Glaucoma Flashcards
definition of glaucoma?
elevation in the IOP and its consequences - destruction of ocular structures and function
where is aqueous humour produced?
ciliary processes
where does the aqueous humour drain?
spaces between the fibres of the pectinate ligaments
iridocorneal angle
conventional drainage of aqueous humour?
85%
what is responsible for movement or aqueous humour in conventional outflow?
thermal convection
what happens in unconventional aqueous outflow?
small amounts (15%) is absorbed by scleral plexus
drugs can facilitate unconventional aqueous drainage, true/ false?
True
main diagnostic procedure of glaucoma?
tonometry
provocative tests
ophthalmoscopy
causes of primary disturbance of aqueous humour?
genetically determined malformation/ malfunction of the iridocorneal angle
causes of secondary drainage problems of aqueous humour?
inability of drainage of aqueous humour due to another ocular disease simultaneously presented:
- obstruction of the iridocorneal angle
- episcleral venous engorgement
- Anterior lens luxation
- synechia after uveitis
- scar after foreign body
- mass
what happens in anterior lens luxation- subluxation?
IOP > 20 mmHg because of luxation -> IOP increases in vitreous body -> high pressure on surface of retina and ONH -> damage of ONH + glaucomatic vision loss
what happens with the elevation in IOP?
destruction of intraocular structures
what is the most dramatic change with glaucoma?
ischaemy: atrophy of the ONH and optic nerve
what are the signs of acute glaucoma?
onset 12-24 hrs Pain vision disturbance conjunctival hyperaemia episcleral congestion corneal oedema fixated, wide pupil, no response to light IOP > 25mmHg corneal opacity
clinical signs of chronic glaucoma?
from few days to weeks vision disturbance episcleral congestion corneal oedema, vascularisation pigmentation, descemet's streaks fixated, wide pupil, no response to light iris and optic disc atrophy IOP increase or norm buphthasmus (dislocation of the lens)
