Laser-Assisted Capsulotomy Centration: A Prospective Trial Comparing Pupil Versus OCT-Based Scanned Capsule Centration

Pupil versus 1st Purkinje capsulotomy centration with femtosecond laser: Long term outcomes with a sinusoidal trifocal lens

PURPOSE

To assess the role of femtosecond laser-assisted capsulotomy centration in the long-term intraocular positioning of a multifocal intraocular lens.

DESIGN

Prospective comparative study.

METHODS

A total of 60 eyes of 30 patients underwent femtosecond laser-assisted Refractive Lens Exchange (RLE). For every patient, capsulotomy centration was randomly performed according to pupil centre (PC) in one eye and first Purkinje reflex (FPR) in the other. The intraocular lens (IOL) positioning, visual acuities, spherical equivalent, internal aberrometry and quality of vision were assessed and compared at 3 years' follow-up between groups (PC and FPR).

RESULTS

Intraocular lens positioning showed a statistically significant difference between groups, with a closer centration to the visual axis in the FPR patients (p < 0.001). Internal aberrometry showed higher values in the PC capsulotomy centration group (p < 0.01).

CONCLUSIONS

FPR centered capsulotomy is associated to a closer centration of the IOL to the visual axis.

Intraoperative trypan blue central landmark and its use in capsulotomy and capsulorhexis centration

PURPOSE

To compare 3 capsulotomy centration methods.

SETTING

Private clinic, Zlin, Czech Republic.

DESIGN

Prospective, consecutive case series.

METHODS

180 eyes undergoing cataract surgery had anterior capsule staining with microfiltered 0.4% trypan blue solution before selective laser capsulotomy. The first 60 eyes (Group 1) had mydriatic dilated pupil centered capsulotomies. The next 60 eyes (Group 2) were centered on the trypan blue central landmark (TCL). The final 60 capsulotomies (Group 3) were centered on the patient fixated coaxial Purkinje reflex (CPR). Measurements between key anatomical landmarks and the TCL, CPR capsulotomies, and implanted intraocular lens (IOL) center were made.

RESULTS

The TCL, observed in >94% of eyes in the study, coincided with the CPR with a displacement of <0.1 ± 0.1 mm. Group 1 capsulotomies were noticeably decentered on the IOLs by 0.3 ± 0.2 mm. The Group 2 symmetrical IOL relationship was maintained with a decentration of 0.15 ± 0.1 mm. Group 3 had a similar decentration with the IOLs with 0.15 ± 0.1 mm. Verification with IOLMaster 700 data and CALLISTO Eye System showed that the CPR and the TCL were coincident with the measured visual axis.

CONCLUSIONS

The clearly visible TCL served as an alternate landmark to the patient fixated CPR, and being on the anterior capsule was not sensitive to tilt. Further patient compliance was not required. Both were superior to dilated pupil centration, to achieve symmetric IOL coverage. This has application for both capsulotomies and capsulorhexes.

Update on Femtosecond Laser-Assisted Cataract Surgery: A Review

The advent of femtosecond lasers has resulted in a new standard in cataract surgery, intended to overmatch the paradigm of conventional phacoemulsification. Femtosecond laser-assisted cataract surgery (FLACS) enables a higher level of reproducibility, precision, accuracy, and customization when performing several steps of cataract (or lens) surgery. Capsulotomy, corneal incisions, lens fragmentation, and arcuate incisions are the main procedures performed using FLACS. As the demand for better refractive outcomes and spectacle independence increases, the features of FLACS are highly relevant, especially when considering the implantation of premium intraocular lenses, such as toric, enhanced depth-of-focus, or multifocal lenses. The present article reviews the state of the art of femtosecond laser-assisted cataract (lens) surgery, contemplating the advantages and limitations of the two types of femtosecond laser pulses available (high and low energy) by evaluating their reported outcomes and complications.

Femtosecond Laser-Assisted Ophthalmic Surgery: From Laser Fundamentals to Clinical Applications

Femtosecond laser (FSL) technology has created an evolution in ophthalmic surgery in the last few decades. With the advantage of high precision, accuracy, and safety, FSLs have helped surgeons overcome surgical limits in refractive surgery, corneal surgery, and cataract surgery. They also open new avenues in ophthalmic areas that are not yet explored. This review focuses on the fundamentals of FSLs, the advantages in interaction between FSLs and tissues, and typical clinical applications of FSLs in ophthalmology. With the rapid progress that has been made in the state of the art research on FSL technologies, their applications in ophthalmic surgery may soon undergo a booming development.

