Silicone

• If silicone oil prolapses into the AC in an eye with an intact iris diaphragm, the prolapsed oil eventually breaks off from the large intravit-real bubble, and a single intracameral droplet is formed. This droplet cannot be forced back into the vitreous cavity.

• If the droplet is relative small, does not interfere with the patient's vision, and is mobile,23 it can be left in situ.

• If the intracameral droplet does need to be removed, two paracenteses are prepared: one for the injection of a viscoelastic and one to drain the silicone oil. Injection of the viscoelastic requires a special technique (see above).

• The surgeon must make sure during the exchange that the silicone oil is in constant contact with the drainage paracentesis; otherwise, the droplet gets "lost," floating to the highest point of the AC. Reestablishing contact between the oil droplet and the paracentesis is not always easy. Inserting a spatula into the AC during drainage in such cases is very helpful. It can press the lower wound lip downwards but also reach into the inside of the silicone oil droplet. If this is achieved, the oil can be completely drained along the spatula even if the droplet itself is not in the immediate vicinity of the paracentesis. The viscoelastic must be left in the AC to prevent further silicone oil prolapse.

• If the silicone oil emulsifies (Fig. 2.5.3), removal becomes more difficult. If possible, the intravitreal oil must be removed first; otherwise, it provides an endless resupply of droplets. The technique of removal does not differ significantly from that described above, but it takes a lot

23 i.e., it does not press against the endothelium continually at the same site.

Fig. 2.5.3 Emulsified silicone oil in the AC. The inferior iridectomy is open; the eye is Pseudophakie, yet the emulsified silicone oil fills at least 40% of the AC superiorly. Silicone oil bubbles are also seen through the iridectomy to adhere to the posterior capsule (See the text for more details.)

Fig. 2.5.3 Emulsified silicone oil in the AC. The inferior iridectomy is open; the eye is Pseudophakie, yet the emulsified silicone oil fills at least 40% of the AC superiorly. Silicone oil bubbles are also seen through the iridectomy to adhere to the posterior capsule (See the text for more details.)

longer to "chase out" all the droplets.24 The viscoelastic may be removed since no silicone oil resupply is possible.

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