Sclera and cornea
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Transcript Sclera and cornea
Sclera and Cornea
Sclera
cornea
Sclera
It forms the posterior portion of the globe
It is perforated posteriorly by the optic nerve.
Parts of sclera
Episclera
-
Sclera proper
Lamina fusca
-
fibrous tissue containing fine
capillaries
collagen fibres of the stroma
located adjacent of the stroma
Blood and nerve supply
Choroidal vessels is supplying blood to Episcleral part
Anterior insertion of Recti muscles, the anterior ciliary arteries form
a dense episcleral plexes. These vessels becomes congestion of
ciliary congestion.
Nerve supply
Short ciliary nerves posteriorly,
Long ciliary nerves anteriorly provide sensory innervation.
Inflammation of episclera
Simple
Nodular
Diffuse
Necrotizing
with inflammation
without inflammation
Types of scleritis
Anterior
scleritis
Posterior scleritis
Cornea
It is transparent part of the eye with circular wrist watch shape
It is 10-11mm diameter
It is the most important refractive state of the eye
The junction of cornea and sclera is called limbus and also
important angle structure of the eye.
Part of cornea
It has 5 layers in the anatomic structure
Epithelium
-
Bowman’s membrane -
Stroma
Decemet’s membrane -
Endothelium
corneal epithelium
rests on a basement of
membrane secreted by
the basal cells.
condensation of
substania propria
-
collagen fibrils
arranged inset of
lamellae, lying
parallel to the surface.
homogenous, very
resistant membrane
-
single layer of flattened
polygonal endothelial
cells
Blood supply and nerve supply
Blood supply :
Cornea is avascular structure.
Nerve Supply :
The cornea nerve, are derived from the long
and short ciliary nerves of the ophthalmic
division of trigeminal nerve.
Types of ulcers
Bacterial ulcer
Fungal ulcer
Viral ulcer
Parasitic ulcer
Degenerative condition
Corneal dystrophies
Bacterial ulcer
It is defined as a break in the corneal
epithelium with added infection
Investigations
Lacrimal sac syringing
Diabetic status
Corneal scrapping
Gram and Giemsa stains for bacteria
Culture on blood agar for aerobic organisms
10% KOH wet preparation for fungus
Culture on Sabouraud’s dextrose agar for fungus
Viral
Ulcer with a branched appearance caused by herpies
simplex virus.
Investigations
Sensation of cornea
Fluorescent stain
Enlarged and tender pre auricular lymph nodes
Keratoconus
Bilateral conical protrusion of central part of the
cornea due to thinning is called Keratoconus
In this condition we have to check keratometry to
know the astigmatism
Corneal dystrophies
Cornea loses its clarity due to deposition of materials
in various layers of the cornea it can be seen by
Childhood
Types of dystrophies
Epithelial dystrophy
-
Map dot finger print
Stromal dystrophy
-
Endothelial dystrophy
-
Granular or macular or
lattice
Fuch’s
Don’ts in a case of corneal ulcer
No Bandage
No steroid drop ( except viral)
No schiotz tonometer