W8: Vision and Eye Conditions

Question 1

Significance of Strabismus

Answer 1

Presentation of squint and misalignment of eye
*atrophy of muscles

ESOTROPHIA = convergent squint
EXOTROPHIA = divergent squint

Complications:
AMBYLOPIA (lazy eye) = suppression of convergent/divergent eye image = poor vision

DIPLOPIA = d/t nerve palsy

Question 2

EYE MOVEMENTS AND MUSCLES AND SPEC N.

Answer 2

SR. - IO - SR

LR (VI). - MR. - LR (VI)

IR. - SO (IV). - IR

Question 3

Horner’s Syndrome

Answer 3

PTOSIS (drooping of upper eyelid)
MIOSIS (pupil constriction)
ANHYDROSIS (loss of facial sweating)
(ipsilateral)

• pancoast tum of the lungs
• sympathetic innervation dmg

Question 4

Anisocoria

Answer 4

unequal pupil size d/t symp. innervation dmg

Question 5

Significance of eye muscle paralysis and infection (and subsequent CN involvement)

Answer 5

A hx of infection (think purulent source around the nasal triangle) can lead to infection spread via venous orbit and blocking the drainage = swelling and congestion thus raising pressure in the central retinal artery

=

• swollen optic head
• dilated veins
• blurred vision, swelling, red eye

*CN involvement with cavernous sinus thrombosis (emissary vein spread to cavernous sinus)

palsies of cranial nerves III, IV, V and VI, producing loss of corneal reflexes, ophthalmoplegia and hypesthesia over the upper part of the face. Papilledema and visual loss may result from obstruction of retinal venous return

Question 6

IVn Palsy

Answer 6

Inability to depress the eyes thus the eyes will shoot upwards

*SO loss

Question 7

VIn Palsy

Answer 7

Inability to abduct the eyes via LR(VI)

Question 8

IIIn Palsy

Answer 8

Widespread palsy = ptosis (Lev. palp. sup. innervated by IIIn),

Non-reactive enlarged pupils

Question 9

Early sign of cataract

Answer 9

Cataracts can make it difficult to see in low light. One of the primary indications that cataracts are developing is the gradual loss of contrast sensitivity, which becomes especially noticeable in dim lighting

Question 10

Cause of Glaucoma

Answer 10

⇧intraoccular pressure of 21mmHg+ = ⇩visual field; cropped and pale optic disc

d/t dysfunctional trabecular meshwork and failure to drain aqueous humour (

Question 11

Glaucoma Presentations

Answer 11

1º OPEN ANGLE = sudden onset
visual field = vision loss, pale optic disc

> prostaglandin analogues; BBlockers; carbonic anhydrase inhibitors
LAser trabeculoplaasty
Trabeculostomy Sx

CLOSE AANGLE = sudden onset, PAIN, headaches

• very painful red eye
• iris sticks to cornea, pressure builds behind posterior chamber

(1)
> IV carbonic anhydrase
> Analgesia
> PILOCARPINE: constrictor eye drops
> steroid drops

(2)
> Irodotomy

Question 12

Uveitis

Answer 12

Isolated autoimmune picture

*chronic TB, systemic picture