Capsular block syndrome associated with femtosecond laser–assisted cataract surgery

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.

Application of Femtosecond Laser in Challenging Cataract Cases

Femtosecond laser can provide precise and customized incision of ocular tissue with excellent accuracy and predictability. Thus, femtosecond laser-assisted cataract surgery (FLACS) can theoretically enhance the safety and efficacy of cataract surgery by providing reproducible and reliable clear corneal incision, limbal relaxing incision, anterior capsulotomy, and lens fragmentation. However, thus far, the superiority of the anatomical and visual outcomes of FLACS over those of conventional cataract surgery have been unclear. Nevertheless, studies have indicated that FLACS can potentially be helpful in improving the safety of cataract surgery in challenging situations, such as zonular weakness, preexisting capsular tear, white cataract, shallow anterior chamber, and pediatric cataracts, which may contribute to enhanced visual and anatomical outcomes. In this review, we provide a summary of the application of femtosecond laser in general cataract cases. In addition, we introduce the application of FLACS in the abovementioned challenging situations and discuss the results of studies regarding the safety and outcome of FLACS in these challenging cases.

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.

[Historical development of energetic cataract surgery]

This article reviews scientific literature analyzing the history of ultrasound and laser phaco surgery of combined or isolated designs: erbium YAG laser, 1.064 μm Nd:YAG laser for dissection of the lens capsule and nucleus, exclusively-laser technique of lens destruction with 1.44 µm Nd:YAG laser without manual, vacuum or ultrasonic action, femtosecond laser assistance with automated transcorneal delivery of radiation into the eye cavity.

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.

Inspection of the lens thickness with preoperative biometric measurements prevents an erroneous interpretation of posterior capsule during FLACS

Optical opacity reduces quality of biometry images, making it potentially difficult to find the correct location for irradiation during femtosecond laser-assisted cataract surgery (FLACS). After experiencing a case of posterior capsule (PC) rupture because of optical opacity, we started lens thickness (LT) inspection, which indicates comparison of between intra- and pre-operatively measured LT. We retrospectively investigated the effectiveness of the LT inspection. One observer reviewed all FLACS treatment summaries for 3 years by CATALYS in the Jikei University Hospital, Tokyo. Based on the lines defining the PC on intraoperative OCT images, all cases were classified into three groups: undescribed, appropriate and inappropriate PC. Among the 1070 cases, 1047 cases had appropriate PC. In 19 cases, the PC line was undescribed because of dense cataract. Among 474 cases with no inspection, 4 cases had an inappropriate PC. Whereas, in 596 cases with the LT inspection, there was no case of an inappropriate PC. LT inspection significantly reduced the cases with inappropriate PC. The safety margins normally work to prevent severe complications. However, rare outlier cases had a high risk of severe complications. We propose LT inspection could be the most practical and convenient way for safety surgery.

The Latest Evidence with Regards to Femtosecond Laser-Assisted Cataract Surgery and Its Use Post 2020

Femtosecond laser-assisted cataract surgery (FLACS) was introduced with the hope of making cataract surgery safer and making the refractive result more predictable. It is only in the last four years that level 1 prospective randomised controlled trials (RCT) using current technology have been published. These, along with a meta-analysis of recent studies have shown that there seems to be little long-term visual benefit when using FLACS with monofocal lenses. The promised decrease in ultrasound energy required to remove a cataract has not been consistently demonstrated. There is level one evidence that the rate of posterior capsular rupture is less with FLACS using modern software. The round capsulotomy may be of increasing importance with the uptake of toric, multifocal and extended depth of focus lenses where a predictable capsulotomy size and precise placement of the lens becomes more important.

The influence of surgeons and technicians on the learning curve of femtosecond-laser cataract surgery

PURPOSE

To demonstrate the influence of the surgeon's and the operating room (OR) technicians' experience upon the outcome of femtosecond laser-assisted cataract surgery (FLACS).

MATERIALS AND METHODS

Our study included 250 eyes from 156 patients who had undergone either cataract surgery or clear-crystalline-lens extraction and where capsulorhexis and lens fragmentation had been performed using the CATALYS® Precision System femtosecond platform (Abbott Medical Optics Inc., Santa Ana, CA, USA).The patients were operated either by an experienced surgeon in the use of femtosecond laser or by an inexperienced surgeon in that field and two technicians. The quantitative outcome measures were: Suction loss rate, vacuum time, number of consumables used by the patient and intraoperative complication rate.

