Femtosecond laser-assisted capsulotomy with capsular marks for toric IOL alignment: Comparison of tensile strength with standard femtosecond laser capsulotomy

Comparison of toric intraocular lens alignment between femtosecond laser-assisted capsular marking and digital marking

PURPOSE

To compare the accuracy of toric intraocular lens (IOL) alignment between femtosecond laser-assisted capsular marking and digital marking.

SETTING

Ruhr University Eye Clinic, Bochum, Germany.

DESIGN

Prospective clinical trial.

METHODS

In this study, 28 eyes of 23 patients, who underwent femtosecond laser-assisted cataract surgery with implantation of a toric IOL, were included. Intraoperatively, both femtosecond laser-assisted capsular marking and digital marking were applied simultaneously and compared in every case. The toric IOL was aligned to the capsular markings. Postoperatively, the axis of the capsular markings and toric IOL alignment was examined. Visual acuity and refractive outcomes were evaluated.

RESULTS

Both alignment methods were performed without intraoperative complications in all cases. 25 eyes were included in the final analysis. Misalignment was significantly lower with femtosecond laser-assisted capsular marking than with digital marking (1.71 ± 1.25 degrees vs 2.64 ± 1.70 degrees, P = .016). Deviation from the target axis of the toric IOL was 1.62 ± 1.24 degrees 4 to 6 weeks postoperatively. Postoperative uncorrected distance visual acuity was 0.14 ± 0.13 logMAR, and residual astigmatism was 0.3 ± 0.23 diopter (D) with an astigmatism ≤0.5 D in 93% of eyes.

CONCLUSIONS

Both methods showed excellent results for the alignment of toric IOLs. However, femtosecond laser-assisted capsular marking was significantly more precise than digital marking and showed good refractive results. In addition, capsular marking offers the possibility to avoid parallax error and evaluating postoperative IOL rotation.

Outcomes of toric IOL implantation guided by iris-registered femtosecond laser capsulotomy markings

PURPOSE

To assess the accuracy and stability of iris-registered femtosecond laser-assisted anterior capsule axis markings (compensating cyclotorsion) along with refractive and visual outcomes after toric IOL implantation.

METHODS

This prospective case series included eyes with visually significant cataracts and regular corneal astigmatism ranging from 1.25D to 4.0D, which received FLACS and toric IOL implantation, at The Eye Institute of West Florida, Largo, Florida, USA. Preoperative iris registration was used in conjunction with a femtosecond laser platform to create cyclotorsion corrected axis marks at the capsulotomy edge to facilitate toric IOL axial alignment. Patients were examined one, seven and thirty days after surgery to assess capsulotomy marks axis, toric IOL axis along with visual and refractive outcomes.

RESULTS

Eighteen eyes of 13 patients aged 74.35 ± 8.65 years were included. Mean pre-op CDVA was 0.24 ± 0.16 LogMAR, while mean post-op UDVA was 0.09 ± 0.09 LogMAR. Mean pre-op corneal astigmatism was 1.85 ± 0.41 D, decreasing to 0.24 ± 0.41 D of refractive astigmatism postoperatively (p < 0.001). The capsular toric axis markings were visible in 100% of eyes throughout the follow-up; the mean difference between intended capsulotomy mark axis and measured capsulotomy mark axis was 1.6°, 1.7° and 1.3 ^o at the 1, 7 and 30 day intervals (p > 0.05), respectively. No capsule-related or any other type of complications was noted.

CONCLUSIONS

Iris-registered femtosecond laser-assisted anterior capsule axis markings are safe and may be considered as an alternative option to the known axis marking techniques for toric IOL axial alignment at the time of cataract surgery.

Comparison of Toric Intraocular Lens Alignment Between Femtosecond Laser-Assisted Capsular Marking and Manual Corneal Marking

PURPOSE

To compare toric intraocular lens (IOL) alignment between femtosecond laser-assisted capsular marking and manual corneal marking.

METHODS

This study prospectively included 72 consecutive eyes (from 72 patients) with cataract and anterior corneal astigmatism of 1.00 diopter (D) or greater that underwent femtosecond laser-assisted cataract surgery with implantation of a toric IOL. These eyes were randomly categorized into two groups based on the IOL alignment method. The femtosecond laser capsular marking group included 36 eyes with capsular markers using the latest femtosecond laser platform. The manual marking group included 36 eyes with manual corneal markers. The preservation of the markers was assessed. Visual acuity and refractive outcomes, as well as deviation from the target axis, were evaluated.

RESULTS

In the femtosecond laser capsular marking group, all capsular markers were retained for at least 3 months. In the manual marking group, 22.2% of the corneal markers disappeared within 1 month and all markers disappeared within 3 months. At 1 month postoperatively, the mean magnitudes of refractive astigmatism were -0.41 ± 0.26 and -0.45 ± 0.31 D (P = .81), and the uncorrected distance visual acuities were 0.07 ± 0.06 and 0.07 ± 0.05 logMAR (P = .56) in the femtosecond laser capsular marking and manual marking groups, respectively. The misalignment of the toric IOL within 1 hour postoperatively was 1.5° ± 1.4° in the femtosecond laser capsular marking group and 4.4° ± 2.1° in the manual marking group (P < .01). The deviation from the target axis of implantation was 1.6° ± 1.3° in the femtosecond laser capsular group and 4.8° ± 2.5° in the manual marking group (P < .01) at 1 month postoperatively.

