Surgical Management of Glaucoma Flashcards
When is surgery the primary treatment modality for glaucoma?
ACG with pupillary block
Primary congenital glaucoma
What does the CIGTS study show?
initial surgical treatment of glaucoma achieves better IOP control than Rx
However, patients have an increased risk of cataract formation
initial surgery also lead to decreased % of VF progression compared to Rx (except in patients with DM)
What is laser trabeculoplasty?
application of laser energy to the TM in discrete spots, causing increased outflow
decreases IOP by 20-25%
What are the indications for laser trabeculoplasty?
POAG
Pigmentary Glaucoma
Exfoliation Syndrome
Steroid-induced Glaucoma
Angle must be open for procedure to be effective
What are contraindications for laser trabeculoplasty?
Inflammatory Glaucoma ICE Syndrome NV Glaucoma Synechial Angle Closure Developmental Glaucoma
How is laser trabeculoplasty performed?
50uM laser is focused through a goniolens at the junction of pigmented and non pigmented TM
How does SLT differ from ALT?
in SLT, there is selective absorption of laser energy by pigmented TM cells, causing less thermal damage to adjacent cells/tissues
How successful is laser trabeculoplasty?
80% of patients experience an IOP decrease for 6 months s/p procedure
50% maintain IOP decrease for 3-5 years
When is incisional surgery indicated for management of glaucoma?
in OAG when non-surgical modalities fail to maintain IOP at adequately low level
What are the different types of filtering surgeries?
Creation of fistulas
Creation of filtering blebs
Re-Routing of aqueous drainage
What are contraindications to incisional glaucoma surgery?
NLP (peform CB ablation instead) Advanced anterior segment NV Active Iritis Rubeosis Iritis CL dependent patients Patients with decreased conjunctiva
What is a trabeculectomy?
a partial thickness filtering procedure in which a block of peripheral corneoscleral tissue is removed beneath a scleral flap
anti-fibrotic agents can be used as well
Where is the flap in a trabeculectomy usually located?
usually positioned superiorly at 1200, 8-10 mm posterior to limbus
What is the MOA for 5 FU?
inhibits thymidylate synthetase, inhibiting DNA synthesis
if used in a trabeculectomy, position 180 degrees away from inferior fornix
What is the MOA for MMC?
an anti-neoplastic/anti-bacterial agent that causes cross linking of DNA
AVOID INTRACAMERAL CONTACT
What are risk factors for bleb failure during surgery?
Anterior segment NV Black race aphakia prior failed filtering procedure uveitis prior CE young age
What is the initial management of bleb failure?
digital massage
What surgical procedures are used to treat ACG with pupillary block?
laser iridotomy (argon or Nd:YAG laser) incisional iridotomy
What is the treatment for secondary angle closure glaucoma?
Treat the underlying cause
Where should and LPI be located? Why?
LPI should be located peripherally, preferentially beneath the eyelid to prevent excess light from entering through the defect
What is the contraindication for LPI?
rubeosis iritis
Why is the Nd:YAG laser preferred to the argon laser when performing LPI?
preferred 2/2 no change in effect based off the color of the iris
What are possible complications of LPI?
Disruption of anterior lens capsule/K endothelium
bleeding
post op IOP increase
delayed closure of iridotomy
What is laser gonioplasty/peripheral iridoplasty?
technique to deepen the AC angle
primarily used in ACG patients with plateau iris
Involves burning the stroma of the iris, causing flattening of the peripheral iris
