Paper 1 CRQ

Question 1

What neurotransmitters are released by postganglionic sympathetic fibres

Answer 1

Noradrenaline

Question 2

When do postganglionic sympathetic fibres not release noradrenaline

Answer 2

Nerves innervating adrenal medulla and sweat glands release Acetylcholine

Question 3

How is dopamine produced

Answer 3

Tyrosine is converted to L-DOPA by tyrosine hydroxylase. L-DOPA is then converted to dopamine by DOPA decarboxylase. Dopamine Beta Hydroxylase converts dopamine into noradrenaline

Question 4

How is adrenaline synthesised from Noradrenaline

Answer 4

action of Phenylethanolamine N methyltransferase (PNMT)

Question 5

Are G protein coupled receptors metabotropic or inotropic

Answer 5

Metabotropic

Question 6

Are Ligand gated ion channels metabotropic or inotropic

Answer 6

Inotropic

Question 7

In a pedigree what does a square denote

Answer 7

Live male

Question 8

In a pedigree what does a circle denote

Answer 8

Live female

Question 9

In a pedigree how is a marriage or partnership shown

Answer 9

Horizontal line between 2 symbols.

Question 10

In a pedigree how is a consanguinous marriage shown

Answer 10

Double horizontal line between 2 symbols

Question 11

In a pedigree how are deceased people denoted

Answer 11

A diagonal line through their symbol

Question 12

What is a proband in genetic testing

Answer 12

First person to receive genetic counselling

Question 13

Aniridia gene

Answer 13

PAX 6

Question 14

What are the optics of the OCT

Answer 14

A broadband low coherence light source is directed at the desired target. a beam splitter is used to simultaneously direct the same light source at a reference mirror. the reflected light from both the desired target and the reference mirror are directed onto a detector and the interference pattern analysed using low coherence inferometry to construct an image of the desired target

Question 15

What measurements are required to calculate IOL power with Hoffer Q and SRT/K

Answer 15

Axial length and Keratometry values

Question 16

What measurements are required to calculate IOL power with Holladay 1 formula.

Answer 16

Axial length and Keratometry values

Question 17

What measurements are required to calculate IOL power with haigis formula

Answer 17

Axial length, Keratometry and pre operative AC depth

Question 18

What measurements are required to calculate IOL power with Holladay 2 formula

Answer 18

uses 7 measurements

Question 19

When is the Hoffer Q formula used

Answer 19

When AL is <21.5mm

Question 20

How can you tell which is the steep axis of the cornea on the biometry

Answer 20

Steep axis at 90 degrees to the axis of negative cylinder. Steep axis = higher K value

Question 21

ICG absorption and emission wavelengths

Answer 21

Absorption 805nm
Emission 835nm

Question 22

What is the function of macula xanthophyll

Answer 22

found in inner and outer plexiform layers is thought to play a role in limiting damage to the photoreceptors from high energy short wavelength light

Question 23

Which plasma protein is IGC tightly bound to

Answer 23

alpha 1 lipoproteins- 80% bound to globulin- total binding 98%

Question 24

How is ICG dye excreted

Answer 24

Hepatobiliary excretion- secreted into bile. If present in circulation at 30 mins means reduced hepatic function

Question 25

What are the optics of CT

Answer 25

An xray tube rotates around the patient taking hundreds of Xrays from different angles which are detected by detector plates and processed by computers to produce the CT images

Question 26

Which culture medium is good for fungi

Answer 26

Sabouraud agar- can take upto 3 weeks to culture a fungus

Question 27

Which stains are used for fungi

Answer 27

These 2 need fluorescence imaging
1) Calcoflour white
2) Acridine orange

These 2 do not need fluorescence imaging
1) PAS
2) Gomori Methanamine Silver stain

Question 28

How to classify fungi causing keratitis

Answer 28

Filamentous fungi
Yeast like organisms

Question 29

How to further classify filametous fungi

Answer 29

Septate and Non septate organisms
Septate organisms (Aspergillus, Fusarium, Acremonium)

Question 30

How to correct symptomatic anisometropia following unilateral cataract surgery

Answer 30

1) Remove the cataract in the fellow eye
2) Isiekonic lenses- alter image size to compensate for small degrees of microtropia
3) Contact lenses reduce relative spectacle magnification

Question 31

What effect does nucleosclerosis have on the human lens

Answer 31

Increased refractive index of the lens resulting in increased myopia

Question 32

Where is the second focal point in Gullstrand schematic eye

Answer 32

On the retina

Question 33

Where does the first and second principal point lie in Gullstrand schematic eye

Answer 33

Close together in the AC where the principal planes meet the principal axis

Question 34

Where does the first nodal point lie in Gullstrand schematic eye

Answer 34

immediately anterior to posterior pole of lens

Question 35

Where does the second nodal point lie in Gullstrand schematic eye

Answer 35

immediately posterior to the posterior pole of the lens- in the vitreous

Question 36

Where does the nodal point in the reduced Schematic eye lie

Answer 36

At the posterior lens material

Question 37

Normal AC/A ratio

Answer 37

3:1 to 5:1

Question 38

What is the gradient method of calculating AC/A ratio

Answer 38

Takes measurements at the same distance but induces changes in accommodation with different lenses. IPD calculation not needed

Question 39

What is the heterophoria method of calculating AC/A ratio

Answer 39

change in deviation for near versus distance. Needs IPD

Question 40

What principle underlies the use of Goldmann Applanation Tonometry

Answer 40

Imbert-Fick principle
P=F/A