Opthalmo

Question 1

What are the differentials for a painless red eye

Answer 1

• Blepharitis
• Ectropion/ Entropion
• Pterygium
• Subconjunctival hemorrhage
• Episcleritis

Question 2

What are the differentials for a painful red eye

Answer 2

Eyelid problem
- Chalazion
- Blepharitis
- Herpes Zoster

Cornea problem
- HSV keratitis
- Corneal ulcer/abrasion
- Arc eye
- Foriegn body

Diffuse Conjunctival injection
- Acute angle glaucoma
- Conjunctivitis
- Dry eyes

Cilliary injection/Scleral involvement
- Scleritis

Anterior Chamber
- Uveitis/iritis
- Hypopyon/Hyphaema

Question 3

Red Eye Ddx

Answer 3

• Painful

1. Eyelid
   a) chalazion
   b) blepharitis
   c) herpes zoster
2. Cornea
   a) HSV keratitis
   b) Corneal ulcer
   c) Arc eye
   d) Foreign body
3. Conjunctiva
   a) Conjunctivitis (bacterial, viral, allergic)
   b) Dry eyes
4. Other
   a) Acute angle closure glaucoma
   b) Anterior uveitis (keratitis)
   c) Scleritis

• Painless
  1. Blepharitis
  2. Ectropion
  3. Entropion
  4. Pterygium
  5. Subconjunctival haemorrhage
  6. Episcleritis

Question 4

Visual Loss Ddx

Answer 4

• Painful
  1. Acute glaucoma
  2. Optic neuritis
• Painless
  1. CRAO
  2. CRVO
  3. Retinal detachment
  4. Vitreous haemorrhage

Question 5

Eyelid laceration

Answer 5

• Penetrating eye injury until proved otherwise
• Ophthalmology referral for repair if:
  1. associated ocular trauma

2. laceration medial to either upper or lower eyelid punctum due to risk of damage to nasolacrimal drainage system
3. Extensive tissue loss or distortion of anatomy
4. Full thickness laceration or involving lid margin

• ADT +/- systemic antibiotics

Question 6

Corneal foreign body

Answer 6

1. Check under eyelid
2. Remove with 25/27G needle with bevel facing away from patient with slit lamp
3. Antibiotic drops/ointment
4. Avoid contact lens use, PO analgesia
5. Review in 24-36 hours
6. Ophthalmology referral if
   - unable to be removed
   - worsening/recurrent symptoms
   - rust ring
   - plant scratches (risk of fungal infection)

Question 7

Corneal abrasion

Answer 7

1. Conjunctival erythema and fluorescein uptake
2. Rx ADT, oral analgesia, topical antibiotics
3. Review daily until healed
4. Avoid contact lens use
5. Ophthalmology review if:
   - plant scratches
   - extensive central epithelial defects

Question 8

Corneal ulcers

Answer 8

1. Usually Gram negative and Gram positives
   a) especially Pseudomonas in contact lens wearers
   b) can blind in 1 day
2. RF: contact lens, diabetics, immunocompromised
3. White or grey spot on cornea, central area of lobulated mass with surrounding fluorescein uptake, hypopyon
4. Rx:
   - ophthalmology review
   - fortified topical antibiotics
   - Systemic antibiotics if severe

Question 9

Flash burns Eye

Answer 9

1. Arc welding, snow blindness, sun lamp, UV keratitis
2. Intense pain, red eye, blepharospasm, tearing
3. Widespread superficial epithelial loss (often pin point) with fuoroscein
4. Rx
   - topical antibiotics QID
   - cycloplegic (homatropine 5% BD)
   - PO analgesia
   - represent if doesn’t improve after 24 hours

Question 10

Chemical injuries eye

Answer 10

1. Alkali worse than acid burns as causes liquefactive necrosis and penetrate deeper
2. Remove particulate matter with cotton bud
3. Irrigate with normal saline until pH 7.4 - 7.5
   check after each litre of fluid
4. Amount of limbic blanching proportional to severity of burn
5. Same day ophthalmology referral

Question 11

Tissue adhesives eye

Answer 11

1. Can cause chemical keratitis
2. Do not force eyelashes open
3. Irrigate
4. Rub with petroleum based antibiotics
5. If unable to open, refer

