–Often it is easy to determine whether the patient followed the request or not; if he did position, debris can be seen on the endothelium (positional keratopathy; see Fig. 50.7).

Fig. 50.7 Positional keratopathy. The debris is heavy, and it tends to settle around the deepest point of the cornea. Its presence is an indicator to the surgeon that the patient positioned and whether his head has truly been held in the horizontal plane. If he has “cheated” and the head has been held at an acute angle, the debris collects more inferiorly

•If a patient is unable or unwilling to position, silicone oil may be used as tamponade.

– The oil may be removed within a few weeks.

50.2.5 If Surgery Failed for a Macular Hole

Even with the best technique and most cooperative patient, there are unsuccessful primary surgeries. Below is my personal technique in these cases. This approach is successful in ~2/3 of the cases.

•Restain the ILM to make sure that it was indeed peeled completely.

–If an eye underwent surgery before with the inverted flap technique, I remove the ILM in the entire macular area, and then complete the procedure as if this were the first operation.

•Drain the subretinal fluid (see above).

•Take a 23–25 g needle and create 6–8 radial cuts of ~0.5 mm around the hole (see

Fig. 50.8).

–The cuts are planned to be of only minimal depth.

–The goal is not to move the retina so that the hole closes on the table but to cause just enough trauma that leads to the formation of a very fine gliosis, which in turn closes the hole.

•Perform a meticulous F-A-X and then exchange the air to silicone oil.

–No positioning is needed.

•Remove the oil in ~1 month.

Fig. 50.8 Radial cuts around a macular hole in case of a reoperation.

See the text for more details