Precision pulse capsulotomy: an automated alternative to manual capsulorhexis in paediatric cataract

Preventing the Argentinian flag sign and managing anterior capsular tears: A review

The Argentinian flag sign (AFS) is a feared complication during cataract extraction. Intralenticular pressures, especially excessive posterior pressure, have been identified as potential mechanisms for capsular stress and tearing associated with AFS. Capsular tension is created by positive intralenticular pressures, which cause the irido-lens diaphragm to move anteriorly once the manual capsulorhexis has been initiated. This tension can cause inadvertent tears that self-propagate to the lens equator, causing an AFS, among other intraoperative complications. Thus, this review highlights the importance of identifying intumescent cataracts as well as a combination of techniques to relieve intracapsular pressures needed to prevent AFS. However, some instances of anterior capsular tears are unavoidable. Therefore, focus will also be placed on techniques during cataract extraction used to manage anterior capsular tears, mitigating extension to the posterior capsule.

Endothelial Cell Loss Following Cataract Surgery Using Continuous Curvilinear Capsulorhexis or Precision Pulse Capsulotomy

Purpose

To compare endothelial cell density (ECD), percentage of hexagonal cells (%Hex) and coefficient of variation (CV) in cell size following lens cataract surgery with phacoemulsification performed using Continuous Curvilinear Capsulorhexis (CCC) or Precision Pulse Capsulotomy (PPC).

Patients and Methods

Sixty-seven subjects were randomly assigned to undergo lens cataract removal with the capsulotomy step performed using either CCC or PPC. Specular microscopy images were obtained pre-operatively, 1 month and 3 months after surgery. ECD, %Hex and CV were analyzed in a masked fashion by an independent reading center.

Results

The mean percentage ECD loss at 1 month was 11.5% in the CCC group and 12.3% in the PPC group (P = 0.818; t-test). At 3 months, the mean percentage ECD loss was 11.7% in the CCC group and 12.4% in the PPC group (P = 0.815; t-test). The mean %Hex at 1 month was 54.3% in the CCC group and 54.7% in the PPC group (P = 0.695; t-test). At 3 months, the mean %Hex was 56.2% in the CCC group and 54.7% in the PPC group (P = 0.278; t-test). The CV at 1 month was 34.4% in the CCC group and 34.3% in the PPC group (P = 0.927; t-test). At 3 months, the CV was 32.7% in the CCC group and 33.4% in the PPC group (P = 0.864; t-test).

Conclusion

No differences in ECD loss, %Hex and CV were observed between patients who received CCC or PPC. PPC use during cataract surgery does not result in any increased endothelial cell loss beyond that normally associated with this surgery.

Automated precision pulse capsulotomy vs manual capsulorhexis in white cataracts: reduction in procedural time and resource utilization

PURPOSE

To compare the utility of precision pulse capsulotomy (PPC) with manual capsulorhexis for capsulotomy in white cataracts.

SETTING

Hospital-based academic practice.

DESIGN

Retrospective analysis of surgical case records and surgical videos from a single surgeon.

METHODS

Cases involving intumescent and nonintumescent white cataracts were identified. Capsulotomy outcomes, surgical outcomes, procedural time, and resource utilization, as well as patient demographic and health data, were analyzed and subjected to statistical testing.

RESULTS

15 cases of white cataract (10 intumescent and 5 nonintumescent) performed using continuous curvilinear capsulorhexis (CCC) were compared with 20 cases (9 intumescent and 11 nonintumescent) performed using PPC. The cases covered a period of 14 months before and 30 months after surgeon adoption of PPC. There were no significant differences between the 2 groups in patient age, sex, ethnicity, ocular history, medical history, and medications. PPC resulted in complete capsulotomies without tags or tears and intracapsular intraocular lens implantation with 360-degree capsular overlap in all 20 cases. There was 1 CCC case resulting in the Argentinian flag sign. Compared with CCC, PPC white cataract cases also demonstrated significant advantages in capsulotomy time, reduced use of trypan blue and ophthalmic viscosurgical device, and less overall procedural time.