RESULTS

Both for the experienced and the inexperienced surgeons, suction loss rates as well as vacuum time decreased progressively as time went by and more surgical procedures had been completed by that surgeon. For a given surgeon suction time decreased significantly, going from 137 to 99s, as the assisting technician gradually gained experience. The number of consumables used in each procedure by the experienced surgeon ranged from 1.10 (for the first 50 cases) to 1.02 from those initial cases onwards. Regarding intraoperative complications, they also decreased progressively as the number of procedures completed by the surgeon increased.

CONCLUSIONS

The experience of each team member involved in such procedures-be it surgeons or technicians-have an impact, to a greater or lesser extent, upon the surgery's outcome, as quantified by the outcome variables of choice.

Posterior capsule rupture with FLACS due to erroneous interpretation of a high OCT intensity area in anterior vitreous

Purpose

We describe a case of posterior capsule rupture during femtosecond laser-assisted cataract surgery (FLACS) due to direct exposure of the posterior capsule to the laser beam.

Observations

A 47-year-old man underwent FLACS for anterior capsule opacity. The CATALYS® system automatically detected the posterior capsule from the optical coherence tomography (OCT) images, after which the operator manually adjusted the line of posterior capsule. Femtosecond laser irradiation was presumed to be completed successfully. However, upon insertion of a phaco-tip, the diced nucleus of the lens dropped into the vitreous chamber. Reviewing intraoperative OCT images of the treatment summary to check the area irradiated by laser, an arc-shaped high-intensity area was observed behind the posterior capsule. This high-intensity was misinterpreted as the posterior capsule, which led to error in application of laser beam during procedure.

Conclusions and importance

Comparison of data acquired using different imaging modalities could enable correct identification of the posterior capsule.

Application of Femtosecond Laser in Anterior Segment Surgery

Femtosecond laser (FSL) is a near-infrared laser that can create reliable and reproducible tissue cutting with minimal damage to adjacent tissue. As the laser can also create incisions with various orientations, depths, and shapes, it is expected to be a useful tool for anterior segment surgery, such as cornea, refractive, and cataract surgery. In this review, the authors will introduce the application of FSL in various anterior segment surgeries and discuss the results of studies regarding the efficacy and safety of FSL in cornea, refractive, and cataract surgery. Experimental studies regarding the potential use of FSL will also be introduced. The studies discussed in this review suggest that FSL may be a useful tool for improving the prognosis and safety of surgeries of the anterior segment.

Clinical and experimental evaluation of new back-flow hydrodissection technique

PURPOSE

To assess the efficacy and safety of a new technique, back-flow hydrodissection.

SETTING

Hirota Eye Clinic, Yamaguchi, and Department of Ophthalmology, University of Tsukuba, Ibaraki, Japan.

DESIGN

Prospective case series and experimental study.

METHODS

For back-flow hydrodissection, the irrigation line was connected to the aspiration port of an irrigation/aspiration handpiece using a female-female connector with the irrigation port open. The balanced salt solution was irrigated from the aspiration tip opening with constant pressure, hydrodissection was performed, and the excess fluid was evacuated via the sleeve lumen. In a clinical study, 200 eyes were randomly assigned to conventional hydrodissection with an irrigation cannula or back-flow hydrodissection. In experimental studies, intraocular pressure (IOP) fluctuation and fluid dynamics in the anterior and posterior chamber were evaluated in porcine eyes.

RESULTS

The lens became freely mobile in the capsular bag in 99 (99%) of 100 eyes and in 96 (96%) of 100 eyes in the back-flow hydrodissection group and conventional hydrodissection group, respectively (P = .369). There were no between-group differences in any other surgery-related parameters, including surgical time and the complication rate. In porcine eyes, conventional hydrodissection induced a significantly larger increase in IOP than back-flow hydrodissection (P < .0001). Conventional hydrodissection immediately washed out fluorescein-stained ophthalmic viscosurgical device (OVD) from the anterior chamber, while there was little leakage of OVD from the eye with back-flow hydrodissection. The endoscopic view showed that conventional hydrodissection induced rapid and severe bulging of the posterior capsule; however, bulging was gentle and mild with back-flow hydrodissection.