Question 12

Blunt ocular trauma

Answer 12

1. Often have orbital wall fractures
2. Closed globe injury
3. Open globe injury
   - ruptures at areas of thinnest sclera
   a) limbus (visible on slit lamp)
   b) behind insertion of rectus muscle (decreased eye movements, loss of red reflex, vitreous bleeding)
4. Look for hyphaema, limbic tears, abnormal pupils, iridodialysis (detached iris - D-shaped pupil), lens damage, raised IOP
5. CT scan if fracture suspected
6. Refer to ophthalmology
7. Rx:
   - reduce IOP
   - head up
   - eye shield
   - antiemetics
   - analgesia

Question 13

Penetrating eye injury

Answer 13

1. Increased risk with small high-velocity projectiles (hammer-chisel > grinding)
2. Decreased visual acuity, shallow anterior chamber, irregular pupil, small subconjuctival haemorrhage, decreased IOP, Seidels sign
3. Ix CT or US
4. Rx
   - minimal examination
   - shield (not pad) eye
   - anti-emetics
   - analgesia
   - no topical treatment
   - IV cephazolin and gentamicin
   - ADT
   - Ophthalmology referral

Question 14

Hyphaema

Answer 14

1. Blood in anterior chamber
2. Usually associated with trauma, but may occur spontaneously in sickle cell and other blood disorders, NAI in children
3. Grading:
   a) Grade 0: no layering, but red cells in anterior chamber
   b) Grade 1: layered, <1/3 anterior chamber
   c) Grade 2: <1/2 anterior chamber
   d) Grade 3: <100% anterior chamber
   e) Grade 4: total filling of anterior chamber
4. Rx
   - Ophthalmology referral
   - Eye shield (not pad)
   - Bed rest with head elevated 30 degrees
   - Cycloplegics (atropine 1% or homatropine 2-5% BD)
   - Acetazolamide or timolol 0.5% BD if raised IOP
   - Avoid aspirin and NSAIDs
5. Complications
   - Glaucoma in 7%
   - Rebleeding in 10% (3 -5th day)
   - Corneal staining
   - traumatic iritis
   - Synechiae formation
   - Visual loss rare
   - Associated injuries

Question 15

Blowout fracture

Answer 15

1. Most commonly through medial or inferior walls
   - lateral wall more solid so tends to occur with extensive facial damage
   - does not extend to rim
2. Signs:
   - bruising and oedema
   - Subcutaneous emphysema with medial wall
   - Inferior rectus entrapment:restriction of upward gaze and diplopia
   - Infraorbital nerve injury (lower lid, cheek, side of nose, upper lip/teeth/gums)
   - Retrobulbar haematoma
   - Enopthalmos may suggest globe rupture
   - Epistaxis, ptosis, trismus
3. Ice pack, PO/IV antibiotics, ADT, NBM, avoid blowing nose, nasal decongestant, soft diet
4. Plastics/opthalmology review
   - usually delayed surgical repair > 1 weeks

Question 16

Blowout fracture associated injuries

Answer 16

1. Retinal tear/detachment
2. Lens dislocation/dubluxation
3. Hyphaema
4. Corneal injuries
5. Retrobulbar haematoma
6. Compressive orbital emphysema

Question 17

Retrobulbar haematoma

Answer 17

1. Proptosis
2. Ischaemia of optic nerve; fixed and dilated pupil
3. Visual loss

Question 18

Lateral canthotomy indications

Answer 18

1. Raised intra ocular pressure >40mmHg in unconscious patient with retrobulbar haemorrhage (normal pressure is 10-21)
2. Rapid afferent pupillary defect
3. Dilated pupil in absence of central cause and CT suggesting retrobulbar haematoma
4. decreased acuity
5. significant pain
6. ophthalmoplegia
   Contraindicated if ruptured globe

Question 19

Lateral canthotomy steps

Answer 19

1. use local anesthetic but warn the patient that they may feel pain
2. crush lateral canthus with forceps for haemostasis
3. Perform the canthotomy:
   - place the scissors across the lateral canthus and incise the canthus full thickness
4. Perform cantholysis:
   a) Grasp the lateral lower eyelid with toothed forceps
   b) Pull the lower eyelid anteriorly
   c) Place the blades either side of the lateral canthal tendon (lower crus), and cut
   d) Eye should come away; may need to cut superior crus

