12.2.4.9 Silicone Oil

Avoid silicone oil use as this seems to adversely affect the outcome of surgery by stimulating membrane formation (Pearson et al. 1993; Heimann et al. 1989), spontaneous break formation (Wilson-Holt and Gregor 1992) and subretinal oil postoperatively. The functional success rates are low (Karel and Kalvodova 1994; Gonvers 1990), and the capacity for silicone oil removal is restricted (Castellarin et al. 2003). Silicone oil is impervious to oxygen and therefore may exacerbate the ischaemia of the eye (de Juan et al. 1986). It is used in only 5 % of my patients at primary surgery (Gupta et al. 2012).

Table 12.4 DifÞculty rating for PPV for combined TRD and RRD

Surgical Pearl of Wisdom

We all operate on patients with advanced diabetic retinopathy and terrible retinal vascular disease. We often add epinephrine to our infusion bottles because it aids dilation and stops bleeding. However, epinephrine can cause sufÞcient retinal vascular vasoconstriction as to effectively create a central retinal artery occlusion during the time of vitrectomy surgery. This may help explain poor vision (even no light perception) and a pale optic nerve after diabetic vitrectomy even when the retina is attached and all Ôlooks goodÕ.

In the Þrst few minutes of the core vitrectomy during a procedure in a diabetic patient with severe retinal vascular disease, assess the perfusion of the major retinal vessels. If they appear constricted or poorly perfused, change over the infusion bottle to one that does not contain epinephrine. You will soon see a dramatic change in the calibre of retinal vessels. The retina will become better perfused.

Nancy M. Holekamp, Barnes Retina Institute, St.

Louis, Missouri, USA

12.2.4.10 Combined TRD and RRD

This is a difÞcult problem because the retina will lift with the membranes during dissection. The patient needs to be operated on urgently because PVR can occur. Use of a small bubble of heavy liquid will stabilise the retina during surgery (Imamura et al. 2003). A bimanual method with chandelier or multiport system should be used to allow manipulation of the retina and membrane (Steinmetz et al. 2002; Han et al. 1994). Find and treat the hole and tamponade with gas; apply PRP. The outcomes for this are reduced often because of PVR with only 50 % achieving improved vision (Rice et al. 1983a).

Fig. 12.54 This patient has active neovascularisation with a combined TRD and RRD. An appropriate surgical approach would be intravitreal injection of an anti-VEGF agent, followed a week later by PPV using a chandelier to allow bimanual dissection of the membranes, with PRP and postoperative tamponade with 14 % perßuorocarbon in air if there are any retinal breaks

Note: Make sure that all membranes are removed near breaks in the retina.

12.2.5 Postoperative Complications

Cataract

This is less common in eyes with diabetic retinopathy than other eyes treated with PPV. The reason for this is unclear but may be due to less oxidative stress on the lens in ischaemic diabetic eyes (Holekamp et al. 2006).

12.2.5.1 Vitreous Haemorrhage

Postoperative vitreous haemorrhage is present in up to 60 % immediately after surgery (Tolentino et al. 1989). Persistent or recurrent haemorrhage occurs in 12Ð27 % (Steel et al. 2008; Laatikainen et al. 1987; Virata and Kylstra 2001; Koutsandrea et al. 2001; Tolentino et al. 1989) with 5Ð10 % requiring surgery (Brown et al. 1992; Novak et al. 1984; Tolentino et al. 1989; Gupta et al. 2012) to clear out the haemorrhage. Postoperative vitreous haemorrhage spontaneously clears more quickly in aphakes (Novak et al. 1984) and