CONCLUSION

Back-flow hydrodissection was safe and effective in disengaging the lens from the capsule, ensuring a freely mobile lens.

Techniques of anterior capsulotomy in cataract surgery

Optimal outcomes of a cataract surgery largely depend on the successful performance of an anterior capsulotomy. It is one of the most important steps of modern cataract surgery which reduces the risk of capsular tears and ensures postoperative stable intraocular lens (IOL). Anterior capsulotomy is considered ideal if it is round, continuous, well-centered, and overlaps the implanted IOL around its circumference. If any of these features is missing, it can be a cause of impedance for desired surgical and visual outcomes. Manual can opener and manual capsulorhexis are the routine standard techniques employed for manual extracapsular cataract extraction and phacoemulsification, respectively. Recent increasing use of femtosecond laser cataract surgery has allowed cataract surgeons to obviate inherent inaccuracies of manual anterior capsulotomy techniques. There is an ongoing quest to find an ideal, risk free, and surgeon-friendly technique of anterior capsulotomy that can be employed for surgery in all types of cataracts.

A novel minimal fluid technique for effective and safe lens hydrodissection during cataract surgery

Traditional hydrodissection may cause posterior capsule rupture (PCR) if excessive fluid accumulates. In this study, we describe the successful application of a novel minimal fluid hydrodissection technique in 100 consecutive cataract surgery cases. This technique separates the nucleus from the capsule utilizing low hydrostatic pressure and precise kinetic movement of a small volume (around 0.2 cc) of balanced salt solution. There were no instances of PCR. This technique is suitable for a range of cases, including femtosecond laser-assisted cataract surgery and posterior subcapsular cataract.

The safety and efficacy of phaco-sleeve irrigation-assisted hydrodissection during femtosecond laser-assisted cataract surgery

Femtosecond laser-assisted cataract surgery (FLACS) changes the intraoperative environment due to the generation of intracapsular gas that induces a high intracapsular volume. Manual hydrodissection (mH) may induce high intracapsular pressure (ICP) and additional intracapsular volume, thereby leading to capsular block syndrome (CBS). Since the phaco-sleeve irrigation-assisted hydrodissection (iH) technique is used to initially groove and split the lens and remove the intracapsular gas, this can reduce the intracapsular volume while bypassing the intracapsular lens prior to the hydrodissection. As iH uses the phaco tip to intentionally vacuum the intraocular fluid for use in inducing the irrigation jet from the sleeve side holes, the ICP cannot surpass the set irrigation pressure, thereby avoiding CBS. Using this technique, we performed FLACS without CBS in 310 cataract eyes. Our findings suggest that the iH technique may be beneficial for patients by preventing CBS during FLACS.

Minimal water-jet hydrodissection

This paper presents a hydrodissection technique performed with high-speed pulse injection of only 0.1 cc liquid and assess its efficacy, safety, and the level of reduction in posterior capsule rupture complications in phacoemulsification cataract surgery. The kinetic energy of moving objects is directly proportional to the mass and to the square of its velocity. The high energy obtained by high-speed pulse injection of a small amount of liquid ensures highly effective dissection. Since the amount of liquid is very small, the increase in intraocular pressure and the risk of rupture in the posterior capsule due to anterior capsular block are greatly reduced. More importantly, several rotations of the lens material in the capsule with effective hydrodissection facilitate the phases of phacoemulsification and irrigation/aspiration. As most capsule ruptures occur during these phases, the complication rate is thus reduced.

Bilateral early capsular block syndrome following implantation of the new trifocal toric lens

A young patient underwent phacoemulsification with endocapsular implantation of trifocal toric lens in both eyes (AT LISA tri toric 939 MP, Carl-Zeiss, Germany). One-week postsurgery, he developed capsular block syndrome (CBS) in both eyes. There was deterioration of uncorrected visual acuity at 1-week postsurgery, with a myopic shift of 2.5 diopters (D) in the right eye and 2.0 D in the left eye. The intraocular pressure was only elevated in the left eye. Neodymium: yttrium-aluminum-garnet laser posterior capsulotomy resolved the block successfully in both eyes. A thick lens with a plate haptic design may have contributed to the early CBS.

