There is usually a reason for this and for this etiology the surgeon has to examine the eye for causes of flat AC.
The causes may be:
a. poorly-constructed wound
b. malfunctioning AI instrument
c. choroidal (serous or hemorrhagic) detachment
In the cases of (a) or (b), re-formation of the AC with viscoelastic material may be all that is necessary. Even air will be sufficient, if that is all that is available. If this stabilizes the AC, one can proceed with caution and implant the IOL. Removal of the air after successful implantation is necessary to prevent either an IOP spike (viscoelastic) or endothelial damage in the case of air.
Choroidal detachments can be disasterous, especially in the elderly with supposedly fragile vessels. Hemorrhagic detachments happen very quickly and can sometimes be seen as shadows in a red reflex that invade the pupil almost too quickly to respond. If this happens in a well – constructed wound, withdrawal of the handpiece and injection of viscoelastic may offer some prevention for further progression. In the case of an open wound, however, one hopes the surgeon has preplaced sutures so that they can be tied as quickly as possible. This may not be successful as the detachment may be too swift in developing. A sharp knife may be used to make one or more stab wounds over the choroid in the hope of draining the subchoroidal cavity. It must be acknowledged that the prognosis for this particular diagnosis is not good. In the event of success, the operation should be aborted and the eye allowed to settle over a number of weeks.