Final - Filtering Surgery Flashcards
MOA: drainage fistula
- what
- bypasses
Creation of an opening/fistula at the limbus, allows direct communication b/w AC and subconj space
TM, SC, and collecting channels
MOA: filtering bleb
- what
- with good IOP control
Elevation of conj at surgical site
Assoc w/ decr vascularity with numerous microcysts in epithelium, low and diffuse or more circumscribed, elevated
MOA: filtering bleb
- functioning bleb
- failed bleb
Loosely arranged tissue, histological clear spaces
Dense collagenous CT
Basic technique
-corneal traction suture
Rectus suture OR corneal suture
To move eye during surgery
Basic technique
-limbal strab incision
Paracentesis site
Self-healing incision into AC to inject fluid at end of procedure
Basic technique
-preparation of conj flap
Critical step - most common cause for failure due to scarring of filtering bleb
At 12 o’clock or a superior quadrant
To minimize fibroblasts/scarring - preserve Tenon’s by dissecting b/w capsule and episclera
Basic technique
-mitomycin C (MMC)
Antimetabolite used during initial stages
Prevent excessive post-op scarring -> reduce risk of failure
Basic technique
-viscoelastic agents
Sodium hyaluronate, Healon
Injected into AC to reduce risk of hypotony, suprachoroidal effusion, minimize post-op bleeding
Complications - prolapse during sx, higher early post-op IOP
Basic technique
-peripheral iridectomy
Sometimes done
May occur after fistula created or after
Basic technique
-closure of conj flap
Suture
Leaking wound may lead to a persistently flat bleb or AC or both
Post-op management
-topicals (3)
Mydriatic-cycloplegics 2-3 weeks
-maintain AC depth
Antibiotic 7-10 days
Steroid 4-6 weeks
- reduce conj scarring
- some prefer low-dose indefinitely
Complications
- high IOP and flat AC
- high IOP and deep AC
Delayed suprachoroidal heme -> choroidal detachment
-few days post-op, pain, nausea, reduced vision
Failing bleb
- typically low to flat, heavily vascularized (-) microcycsts
- tx: topical steroids
Complications of:
Uveitis
Hyphema
Dellen (saucer-like depression in periph K)
Loss of central vision
Ocular decompression retinopathy (intraretinal heme immediately after)
Other early post-op
Complications of: Failure of filtration Leaking bleb Bleb infections Cataracts Spontaneous hyphema Hypotony, ciliary detachment K changes (reduced endo cells) Eyelid changes Sympathetic ophthalmia
Late post-op
