DIS - Glaucoma Histopathology II - Week 2 Flashcards
Between apoptosis and necrosis, which is more likely to be associated with open angle glaucoma and closed angle glaucoma?
Open angle - apoptosis
Closed angle - necrosis
What produces aqueous humour? How does it flow once made?
Produced by the ciliary body and flows around the lens to the anterior chamber, nourishes the lens and corneal endothelium
Describe what two structures drain the aqueous humour (and percentages).
5-15% drains via the trabecular meshwork into schlemms canal
85-95% drains via the uveo-scleral route
What structures allow rapid, fine control of aqueous outflow and where are they found exactly?
Giant vacuoles found on the endothelial surface of schlemms canal
What do trabecular cells cover, what do they produce, and what does this substance do?
They cover beams of cribiform meshwork, producing a gel filler of GAGs, glycoproteins, and fibrillar material
It is thought to slow down flow and stick to debris
What do trabecular cells do to debris?
They are highly phagocytic and clean debris from the meshwork
List three things that can cause meshwork blockage
Pigment blockage
Debris
Vacuole dysfunction
What two post-trabecular dysfunctions can cause an angle compromise?
Decreased venous drainage
Increased venous backpressure
What is irido-corneal endothelial (ICE) syndrome?
Anterior membrane overgrowth, causing angle closure
The PTM is occluded by the iris
What is the abnormality in congenital glaucoma?
Malformed trabecular structures
List three possible causes of secondary open-angle glaucoma.
Resistance to outflow
Increased debris in the TM exceeding phagocytic capacity
GAGs in connective tissue block flow
List two causes of resistance to trabecular meshwork outflow.
Pigment dispersion
Pseudoexfoliation
List a cause of TM debris exceeding phagocytic capacity.
Steroid use
List a cause of GAGs in connective tissue blocking flow.
Steroid response TIGR gene
What kind of mode of inheritance does congential glaucoma causing malformed TM have? Why does it occur (briefly)?
What are the two most common results of this mutation? Is a large CDR seen?
Autosomal recessive
A protein needed for proper cleavage of the anterior chamber is abnormal
Gies impaired or no drainage
Often anterior insertion of the iris onto the cornea is seen
Large CDR is seen
Name the two expressions of congenital glaucoma and note their severity.
List four characteristics of these expressions.
Note whether or not they are bilateral.
Axenfeldt-Rieger (minor to moderate)
Peter’s (severe)
Child (0-2) has high to very high IOP
Abnormal iris/lens/cornea
Buthalmos (large eyeball) with leukocoria (white pupil)
Asymmetry between the eyes (colour and size)
Are often bilateral (75%)
List 5 common signs and symptoms of Axenfeldt-Reigers syndrome.
Photophobia Epiphora Hard eye Large cloudy cornea Anterior schwalbes line
What is common in 15% of Axenfeldt-Rerigers syndrome and what is IOP like?
Posteiror embryotoxin common in the nasal margin
IOP is generally normal, major disorder gives high IOP