Prospective evaluation of intraoperative intraocular lens stress fracture during cataract surgery.

PURPOSE: To determine the incidence and risk factors of intraocular lens (IOL) stress fracture during cataract surgery.

SETTING

Ivey Eye Institute, London, Ontario, Canada.

DESIGN

Prospective, randomized cohort study.

METHODS

Patients scheduled for routine cataract surgery were randomized into 2 study groups. The 2 groups only differed in the use of Monarch IOL delivery cartridges for insertion of an Acrysof IQ SN60WF IOL. The cartridge C group used Monarch cartridge C, and the cartridge D group used Monarch cartridge D. Patients were examined for IOL stress fractures.

RESULTS

A total of 386 study eyes were enrolled. The overall incidence of IOL stress fracture was 6.22%. The incidence of IOL stress fracture with cartridge C and cartridge D groups were 3.16% and 9.18%, respectively (P = .01). The IOL stress fracture rate for IOL power less than 18.0 D was 3.45%, IOL power between 18.0 D to 23.5 D was 6.49%, and IOL power over 23.5 D was 10.81%. A total of 24 IOL stress fractures were observed. Among IOL stress fractures, 45.8% were equal to or less than 1.0 mm in length. Two thirds of stress fractures were located over the central 4 mm of the IOL optic. No subjective adverse visual outcomes were reported from any of the observed IOL stress fractures.

CONCLUSION

Intraocular lens stress fracture is recognizable risk during cataract surgery. Risk factors for IOL stress fracture include smaller IOL delivery cartridges and IOLs of higher refractive powers. There was a low risk for IOL stress fracture resulting in adverse subjective visual outcomes.