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Erika Fernández-Muñoz,1,&ast; Yolanda Chávez-Romero,1,&ast; Ricardo Rivero-Gómez,1,&ast; Rebeca Aridjis,2,&ast; Roberto Gonzalez-Salinas1,&ast; 1Anterior Segment Surgery Department. Asociación para Evitar la Ceguera en México I.A.P., Mexico City, Mexico; 2LaSalle School of Medicine, Mexico City, Mexico&ast;These authors contributed equally to this workCorrespondence: Erika Fernández-Muñoz, Anterior Segment Surgery Department, Asociación para Evitar la Ceguera en México I.A.P, Vicente García Torres 46, Barrio San Lucas, Coyoacán, PO. 04030, Mexico City, Mexico, Tel +52 55 10841400, Ext 1144, Email efernandez2108@gmail.comPurpose: To determine the energy expenditure in phacoemulsification surgery expressed as cumulative dissipated energy (CDE) among the divide and conquer, ultrachopper-assisted divide and conquer, and phaco-chop techniques for dense cataract removal.Patients and Methods: The clinical data were obtained from the medical charts of dense cataracts patients undergoing routine phacoemulsification employing any of three phaco-fragmentation techniques, including divide and conquer using the Kelman 0.9 mm tip, the ultrachopper tip, and the phaco-chop technique using the Kelman 0.9 mm tip. Cumulated dissipated energy (CDE), longitudinal ultrasound time (UST), and endothelial cell loss were compared among groups at the one-month postoperative.Results: Surgeries from 90 eyes were analyzed, among whom the conventional divide-and-conquer technique group included 30 patients, 32 in the ultrachopper group, and 28 in the phaco-chop technique group. The average CDE in the conventional divide and conquer group was 44.52 ± 23.00, the ultrachopper technique was 43.27 ± 23.18, and 20.11 ± 11.06 in the phaco-chop group. Phaco-fragmentation chop demonstrated significantly lower CDE than the other techniques (p= < 0.0001). The phaco-chop technique showed statistically significantly lower CDE when compared to the other two groups (p=< 0.0001) with 93.96 ± 39.71 seconds. There were no statistically significant differences in postoperative endothelial cell density between groups (p=0.4916).Conclusion: The use of the phaco-chop technique in hard cataract phacoemulsification represents a lower energy expenditure than divide and conquer and ultrachopper techniques; nevertheless, no differences regarding endothelial density loss were evidenced.Keywords: dense cataracts, ultrachopper, phaco-chop, stop-and-chop technique, divide-and-conquer technique, cumulative dissipated energy

AIM: To analyze the advantages of capsulorhexis-chop forceps assisted prechop(CCFP)technique in hard cataract phacoemulsification.METHODS: Prospective study. A total of 100 cases(100 eyes)with age-related grade IV hard cataract were included and randomly divided into 2 groups according to random number table, with 50 patients(50 eyes)in CCFP technique group(group A)and 50 cases(50 eyes)in stop-and-chop technique group(group B). The corneal endothelial cell count before and after operation, intraoperative US time, postoperative corneal endothelial cell loss rate, corneal edema grade at 1 and 7d and best corrected visual acuity(BCVA)were compared and statistically analyzed.RESULTS: The mean US time of group A was lower than that of group B [26.66(16, 40)s vs. 36.12(23, 46)s; Z=-5.56, P

Kazuki Matsuura,1,2 Nao Takanashi2 1Department of Ophthalmology, Nojima Hospital, Kurayoshi-city, Japan; 2Department of Ophthalmology and Visual Science, Tottori University, Yonago-city, JapanCorrespondence: Kazuki Matsuura, Nojima Hospital, 2714-1, Sesaki-machi, Kurayoshi-city, Tottori Prefecture, 6820863, Japan, Tel +81-858-22-6231, Fax +81-858-22-6843, Email matsuura.kzk@gmail.comAbstract: The stop-and-chop technique, which involves occlusion and chopping using vacuum to stabilize the nucleus, is an excellent combination of the divide-and-conquer and phaco-chop techniques. However, effectively chopping an un-solid (soft to moderate) nucleus is not easy, since the optimal vacuum to hold an un-solid nucleus is often associated with breaking of occlusion and aspiration of the nucleus. We modified the stop-and-chop technique such that occlusion and tight nucleus holding using ultrasound (US) power is not necessary. After completing the central groove and cracking the nucleus into two hemi-sections, the right nucleus half is chopped without nucleus rotation and occlusion. The right hemi-nucleus is stabilized by pressing against the right sac with the US tip without occlusion. Since this technique can reduce the risk of nucleus perforation and posterior capsular rupture, the surgeons can place the US tip firmly in a deep position, which provide safe and efficient nucleus division.Keywords: cataract surgery, divide-and-conquer technique, stop-and-chop technique, power free phacoemulsification, stop-and-press technique

