Pneumatic Displacement of Submacular Hemorrhage
Overview
A technique for displacing submacular blood away from the fovea using an intravitreal gas bubble, with or without tissue plasminogen activator (tPA). Used when submacular hemorrhage threatens the macula, since blood is directly toxic to the retina and damages the ellipsoid zone.
Mechanism / How It Works
- Intravitreal injection of expansile gas (SF6 or C3F8)
- ± Intravitreal or subretinal tPA to lyse the clot and facilitate displacement
- Patient positioned face-down to allow the gas bubble to push the hemorrhage inferiorly, away from the fovea
- Rationale: Subretinal blood causes direct photoreceptor toxicity — iron from hemoglobin, fibrin contraction, and barrier to metabolite exchange between RPE and photoreceptors
Indications & Contraindications
- Indicated: Submacular hemorrhage from any cause — RAM, wet AMD with hemorrhagic PED, trauma
- Details on contraindications and technique to be expanded
In the RAM Context
From the RAM source: submacular hemorrhage from ruptured hemorrhagic retinal-arterial-macroaneurysm can be treated with pneumatic displacement ± tPA. This is particularly important because hemorrhage is directly toxic to the ellipsoid zone.
Related
- retinal-arterial-macroaneurysm — cause of submacular hemorrhage
- yag-posterior-hyaloidotomy — alternative for premacular (not submacular) hemorrhage
- intravitreal-injections — delivery of gas and tPA
Sources
- macroaneurysm-eyewiki (brief mention in RAM management)
Gap: Needs dedicated source on technique details, tPA dosing, gas choice, positioning protocols, outcomes, and comparison with surgical evacuation.