Ocular Trauma

Question 1

initial assessment

Answer 1

good history of incident

visual acuities

examination of eye

use fluorescein drops and a bright blue light to examine cornea

Question 2

what is a quick but sensitive test to examine clarity of vision

Answer 2

ability to read news print with refractive errors corrected

Question 3

if the patient cannot open the eye to be examined what can be done

Answer 3

fews drops of local anaesthetic (eg tetracaine 1%)

Question 4

which imaging is good and which should be avoided

Answer 4

CT is good

avoid MRI as FB may be magnetic

Question 5

what must be done if there is a suspicion of IOFB

Answer 5

X ray of orbit

Question 6

orbital blowout fracture

Answer 6

blunt injury can cause a sudden increase in pressure in the orbit, and may cause blowout fracture withn the orbital contents herniating into the maxillary sinus

typically affects medial wall (ethmoid bone) and floor (maxillary bone)

Question 7

signs of orbital blowout fracture

Answer 7

pain

muscle entrapment

decreased visual acuity

hypoesthesia in the infraorbital region due to infraorbital nerve (CNV2) injury

periorbital ecchymosis (discolouration of skin due to bleeding underneath)

Question 8

what does this CT scan show

Answer 8

orbital blowout fracture and herniation of contents into maxillary sinus

Question 9

what is a classical orbital blowout fracture CT sign

Answer 9

tear drop sign - herniation or orbital fat inferiorly

Question 10

which muscle is often trapped in an orbital blowout fracture and what clinical feature does this result in

Answer 10

often entraps inferior rectus/inferior oblique muscles

pain on upward gaze and diploplia

Question 11

investigation and treatment of orbital blowout fracture

Answer 11

CT

fracture reduction and muscle release

Question 12

hyphaema

Answer 12

blood in anterior chamber

may affect acuity

Question 13

clinical features of traumatic uveitis

Answer 13

acute pain, photophobia, decreased acuity, lacrimation (not sticky), circumcorneal redness, small/irregular pupils

Question 14

commotion retinae

Answer 14

bruised retina

degeneration of the layers of the retina secondary to shock waves caused by blunt trauma/blast injury

Question 15

Answer 15

optic nerve avulsion

Question 16

globe rupture

Answer 16

any full thickness injury of the cornea/sclera is considered a globe rupture

must be handled with care

Question 17

where is a scleral rupture most common

Answer 17

insertion of intraocular muscles or at the limbus, where the sclera is thinnest

Question 18

indications of globe rupture

Answer 18

hyphema, loss of anterior chamber depth or deviation of pupil towards laceration or irregular pupil (tear drop shape)

must be handled with care

Question 19

what must be done on presentration with penetrating trauma

Answer 19

history and examination

X ray to exclude intra-ocular foreign bodies (±skull x ray and CT to exclude intracranial involvement)

Question 20

what autoimmune inflammatory response is there a risk of in uveal injury

Answer 20

sympathetic ophthalmia

bilateral granulomatous uveitis that is thought to be an autoimmune inflammatory response towards ocular antigens

may lead to bilateral blindness

Question 21

how should a large foreign body be dealt with

Answer 21

done remove it, support it with padding

pad the unaffected eye to prevent damage from conjugate movement

Question 22

chemosis

Answer 22

swelling of conjunctiva

Question 23

when should a foreign body be considered to have penetrated

Answer 23

irregular pupil, shallow anterior chamber, localised cataract or gross inflammation

Question 24

what must be done to all IOFB

Answer 24

X ray

Question 25

corneal abrasion

Answer 25

occurs without keratitis often in trauma, usually from small fast-moving objects

may cause intense pain

Question 26

what should be applied to a corneal abrasion before examining

Answer 26

local anaesthetic - 1% tetracaine

Question 27

what prophylactic ABx may be used on a corneal abrasion

Answer 27

chloramphenicol

Question 28

clinical features of a corneal abrasion

Answer 28

intense pain

photophobia ± decreased vision

Question 29

what can be used to view the cornea and aid diagnosis of corneal abrasion

Answer 29

fluorescein drops and a bright blue light to aid diagnosis

(corneal lesions stain green, drops are orange and become yellow on contact with eye)

Question 30

when should signs of corneal abrasion healing start

Answer 30

within 48 hours

Question 31

initial treatment of burns

Answer 31

PROMPT

instil anaesthetic drops (eg 1% tetracaine) every 2 mins until the patient is comfortable, then hold lids open and bathe in copious amounts of clean water/saline while the specific antidote is sought

check Toxbase if available, check pH and irrigate until normal (around 7.6)

Question 32

what are some late serious sequlae of burns

Answer 32

corneal scarring, opacification and lid damage

Question 33

are alkaline or acid burns more serious

Answer 33

alkaline

Question 34

alkaline chemical burns

Answer 34

serious

rapid penetrationof intraocular structures

scarring changes to conjunctiva and cornea

Question 35

acid chemical burns

Answer 35

coagulates protein, little penetration