ÐYou can adjust the indentation higher (tightening the band) or lower (loosening the band).

ÐThe location can be changed only by replacing the suture.

¥With a sponge, it is not possible to know the indentationÕs Þnal effect until the sutures are tightened, at which point neither the location nor the height can be adjusted without removing and replacing the sutures.

ÐThe nurse should grab the two ends of the sponge and gently stretch it. The surgeon ties the suture with an initial double or triple throw; the nurse grabs the knot with a smooth forceps and holds it until the second double throw is in place. This prevents loosening of the knot while it is being tied. A Þnal throw (double or simple) may be used as an absolute reassurance.

ÐThis is then repeated for each suture. The nurse must be careful not to pull the sponge through a suture loop that is already in place.

54.4.2.8 Closing the Conjunctiva

Vicryl suture is used; the drainage sclerotomy needs a (single) suture only if it is outside the bed of the buckle. In this case try a preplaced suture62 and tie it right after the drainage has been completed.

54.4.2.9 Gas Tamponade

The gas is injected into a vitreous cavity that still has a considerable amount of gel. No more than 0.5 ml of pure gas should be injected, the IOP monitored, and the patient be asked to position so that the gas bubbleÕs buoyancy pushes the retina around the break against the RPE (see Sect. 35.2.3).

The gas should not be injected through an inferior location to avoid the Þsh-egg formation and subretinally trapping the gas (see Fig. 54.9).63 The needle is best kept inside the enlarging bubble.

Fig. 54.9 Complications as a result of the injected gas. (a) Bubbles in the vitreous cavity Ð the intraocular penetration of the needle was too inferior. (b) One small gas bubble is trapped subretinally, under attached retina. The bubble need not be removed, it will absorb spontaneously; still, it is best to avoid this complication by injecting the gas properly (see the text for details)

62So you do not have to suture the sclera while the eye is soft.

63Occurs less frequently than with air (see Sect. 14.2).