Relationship Between Postoperative Intraocular Lens Shift and Postoperative Refraction Change in Cataract Surgery Using Three Different Types of Intraocular Lenses

Introduction

Understanding the relationship between postoperative intraocular lens (IOL) shift and refractive change is crucial for the accuracy of predicted postoperative refraction (PPR). We assessed the relationships between different IOL fixation methods, haptic designs, and several metrics.

Methods

Single-center, open-label study which included 69 eyes. We preoperatively measured the anterior chamber depth (ACD), lens thickness (LT), axial length (AL), and PPR. AcrySof IQ (n = 27) and FineVision (n = 24) were fixed in the bag, and FEMTIS (n = 18) was fixed in capsulorhexis. At 1 day, 1 week, and 1 month postoperatively, we checked the IOL position and refraction and compared the IOL shift, refraction change, and the margin of error of the predicted PPR (PR-PPR difference). We also analyzed the correlation between postoperative and preoperative variables.

Results

FEMTIS showed the highest stability in terms of IOL shift and refraction. The in-the-bag-fixated IOLs showed a significant forward shift between 1 day and 1 week postoperatively. There were significant differences in the PR-PPR difference between the IOLs. ACD and AL showed significant positive correlations, and LT showed a significant negative correlation with IOL shift and change in PR between 1 day and 1 week, but not between 1 week and 1 month postoperatively.

Conclusion

The relationship between postoperative IOL shift and refraction change varied according to IOLs with different haptic types. Capsulorhexis fixation may be more stable than in-the-bag fixation. Furthermore, preoperative ACD, LT, and AL may be useful factors to predict IOL shift, change in PR, and to a lesser extent the degree of the margin of error in clinical practice. Our findings may improve the accuracy of PPR and refractive outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-021-00390-x.

[New intraocular lens designs for femtosecond laser-assisted cataract operations : Chances and benefits]

BACKGROUND

The perfection and high reproducibility of capsulotomy in femtosecond laser-assisted cataract surgery (FLACS) lead to the possibility of new intraocular lens (IOL) designs for capsulotomy fixed implantation.

ISSUE

Which different designs have so far been presented for which problems in capsulotomy fixation?

MATERIAL AND METHOD

An evaluation of the literature and conference data was carried out.

RESULTS

Currently four different types of femtolenses for capsulotomy fixation are described in the literature or are commercially available. The first described was the lens in the bag or Tassignon IOL, which was developed for secondary cataract prevention, the second was the Masket IOL for reduction of negative dysphotopsia and third the 90F designed by Dick. All three types are or will be produced by Morcher. The fourth lens is the Femtis from Oculentis. All lenses are characterized by a high level of safety during implantation, The Tassignon lens leads to reduction of secondary cataract, especially in juvenile cataract because of the additional posterior capsulotomy. In studies the Masket IOL could show a decrease of negative dysphotopsia. In comparison to standard lenses, the 90F and Femtis in particular showed better results with respect to tilt, rotation and decentration.

CONCLUSION

The new IOL designs for capsulotomy fixation show a safe implantation procedure and indications for a very stable position in the capsular sac. Further studies must be carried out to confirm the possible advantages in comparison to standard IOL with respect to postoperative results for refraction, tilt, rotation and decentration and possible induction of aberrations.

[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.

Swivel haptics anterior capsule-fixated intraocular lens

The purpose of the study is to report the feasibility of implantation of a new design of anterior capsule-fixated intraocular lens (IOL). The new IOL design is a foldable, hydrophilic, open-loop posterior chamber IOL with two extra polymethyl methacrylate swivel haptics created on the optic surface to capture the anterior capsulotomy after the IOL is implanted in the bag. In the pilot phase, the new IOL was implanted in 10 eyes of 10 patients of which 8 eyes underwent phacoemulsification and 2 eyes had laser cataract surgery. The mean spherical equivalent changed from *1.75 D to −0.75 D at 6 months. Postoperatively, from 1 week to 6 months, all eyes showed stable refraction and anterior chamber depth with no evidence of decentration. Subjective questionnaire revealed high patient satisfaction with no complaints of dysphotopsia. No intra- or postoperative complications such as swivel haptic breakage, iris chafing, pigment dispersion, postoperative uveitis, or endophthalmitis occurred in any of the eyes necessitating explantation of the IOL. The new IOL design was feasible to implant and provided satisfactory outcomes in terms of no dysphotopsias and stable effective lens position.

