There are a few posts discussing iris scans after cataract surgery on pages 112 and 113 of
The NEXUS Information Thread, beginning with post number
1675. There is additional discussion on page 537, beginning with post number
8043.
You may also want to take a look at this article:
Iris recognition as a biometric method after cataract surgery
Conclusion
Cataract procedures are able to change iris texture in such a way that iris pattern recognition is no longer feasible or the probability of false rejected subjects is increased. Patients who are subjected to intraocular procedures may be advised to reenroll in biometric iris systems which use this particular algorithm so as to have a new template in the database.