Analysis of Forces Acting Upon Submacular Hemorrhage in Pneumatic Displacement

In Brief Purpose: To analyze the forces affecting pneumatic displacement of submacular hemorrhage and determine an efficient postoperative positioning method for patients. Method: Geometric analysis of the forces that act upon submacular hemorrhage in the absence and presence of a gas bubble. Results: A component of gravity force of the hemorrhage parallel to the subretinal space is responsible for pneumatic displacement. This component is largest when the patient is looking straightforward and is absent when the patient is positioned facedown. Conclusion: Face down positioning is not optimal for pneumatic displacement of submacular hemorrhage and should be avoided. The submacular hemorrhage displacement is increasingly effective as the eye approaches a horizontal position and the gravity force becomes parallel to the subretinal space while the hemorrhage is within the gas bubble. Facedown positioning is not optimal for pneumatic displacement of submacular hemorrhage and should be avoided.