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. 2023 Jul 17;37(18):3865–3868. doi: 10.1038/s41433-023-02616-7

Table 2.

Summary details of studies comparing the energy requirements of phaco-chop and divide-and-conquer phacoemulsification.

Study Year Machine Technique Mean cataract grade Mean effective phaco time (s) Mean phaco time (s) Mean phaco energy/power Findings
El-Sobky et al. [5] 2016 Geuder Megatron G PC (n = 25) 2.5 (LOCS III) 12.6 18 Reduced phaco-time (p < 0.001) and EFT (p < 0.001) for phaco-chop technique
DQ (n = 25) 2.6 (LOCS III) 19.9 27.7
El-Din Farahat et al. [6] 2016 Geuder Megatron s3 PC (n = 15) 3 (LOCS III) 22.57 Reduced EFT (p < 0.001) for phaco-chop technique
DQ (n = 15) 3 (LOCS III) 48.47
Elnaby et al. [7] 2008 Geuder Megatron G PC (n = 7) N1 (LOCS III) 14.57 1559.14 J Reduced EFT (p < 0.033) for phaco-chop technique
DQ (n = 8) N1 (LOCS III) 21.62 2313.87 J N1: 33% reduction in phaco energy using phaco-chop
PC (n = 14) N2 (LOCS III) 17.5 1872.5 J N2: 22% reduction in phaco energy using phaco-chop
DQ (n = 13) N2 (LOCS III) 22.38 2395.15 J N3: 7% reduction in phaco energy using phaco-chop
PC (n = 4) N3 (LOCS III) 34.25 3664.75 J No statistical analysis of phaco energy
DQ (n = 4) N3 (LOCS III) 36.75 3932.25 J
Wong et al. [8] 2000 Series 20,000 Legacy phacoemulsification unit (Alcon Laboratories)
(a) PC (n = 75) 1.52 (LOCS) 23.4 84 26.90% Reduced mean phaco time (p < 0.0001) and EFT (p < 0.0001) for phaco-chop
DQ (n = 50) 1.66 (LOCS) 58.8 204 28.60% No difference in mean phaco power (p = 0.0701)
(b) PC (n = 62) 1.7 (LOCS) 17.4 72 25.30% Reduced mean phaco time (p < 0.001) and EFT (p = 0.01) for phaco-chop technique
DQ (n = 55) 1.7 (LOCS) 50.4 144 35.10% Reduced phaco energy for phaco-chop technique (p < 0.001)
Storr-Paulsen et al. [9] 2008 Storz Millennium phacoemulsification machine (Bausch & Lomb, Inc.) PC (n = 60) 2.9 (Emery scale) 3.98 Reduced EFT (p < 0.0001) for phaco-chop technique
DQ (n = 60) 2.8 (Emery scale) 12.79
Yigit et al. [10] 2019 Bausch & Lomb Stellaris, Inc PC (n = 50) 3.7 (LOCS III) 22.54 41.2 30.20% Reduced mean phaco time (p = 0.013) and EFT (p = 0.024) for phaco-chop technique
DQ (n = 50) 3.9 (LOCS III) 30.62 63 32.90% No difference in mean phaco energy (p = 0.0701)
Prasad et al. [11] 2020 PC (n = 50) 2 (LOCS III) 16.58
Reduced EFT (p < 0.0001) for phaco-chop technique
DQ (n = 50) 2 (LOCS III) 27.12

a retrospective, pilot study, b prospective study, DQ divide-and conquer, EFT effective phaco-time, J joules, LOCS Lens Opacities Classification System, PC phaco-chop, PT phaco-time, s seconds.