Comparison between the prechopping method with a reverse chopper and the routine stop-and-chop method in treating cataract with grade IV hard nucleus

Corneal Edema after Cataract Surgery

This systematic review investigates the prevalence and underlying causes of corneal edema following cataract surgery employing manual phacoemulsification. A comprehensive search encompassing databases such as PubMed, Embase, ProQuest, Cochrane Library, and Scopus was conducted, focusing on variables encompassing cataract surgery and corneal edema. Two independent reviewers systematically extracted pertinent data from 103 articles, consisting of 62 theoretical studies and 41 clinical trials. These studies delved into various aspects related to corneal edema after cataract surgery, including endothelial cell loss, pachymetry measurements, visual performance, surgical techniques, supplies, medications, and assessments of endothelial and epithelial barriers. This review, encompassing an extensive analysis of 3060 records, revealed significant correlations between corneal edema and endothelial cell loss during phacoemulsification surgery. Factors such as patient age, cataract grade, and mechanical stress were identified as contributors to endothelial cell loss. Furthermore, pachymetry and optical coherence tomography emerged as valuable diagnostic tools for assessing corneal edema. In conclusion, this systematic review underscores the link between corneal edema and endothelial cell loss in manual phacoemulsification cataract surgery. It highlights the relevance of factors like patient demographics and diagnostic modalities. However, further research is essential to unravel the complexities of refractive changes and the underlying mechanisms.

Comparison of pre-chop technique using a reverse chopper and classic stop-and-chop technique in the treatment of high myopia associated with nuclear cataract

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01658-0.

"Chopper Shield" Technique to Protect Corneal Endothelium During Phacoemulsification Surgery for Rock Hard Cataracts

Purpose

To describe an innovative technique of using a chopper as a shield for preventing mechanical corneal endothelial trauma that can occur during the phacoemulsification of brunescent cataracts.

Methods

This prospective study included patients with hard cataracts (grade nuclear opalescence 4 and above on LOCS III) who underwent phacoemulsification surgery. The chopper shield technique was performed in 48 eyes of 44 patients. The technique entailed placing the chopper horizontally as a shield anterior to the emulsifying nuclear fragment between the phaco tip and corneal endothelium to prevent nucleus fragments from coming into contact with the corneal endothelium. Outcome measures included cumulative dissipated energy (CDE), corneal edema (day one), CCT (assessed at one day, one week, and one month), and endothelial cell density assessed at three months.

Results

Of the 48 eyes included in the study, 23 were males and 25 were females (mean age: 70.02±5.98years). Preoperatively, mean central corneal thickness (CCT) was 529.62±21.70 microns, and endothelial cell counts were 2258.76±182.22 cells per mm². Postoperatively on day one, CCT increased to 563.93±24.53 microns, a 6.47% increase from preoperative central corneal thickness. CCT became 534.83±22.64 microns on postoperative day seven, a 0.98% increase from preoperative CCT. Endothelial cell loss was 6.77% at three months from the day of surgery.

Conclusion

The chopper shield technique offers continuous protection to the corneal endothelium by minimizing endothelial cell loss during phacoemulsification of dense nuclear cataracts.

Application of a prechop technique using a reverse chopper in small pupil cataract surgery

Background

To analyze the value of a prechop technique for splitting the nucleus of the lens using a reverse chopper in small-pupil cataract surgeries. A prospective case-control study. Thirty-four cataract patients (34 eyes) who were treated in our center from March 2019 to December 2019 were enrolled and then divided into two groups: small pupil group (18 patients; 18 eyes) and normal pupil group (16 patients; 16 eyes).

Methods

The prechop technique was applied in both groups, and the patients were followed up for three months. The best-corrected visual acuity (BVCA), surgical complications, corneal endothelial cell loss, pupil function, operative time, and cumulative dissipated energy (CDE) were compared between these two groups, and the safety of the nucleus-chopping technique was evaluated. Data were analyzed using the SPSS 23.0 software packages. BVCA, surgical complications, rate of corneal endothelial cell loss, pupil function, operative time, and CDE.

Results

The surgery was smooth in all cases. The operative time, intraoperative ultrasound energy consumption, BVCA, and surgical complications indicated no significant difference between the two groups (all P>0.05). In the small pupil group, BVCA was significantly improved after surgery and achieved its optimal value three months after surgery (χ²=49.38; P=0). The diameter of the pupil was about 3.22 mm in the small pupil group before nucleus chopping. The postoperative pupil morphology was not statistically different from that before surgery (pupil morphology: χ²=0.131; P=0.717); however, the pupillary light reflex was significantly improved after surgery (χ²=8.378; P=0.004), and the pupil diameter was significantly increased (T=-3.494; P=0.003). The rate of corneal endothelial cell loss was higher in small pupil group than in the normal pupil group in the 3rd postoperative month, but the difference was not statistically significant (T=-0.023; P=0.982).

Conclusions

The prechop technique using a reverse chopper in small-pupil cataract surgery occupies a similar operative time, cumulative energy consumption during operation, BVCA, pupil morphology, and rate of corneal endothelial cell loss, comparing with those in normal-pupil cataract surgery. To such a degree, it is a safe, high-efficiency, a simple and easy-to-operate nucleus-chopping technique that can be used in small-pupil cataract surgery.