**6.3 Foreign particles within the interface**

Foreign particles in the interface can be left in place without any attempt to remove them if there has been no associated inflammation and edema and they have been out of the optical zone of the cornea (Figure 21).

Fig. 21. One piece of sponge entraped in the donor\_ host interface.

Small filaments in the interface do not affect the visual acuity even if they are located within the optical zone.