CONCLUSIONS

PPC is a safe and highly effective method to create consistent capsulotomies in both intumescent and nonintumescent white cataracts. The use of PPC provides benefits of significant reductions in capsulotomy time, overall procedural time, and resource utilization, resulting in a streamlined treatment of these complex cataract surgery cases.

Recent developments in anterior capsulotomy for cataract surgery

PURPOSE OF REVIEW

Successful anterior capsulotomy is an important step in cataract surgery. This article reviews the various anterior capsulotomy techniques available to surgeons to optimize the step, including those that have become available since the introduction of femtosecond-laser-assisted cataract surgery (FLACS). Studies comparing the relative advantages of each technique will be emphasized.

RECENT FINDINGS

Manual continuous curvilinear capsulorhexis (CCC) and FLACS remain the two most widely studied techniques for achieving anterior capsulotomy. Each technique has been shown to be effective for a wide range of patients and cataract surgery complications. Meta-analyses have shown that FLACS provides similar results to manual CCC for long-term cataract surgery outcomes. Several alternative methods for anterior capsulotomy have been described, which aim to provide some of the advantages of laser capsulotomy at a lower cost; among these, precision pulse capsulotomy (PPC) and selective laser capsulotomy (SLC) have been investigated the most in the literature so far.

SUMMARY

Cataract surgeons have an increasing number of techniques for anterior capsulotomy available. Manual CCC and FLACS remain the most widely used, and most well studied. The latest techniques, PPC and SLC, have shown promise in the few studies performed since they were introduced.

Use of P1-P4 Purkinje reflections as a surrogate sign for intraoperative patient fixation

Circumferential, even anterior capsular overlap maximizes intraocular lens stability and posterior capsular opacification mitigation and provides best long-term outcomes for the cataract patient. P1 and P4 Purkinje reflections at patient fixation may provide a reliable marker for capsulotomy centration. However, patient fixation may be hindered during surgery because of anesthesia or light sensitivity. In this study, we demonstrate that the relationship between the P1 and P4 Purkinje reflections previewed prior to surgery when the patient is fixating may be recreated intraoperatively if fixation becomes difficult. The final position of P1 and P4 relative to one another at fixation is invariant in a given patient, but there are variations among patients. Knowledge of the P1 and P4 relationship can be used as a surrogate sign of patient fixation to assist in capsulotomy centration during cataract surgery.

Precision pulse capsulotomy: performance metrics and utility in routine and complex cases

PURPOSE

To evaluate precision pulse capsulotomy (PPC) performance.

SETTING

University and private practice in the United States and South Korea.

DESIGN

Multicenter retrospective analysis.

METHODS

The surgical videos of 337 cataract surgeries with PPC capsulotomy performed by 4 surgeons at 4 centers were used to assess capsulotomy outcomes including completion rate, diameter, roundness (ovality), and quality of capsular overlap.

RESULTS

PPC use resulted in 99.4% free-floating capsulotomies from 337 cases. Video image analysis in a subset (n = 52) yielded a mean capsulotomy diameter of 5.0 mm ± 0.16 mm SD (95% CI, 4.96-5.04 mm). Capsulotomies were round to slightly oval at the end of the case with a mean ovality of 3.0% ± 2.86% (95% CI, 2.22%-3.78%; 360 degrees capsular overlap was obtained in 98% of cases. The offset of the capsulotomy center with the intraocular lens (IOL) optic center was 197 μm ± 122 μm (SD) (95% CI, 148-246 μm). PPC was used successfully in traumatic cataracts with compromised anterior and posterior capsule, phacodonesis, intumescent cataract with constricted pupil, and zonular dialysis and in penetrating keratoplasty with open-sky extracapsular cataract extraction.

CONCLUSIONS

Surgeons obtained good PPC capsulotomy outcomes in routine and challenging cases. Little variation was observed in achieving free-floating capsulotomies with approximately 5.0 mm diameter and complete capsular overlap. Variation was observed in the amount of offset between the capsulotomy center and the center of the IOL optic. PPC was useful in cases with multiple comorbidities that challenge capsulotomy performance.