ÐIt is wrong, though, to issue a blanket instruction of Òbe facedown,Ó which would soon expose an equatorial break as the gas bubble shrinks. The surgeon should carefully think in each case about what head position will provide the longest possible period of gas/break contact.

¥Whether gas or oil has been used, a patient with a phakic or aphakic eye should avoid the supine position, especially in the Þrst few days.76 In case of pseudophakia, this is less important.

54.5.3 Follow-Up Visits

Typically, the risk of redetachment has two peaks. The Þrst is usually early, as the gas absorbs; this RD is break related.77 The second one is several weeks later, as PVR develops. The patient should be counseled about this and the symptoms preceding (ßashes) or accompanying (curtain) the detachment.

54.5.4 Prognosis

If the macula was on, excellent outcome is to be expected. If it was off, the functional result is difÞcult to predict since it is inßuenced by many factors: duration of the detachment, height of the detachment, ability to drain all the submacular ßuid, and individual factors such as the condition of the patientÕs systemic circulation, the degree of myopia etc.

54.5.5 RD After Silicone Oil Removal

In up to a Þfth of the eyes, the retina redetaches within a few weeks after the oil has been removed.78 Often a small retinal break is found during the reoperation (see Fig. 35.5), which in turn is most commonly caused by residual vitreous. If no break is identiÞable, the surgeon must wonder whether the RPE and/or the IPM are at fault. In the latter case, the oil must be reimplanted.

54.6Pneumatic Retinopexy

The principle behind the procedure is that a chorioretinal adhesion is created around the break, either by cryopexy of laser, and a pure gas bubble is employed to reattach the retina.

76To defer as much as possible the development of cataract in the phakic eye and to avoid silicone oil prolapse into the AC in the aphakic eye.

77However, in some cases it takes a lot longer for the residual traction to open the break and cause an RD.

78This is a risk every patient must know in advance.