Sclera

Question 1

How does thickness in sclera change moving anteriorly from eom insertions

Answer 1

Thickness increases as it moves anteriorly towards limbus

Question 2

Sclera around optic nerve is thickest and blends with

Answer 2

Nerve dura sheath

Question 3

Passage for optic nerve axons and central retinal vessels

Answer 3

Lamina cribrosa

Question 4

What does the posterior scleral foramen contain

Answer 4

Lamina cribosa

Question 5

Scleral foramina

Answer 5

Anterior scleral foramen -cornea

Posterior scleral foramen - lamina cribosa

Question 6

What occupies internal and external scleral sulcus

Answer 6

TM and Conjunctiva

Question 7

Shape of anterior scleral foramen

Answer 7

Elliptical anteriorly and circular posteriorly

Question 8

Structures important for aqueous drainage thats in the the corneoscleral junction

Answer 8

TM, Canal of Schlemm, scleral spur

Question 9

Scleral spur is attached to

Answer 9

Ciliary muscle and canal of schlemm

Question 10

Myelination of ON happens

Answer 10

As they leave the eye Posterior to lamina cribosa

Question 11

Weakest part of the fibrous tunic of the eye

Answer 11

Lamina cribosa

Question 12

When does ONH cupping occur

Answer 12

Elevated IOP

Question 13

Effect of sclera on ONH

Answer 13

Changes in IOP can cause stress in CT in lamina cribosa if sclera is stiff

This causes decrease in blood supply to ON
Damaged axons
Glaucoma

Question 14

Sclera regions

Answer 14

Episclera
Sclera stroma
Lamina fusca

Question 15

Merges w tenons capsule at the limbus

Answer 15

Episclera

Question 16

Thin and delicate fibrovascular layer

Answer 16

Episclera

Question 17

Scleral stroma is continuous with

Answer 17

Corneal stroma

Question 18

What is the episclera made of

Answer 18

Loose CT

Question 19

Sclera layer that acts as synovial; membrane for smooth movement of eye

Answer 19

Episclera

Question 20

Episclera thickness

Answer 20

Thickest anterior to rectus insertions thins out towards posterior pole

Question 21

What provides nourishment to a vascular sclera

Answer 21

Episclera and choroid

Question 22

Scleral stroma composition compared to cornea

Answer 22

Bundles of collagen are thicker here of quite variable diameters

Question 23

Lamina fusca contains

Answer 23

Melanocytes of choroid all origin that travel through emissary canals to get to sclera

Question 24

Lamina fusca attachment

Answer 24

Attached to underlying uveal tract

Loose attachment to choroid (thin collagen)

Strongly attached to ciliary muscle

Question 25

Which layer of the sclera blends w tenons capsule

Answer 25

Episclera

Question 26

main blood supply of episclera derives from

Answer 26

Anterior ciliary arteries Other: long and shirt posterior ciliary arteries

Question 27

Arise from episclera arterial circle formed by anterior ciliary arteries

Answer 27

Superficial and deep episclera plexus

Question 28

Blood supply to equator and posterior aspects of episclera come from

Answer 28

Posterior ciliary arteries

Question 29

Stroma of sclera blood supply

Answer 29

A vascular Diffusion from episclera and choroidal plexuses

Question 30

Metabolic rate of sclera

Answer 30

Low

Question 31

What are emissary canals

Answer 31

Tunnels that traverse the stroma of the sclera and transmit arteries nerves and veins

Question 32

Emissary canals are most likely found in

Answer 32

Superior and inferior aspects of the sclera

Question 33

Posterior emissary

Answer 33

Posterior long and short ciliary arteries Short and long ciliary nerves

Question 34

Middle emissary

Answer 34

Vortex veins

Question 35

Anterior emissary

Answer 35

Anterioir ciliary vessels Small branches from episcleral vessels communicating w canal of schlemm

Question 36

Schlemm canal drains aqueous into

Answer 36

Episclera

Question 37

Circular band of collagen bundles extending from the inner aspect of the sclera towards the angle of the ant angle

Answer 37

scleral spur

Question 38

Where is scleral spur located between

Answer 38

Ciliary body and schlemm canal

Question 39

Scleral spur attachment to ciliary muscle helps

Answer 39

Contraction tension at scleral spur which opens TM and assists in aqueous drainage

Question 40

Sclera innervation (general)

Answer 40

Short and long ciliary nerves (posterior emissary) perforate the sclera around optic nerve

Question 41

Posterior sclera innervation

Answer 41

Short ciliary nerves

Question 42

Anterior sclera innervation | Episclera, TM and canal of schlemm

Answer 42

2 long anterior ciliary nerves

Question 43

GAGs and fibroblast in sclera

Answer 43

Less in cornea than in cornea

Question 44

Water composition of sclera

Answer 44

70% slightly less than cornea

Question 45

Abundant collagen type in sclera

Answer 45

Type I (most of scleras weight)

Question 46

Cells involved in CT remodeling of sclera

Answer 46

MMPs secreted by fibroblasts and inflammatory cells

Question 47

Sclera growth enables

Answer 47

Myopia elongation of the eye

Question 48

Sclera has more GAGS than cornea

Answer 48

Yes

Question 49

Blue sclera is associated with

Answer 49

CT disorders ( Marfan’s and Ehlers-Danlos syndrome, osteogenesis imperfecta ) Abnormal thin sclera can allow to see choroid

Question 50

Yellow tint in sclera

Answer 50

Lipid accumulation (older ppl) Liver disease

Question 51

Hyaline scleral plaques

Answer 51

Areas of thinned sclera anterioir to EOM insertions

Question 52

No involvement of palpebral conjunctiva or discharge in episclera this Photophobia Eyelids affected

Answer 52

Conjunctivitis

Question 53

Scleritis

Answer 53

Serious, usually autoimmune Antibodies target sclera Painful

Question 54

Axenfelds nerve loop

Answer 54

Extension of long ciliary nerve makes look Pigments Maybe painful to move