To evaluate the clinical results after phacoemulsification in mature and immature cataracts.

Mature cataract was defined as a classification of C5 by Lens Opacities Classification System III compared with other types of cataracts as controls. The present study included 37 (37 eyes) patients diagnosed with mature cataracts that received phacoemulsification and were followed up for at least 1 year. Thirty-seven (37 eyes) patients with other types of cataracts were selected randomly as controls. Intraoperative factors and rate of complications during and after surgery were evaluated. Best corrected visual acuity (BCVA), corneal endothelial cell density and central macular thickness (CMT) were measured during the 1 year of follow-up and compared with the controls.

Twenty-seven eyes (mature cataracts) and 36 eyes (controls) received a complete continuous curvilinear capsulorhexis (CCC). The success rate of complete CCC was significantly high in the control eyes ( p = 0.025). However, in mature cataract patients, 3 cases of posterior capsule rupture occurred among the 6 cases of radial tear of the anterior capsule, resulting in implantation of the lens in the sulcus. Posterior capsular ruptures were observed in 4 patients with mature cataracts and in 1 control with no statistically significant difference in the occurrence rate. Total phacoemulsification time and effective phacoemulsification time were significantly longer in the mature cataract patients ( p = 0.038 and p = 0.041, respectively). BCVA, the amount of corneal endothelial cell density reduction and CMT at postoperative 1 year was not different between the two groups.

The success of complete CCC was a significant factor for the occurrence of intraoperative complications in mature cataract surgery. Based on the clinical results, the mature cataract patients and controls had a similar visual prognosis.