Fascia Bulbi, Tenon's Capsule

Question 1

a) What is Tenon’s capsule
b) describe the appearance of the inner surface

Answer 1

a) Thin membrane that separates the eyeball from orbital fat
b) inner surface: shiny and smooth

Question 2

Is it in contact with the slera?

Answer 2

Attached firmly to sclera 1.5mm posterior to corneoscleral junction

Elsewhere, separated by potential space: episcleral space

Question 3

What connects the sclera to Tenon’s capsule?
What space do they cross?

Answer 3

numerous delicate bands of connective tissue
Cross episcleral space

Question 4

What is attached to the outer surface of Tenon’s capsule?

Answer 4

corse trabecular that run through orbital fat

Question 5

What is Tenon’s capsule also known as?

Answer 5

Fascial space of the eyeball
Fascia Bulbi

Question 6

What does Tenon’s capsule fuse with posteriorly?

Answer 6

meninges around optic nerve and with sclera around exit of optic nerve

Question 7

What is Tenon’s capsule pierced by

Answer 7

• posteriorly, pierced by vortex veins and ciliary nerves + vessels
• Tendons of all six EOMs. Reflects along tendons to form tubular sleeve

Question 8

How far do the tubular sleeves (formed by reflection of Tenon’s capsule along muscle tendon) of the following muscles extend:
a) superior oblique
b) inferior oblique

Answer 8

a) to trochlea
b) to origin of muscle on floor of orbit

Question 9

What are the medial and lateral check ligaments?

Answer 9

Tubular sleeves of medial and lateral recti) - formed by reflection of Tenon’s capsule along their tendon’s.

Medial rectus sleeve is attached to lacrimal bone

Lateral rectus sleeve is attached to zygomatic bone

Act to limit action of muscles on eyeball

Question 10

Where does the tubular sleeve of the following muscle tendons expand to:
a) superior rectus tendon
b) inferior rectus

What is their function?

Answer 10

a) to levator palpebrae superioris
b) inferior tarsal plate

Function not entirely known.
Superior thought to ensure that both muscles act together when looking up

Inferior thought to assist in pulling down lower lid and maintaining appropriate alignment of the lid with the globe when pt looks down

Question 11

What is the function of the fascial sheath of the eyeball?

Answer 11

TO position and support the globe
Permit actions of EOM
Note eyeball and sheath move TOGETHER on bed of orbital fat.