Femtosecond laser-assisted cataract in vitreoretinal surgery

PURPOSE

To assess the safety and surgical results of femtosecond laser-assisted phacovitrectomy.

METHODS

Fifteen patients over 50 years of age with coexisting vitreoretinal pathologies and cataract underwent combined femtosecond laser-assisted cataract extraction and sutureless 25-G and 27-G vitreoretinal surgery.

RESULTS

The indication for surgery was macular hole in 6 patients, epiretinal membrane in 6, vitreous hemorrhage in 2, and retinal detachment in 1. The mean preoperative best-corrected visual acuity (BCVA) was 0.64 ± 0.23 logMAR and the mean postoperative BCVA was 0.19 ± 0.11 logMAR. In 4 patients with epiretinal membrane with corneal astigmatism of 3.35 ± 0.32 D as mean value, a toric intraocular lens (IOL) was implanted: mean residual refractive cylinder was 0.47 ± 0.23 D. Three months postoperatively, mean IOL rotation was 1.64 ± 0.28°. All patients improved their visual acuity. The intraoperative complications of femtosecond laser were 1 subconjunctival hemorrhage, 1 case of miosis, and 1 suction loss. The surgeon was able to maintain a clear view of the retina at all times. After surgery, a better fundus examination was possible with no capsular opacification. Mean follow-up was 6 months.

CONCLUSIONS

Femtosecond laser cataract in vitreoretinal surgery appears a safe and effective technique with potential benefits: the precision and centration of the capsulorhexis may potentially reduce the risk of IOL prolapse into the anterior chamber in gas-filled eyes. Implantation of the toric IOL was effective in reducing preexisting corneal astigmatism and provided good rotational stability and refractive outcome.

Effect of femtosecond laser-assisted lens surgery on posterior capsule opacification in the human capsular bag in vitro

PURPOSE

To compare posterior capsule opacification (PCO) by observing lens epithelial cell growth in the human capsular bag in vitro between conventional lens surgery using phacoemulsification (Phaco) technique and femtosecond laser-assisted lens surgery (FLACS).

METHODS

For the in vitro human capsular bag model, 18 cadaver eyes from nine human donors underwent three types of lens surgery. Three groups consisting of six capsular bags were established, that is FLACS, Phaco and extracapsular lens extraction (ECCE). The capsular bag was transferred into equal cell culture conditions after using one of the defined surgical approaches. Cellular growth of lens epithelial cells was observed and photo-documented. The time until full cell-coverage of the capsular bag was measured.

RESULTS

The human capsular bag model can be successfully prepared using FLACS. There was no statistically significant difference in time until cell-coverage of the human donor capsular bag in vitro in all three surgical settings (ECCE versus Phaco p = 0.6; ECCE versus FLACS p = 1.0; Phaco versus FLACS p = 1.0).

CONCLUSIONS

In our in vitro human capsular bag model, we could not observe a statistically significant difference in PCO formation using different surgical approaches of lens extraction. Therefore, PCO formation might not be attributed to the type of surgery. Furthermore, this study shows that FLACS can be used for the human capsular bag model preparation and validates the human capsular bag model for future research.

Femtosecond laser-assisted cataract surgery--current status and future directions

Femtosecond laser-assisted cataract surgery (FLACS) putatively offers several advantages over conventional phacoemulsification. We review the current status of FLACS and discuss the evolution of femtosecond lasers in cataract surgery and the currently available femtosecond laser platforms. We summarize the outcomes of FLACS for corneal wound creation, limbal relaxing incisions, capsulotomy, and lens fragmentation. We discuss surgical planning, preoperative considerations, clinical experiences including the learning curve and postoperative outcomes with FLACS, and also the cost effectiveness of FLACS. We present the intraoperative complications and management of challenging cases where FLACS offers an advantage and also speculate on the future directions with FLACS. Further advancements in laser technology to refine its efficacy, advancement in intraocular lens design to harness the potential benefits of FLACS, and a reduction in cost are needed to establish a clear superiority over conventional phacoemulsification.

