Comparison of the phaco chop and drill-and-crack techniques for phacoemulsification of hard cataracts: A fellow eye study

[Rotational technique for emulsification of soft lens nucleus]

Effective and atraumatic removal of a soft lens nucleus requires different surgical techniques compared to phacoemulsification of a dense nucleus.

PURPOSE

This study was conducted to develop a non-ultrasound technique for emulsification of a soft lens nucleus.

MATERIAL AND METHODS

Fifty-seven patients (57 eyes) underwent surgery. In 23 cases, early or immature cataracts were detected, and in 34 cases, lens removal was performed for refractive purposes in high myopia and complex myopic astigmatism. Phacoemulsifier Centurion Vision System (Alcon Laboratories, Inc., USA) was used for the surgery. Aspiration of soft lens nucleus was done using a rotational technique. The following aspects were evaluated in the course of the surgery: the volume of the required irrigation solution, and the frequency needing to involve ultrasound for complete emulsification of the lens nucleus. Intraoperative and postoperative complications were also assessed.

RESULTS

The surgery was uneventful in all cases. There were no violations of the integrity of capsulorhexis edge. The need for short pulses of minimal power ultrasound during the removal of the soft lens using this technique arose only in 11 (19.3%) cases. The effective ultrasound time was less than 1 second. The required volume of irrigation solution was 33.0 (24.0; 43.0) ml, which does not differ significantly from that in ultrasonic phacoemulsification.

CONCLUSIONS

The use of modern phacoemulsifiers providing a high vacuum level allows successful removal of a soft lens without using ultrasound, which prevents its negative impact on the ocular tissues. The use of adequate surgical techniques, including the optimal direction of rotation of the lens nucleus in the rotational technique, improves the efficiency of soft lens nucleus removal.

A randomized controlled trial to assess safety and efficacy between terminal chop, stop and chop, and direct chop

PURPOSE

The goal in developing new techniques of cataract surgery is to provide a safer, more efficient surgical experience with the lowest complication rate and endothelial cell loss. We compared the efficiency and safety of stop-and-chop, direct chop, and the novel terminal chop techniques of nuclear fragmentation for cataracts grade II-V.

METHODS

We conducted a prospective randomized clinical trial comparing three different techniques of phacoemulsification, namely, stop-and-chop, direct chop, and terminal chop to assess any differences between them and to establish whether any one method was superior to the others. The pre- and postoperative parameters studied, included central corneal thickness (CCT), ultrasonic time (UST), endothelial cell density (CD), cell loss and effective phacoemulsification time (EPT), average cumulative dissipative energy (CDE), and best-corrected visual acuity, among others.

RESULTS

307 eyes were recruited to the study, 102 were recruited to the stop-and-chop group, 103 to the direct chop group, and 102 to the terminal chop group. Statistical differences were found between the techniques with regard to postoperative CCT among NS II (P. 0001) and NS IV cataracts (P = .005) with the lowest values in the terminal chop group among NS II, NS III, and NS IV cataracts. Endothelial cell loss was minimum with a terminal chop in NS II (P = .018) and NS IV cataracts (P = .245). CDE was minimum in terminal chop across different cataract densities.

CONCLUSION

Terminal chop showed improvement over the other two techniques in terms of CDE and was comparable to them with regard to other parameters.

Efficacy and safety of the eight-chop technique in phacoemulsification for patients with cataract

PURPOSE

The aim of this study was to estimate the efficacy of the 8-chop technique in phacoemulsification surgeries of patients with cataract.

SETTING

Sato Eye Clinic, Chiba-ken, Japan.

DESIGN

Prospective study.

METHODS

Patients were classified into 3 groups (Grade II, Grade III, and Grade IV; n = 50 each) according to the firmness of their lens nuclei. The Eight-chopper I was used for Grade II, Eight-chopper II for Grade III, and Lance-chopper for Grade IV. The best-corrected visual acuity, intraocular pressure (IOP), and endothelial cell density were evaluated at 7 and 19 weeks postoperatively. The primary outcome measures were the mean operative time, mean phaco time, cumulative dissipated energy (CDE), and volume of fluid used.

RESULTS

150 cataract surgeries were performed. The operative time (minutes), phaco time (seconds), CDE, and volume of fluid used (milliliters) differed significantly among the 3 groups, increasing in the following order: Grade II, Grade III, and Grade IV ( P < .01). The corneal endothelial cell density did not decrease significantly in the 3 groups at 19 weeks postoperatively ( P = .09). The rate of endothelial cell loss was 0.9% ± 5.9%, 1.0% ± 10.3%, and 5.3% ± 11.1% in the Grade II, III, and IV groups at 19 weeks postoperatively, respectively. There were significant reductions in the IOP at 7 and 19 weeks postoperatively compared with the preoperative IOP in the 3 groups ( P < .01).

CONCLUSIONS

The 8-chop technique was effective and safe in phacoemulsification for patients with cataracts with lens nuclei of varying hardness.

Application of prechop technique in phacoemulsification for cataract patients with highly liquefied vitreous: a retrospective study

Background

Phacoemulsification using phaco-chop technique has many challenging features in cataract patients with highly liquefied vitreous. This study aimed to compare the intraoperative parameters and safety between prechop technique and traditional phaco-chop in phacoemulsification for these patients.

Methods

A total of 54 eyes of 54 patients with high myopia-related or post-vitrectomy cataract that underwent phacoemulsification combined with intraocular lens implantation were included in this retrospective study. Of them, 25 eyes that received manual prechop were included in the prechop group, and 29 eyes with best match of age, axial length and nuclear opalescence (NO) that received standardized phaco-chop were included as the control group. The intraoperative complications and surgery parameters were compared between groups.

Results

No surgical complications were observed in the prechop group, while 2 eyes with posterior capsular rupture and 1 eye with a broken ciliary zonule (10.3%) were found in the control group. There was no significant difference in phaco time, average energy, and cumulative dissipated energy (CDE) between groups (all P > 0.05), but for hard nuclear cataracts with NO grading ≥ 5, prechop group required less phaco time (P = 0.008) and CDE (P = 0.029). There were significant correlations between phaco time vs. NO (r = 0.762 vs. 0.581, both P < 0.005) and CDE vs. NO (r = 0.717 vs. 0.668, both P < 0.001) in the prechop group and control group, respectively.

Conclusions

The prechop technique which seemed to have less intraoperative complications, reduced phaco time and CDE compared to standardized phaco-chop might be a good alternative for cataract patients with highly liquefied or vitrectomized vitreous, especially those with hard nuclear cataracts.