Comparative clinical outcomes of Tecnis toric IOL implantation in femtosecond laser-assisted cataract surgery and conventional phacoemulsification surgery

Clinical efficacy of femtosecond laser-assisted phacoemulsification in diabetic cataract patients

BACKGROUND

Diabetic patients with cataracts encounter specific difficulties during cataract surgery due to alterations in microcirculation, blood supply, metabolism, and the microenvironment. Traditional phacoemulsification may not fully tackle these issues, especially in instances with substantial preoperative astigmatism. The utilization of femtosecond laser-assisted phacoemulsification, in conjunction with Toric intraocular lens (IOL) implantation, offers a potentially more efficient strategy. This research seeks to evaluate the efficacy and possible complications of this approach in diabetic cataract patients.

AIM

To investigate the clinical efficacy and complications of femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation in diabetic cataract patients, comparing it with traditional phacoemulsification methods.

METHODS

This retrospective study enrolled 120 patients with diabetes cataract from May 2019 to May 2021. The patients were divided into two groups: the control group underwent traditional phacoemulsification and Toric IOL implantation, while the treatment group received Len Sx femtosecond laser-assisted treatment. Outcome measures included naked eye vision, astigmatism, high-level ocular phase difference detection, clinical efficacy, and complication.

RESULTS

There were no significant preoperative differences in astigmatism or naked eyesight between the two groups. However, postoperative improvements were observed in both groups, with the treatment group showing greater enhancements in naked eye vision and astigmatism six months after the procedure. High-level corneal phase difference tests also indicated significant differences in favor of the treatment group.

CONCLUSION

This study suggests that femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation appears to be more effective in enhancing postoperative vision in diabetic cataract patients compared to traditional methods offering valuable insights for clinical practice.

Lens capsule-related complications in femtosecond laser-assisted cataract surgery: a study based on video analysis

PURPOSE

To analyse the occurrence and potential causes of lens capsule-related complications during femtosecond laser-assisted cataract surgery (FLACS).

METHODS

This prospective consecutive cohort study included the first 1600 eyes (from 1140 consecutive patients) who received FLACS performed by the same surgeon from May 2015 to December 2018. The potential causes and characteristic signs of capsulotomy-related complications, including incomplete capsulotomies and radial anterior capsule (AC) tears, were summarised based on the agreement of two ophthalmologists after they analysed the surgical videos. Subgroup analysis was conducted to characterise the capsulotomy learning curve.

RESULTS

Of the 1600 eyes, 52 (3.25%) had incomplete capsulotomies and 22 (1.38%) had radial AC tears. The most common causes of incomplete capsulotomies were eye tilt (16 eyes, 30.77%), air bubbles or ocular secretions at the interface (14 eyes, 26.92%) and white cataracts (7 eyes, 13.46%). Additionally, 54.55% (12/22) of AC tears were due to incomplete capsulotomy and secondary capsulorhexis. A significant difference was noted between the first 200 eyes and subsequent groups in terms of the incidence of incomplete capsulotomies. No difference was observed in the incidence of AC tears after the initial 100 procedures.

CONCLUSION

The most common causes of incomplete capsulotomies were eye tilt and air bubbles or ocular secretions at the interface. Secondary capsulorhexis after incomplete capsulotomy is the main risk factor for AC tears. There was a steep learning curve for laser capsulotomy in the first 100 operated eyes, as evidenced by the higher complication rate, but this stabilised after 200 procedures.

Influence of anterior capsulorhexis shape, centration, size, and location on intraocular lens position: finite element model

PURPOSE

To evaluate the influence of anterior capsulorhexis shape, dimension, and eccentricity on intraocular lens (IOL) position.

SETTING

Laboratory investigation.

DESIGN

Computational model.

METHODS

A finite element model of the human crystalline lens capsule and zonule was created and the anterior capsule opened to simulate centered and decentered circular and elliptic rhexis. The model calculated capsular bag stress, IOL rotation, tilt, decentration, and vaulting, related to both capsular landmarks (absolute) and a reference IOL position defined as that obtained with a 5.0 mm circular and centered rhexis.

RESULTS

Mean von Mises stress along the IOL major z-axis was significantly higher than that along the perpendicular x-axis in all cases (P < .001), both at the equator and at the rhexis edge. Stress at the equator was always greater than that at the rhexis edge (P < .001) regardless of the rhexis shape and position. As rhexis eccentricity increased, the stress difference between the z- and x-axes increased. Absolute IOL tilt (range 10-1 to 10-7 degrees), decentration (10-3 to 10-7 mm), rotation (10-2 to 10-3 degrees), and vaulting (10-1 mm) were negligible from an optical standpoint, but all of them were significantly greater for decentered rhexis (both round and elliptic) compared with centered (P < .05).

