There are several ways to fix a retinal detachment. The decision of which type of surgery and anesthesia (local or general) to use depends upon the characteristics of your detachment.
A gas bubble is injected into the vitreous space inside the eye. The gas bubble pushes the retinal tear closed against the back wall of the eye. Your ophthalmologist will ask you to maintain a certain head position for several days. The gas bubble will gradually disappear.
A flexible band (scleral buckle) is placed around the eye to counteract the force pulling the retina out of place. The ophthalmologist often drains the fluid under the detached retina from the eye, pulling the retina to its normal position against the back wall of the eye.
The vitreous gel, which is pulling on the retina, is removed from the eye and usually replaced with a gas bubble. Your body’s own fluids will generally replace the gas bubble.