Describe the seperation of the eye
dimensions of the anterior chamber. What is inside
Aq humour
3mm depth ( reduce with accom & shallower in hyperopes)
11.3 - 12.4mm diameter
Components of aq
pH= 7.2
RI=1.3
more dense than H2O (99%)
250ul
low proteins (for transparency)
glucose
electrolytes
ascorbate (protect from UV)
Pathway of aq production and drainage
Cil body>in front of lens> thru pupil> exits thru trab (70-95%) or uveoscleral(5-30%)
production of aq
in cil processes
secreted by non pig epi (inner)
osmosis (10%) of H2O from stroma to non pig epi
ultra-filtration (20%) ( mvt down hydrostatic pressure gradient) of proteins and glucose
active transport (70%) of ions from stroma to non pig epi
what affects rate of aq production?
sympathetic nervous system
Alpha receptors decrease aq production
Beta receptors increase aq production (beta blockers reduce aq production)
rate X constant: day rate = 3.1ml/min. night rate = 1.6ml/min
iop higher AM lower PM
components in the anterior chamber angle
cil body
scleral spur
trab mesh
schwalbe line - most anterior structure. white line. facilitates aq outflow
describe the trab meshwork 3 parts
connective tissue, seive, triangle
uveal trabeculae- innermost- iris root to schwalbe. aq pass freely (25- 75um wide)
corneo-scleral trab- scleral spur to cornea. convoluted pathway. coll fibres enclosed by endo cells
juxta-canalicular trab- outermost-dendritic cells joined by gap junctions. intercell space filled with coll & eleastic fibres in glycopro matrix
Structure and function of scleral spur
inward extension of sclera
ring of fibres- 80% coll & 5% elastic tissue
keeps corneo scleral meshwork open when adjacent cil mesh relaxes
enables mvt of cil mesh when cil msc contracts
How is aq outflow regulated?
contraction of cil msc- expands trab>increases aq outflow>decrease IOP
contraction of trab cells- decrease outflow> increase IOP
trab acts as filter- trab endocells do phagocytosis> remove unwanted debris
Decribe the stages of trab outflow pathway
trab meshwork
canal of schelmm COS
intra-scleral venous plexus- pressure grad prevents backflow of bld into COS
epi scleral viens / conjuctival viens
anterior cil viens
structure of C.O.S.
single layer of endo cells
tight junc
inner wal = giant vacuoles(regulate pressure for aq transport)
(open to more hydrostatic pressure= more outflow)
describe the uveo-scleral outflow pathway
aq enters cil body
btween cil msc ad fibres
supraciliary & suprachoroidal spaces
epi-scleral vasculature
what is the normal iop
11-24mmHg
balance btwn aq production and drainage
Structure of vitreous
what are the attachments to the vitreous
describe the development of vitreous
hyaloid artery from ONH to post lens during gestation (primary vit)
reabsorbed and disppears after birth
leaves empty canal thru central vit (Cloquets canal)
remaining vit = secondary
what are vit floaters
“muscae volitantes”
clumps of coll fibrils cast shadow on ret
move as eye move bz vit = gel
what happens in vit aging
syneresis
name the other vit pathologies
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