Angle Recession Flashcards
Things to watch out for in someone with history of eye trauma
It’s usually in OS
- corneal scar
- iris tear
- angle recession (damage to TM
- RD
- blowout fracture
- optic atrophy
- ptosis
- vossius ring
- glaucoma
Things to consider with a larger pupil
CN 3 palsy
Adies
Sphincter tear
Pharmacological
APD: efferent or affernet?
Afferent
- ON damage
- retina damage
Aniso: efferent or afferent
Efferent
Diff for miotic pupil
Horners
ARP
Secondary glaucoma’s that affect the angle
- PAS from narrow angles closing (emergency to prevent CRAOs) or uveitis (also plateau iris can look like narrow angle)
- NVA-CRVO/DM
- toxic material damages TM (PXF, PDS)
What is sometimes the only way to differentiate plateau iris vs narrow angle
A PI will not fix the plateau iris
Angle recession glaucoma
History of blunt trauma, unilateral elevated IOP associated with optic nerve damage, iris sphincter tear, and vossius ring
Vossius ring
Circular deposition of pigment on the anterior capsule of the lens due to iris-lens contact during trauma
Gonioscopy and angle recession
Must be performed in order to definitively diagnose angle recession glaucoma. Angle recession is characterized by a very deep angle with an uneven iris insertion, a recessed iris, and a widened CB band. The recession may occur for any number of clock hours. Bc recession is unilateral, the other eye can be used as comparison on gonioscopy to continue recession. Although the angle appears open, the trauma causes damage to the TM; the greater the extent of damage, the greater the risk of developing elevated IOP and glaucoma
Chance of glaucoma in angle recession
10% of patients with angle recession involving at least 2/3 of the angle will develop glaucoma
Uveitic glaucoma
Often caused by posterior synechiae and/or PAS (can only be viewed through gonio) causing angle closure glaucoma. Recall that during active episodes of uveitis, the iris thickens and becomes sticky (due to inflammation) and may become stuck to the lens (posterior synechiae) or the TM (PAS). 360 degrees of PS are required in order for the IOP to become elevated due to the peripheral iris moving forward into apposition with the TM. The number of clock hours of pAS required to obstruct enough TM to cause IOP elevation is dependent on each patient; however in most patients, 6 or more clock hours is associated with a increase in IOP.
Rubeotic glaucoma
Caused by NVA. Fibrous tissue always accompanies neo, and can obstruct AH outflow by physically blocking the TM, or by pulling the iris into contact with the TM, resulting in secondary angle closure glaucoma.
Intermittent angle closure glaucoma
Associated with narrow AC angles
Iridodialysis
Separation of the iris root from the attament to the CB due to ocular trauma. It often has a similar appearance as a PI. Patients may also have a traumatic cataract and an iris sphincter tear