Illuminated Chop Using an Illuminated Chopper in Cataract Surgery: on the Way to Minimal-energy Phacoemulsification

Purpose: To minimize ultrasound power use and surgical phaco time in illuminated chop cataract surgery.Methods: The charts of patients who underwent senile cataract surgery by a single surgeon were reviewed retrospectively. A conventional intracameral endoilluminator was used in a Stop & Chop group (n = 45), while an illuminated chopper was used in an illuminated chop (I-Chop) group (n = 71). EFX, a unitless value that roughly correlates with ultrasound energy during phacoemulsification, surgical phaco time, and changes in endothelial cell count were compared between the two groups and the ratio of zero phacoemulsification in the I-Chop group was evaluated.Results: EFX of the Stop & Chop and I-Chop groups was 18.08 ± 16.15 and 0.82 ± 3.53, respectively (p = 0.001), while the surgical phaco time was 185.08 ± 41.42 and 162.04 ± 49.65 seconds (p = 0.01). However, the endothelial loss did not differ in the two groups (7.03 ± 7.89 vs. 7.13 ± 9.47%, p = 0.76). In the I-Chop group, 56 (86%) eyes had zero phaco energy and patients with EFX >1 (n = 6) had more severe nuclear sclerosis grading (2.90 ± 0.71 vs. 4.5 ± 1.0; p = 0.001).Conclusions: The I-Chop group had lower EFX and shorter surgical phaco time than the Stop & Chop group. Illuminated chop using an illuminated chopper is one way to attain minimal phacoemulsification.