CONCLUSIONS

Anterior capsulorhexis irregularity and/or eccentricity increase IOL tilt, decentration, rotation, and vaulting in a numerically significant but optically negligible way. Von Mises stress is much greater at the capsular bag equator compared with the rhexis edge and highly asymmetrically distributed in all cases. Stress asymmetry may influence postoperative biologic processes of capsular bag shrinking and further IOL tilting or decentration.

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.

Cataract: Advances in surgery and whether surgery remains the only treatment in future

Background

Cataract is the world's leading eye disease that causes blindness. The prevalence of cataract aged 40 years and older is approximately 11.8%-18.8%. Currently, surgery is the only way to treat cataracts.

Main Text

From early intracapsular cataract extraction to extracapsular cataract extraction, to current phacoemulsification cataract surgery, the incision ranges from 12 to 3 ​mm, and sometimes to even 1.8 ​mm or less, and the revolution in cataract surgery is ongoing. Cataract surgery has transformed from vision recovery to refractive surgery, leading to the era of refractive cataract surgery, and premium intraocular lenses (IOLs) such as toric IOLs, multifocal IOLs, and extended depth-of-focus IOLs are being increasingly used to meet the individual needs of patients. With its advantages of providing better visual acuity and causing fewer complications, phacoemulsification is currently the mainstream cataract surgery technique worldwide. However, patient expectations for the safety and accuracy of the operation are continually increasing. Femtosecond laser-assisted cataract surgery (FLACS) has entered the public's field of vision. FLACS is a combination of new laser technology and artificial intelligence to replace fine manual clear corneal incision, capsulorhexis, and nuclear pre-fragmentation, providing new alternative technologies for patients and ophthalmologists. As FLACS matures, it is being increasingly applied in complex cases; however, some think it is not cost-effective. Although more than 26 million cataract surgeries are performed each year, there is still a gap in the prevalence of cataracts, especially in developing countries. Although cataract surgery is a nearly ideal procedure and complications are manageable, both patients and doctors dream of using drugs to cure cataracts. Is surgery really the only way to treat cataracts in the future? It has been verified by animal experiments that lanosterol therapy in rabbits and dogs could make cataract severity alleviated and lens transparency partially recovered. Although there is still much to learn about cataract reversal, this groundbreaking work provided a new strategy for the prevention and treatment of cataracts.

Conclusions

Although cataract surgery is nearly ideal, it is still insufficient, we expect the prospects for cataract drugs to be bright.

The efficacy of ultrasonic emulsification with IOL implantation in patients with primary angle-closure glaucoma combined with cataract

PURPOSE

This study aimed to investigate the clinical efficacy of ultrasonic emulsification plus IOL implantation in patients with primary angle-closure glaucoma and cataract.

METHODS

The clinical data of 81 patients (91 eyes) with primary angle-closure glaucoma comorbid with cataract in our hospital were retrospectively analyzed and divided into two groups based on surgical modality. Group A (n=40, 45 eyes) underwent trabeculectomy and group B (n=41, 46 eyes) underwent ultrasonic emulsification and IOL implantation. The success rate, best corrected visual acuity, intraocular pressure, anterior chamber depth, anterior chamber angle, visual field, cornea's endothelial cell count, complications, and patient satisfaction were compared between the two groups.

RESULTS

The surgical success rate in group B was 97.83%, significantly higher than 86.67% in group A (P < 0.05); Compared with group A, group B had higher best-corrected visual acuity and lower intraocular pressure (P < 0.05) as well as higher central and peripheral anterior chamber depths at 3 months postoperatively (P < 0.05); After surgery, group A had significantly lower postoperative cornea's endothelial cell count (P < 0.05). Compared with group A, MS was higher and MD was lower in group B at 3 months postoperatively (P < 0.05); the complication rate in group B was 8.70%, lower than 28.89% in group A (P < 0.05).

CONCLUSION

The clinical efficacy of ultrasonic emulsification combined with IOL implantation is remarkable in patients with primary angle-closure glaucoma and cataract, which is conducive to improving postoperative visual acuity, lowering intraocular pressure, increasing the atrial angle, and improving visual field defects. It is also with high safety, but has little effect on cornea's endothelial cell count.

Comparison of Nd:YAG Laser Capsulotomy Rates Between Refractive Segmented Multifocal and Multifocal Toric Intraocular Lenses

PURPOSE

To investigate the early incidence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy according to intraocular lens (IOL) type (nontoric vs toric) and surgical techniques (femtosecond laser-assisted cataract surgery vs conventional phacoemulsification) in eyes with refractive multifocal IOLs.

DESIGN

Retrospective case-control study.

