Eye

Question 1

You note a patient with severe myopia has a globe (eye) which is non-spherical. A colleague suggests this is due to a “staphyloma”. Which of the following is most correct?

1. This is a localised an inflammatory weakness in the collagenous coat due to staph exotins
2. This is due to localised scleral thinning/ buldging
3. This is due to scleromalacia perforans associated with rheumatoid arthritis
4. This is due to localised staph infection (predominately Staph aureus)
5. This is due to localised staph infection and it usually post trauma/ 2secondary to staph epidermidis

Answer 1

2. *This is due to localised scleral thinning/ buldging

Question 2

Which of the following is the LEAST common primary tumor/mass of the orbit (separate to globe)

1. Capillary haemangioma
2. Lymphangioma
3. Pleomorphic adenoma of the salivary gland
4. Dermoid cyst
5. Hodgkin’s lymphoma

Answer 2

5. *Hodgkin’s lymphoma

Question 3

Regarding thyroid orbitopathy: (March 2015)

a. Even post treatment may persist

Answer 3

• Most common cause of proptosis in adults. Most commonly assoc w Grave’s
• Increase in the size of the intra-orbital muscles & orbital fat volume
- Venous congestion of the superior ophthalmic vein
• Aetiology thought to relate to TSH antibodies activating T-lymphocytes => inflammatory response
- Inflammation, mucopolysaccaride deposition, collagen deposition, fibrosis

• IM SLO – inferior rectus, medial rectus, superior rectus, lateral rectus & obliques

ANSWER: Thyroid orbitopathy may persist even following treatment – may require surgical management for cosmetic reasons & to manage corneal ulceration & optic nerve compression

Question 4

A woman presents with a swollen medial rectus muscle, with streaky change in the surrounding fat. Her eye is painful. What is the most likely diagnosis? (March 2017)

a. Thyroid eye disease
b. Idiopathic orbital inflammation

Answer 4

ANSWER: Idiopathic orbital inflammation

Question 5

Regarding uveal melanoma: (March 2014)

a. Ciliary body melanoma has a better prognosis than iris melanoma
b. Iris melanoma has a better prognosis than choroidal melanoma
c. Naevi is a precursor lesion to uveal melanoma
d. Spreads to cervical lymph nodes
e. Commonest haematogenous spread is to the liver

Answer 5

Primary uveal melanoma
o Most common intra-occular primary malignancy

Epidemiology:

- Caucasions
- Increased incidence w age (<2% under age 20)

Clinical:

• Choroidal & ciliary body melanoma only seen on fundoscopy, or alerted to by symptoms of retinal detachment / advanced disease
• Iris melanomas detected by patient or family etc

Pathology:
- Arise from the ciliary body or the choroid
Three histological subtypes:
•	Mixed melanoma
•	Epithelioid melanoma
•	Necrotic melanoma

Poor prognostic factors:

- Older age >60 years
- Larger tumours
- Anterior location in the globe
- Epithelioid cells (mixed or epithelioid histology)
- Extra-occular extension - Along the ciliary vessels & nerves. Less commonly spreads along the optic nerve
- Amelanotic
- Location: Iris melanoma has the best prognosis. Ciliary body has the worst prognosis. Based on rate of metastases

Metastases:

• Liver > lung > bone > kidney > brain
• Metastases to the liver may occur late, 10-15 years
• 80-90% of patients with metastatic disease have liver lesions

Orbital melanoma:
o Choroid (85%) > ciliary (10%) > iris (5%)
o Spindle cell naevus lesions are considered pre-malignant
o May be heavily pigmented or amelanotic - Amelanotic lesions are more aggressive

DDx of ocular melanoma:
o Choroidal metastases: breast & lung primaries most common
	- Extra-occular orbital metastases most commonly from melanoma, or thyroid, kidney, GI primaries
o Choroidal haemangioma (benign)
o Retinal detachement
o Choroidal osteoma
o Idiopathic inflammatory pseudotumour
o Retinoblastoma – calcification in 95%

ANSWER: There are several true answers – iris melanoma has the best prognosis of the three locations, spindle cell naevus is a known precursor lesion and the commonest haematogenous spread is to the liver. Lymph nodes are not typically involved.

Question 6

Retinoblastoma: (March 2015)

a. Autosomal recessive inheritance
b. Secondary cancer includes chondrosarcoma
c. Pituitary involvement if called trilateral retinoblastoma
d. Contralateral retinocytoma means the condition is inherited
e. Spreads to lung over liver

Answer 6

Retinoblastoma
o Most common intra-occular neoplasm of childhood
o Heterogenous mass w calcifications, necrosis & increased vascularity
o Trilateral retinoblastoma: bilateral retinoblastoma & pineoblastoma

Cause:
- Sporadic or secondary to a germline mutation in the RB tumour suppressor gene (55% overall)
• Bilateral cases (30-40%) almost universally have the germline mutation
• Unilateral cases (60-70%) are caused by a germline mutation in 15%, w the remainder sporadic
• 90% penetrance of the RB germline mutation - Also at risk of developing trilateral retinoblastoma & osteosarcoma

Histology:
- Flexner-Wintersteiner rosettes (specific to retinoblastoma) & Homer-Wright rosettes (found in other PNETs)

Patterns of spread

- Along the optic nerve into the orbit
- Leptomeningeal
- Haematogenous metastases: Bone, BM, Liver. Less commonly to local nodes

Retinocytoma: benign retinal tumour
o No necrosis or mitotic activity
o Clinically & morphologically distinct, however has the same genetic implications as retinoblastoma (e.g. retinocytoma in the contralateral eye to retinoblastoma implies RB germline mutation)

ANSWER: Contralateral retinocytoma means the retinoblastoma is inherited

Question 7

What is the most common childhood orbital tumour? (August 2014)

a. Haemangioblastoma
b. Lymphoma
c. Retinoblastoma
d. Optic sheath meningioma

Answer 7

• Retinoblastoma is the most common intra-occular mass in childhood
• Haemangioma is the most common intra-orbital lesion in childhood
• Optic sheath meningiomas are rare in children - If they are present, suspect a diagnosis of NF2

ANSWER: Retinoblastoma is the most common childhood orbital tumour

Question 8

A patient has a calcified mass of the globe. What is the most likely diagnosis? (March 2017)

a. Retinoblastoma

Answer 8

ANSWER: Retinoblastoma should be on the differential for a calcified mass of the globe, particularly in a child.

Question 9

Regarding phthisis bulbi: (March 2015)

a. Ciliochoroidal effusion
b. Chronic retinal detachment
c. Bony elements
d. Cyclitic membrane

Answer 9

Causes of phthisis bulbi (end-stage eye):
o Trauma - Results in ciliochoroidal effusion & cyclitic membrane
o Infection
o Other inflammatory processes
o Radiation
o Chronic retinal detachment
o Persistent hyperplastic primary vitreous

Pathology:
o Small globe (<20mm)
o Thickened & folded posterior sclera
o Dystrophic calcification +/- intra-ocular bone from osseous metaplasia

ANSWER: All options are correct – ciliochoroidal effusion and cyclitic membranes are the result of trauma, chronic retinal detachment is another cause & bony elements are a complication

Question 10

What is a true finding in phthisis bulbi? (March 2014)

a. Osseous metaplasia
b. Optic nerve hypertrophy

Answer 10

ANSWER: Osseous metaplasia