CONCLUSIONS

IOL misalignment was significantly lower in the femtosecond laser-assisted capsular marking group than in the manual corneal marking group. In addition, the long-term preservation of the capsular marker is helpful in evaluating the rotation of the toric IOL. [J Refract Surg. 2020;36(8):536-542.].

Iris Registration Capsulotomy Marking Versus Manual Marking for Toric Intraocular Lens Alignment in Cataract Surgery

PURPOSE

To compare the accuracy of toric intraocular lens (IOL) alignment and visual outcomes using femtosecond laser-assisted capsulotomy marking (CM) versus conventional slit lamp-assisted manual marking (MM).

DESIGN

Prospective cohort study.

METHODS

A total of 57 patients who required cataract surgery and toric IOL implantation (Acrysof SN6AT3-T8) were assigned to the CM group (26 eyes) or the MM group (31 eyes). Uncorrected distant visual acuity (UCDVA), best-corrected distant visual acuity (BCDVA), residual astigmatism (RA), IOL misalignment, and modulation transfer function (area ratio [AR] value) were measured 1 and 3 months after surgery.

RESULTS

Postoperative UCDVA (logarithm of minimal angle of resolution [logMAR]) was significantly lower in the CM group than that in the MM group (P < .05). Postoperative RA and IOL misalignment were significantly lower in the CM group than that in the MM group (both P < .05). No significant difference between the groups was observed for BCDVA or AR value (both P > .05). UCDVA (logMAR) was positively correlated with RA (r = 0.339; P < .05) and IOL misalignment (r = 0.317; P < .05) and negatively correlated with the the AR value (r = -0.272; P < .05); RA was positively correlated with IOL misalignment (r = 0.405; P < .05).

CONCLUSIONS

The accuracy of the axis alignment was significantly higher in the CM group, which resulted in lower residual astigmatism and better visual outcomes.

FOCUSED (Femtosecond Optimized Continuous Uncorrected Sight with EDOF and Diffractive Multifocal IOLs) - A Review

PURPOSE OF REVIEW

The aim of this article is to review techniques to maximize all-distance uncorrected visual acuity and minimize photic phenomena after the implantation of multifocal and extended-depth of focus (EDOF) intraocular lenses (IOLs). This review examines the role of femtosecond laser-assisted cataract surgery (FLACS) in postoperative minimization of astigmatism and optimization of outcomes with multifocal and EDOF lenses.

RECENT FINDINGS

By incorporating intraoperative and preoperative imaging, femtosecond platforms such as those that utilize iris or conjunctival vessel registration, can enable a precision of corneal incisions and toric IOL markings that enable the lowest possible postoperative levels of astigmatism. Current studies suggest that with increasing IOL complexity, that is, trifocal versus bifocal, image degradation with even low levels of postoperative astigmatism are increased. To this end, current data support the utility of femtosecond laser arcuate incisions to enable the achievement of 0.5 D or less postoperative astigmatism for best outcomes with multifocal lenses.

SUMMARY

The synergistic combination of multifocal/EDOF IOLs with FLACS is an extremely promising route in achieving postoperative spectacle independence for patients. The marriage of the precision of FLACS with the increasing complexity of multifocal/EDOF IOLs will fuel nomogram adjustment and systematic improvements, such as the Wörtz-Gupta formula. Such strategies provide an unprecedented precision to cataract surgery that makes FOCUSED (Femtosecond Optimized Continuous Uncorrected Sight with EDOF and Diffractive Multifocal IOLs) a reality.

Femtosecond laser-assisted refractive capsulorhexis - Precise capsulotomy with accurate toric intraocular lens alignment

Femtosecond laser-assisted cataract surgery with refractive capsulorhexis and toric intraocular lens (IOL) implantation was performed in 14 eyes with senile cataract and a preexisting regular corneal astigmatism of 1.5 D or more. Intraoperatively, the accuracy of the capsular rim marks was confirmed using the digital overlay of CALLISTO Eye and Z Align (Carl Zeiss Meditec, Germany). Postoperatively, the mean deviation from target axis of implantation was 2.07° ± 1.49°. Refractive capsulorhexis combines the advantages of a femtosecond laser capsulotomy with a one-step visual guide for intraoperative toric IOL alignment as well as postoperative assessment of rotational stability.

[Current value of femtosecond laser-assisted cataract surgery]

After more than 10 years of experience with the femtosecond laser in cataract surgery, it can be concluded that the safety profile of femtosecond laser-assisted cataract surgery (FLACS) is comparable to that of conventional cataract surgery. This technique offers the possibility to perform incisions with a precision superior to that of any surgeon in the world, based on the connection of preoperative and intraoperative diagnostics. This results in new possibilities to revolutionize the surgical procedure of cataract surgery and to generate new therapeutic approaches for the treatment of cataracts. The combination of keratotomy for correcting astigmatism, intraocular lenses supported by capsulotomy and individually adapted fragmentation patterns is already a component of a personalized cataract surgery.