Ophthamology

Question 1

Name the 6 important aspects of the ophthalmic physical exam

Answer 1

Visual Acuity - 20/##, pinhole, ischihara colour fields
Pupils - PEERLA
Confrontational visual fields and eye movements
Intra-ocular pressure - normal is 10-21mmHg
Fundoscopy - Cup to disc, macula, periphery
Slit Lamp - LLL, S/C, K, A/C, I, L

Question 2

Describe the principle of pinhole occulusion

Answer 2

By using a pinhole it focuses the light at the centre of the lens removing any affects of refraction error.
If improves mean there is a refractive error (myopic, peripheral cataract)
If does not improve means there is conclusions (retina or optic nerve lesion)

Question 3

List the mechanism of action of the Glaucoma eye drops

Answer 3

Non-selective alpha agonist (phrine)
- decrease aqueous production and increase flow through the trabecular meshwork
Selective alpha2 agonist (onidine)
- decrease aqueous production and increase uveoscleral outflow
Beta-Blockers
- decrease production of aqueous
Carbonic anhydrase inhibitors (zolamide)
- decrease production of aqueous production
Prostaglandin analogues (Prost)
- increase uveoscleral outflow

Question 4

Discuss the management of a globe rupture

Answer 4

1) Prevent further damage: limit examination, keep covered, provide anti-emetics, analgesia
2) CT of head and globe
3) Antibiotics
4) Urgent ophthalmic surgery

Question 5

List the findings for foreign body in the eye

Answer 5

Symptoms: 
- foreign body
- tearing
- redness
- pain
- photophobia
- vizualization, rust ring
- Seidel sign (extrusion of fluorescein dye due to perforation)
Management: 
- remove foreign body
- begin antibiotic eye drops (moxifloxacin)

Question 6

List some concerns with contact lens wearers

Answer 6

• Greater likelihood of red eye being infectious keratitis

- Risk of pseudomonas infection following abrasion (must not patch eye)

Question 7

List the findings for vitreous hemorrhage and compare to retinal detachment

Answer 7

Symptoms: 
- floaters, flashes
- loss of vision
- loss of red reflex
- possible RAPD (detachment),
- hemorrhage seen on fundoscopy
Management: 
- resorb within 3-6 months, must figure out reason for hemorrhage though. 
- Retinal detachment require surgery (scleral buckle or retinal pneumopexy

Question 8

Discuss the diagnosis and management of corneal ulcer

Answer 8

bacterial causes: 
- strep, staph, h flu in children
Symptoms: 
- eye pain, redness, 
- photophobia, tearing
- exudate in anterior chamber
- hypopyon
- positive fluorescein stain (green showing epithelial defect) 
Treatment: 
- Antibiotic eye drops, cycloplegics

Question 9

Discuss the diagnosis and management of corneal abrasion

Answer 9

It is an epithelial defect from trauma on the eye
Symptoms: 
- pain, redness, 
- photophobia, tearing
- fluorescein uptake 
Treatment: 
- antibiotic drops
- cover eye (unless CL wearer or organic material)

Question 10

Differentiate between Orbital and Pre-orbital cellulitis

Answer 10

Orbital
- both caused by staph aureus or strep pneumonia
- more likely to be caused by sinusitis, tooth infection or skin infection, vs trauma or skin infection in pre
Symptoms:
- severe eye pain with decreased visual acuity in orbital
Signs:
- tender, swollen and erythematous eyelids in both
- Ophthomalplegia, pain with eye movements, proptosis, RAPD in orbital
- Treatment:
- IV antibiotics
- admission to hospital
- ENT or Ophtho consult vs antibiotics only in pre

Question 11

List the different strabismus conditions

Answer 11

Tropia:
- alternating (switch eyes) or non-alternating (always same eye)
- concomitant (does not change with gaze) vs non-concomitant (changes with gaze)
Phoria:
- only detected with cover-uncover test, so should be done between 6 months and 5 years

Question 12

Differentiate Between the Cover Tests

Answer 12

Cover Test:
Alternating
- in alternating when the fixating eye is covered the tropic eye will become fixating and the other will become malaligned
- in non-alternating when the fixating eye is covered the malaligned eye will fixate, but the other eye will be aligned as well and will return to fixating eye when cover is removed
Cover-Uncover test:
- in phoria when the one eye is covered it will move into the tropic position. When it is uncovered you will see it move to centre to pick up fixation

Question 13

List the different causes of strabismus

Answer 13

Paralytic:
- Muscular: grave’s disease, myasthenia gravis
- Cranial Nerves: ischemic, tumour, multiple sclerosis, brain trauma
Non-paralytic:
- Vision: accommodative due to refractive error
- Structural: anisometropia, cataract, retinoblastoma

Question 14

List the differential for Anterior Uveitis

Answer 14

Infectious: 
- herpes zoster
- herpes simplex
- cytomegalovirus
Inflammatory: 
- PAIR (psoriatic, ankylosing spondylitis, inflammatory bowel disease, reactive)
- SLE

Question 15

Discuss the diagnosis and management of anterior uveitis

Answer 15

Symptoms: 
- pain, redness
- photophobia
- Ciliary flush
- miosis
- posterior syncheciae
- cells and flare
- keratin precipitates
Treatment: 
- underlying cause (anti-virals, systemic steroids)
- prednisolone eye drops

Question 16

Discuss the diagnosis and management of open angle glaucoma

Answer 16

Symptoms:
- asymptomatic peripheral (arcuate) vision loss
- high intra-ocular pressure
- increased cup to disc ratio
Treatment:
- glaucoma eye drops
- selective laser trabeculoplasty, trabeculotomy

Question 17

Discuss the diagnosis and management of acute angle closure glaucoma

Answer 17

Symptoms: 
- acute onset and progressive severe eye pain
- haloes
- redness, photophobia
- decreased visual acuity
- high intraocular pressure
- white-hazy cornea
- fixed mid-dilated pupil
Treatment: 
- Reduce pressure with azetazolamide, glycerine (hyperosmotic) and mannitol (hypertonic solution)
- Peripheral iridotomy

Question 18

Compare the risk factors of open angle and closed angle glaucoma

Answer 18

Open Angle:
- Increased age
- African-American
- Increased intra-ocular pressure
- Family History
Closed angle
- Increase age
- Female
- Hyperopia
- Chines, Inuit