Choice of Fragmentation Algorithm Affects the Reduction in Cumulative Dissipated Energy during Femtosecond Cataract Surgery

1. Harvey Uy¹
2. Keith Edwards²
3. Louis "Skip" Nichamin³
3. Pik Sha Chan¹

¹Asian Eye Institute, Makati City, the Philippines
²LensAR Inc, Orlando, Florida, USA\
³Laurel Eye Center, Brookville, Penssylvania, USA

Purpose: Various laser treatment algorithms can create different lens cutting patterns that can affect the ability of femtosecond laser lens fragmentation (LLF) to reduce phacoemulsification ultrasound energy during femtosecond cataract surgery. (FCS). The purpose of this study is to determine the effectiveness of different LLF treatment algorithms in reducing the amount of ultrasound energy used during FCS.

Methods: Prospective, randomized, open label, interventional clinical trial. Eighty-seven eyes were randomly assigned to receive either one of 3 different laser lens fragmentation patterns or to undergo conventional phacoemulsification without LLF (control group). Main outcome measure: reduction in phacoemulsification ultrasound energy as measured by cumulative dissipated energy (CDE).

Results: The mean CDE for the control group was 21.6 ± 15.8 while the mean CDE for the 3 combined LLF groups was 12.9 ± 15.8 (P = 0.0089). By cataract grading, the mean CDE's for the control group were 9.0 ± 6.9 (Grade 1), 18.4 ± 6.4 (Grade 2), 21.0 ± 11.2 (Grade 3) and 33.0 ± 24.8 (Grades 4). The best of the 3 laser treatment algorithms utilized mean CDE values of 0.7 ± 0.9 (Grade 1), 0.9 ± 1.6 (Grade 2), 5.6 ± 4.4 (Grade 3), and 18.9 ± 13.3 (Grade 4).

Conclusions: LLF fragmentation prior to FCS significantly reduces the amount of ultrasound energy required to remove up to Grade 4 cataracts. The choice of laser treatment algorithm to create cutting patterns influences the amount of ultrasound energy reduction.