Preliminary clinical investigation of cataract surgery with a noncontact femtosecond laser system

Background and Objective

Femtosecond laser‐assisted cataract surgery (FLACS) is rapidly gaining popularity due to the improved consistency and predictability for capsulorhexis. This study aimed to investigate the preliminary clinical outcomes of FLACS with a noncontact femtosecond laser system.

Patients and Methods

This prospective study enrolled 25 eyes in the trial group underwent FLACS (LLS‐fs 3D, LENSAR, USA), and 29 eyes in the control group underwent conventional cataract surgery (Stellaris, Bausch & Lomb, USA). The phacoemulsification time, energy, and complications during operation were recorded. Postoperative refraction at 1 day, 1 week, 1 and 3 months, the capsulorhexis size and corneal endothelial density at 1 and 3 months were also measured.

Results

Compared to the control group, reduction in phacoemulsification time was 51.5% (P = 0.02), and in overall energy, 65.1% (P = 0.02) in the trial group. In the trial group and the control group, total time of cataract procedure was 10.04 ± 1.37 minutes, 10.52 ± 1.92 minutes, respectively (P = 0.31); the absolute difference between attempted and achieved capsulorhexis diameter at 1 month was 192.9 ± 212.0 µm, 626.9 ± 656.6 µm, respectively (P = 0.04), and at 3 months, 256.6 ± 181.9 µm, 572.1 ± 337.0 µm, respectively (P= 0.03); the absolute difference between attempted and achieved spherical equivalent at 3 months was 0.16 ± 0.16 D, 0.74 ± 0.65 D, respectively (P < 0.01); mean corneal endothelial cell loss at 1 month was 15.6% and 14.2%, respectively (P = 0.77), and at 3 months, 2.9%, 4.2%, respectively (P = 0.50).

Conclusions

With the noncontact femtosecond laser system, FLACS can significantly improve the accuracy and repeatability of capsulorhexis, reduce the phacoemulsification time and overall energy, and enhance the predictability and stability of postoperative refraction. Lasers Surg. Med. 47:698–703, 2015. © 2015 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Femtosecond laser cataract surgery

Femtosecond laser (FSL) cataract surgery is in its infancy but is rapidly gaining popularity due to the improved consistency and predictability for corneal incisions and anterior capsulorhexis. It enables subsequently less phacoemulsification energy and time to be employed, which has gains in terms of reduced corneal oedema. In addition, the FSL allows better circularity of the anterior capsulotomy, capsule overlap, intraocular lens (IOL) placement and centration of the IOL. These advantages have resulted in improved visual and refractive outcomes in the short term. Complication rates are low which reduce with surgeon experience. This review article focuses on the Alcon LenSx system.

Prostaglandin release during femtosecond laser-assisted cataract surgery: main inducer

PURPOSE

To investigate a possible correlation between intraocular prostaglandin concentrations and partial steps of laser-assisted cataract surgery.

METHODS

Aqueous humor was collected from 67 patients after laser-assisted cataract surgery pretreatment (only capsulotomy, only fragmentation, or both) and at the beginning of routine cataract surgery. Total prostaglandin levels were measured in all four groups using an enzyme-linked immunoassay.

RESULTS

Significantly higher levels of aqueous humor prostaglandins were detected right after the full treatment (capsulotomy and fragmentation [330.6 ± 110.6 pg/mL; P = .01] or only laser capsulotomy [362.4 ± 117.5 pg/mL; P = .01]), whereas the control group showed lower values (52.5 ± 8.1 pg/mL). By itself, laser-assisted cataract surgery fragmentation did not lead to a prostaglandin increase (186.8 ± 114.0 pg/mL; P = .14).

CONCLUSIONS

This study identified the anterior capsulotomy as the main trigger for an increase of prostaglandins in the aqueous humor immediately after laser-assisted cataract surgery. Optimized energy settings in combination with nonsteroidal anti-inflammatory drugs might help reduce the phenomenon of laser-induced miosis.