High-risk factors for zonular complications during cataract surgery in eyes with pseudoexfoliation syndrome

Aims To predict high-risk factors for zonular complications during cataract surgery due to pre-existing severe zonular dehiscence in eyes with pseudoexfoliation (PXF) syndrome. Methods 315 eyes of 315 consecutive patients with PXF scheduled for phacoemulsification surgery underwent preoperative examination of various ocular parameters using an anterior segment-optical coherence tomography and other devices. When zonular complications occurred during surgery due to zonular dehiscence, scleral fixation of the intraocular lens (IOL) or implantation of a capsular tension ring (CTR) was performed. High-risk factors for these intraoperative zonular complications were examined using classification-tree and logistic regression analyses. Results Of the 315 eyes, 31 (9.84%) underwent scleral IOL fixation or CTR implantation. High-risk factors identified by classification-tree analysis were a small pupillary diameter after mydriasis <6.30 mm, a shallow anterior chamber depth <2.074 mm and lens decentration >0.260 mm. Based on exact logistic regression analysis, the OR was 4.81-fold higher for eyes with poor mydriasis than for eyes without poor mydriasis (p=0.006, 95% CI 1.49 to 18.23), 23.99-fold higher for eyes with poor mydriasis and a shallow anterior chamber (p<0.001, 5.92 to 109.02) and 287.39-fold higher for eyes with poor mydriasis, a shallow chamber and great lens decentration (p<0.001, 50.46 to infinity). Conclusion In eyes with PXF, high-risk factors for zonular complications during cataract surgery due to pre-existing severe zonular dehiscence were poor mydriasis, shallow anterior chamber and large lens decentration, suggesting the importance of evaluating these conditions preoperatively.