Intraoperative Anterior Segment Optical Coherence Tomography in the Management of Cataract Surgery: State of the Art

Background: The introduction of non-invasive diagnostic tools in ophthalmology has significantly reshaped current clinical practice in different settings. Recently, different anterior segment (AS) intraoperative optical coherence tomography (i-OCT) systems have been employed for different interventional procedures including cataract surgery. Materials and Methods: A review on the use of AS i-OCT in the management of cataract surgery, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). The level of evidence according to the Oxford Centre for Evidence-Based Medicine (OCEM) 2011 guidelines, and the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system were assessed for all included articles. Results: Out of 6302 articles initially extracted, 6302 abstracts were identified for screening and 32 of these met the inclusion/exclusion criteria for full-text review; 19 articles were excluded. Conclusions: The use of AS i-OCT in cataract surgery, even if only a few studies have a high level or grade of evidence, may represent a useful tool for novel surgeons approaching phacoemulsification but also for expert ones for teaching purposes and to plan and manage complicated cases.

Femtosecond Laser Assisted Cataract Surgery: A Review

Femtosecond laser assisted cataract surgery (FLACS) offers a level of precision, accuracy and customization that is not possible with manual phacoemulsification (MP). With the increase of patient expectations and premium intraocular lens utilization in the era of refractive cataract surgery, predictability and accuracy has become of utmost importance. FLACS has four main functions: creation of a consistently sized round capsulotomy, treatment of keratometric astigmatism with arcuate incisions, construction of clear corneal incisions, and fragmentation and/or softening of the lens. However, FLACS may have limitations due to suction loss, incomplete capsulotomy or poor pupillary dilation. Patient selection and surgeon experience is critical. This review article will focus on the various platforms available for FLACS, the steps in cataract surgery it can perform, and overall advantages and limitations of the technology.

Early results of circularity and centration of capsulotomy prepared by three different methods

AIM

To compare the difference of capsulotomy produced by precision pulse capsulotomy (PPC), manual (M-CCC), and femtosecond laser assisted capsulotomy (FLAC) in relation to intraocular lens (IOL) centration, circularity and its effect on visual outcomes.

METHODS

Prospective, non-randomized comparative study conducted at LV Prasad Eye Institute, Hyderabad, India. Sixty eyes of 52 patients were grouped into 3 (FLAC, PPC and M-CCC) based on capsulotomy techniques used. Twenty consecutive eyes with uneventful phacoemulsification and with no comorbidities affecting the capsulotomy or visual outcome were included in each group. The main outcome measure was IOL centration in relation to capsulotomy and pupil. Secondary outcome measures were post-operative visual acuity, manifest refraction and aberration profile between groups.

RESULTS

At 5wk the visual, refractive outcomes and endothelial cell density were comparable between the 3 groups. The median circularity index of FLAC was statistically significantly different to M-CCC or PPC (1-10) groups (P<0.01) but PPC (11-20) was comparable to FLAC. Decentration of IOL center in relation to capsulotomy was seen only between the PPC (1-10) group and FLAC group (P=0.02). The IOL was well centered in relation to the pupil in all the groups (P=0.46). The quality of vision parameters like the higher order aberrations, spherical aberration, coma, trefoil, modular transfer function, and Strehl ratio were comparable between the groups.

CONCLUSION

Our study shows that despite differences in the morphology of capsulotomy produced by PPC, M-CCC, FLAC a well-centered IOL can be achieved. The measured capsular morphology parameters do not affect visual outcomes.

[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.

Comparison of refractive outcomes between femtosecond laser-assisted cataract surgery and conventional cataract surgery

The purpose of our study is to compare the predictive accuracy of femtosecond laser-assisted cataract surgery with the results of conventional cataract surgery. This prospective study included 83 eyes from 83 patients who underwent femtosecond laser-assisted cataract surgery and 83 eyes from 83 patients who underwent conventional cataract surgery. Preoperative IOL power calculations were performed with the partical coherence interferometry. Femtosecond laser-assisted capsulotomy was based on 5.2 mm scanned capsule center. Following phacoemulsification, 1-piece IOL was inserted into the capsular bag. Refractive outcome was measured 3 months postoperatively with manual refraction. Predicted refraction was assessed by the Barret-Universal II, Haigis, Hoffer Q, SRK/T, and T2 formulas. We applied optimized IOL constants and retrospectively personalized IOL constants. There was no difference in preoperative demographic data. When the optimized IOL constants were used, the femtosecond laser-assisted group produced significantly lower MAEs in the Barret-Universal II, Hoffer Q, SRK/T, and T2 formulas (P < .05). After the personalization of IOL constants, there were statistical differences in the Barret-Universal II, Hoffer Q (P < .05). The standard deviation of ME and MedAE were also relatively lower with femtosecond laser-assisted group. In conclusion, femtosecond laser-assisted cataract surgery with Catalys femtosecond laser system produced better refractive outcomes than conventional cataract surgery.