Question 20

Eyelid disorders

Answer 20

1. Blepharitis
   - usually Staph infection of eyelash follicles
   - itchy, heavy eyes with oedema and redness
   - topical antibiotic to lid, hygiene, lubrication
2. Ectropion
   - lids turned outwards with exposure of conjunctiva
   - lubrication and routine referral
3. Entropion
   - inward rotation of eyelid
   - if cornea intact; lubrication and routine referral
   - of corneal abrasion: tape back eyelid and topic antibiotics
4. Chalazion (Meibomian cyst)
   - firm, non-tender nodule palpable in eyelid
   - warm compresses for 1-2 weeks, excision and drainage if does not settle, topical Abx if ruptured
5. Stye (external hordeolum)
   - acute suppurate infection of glands of Zeis
   - usually S. Aureus
   - Swelling extending from lid margin, may be pus filled
   - Warm compresses, topical antibiotics

Question 21

Dacryocystitis

Answer 21

1. Blockage of lacrimal drainage system
2. In infants, may be a complication of congenital or acquired nasolacrimal duct obstruction
3. May also be trauma or stone related
4. Pain, redness and swelling below medial cants
5. Rx
   - IV antibiotics if complicated by cellulitis
   - Nasolacrimal duct probing
   - Nasal endoscopy for excision of intranasal duct cyst
   - Dacryocystorhinostomy and stent placement if secondary to facial trauma
6. Dacryoadenitis
   - inflammation of lacrimal gland
   - outermost part of upper eyelid swelling, excessive tears, discharge
   - acute form usually due to staph
   - IV Abx

Question 22

Preseptal cellulitis organisms

Answer 22

1. Strep pneumoniae and Staph aureus most commonly
2. Haemophilus in unvaccinated individuals
3. Gram negatives
4. Anaerobes

Question 23

Orbital cellulitis sources

Answer 23

1. Paranasal sinuses (esp ethmoid)
2. Skin infection
3. Haematogenous spread

Question 24

Orbital cellulitis Sx

Answer 24

1. Hx of diabetes, sinusitis
2. Headache
3. Decreased eye movements
4. Chemosis
5. Swelling does not extend to upper eyebrow and eyelid
6. Proptosis (late finding)
7. Pupil dilatation and RAPD (very late)

Question 25

Orbital cellulitis complications

Answer 25

1. Endopthalmitis 2. Visual loss 3. Optic nerve compression 4. Meningitis 5. Cerebral abscess

Question 26

Orbital cellulitis Ix and Rx

Answer 26

1. CT - oedema of orbital contents (EOM) - intra-orbital abscess - gas/air-fluid level - fluid in adjacent sinuses - fat stranding 2. Blood cultures 3. FBC, CRP 4. Rx - Periorbital: oral augmentin or cephalexin - Orbital or unwell: flucloxacillin and cefotaxime IV a) both 50mg/kg b) urgent ophthalmology consultation c) may require urgent decompression - Analgesia - Parental explanation/reassurance

Question 27

Conjunctivitis causes

Answer 27

1. Viral - adenovirus - influenza - measles - mumps - HSV/HZV - Epidemic keratoconjunctivitis 2. Bacterial - streptococcal - chlamydia - gonococcal 3. Allergic 4. Dry eyes

Question 28

Conjunctivitis Sx and Rx

Answer 28

1. Viral - coryza, watery discharge, irritation, minimal pain - photophobia, FB sensation, excessive tearing in epidemic keratoconjunctivitis - bilateral in 90%; good vision - pre-auricular lymph node may be palpable - Rx: no Abx unless immunocompromised, hand hygiene, cool compress, lubricant eye drops, nasal decongestants - lasts for 5-7 days, occasionally 3 weeks 2. Bacterial - lid oedema, purulent discharge - Rx: conjunctival swab, topical Abx, eye hygiene to clear secretions - Systemic therapy if STD; esp in neonates - Optical referral if does not improve after 2 days 3. Allergic - Itchy, atopic history - Oedematous conjunctiva with papillae on inferior conjunctival fornix - Rx: cool compresses, lubricant eye drops, antihistamines, steroid eye drops after ophthalmology advice 4. Dry eyes - symptoms worse in evening; systemic rheum conditions - Rx: lubricants and routine referral