MCQs - Conditions of the Episclera, Sclera, Limbus & Conjunctiva

Question 1

choriostoma

Answer 1

normal tissue in abnormal location

for example dermoid is a congenital choriostoma

Question 2

Which site is the most common region for scleral rupture associated with blunt trauma in small animals?

a.At the posterior pole
Well done
b.Dorsal part of the globe
c.Near the limbus
d.Ventral part of the globe

Answer 2

Which site is the most common region for scleral rupture associated with blunt trauma in small animals?

a. At the posterior pole

Your answer is correct.
Globe rupture associated with blunt trauma occurs most commonly at the posterior pole, near the optic nerve or at the equator.

The correct answer is: At the posterior pole

Question 3

Unlike the cornea, the sclera is not transparent because structurally:

a. The scleral collagen fibres are regularly spaced
b. The scleral collagen fibres are orientated in a parallel fashion throughout the tissue
c. The sclera fibres vary in size and orientation
d. The scleral collagen fibres are a consistent diameter and shape

Answer 3

Unlike the cornea, the sclera is not transparent because structurally:

The sclera fibres vary in size and orientation

Your answer is correct.
Structurally the sclera is similar to the cornea, but it is not transparent because the scleral collagen fibres differ in diameter and shape, are not regularly spaced, and are interwoven.

Question 4

Signs of scleritis include:

a. Non-painful episcleral masses; episcleral hyperaemia; thickened sclera; glaucoma
b. Painful, thickened sclera; episcleral hyperaemia; choroiditis
c. Painful episcleral masses; anterior uveitis
d. Non-painful, thickened sclera; episcleral hyperaemia; choroiditis

Feedback
Your answer is correct.
Scleritis manifests as regional or diffuse thickening of the sclera with hyperaemia of the overlying episclera and conjunctiva. There is often ocular pain. Severe or chronic disease can lead to involvement of the adjacent choroid, and this can result in retinal detachment.

The correct answer is: Painful, thickened sclera; episcleral hyperaemia; choroiditis

Answer 4

Signs of scleritis include:

b. Painful, thickened sclera; episcleral hyperaemia; choroiditis

Your answer is correct.
Scleritis manifests as regional or diffuse thickening of the sclera with hyperaemia of the overlying episclera and conjunctiva. There is often ocular pain. Severe or chronic disease can lead to involvement of the adjacent choroid, and this can result in retinal detachment.

The correct answer is: Painful, thickened sclera; episcleral hyperaemia; choroiditis

Question 5

Histologically, from inner to outer, the sclera is arranged as follows:

a. White fibrous tissue (the sclera proper); loose connective tissue (the episclera); elastic fibres (lamina fusca)
b. White fibrous tissue (the sclera proper); elastic fibres (the lamina fusca); loose connective tissue (the episclera)
c. Elastic fibres (the lamina fusca); a dense white fibrous tissue (the sclera proper); loose connective tissue (the episclera)
d. Loose connective tissue (the episclera); a dense, white fibrous tissue (the sclera proper); elastic fibres (the lamina fusca)

Answer 5

Histologically, from inner to outer, the sclera is arranged as follows:

c. Elastic fibres (the lamina fusca); a dense white fibrous tissue (the sclera proper); loose connective tissue (the episclera)

Question 6

Which of the following does not arise as a consequence of symblepharon?

a. Epiphora
b. Ocular motility disorder
c. Exposure keratitis
d. Exophthalmos

This is not a consequence of symblepharon, so this is the correct answer - well done

Answer 6

Which of the following does not arise as a consequence of symblepharon?

d.Exophthalmos

This is not a consequence of symblepharon, so this is the correct answer - well done

Question 7

Possible causes of symblepharon include: (you may choose more than one answer)

Select one or more:

a. Chemical injury
b. Feline immunodeficiency virus
c. Feline herpes virus-1 infection
d. Feline infectious peritonitis

Answer 7

Possible causes of symblepharon include: (you may choose more than one answer)

a. Chemical injury
c. Feline herpes virus-1 infection

Question 8

Abnormal protrusion of the uveal tissue through a weak point in the sclera is termed:

a. Staphyloma
b. Symblepharon
c. Choristoma
d. Dermoid

Answer 8

Abnormal protrusion of the uveal tissue through a weak point in the sclera is termed:

a.Staphyloma

Well done. A staphyloma is defined as a thinned, bulging region of sclera lined by uveal tissue

Question 9

Methods to determine if a globe is ruptured include:

a. Direct pupillary light reflex
b. Aqueocentesis
c. Globe retropulsion
d. Ultrasonography

Answer 9

Methods to determine if a globe is ruptured include:

d.Ultrasonography

Ultrasonography can be useful in cases of posterior rupture. Continuity of the posterior scleral wall is lost and echogenic material consistent with vitreal haemorrhage may be seen.

The correct answer is: Ultrasonography

Question 10

9. Optic nerve cupping occurs due to structural changes in the lamina cribosa and:
   a. Congestion of the optic nerve vessels which causes axon death
   b. Inflammation of the optic nerve vessels which causes axon death
   c. Inflammation of the nerve fibre axons which causes axon death
   d. Reduced blood supply which causes axon death

Answer 10

Optic nerve cupping occurs due to structural changes in the lamina cribosa and:

Reduced blood supply which causes axon death

Your answer is correct.
Optic nerve cupping occurs as the lamina cribrosa is distorted and compressed posteriorly by increased IOP. This affects axoplasmic flow and reduces the blood supply to the optic nerve head, leading to optic axonal nerve death.

The correct answer is: Reduced blood supply which causes axon death
Correct

Question 11

The most common tumour to affect the limbus of a dog is:

a. Melanoma
b. Lymphoma
c. Squamous cell carcinoma
d. Haemangiosarcoma

Answer 11

The most common tumour to affect the limbus of a dog is:

a.Melanoma