATOMY(OCULAR)
SUBJECT MENTOR: DR. KAUSHIK SINHA
TOPIC: SCLERAL MICROSTRUCTURE

2. INTRODUCTION
• Sclera constitutes more
than 80% of the eye wall.
• It forms the posterior
opaque fifth-sixth part of
the external fibrous tunic
of the eyeball.
• It’s whole outer surface is
covered by Tenon’s
Capsule.
• It’s inner surface lies in
contact with the choroid.

3. SCLERAL APERTURES
• It has three sets of apertures:
1. Posterior apertures are situated around the optic
nerve and transmit long and short ciliary nerves
and vessels.
2. Middle apertures are situated 4-7 mm posterior
to the equator.
3. Anterior apertures are situated 3-4 mm away
from the limbus and transmit anterior ciliary
vessels and ciliary nerves.

4. MICROSTRUCTURE OF
SCLERA
It consists of three
layers:
1. Episcleral Tissue
2. Scleral Proper
3. Lamina Fusca

5. EPISCLERAL TISSUE
• It is a thin, dense vascularised layer of the
connective.
• It covers the sclera proper.
• It becomes continuous with the Tenon’s
capsule.
• The capillary network present in the anterior
part becomes prominent during inflammation
giving rise to ciliary flush.

6. SCLERA PROPER
• It is an avascular structure which consists of
dense bundles of collagen fibres crossing each
other in all directions.
• This arrangement makes the sclera opaque.
• Mucopolysaccharides are present in the
interfibrillar space of the collagen fibres.
• Few fibroblasts are also present in this layer.

7. LAMINA FUSCA
• It is the innermost part of sclera.
• It blends with suprachoroidal and supraciliary
lamina of the uveal tract.
• It is brownish in colour owing to the presence
of pigment cells.

8. NERVE SUPPLY OF THE SCLERA
• The sclera is supplied by branches from the long
ciliary nerves anteriorly and short ciliary nerves
behind the equator.
FUNCTIONS:
• It is the opaque, fibrous, tough, protective layer of
the eye.
• It is directly continuous with the cornea in front
and with the sheath covering the optic nerve
behind.
• It forms the entire visible white exterior of the
eye.