Ophthalmology

Question 1

WHAT IS PERIORBITAL CELLULITIS?

Answer 1

Infection affecting the fat and muscles posterior to the orbital septum, within the orbit but not involving the globe

Question 2

What are the most common causative organisms in periorbital cellulitis?

Answer 2

1. Haemophilus influenzae
2. Streptococcus pneumoniae
3. Staphylococci

Question 3

What are the clinical features of periorbital cellulitis?

Answer 3

1. Acute swelling of the orbital tissues
2. Proptosis
3. Oedema
4. Limited eye movement

Question 4

What are the investigations for periorbital cellulitis?

Answer 4

1. Full blood count – WBC elevated, raised inflammatory markers.
2. Clinical examination involving complete ophthalmological assessment – Decreased vision, afferent pupillary defect, proptosis, dysmotility, oedema, erythema.
3. CT with contrast – Inflammation of the orbital tissues

Question 5

What is the management of periorbital cellulitis?

Answer 5

1. Requires imediate admission
2. Beta lactamase resistant antibiotics for staphylococci, amoxicillin and augmentin for haemophilus

Question 6

WHAT IS A SQUINT?

Answer 6

A squint is a condition in which the visual axes of each eye are not directed simultaneously at the same object.

Question 7

What are the investigations for a squint?

Answer 7

Facial appearance

Corneal reflections - symmetrical on pupil

Head tilt

Test ocular movements

Cover test

Question 8

What is the management of a squint?

Answer 8

1. Referral to secondary care
2. Eye patches can be useful to prevent ambylopia

Question 9

WHAT ARE THE FEATURES OF A RETINOBLASTOMA?

Answer 9

1. absence of red-reflex, replaced by a white pupil (leukocoria) - the most common presenting symptom
2. strabismus
3. visual problems

Question 10

What is the management of a retinoblastoma?

Answer 10

1. Enucleation is not the only option
2. Depending on how advanced the tumour is other options include external beam radiation therapy, chemotherapy and photocoagulation