secondary glaucoma Flashcards
What is secondary glaucoma?
Occurs secondary to another ocular or systemic disorder
* Open angle
What are the 3 mechanism of secondary glaucoma?
- pre trabecular
- trabecular
- post trabecular
What is pre trabecular
iris or other tissue obstructs the angle to prevent aqueous humour from reaching the trabecular meshwork.
-something is stopping access to trabecular meshwork
-so aq can’t drain
What is trabecular?
aqueous outflow obstructed by clogging up of the trabecular meshwork or alterations in the trabecular tissues
What is post trabecular?
something is blocking the drainage after it has passed through the trabecular meshwork
obstruction distal to trabecular meshwork and canal of schlemm (raised episcleral venous pressure)
How is secondary glaucoma similar to poag?
The key signs of nerve damage remain the same as POAG
– The methods of investigation remain the same as POAG
– The disease progression remains the same as POAG
however secondary glaucoma will have additional signs indicating it has secondary causes
What is the aetiology/pathogenesis of PXF glaucoma?
Pseudoxfoliative material clogs up the trabecular meshwork leading to the decrease in aqueous outflow raising the IOP.
What is pseudo exfoliave glaucoma?
Develops secondary to pseudoexfoliation syndrome (PXF)
Why is pseudoexfoliative material produced?
Pseudoexfoliative material is produced by abnormal basement membranes of ageing epithelial cells in the trabeculum, equatorial lens capsule, iris and ciliary body
Where is pseudo exfoliative material deposited on?
anterior lens capsule ciliary body
iris trabeculum cornea
What are the symptoms of a PXF glaucoma?
- Usually over 70s
- Raised IOP (usually higher than in POAG)
- Poor pupil dilation
What are the signs of PXF glaucoma?
Iris:
- PXF at the pupillary margin
- Atrophy (visible on transillumination) * Anterior lens capsule:
- Central disc of PXF, clear mid-zone, peripheral band of PXF
* Cornea:
- PXF and/or pigment on endothelium (commonly diffuse pattern)
A
PXF material at iris, lens and cornea
What is the referral of PXF glaucoma?
routine referral for the open angle glaucoma
What is the management of PXF glaucoma?
– Medical treatment for IOP (as in POAG)
– Usually require surgery: laser trabeculoplasty
– Follow-up with trabeculectomy if necessary
What is the differential diagnosis of PXF glaucoma?
POAG
Primary angle-closure glaucoma (PACG)
Pigment dispersion syndrome (PDS)
True exfoliation or capsular delamination
Amyloidosis
