Green Corrections Flashcards
Where are Meibomian glands located
Posterior to the grey line
What is posteiror blepharitis
Meibomian gland dysfunction
What is chalazion
Lipogranulomatous inflammatory cyst from blocked MEibomian gland
Orientation of optic canal
Infeorlateral
Where does the the ciliary body have greatest AP length?
Temporally
Longest inferotemporally
Where does bloodsupply to iris run?
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
Lymph from right and left sideof body
Right - right lymphatic duct - right subclavian vein
Left - thoracic duct - left subclavian vein
What are layers of blood vessels
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
Structure of collagen
LEft handed helix
Glycine - X - Y
X proline
Y hydroxyproline
Vit C hydroxylation of Y position, Triple helix formation by S-S bonds
What are MMPs? What are their inhibitors?
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
What are lens proteins?
alpha crystallins found on chromosome 21 and 11
How are secondary lens fibres fromed?
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
Where is pericyte coverage highest
REtinal vessels
Maintains blood retinal barrier
Regulate permeatbility
What is aflibercept
Becavizumab
Ranibizumab
Fusion protein acting as decoy receptor molecule for VEGF
Becavizumab - monoclonal antibody to VEGF
Ranubizumab - monoblonal antibody fragment from same mouse antibody
What are functions of VEGF?
Intraceelular tyrosine kinase activity
Divison of vascular endothelial cells, vascular dilatation, permeatbility
Promoted by TNFa, TNFb, IL1a, IL6m PGE2, EGF, FGF, ILGF1
How long is rod outer segment renewal cycle? When does rod disc shedding and phagocytosis occur
9-10 days
Morning
Where are iris colobomas?
Inferonasal
Incomplete closure of embryonic optic fissure
When does myelination of optic nerve start?
Month 7
Finishes by 1-3 months of age
What part of vitroeus liquefies first
Central