Green Corrections

Question 1

Where are Meibomian glands located

Answer 1

Posterior to the grey line

Question 2

What is posteiror blepharitis

Answer 2

Meibomian gland dysfunction

Question 3

What is chalazion

Answer 3

Lipogranulomatous inflammatory cyst from blocked MEibomian gland

Question 4

Orientation of optic canal

Answer 4

Infeorlateral

Question 5

Where does the the ciliary body have greatest AP length?

Answer 5

Temporally
Longest inferotemporally

Question 6

Where does bloodsupply to iris run?

Answer 6

Major and minor arterial circles run theorugh iris stroma
Blood supply from anterior ciliary arteries and long posterior ciliary arteries

Mino arterial circle of iris at levle of colarette

Question 7

Lymph from right and left sideof body

Answer 7

Right - right lymphatic duct - right subclavian vein

Left - thoracic duct - left subclavian vein

Question 8

What are layers of blood vessels

Answer 8

tunica intima - contains internal elastic lamina - fragmented in GCA

Media - mcuular layer with sMCs

Adventitia - main CT layer - external elastic lamina in arteries

Veins have thinner media, larger lumen and less msucles

Question 9

Structure of collagen

Answer 9

LEft handed helix

Glycine - X - Y

X proline
Y hydroxyproline

Vit C hydroxylation of Y position, Triple helix formation by S-S bonds

Question 10

What are MMPs? What are their inhibitors?

Answer 10

Zinc and Calcium dependent endopeptidases
Degrade extracellular matrix

Released by neitrophils during inflammatory response or normal cells for growth repair

TIMPs are endogenous inhibtors in normal tissues

Question 11

What are lens proteins?

Answer 11

alpha crystallins found on chromosome 21 and 11

Question 12

How are secondary lens fibres fromed?

Answer 12

Formed from anterior lens epithelium

FGF - fibroblast growth factor stimulates differentiation of anteirorlens epithelial cells into lens fibres through elongation, withdrawal from cell cycle, loss of organelles and nucleus

Question 13

Where is pericyte coverage highest

Answer 13

REtinal vessels
Maintains blood retinal barrier
Regulate permeatbility

Question 14

What is aflibercept
Becavizumab
Ranibizumab

Answer 14

Fusion protein acting as decoy receptor molecule for VEGF

Becavizumab - monoclonal antibody to VEGF

Ranubizumab - monoblonal antibody fragment from same mouse antibody

Question 15

What are functions of VEGF?

Answer 15

Intraceelular tyrosine kinase activity

Divison of vascular endothelial cells, vascular dilatation, permeatbility

Promoted by TNFa, TNFb, IL1a, IL6m PGE2, EGF, FGF, ILGF1

Question 16

How long is rod outer segment renewal cycle? When does rod disc shedding and phagocytosis occur

Answer 16

9-10 days

Morning

Question 17

Where are iris colobomas?

Answer 17

Inferonasal

Incomplete closure of embryonic optic fissure

Question 18

When does myelination of optic nerve start?

Answer 18

Month 7
Finishes by 1-3 months of age

Question 19

What part of vitroeus liquefies first

Answer 19

Central

Question 20

What is mosiacism?

Answer 20

Cells arise from same zyngote

Question 21

What is chierism

Answer 21

Cells arise from two or more zygotes

Question 22

What is lyonization

Answer 22

X inactivations - one X-chromosome is randomly inactivated
Patchy expression of mutant C linked genes

Question 23

What are -ximab vs -zumab antibodies

Answer 23

ximab are gnetically engineered to introduce human constant domains to murine antibodies

Zubmab are fully humanised monoclonal antibodies

Question 24

What are ribozymes

Answer 24

USed to cut mRNA of target gene to block transcription

Question 25

Where are MCH class I vs II present

Answer 25

MCH class I on every nucleated cell E.g HLA B27 MHC alss II only expressed by antigen presenting cells Intracellular antigens such as viral protein complexed with MHC I are presented to CD8 T cells Extracellular antigen presented with MHC II for CD4 cells

Question 26

Wet heat sterilisation

Answer 26

120 15 mins 130 10 mins 135 5 mins

Question 27

Dry heat sterilisation

Answer 27

160 for 180mins 170 for 60 mins 180 for 30 mins

Question 28

What does toxoxariasis cause?

Answer 28

Nematodal infeciton Posterior uveitis - leukocoria

Question 29

Angle of deviation in prims

Answer 29

D = (n-1) a Crown glass has 1.5 n for from crown glass prims D=a/2

Question 30

When a plane mirror is rotated by 90 degrees what ahppens to the reflected light

Answer 30

Rotated by 180 degrees Angle of deviation is twice the angle of rotation

Question 31

Adjustment for sulcus lens power if power > 28D

Answer 31

-1.5 from capsular bag power

Question 32

Adjustment for sulcus lens power if power < 17.5D

Answer 32

-0.5 from capsular bag power

Question 33

Adjustment for sulcus lens power if power between 17.5D and 28D

Answer 33

-1D from capsular bag power

Question 34

What does a patients refractive error have a greater effect on direct or indirect ophthalmoscopy

Answer 34

Direct

Question 35

How to do rotic transposion

Answer 35

CYL to same sign as base cruve Sphere - base cruve to get numerator Base curve at axis 90 degree to CYL New CYL by adding base cruve to power of CYL

Question 36

Gallilean telescope image

Answer 36

Erect magnified at infintiy Lenses separated by difference between fcal lengths

Question 37

What tumours is NF1 associated with

Answer 37

Neurofibromas, phaeochromocytoma, optic nerve glionma Chromosome 17

Question 38

What tumours is NF2 associated with

Answer 38

Bilateral acoustic neuroma Meningioma Chromosome 22

Question 39

When are dalen fuchs nodules seen?

Answer 39

Epithelioid cells (acitvated macrophages) between Brch's and RPE GRanulomatous inflammation in sympathetic ophtahlmia and VKH

Question 40

What % of uveal tract melanoma occur in iria, ciliary body, choroid

Answer 40

Iris 8% Ciliary body 12% Choroid 80%

Question 41

What does amyloid stain on H&E

Answer 41

Pink eosin (basic)

Question 42

What are zero order kinetics

Answer 42

Non-linear - metabolism of drug independent of concentration First order are linear - rate is proportional to concentration of drug

Question 43

What drugs can pass blood retinal barrier

Answer 43

Lipid soluble

Question 44

What are side effects of ciclosportin

Answer 44

Calciuneurin inhibitor, inihibtos IL2 formation Nephrotoxicity Tremor Hirsuitism Ginginal hypertrophy

Question 45

when does hydroxyamphetamine fail to dilate in horners

Answer 45

3rd order lesions

Question 46

How do hair cells in cochlea depolarise?

Answer 46

Influx of potassium from endolymph

Question 47

What does the suprachiasmatic nucleus control

Answer 47

Circadian rhythm via action of pacemaker cells

Question 48

Where doe cells in layer 5 of PVC project

Answer 48

Superior colliculus 2/3 to secondary visual cortex 6 back to LGN

Question 49

What process involved in formation of aqueous

Answer 49

Active secretion Passive diffusion Ultrafiltration of water and solutes