Abstract Background To evaluate the safety and efficacy of the pre-chop technique using a novel reverse chopper vs. the classic stop-and-chop technique in phacoemulsification for patients with high myopia and associated grade III–IV nuclear cataracts. Methods In this prospective cohort study, a total of 44 consecutive patients (44 eyes) with grade III–IV nuclear cataracts who were admitted to our hospital for cataract surgery between March 2018 and September 2018 were enrolled. All patients had ocular axial length > 27 mm and myopic refraction more than -10 diopters. Patients were randomly divided into a pre-chop group and stop-and-chop group using a randomization table. Nucleus splitting was performed surgically in both groups using either the pre-chop technique with reverse chopper or the classic stop-and-chop technique. Results Postoperative visual acuity was significantly improved in both groups compared with preoperative values. Significantly better visual acuity, lower degree of corneal edema and lower rates of corneal endothelial cell loss were observed in the pre-chop group compared to those in the classic stop-and-chop group. No complications were reported in either group. Conclusions In treating patients with high myopia associated with grade III–IV cataracts, the pre-chop technique using a reverse chopper reduces damage to corneal endothelial cells and improves visual acuity better than the classic stop-and-chop technique.

Background: To evaluate the safety and efficacy of the pre-chop technique using a novel reverse chopper vs. the classic stop-and-chop technique in phacoemulsification for patients with high myopia and associated grade III-IV nuclear cataracts.Methods: In this prospective cohort study, a total of 44 consecutive patients (44 eyes) with grade III-IV nuclear cataracts who were admitted to our hospital for cataract surgery between March 2018 and September 2018 were enrolled. All patients had ocular axial length > 27 mm and myopic refraction more than -10 diopters. Patients were randomly divided into a pre-chop group and stop-and-chop group using a randomization table. Nucleus splitting was performed surgically in both groups using either the pre-chop technique with reverse chopper or the classic stop-and-chop technique.Results: Postoperative visual acuity was significantly improved in both groups compared with preoperative values. Significantly better visual acuity, lower degree of corneal edema and lower rates of corneal endothelial cell loss were observed in the pre-chop group compared to those in the classic stop-and-chop group. No complications were reported in either group.Conclusions: In treating patients with high myopia associated with grade III-IV cataracts, the pre-chop technique using a reverse chopper reduces damage to corneal endothelial cells and improves visual acuity better than the classic stop-and-chop technique. [ABSTRACT FROM AUTHOR]

Phacoemulsification is a widely adopted technique in cataract surgery that offers a minimally invasive approach to lens removal and intraocular lens implantation. Among the various methods of phacoemulsification, "direct-chop" and "stop-and-chop" techniques are particularly notable for their efficiency and safety profiles. This review aims to evaluate the effects of these two techniques on corneal endothelial cells and visual acuity, specifically under topical anesthesia. Cataract surgery outcomes hinge on the preservation of corneal endothelial cells and the achievement of optimal visual acuity. Endothelial cell loss can lead to corneal decompensation, while visual acuity is a primary measure of surgical success. The "direct-chop" technique involves the immediate chopping of the lens nucleus after groove creation, reducing phacoemulsification time and energy. Conversely, the "stop-and-chop" technique incorporates a central groove before chopping, offering increased control and safety. This review synthesizes current research and clinical studies to compare these techniques, focusing on their respective impacts on endothelial cell count and postoperative visual acuity. It examines the advantages and disadvantages of each approach, considers the role of surgeon experience, phacoemulsification energy, and anterior chamber stability, and assesses patient outcomes under topical anesthesia. The findings aim to provide insights that can guide surgeons in selecting the most appropriate technique for their patients, ultimately enhancing surgical outcomes by ensuring the preservation of corneal health and the achievement of superior visual acuity., Competing Interests: Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Upasani et al.)