Risk for Capsular Rupture With Venturi and Peristaltic Vacuum Systems
To objectively compare the risk of capsular rupture caused by contact of phacoemulsification tips with the capsular bag using different vacuum pumps, ultrasound modalities, and contact angles.
Phacoemulsification was performed using either peristaltic or venturi pumps with either transversal or micropulsed longitudinal ultrasound. While ultrasound and vacuum were engaged, the phaco tips were touched to a capsular surrogate to achieve either tip occlusion or tip contact only. Following testing, the capsular surrogate was investigated under a surgical microscope to identify breakage. P value for significance was set at 0.01 because of Bonferroni correction.
With tip-capsular surrogate contact, peristaltic mode was more likely to cause capsular rupture than Venturi mode, though this difference was not statistically significant (66.3% vs 60.3%, P = .0128). When tip occlusion data was included, this difference decreased (44.2% vs 40.2%, P = .0473). Transversal ultrasound was significantly more likely to cause capsular rupture than micropulsed longitudinal ultrasound regardless of whether tip occlusion data was included (46.5% vs 37.8%, P < .0001) or excluded (69.8% vs 56.8%, P < .0001).
There is no clear difference in risk of capsular rupture using Venturi rather than peristaltic vacuum pumps. Transversal ultrasound does increase risk of capsular rupture compared to micropulsed longitudinal ultrasound.