Test 17  (paediatric ophthalmology) 

 

Refer to the picture above for question 1.

1. The organisms responsible for the above appearance include:

a. 

b. 

c. 

d. 

e. 

Answera.T   b.T  c.F  d.T e.F
The picture shows a raised lesion in the retina due to toxocariasis.
a. is the electron microscopy of the egg.
b. is the microscopy of the egg.
c. shows two dog dungs containing adult Toxocara canii worms (in white).
d. is the larveted egg of Toxocara canii.
e. is a sporulated oocyst of Toxoplasma gondii.
The oocyst contains two sporocysts, each of
which contain four sporozoites.

 
 

---

Refer to this picture for question 2.

 
2. The following conditions are associated with the picture above:

a. 

b. 

c. 

d. 

e. 

Answera.T   b.T   c.F   d.T  e.T
The referring picture shows a retinoblastoma.
a. is Ewing's tumour of the bone and is not associated with this condition.
b. is osteosarcoma and shows an increased incidence in retinoblastoma. Osteosarcoma shows a characteristic triangular shape near the epiphyses when viewed on the X-ray.
c. is Choroidal melanoma.
d. shows Flexner-Wintersteiner's rosettes a feature of retinoblastoma.
e. shows pinealoma (note the central white lesion) 
which shows an increased incidence in retinoblastoma. 
 

---

Refer to the picture above for question 3.

3. Related features in this boy include::

a. 

b. 

c. 

d. 

e. 

Answera.F   b.T  c.F  d.T  e.F
This boy has oculocutaneous albinism which is an 
autosomal recessive condition. The family tree illustrates an X-linked recessive condition which is found in ocular albinism.
b. shows an albino fundus and the choroidal vessels are clearly visible due to absent pigment in the RPE.
c. shows advanced choroideremia in which the choroidal vessels show atrophy.
d. shows lung fibrosis which can occur in 
Hermansky-Pudlack syndrome in which albinism is associated with platelet abnormality (with increased bleeding time) and lung fibrosis.
e. shows normal RPE pigmentation which is usually absent in oculocutaneous albinism. (see picture below for an albino RPE).

 
 

---

Refer to this picture for question 4.

4. Associated features include:

a. 

b. 

c. 
d. 

e. 

Answera.T  b.T  c.F  d.F  e.T
The referring picture shows polydactyly 
and is a feature of Bardet-Biedl's syndrome.
This is associated with mental retardation, 
obesity (c), pigmentary retinopathy (b), hypogonadism and renal problems.
In addition to the classical polydactyly, the 
digits may show bradydactyly ie. shortened digits and syndactyly (a).
Ptosis and preauricular tags are not associated with this condition.

 
 

---

Refer to the picture above for question 5.

5. The following investigation(s) is/are useful for confirming 
     the diagnosis:
 

a.	b.
c.	d.
e.

 
Answera.F   b.F  c.T   d.F  e.F
The referring picture shows Best's disease. 
The investigation of choice is EOG (electro-oculogram). The electrodes are attached to the medial and lateral canthal to record the potentials.
a. is EEG for recording brain wave and is frequently used in the investigation of epilepsy.
b. is ECT (electroconvulsive therapy) for depressive patient.
d. is ERG (electroretinogram), a contact lens is used in this study.
e. is visual evoked potential.

 
 

More MCQs

An albino retina vs a normal retina.  Note the absence of pigments in the RPE.