METHODS

Nine hundred thirteen eyes from 483 patients implanted with Lentis Mplus LS-313 MF20 (767 eyes) or Lentis Mplus Toric LU-313 MF20T (146 eyes) IOLs (Oculentis GmbH, Berlin, Germany) were enrolled. We compared the incidence of Nd:YAG laser capsulotomy between the nontoric and toric groups. In addition, the incidence of Nd:YAG laser capsulotomy was also evaluated according to the surgical technique used.

RESULTS

The overall incidence of Nd:YAG laser capsulotomy was 10.2% (93/913 eyes). The Nd:YAG laser capsulotomy rate was significantly higher in the toric group (24/146; 16.4%) than in the nontoric group (69/767; 9.0%; P = .007). Of the 913 enrolled eyes, 448 eyes (49.1%) underwent femtosecond laser-assisted cataract surgery and 465 eyes (50.9%) underwent conventional phacoemulsification cataract surgery. There was no significant difference in the incidence of Nd:YAG laser capsulotomy between eyes with femtosecond laser-assisted cataract surgery and eyes with conventional phacoemulsification cataract surgery.

CONCLUSION

Patients with refractive multifocal toric IOLs had higher early incidence rates of Nd:YAG laser capsulotomy when compared to those with refractive multifocal nontoric IOLs. Furthermore, femtosecond laser-assisted cataract surgery could not reduce the early incidence of Nd:YAG laser capsulotomy in this study.

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.

Clinical Results After Precision Pulse Capsulotomy

Purpose

To compare residual refractive error and complication rates between eyes undergoing a manual capsulotomy and those receiving a precision pulse capsulotomy using an automated device.

Patients and Methods

This study was a non-interventional two-arm retrospective chart review of clinical results after bilateral cataract surgery or refractive lens exchange (RLE) surgery with a monofocal toric intraocular lens (IOL) or a trifocal IOL where a manual capsulorhexis (Manual) or automated precision pulse capsulotomy (PPC) was performed.

Results

Exams from 243 eyes (122 PPC, 121 Manual) from 124 patients were reviewed; about 75% of which had a trifocal IOL implanted. There was no statistically significant difference in the MRSE with either IOL type, or overall. The overall percentage of eyes with residual refractive cylinder ≤ 0.50 D was significantly higher in the PPC group (89% vs. 79% in the manual group, p = 0.03), primarily driven by results with the toric IOL. Best corrected distance visual acuity was not statistically significantly different by group. Capsulotomy-related complications were lower in the PPC group relative to the manual group (4.1% vs. 6.6%), but this result was not statistically significant (p = 0.38).

Conclusion

Significantly more eyes had refractive cylinder ≤0.50 D in the PPC group. For all other measures, the automated PPC device produced clinical results equivalent to those achieved with a manual capsulorhexis.

Outcomes of toric intraocular lens implantation after femtosecond laser and traditional cataract surgery

CLINICAL RELEVANCE

Having an understanding of the refractive outcomes of different forms of cataract surgery will assist optometrists in explaining the implication of such procedures to patients being referred for such procedures.

BACKGROUND

The purpose of this study was to compare the refractive outcomes after toric intraocular lens implantation between femtosecond laser-assisted cataract surgery and traditional phacoemulsification.

METHODS

This retrospective non-randomised case series included 114 eyes of 92 consecutive patients (59 male and 55 female) aged 71.65 ± 10.46-years (range 57 to 92-years), who underwent either femtosecond laser-assisted cataract surgery (using two laser platforms) (group 1) or traditional phacoemulsification (group 2) between August 2013 and September 2015. Pre-operative keratometric values, the attempted refraction from the biometry platform and the toric intraocular lens web-based calculator, and the one month post-operative manifest refraction were assessed to evaluate the refractive outcomes of the two groups.

RESULTS

Mean pre-operative topographic corneal astigmatism was -1.94 ± 0.73 D (range 0.91 to 4.61 D) and -1.98 ± 0.60 D (range 1.07 to 3.43 D) for groups 1 and 2, respectively (p > 0.05). Mean axial length was 24.22 ± 0.73-mm (range 21.78 to 29.30-mm) and 24.60 ± 1.09-mm (range 21.82 to 25.95-mm) for groups 1 and 2, respectively (p > 0.05). Multivariate vector analysis of the remaining refractive error between the two groups (desired refraction minus achieved refraction) revealed no statistically significant difference (p > 0.05). Analysis within each group demonstrated a higher accuracy of refractive outcomes for the femtosecond laser-assisted cataract surgery eyes (p < 0.05) when compared to the traditional phacoemulsification (p > 0.05).

CONCLUSION

Femtosecond laser-assisted cataract surgery and traditional phacoemulsification demonstrate similar refractive outcomes after toric intraocular lens implantation, while femtosecond laser-assisted cataract surgery seems to provide a slightly higher accuracy.