The superior chop: Efficacy of nitinol filament (Zeiss Miloop) nuclear disassembly and primary chop technique for moderate density cataracts

Benjamin Wai Yin Au, Anton Van Heerden

Meeting:  2022 RANZCO


Date:      -

Session Title: CATARACT

Session Time:      -

Purpose: To compare the efficacy of nitinol filament (Zeiss miLoop) nuclear disassembly with primary chop technique for moderate density cataracts.

Method: Prospective randomised two-surgeon non- blinded surgical audit of primary chop nuclear disassembly (control) against Miloop disassembly with chop techniques. Pre-audit randomisation of 20 Miloop and 10 control surgery order was conducted. Patients with nuclear cataract grade 3 or 4 (based on LOCIII) assessed by either author pre-operatively were recruited. Pre-operative central endothelial cell count was performed. Surgery conducted by pre- determined randomised technique. Surgical timing and cumulative dissipated energy (CDE) were recorded. Three weeks post-operative endothelial cell count was recorded and difference calculated. All surgeries were per- formed by either authors using Alcon Centurion with Duovisc Viscoelastic. Patients undergoing Miloop would also have Vision Blue for ease of identifying rhexis edge.

Preliminary results: Thus far nine patients have been recruited for the audit (six chop and three Miloop and three Miloop). As of present six patients have completed their three-week post op review. Three patients were randomised to the chop arm and two to the Miloop arm. However, one patient from the chop arm had iris pro- lapse after rhexis formation and was converted to primary chop and analysed as part of the control group in this audit. Preliminary results for control (4) vs chop (1) are: Pre-operative CDE 2570 vs 2631, Average surgical time 21 vs 24 minutes. Mean % endothelial loss was 29.8% vs 8.5% and average CDE 11.21 vs 10.29. Current sample size is too small for statistical analysis..

Conclusion: Preliminary results suggest that nitinol filament nuclear disassembly may reduce endothelial cell loss compared to primary chop techniques.