Femtosecond laser-assisted cataract surgery, technology, outcome, future directions and modern applications

Since its introduction in 2009 femtosecond laser-assisted cataract surgery (FLACS) has promised to revolutionize cataract surgery. Despite its promise, the assessment of FLACS's perceived benefits has proven to be far more complicated than initially might have been thought. Most studies to date have not provided validation of FLACS technology as a clinically significant advancement on our current techniques. We review FLACS technology and outcomes including detailed analysis of safety, efficacy, cost effectiveness and future prospects using data from the literature and our own published clinical experience.

Preliminary Results of Femtosecond Laser-assisted Cataract Surgery in a Private Clinic in Iran

Purpose:

To report the preliminary results of femtosecond laser-assisted cataract surgery in Iranian patients.

Methods:

This prospective case series included 21 eyes of 21 patients with cataract. Mean patient age was 66.7 ± 10 years. The patients underwent femtosecond-laser assisted cataract surgery (VICTUS Femtosecond Laser Platform: Bausch + Lomb) and intraocular lens (IOL) implementation in Bina Eye Hospital, Tehran, Iran between May and October, 2014. Visual outcomes, intraocular pressure (IOP), and complications were evaluated three months after surgery.

Results:

Mean preoperative best-spectacle corrected visual acuity (BSCVA) was 0.40 ± 0.21 logMAR which significantly improved to 0.02 ± 0.03 logMAR three months postoperatively (P < 0.001). Mean preoperative IOP was 17.88 ± 2.70 mmHg which significantly decreased to 12.5 ± 1.51 mmHg three months after operation (P < 0.001). Mean duration of operation for these patients was 29.30 ± 8 minutes and mean femtosecond laser process time was 4.20 ± 2 minutes. In terms of complications, 9 patients developed fine subconjunctival hemorrhage and eye redness and 2 patients had mild corneal edema which all subsided within less than 7 days. Serious complications such as anterior or posterior capsule tears were not encountered.

Conclusion:

Femtosecond laser-assisted cataract surgery is a relatively new method of cataract

Irrigation dynamic pressure-assisted hydrodissection during cataract surgery

The irrigation dynamic pressure-assisted hydrodissection technique (irrigation-hydro [iH]) does not require performing manual hydrodissection using a syringe and cannula to achieve cortical-capsular cleavage during cataract surgery. Since the iH technique uses the phaco tip to intentionally vacuum the intraocular fluid in order to induce the irrigation dynamic pressure for cortical-capsular cleavage, there is a reduction in the intraocular pressure (IOP) from the bottle-height-dependent hydrostatic pressure. Thus, since the peak irrigation pressure derived from the phaco tip sleeve will be limited by the height of the irrigation fluid bottle, this is advantageous in helping to avoid excessively high IOP during cortical-capsular hydrodissection. Using this technique, we were able to effectively perform phacoemulsification without complications in 607 of 609 cataract eyes. Our findings show that utilization of the iH technique would be of benefit to patients, as it prevents high-pressure hydrodissection-related complications, such as capsular block syndrome and tears in the anterior hyaloid membrane during cataract surgery.

Use of the phaco tip technique for lens cleavage and removal during cataract surgery

Use of the phaco tip technique for lens cleavage and removal does not require manual hydrodissection using a syringe and cannula, or cortical removal using an irrigation/aspiration tip. The phaco tip is the only surgical instrument required for this technique. Its advantages include maintaining a stable intraocular pressure during cortical cleaving hydrodissection and lens removal, which includes the cortex.

Update and clinical utility of the LenSx femtosecond laser in cataract surgery

The introduction of femtosecond lasers to cataract surgery has been the major disruptive technology introduced into ophthalmic surgery in the last decade. Femtosecond laser cataract surgery (FLACS) integrates high-resolution anterior segment imaging with a femtosecond laser allowing key steps of cataract surgery to be performed with computer-guided laser accuracy, precision, and reproducibility. Since the introduction of FLACS, there have been significant advances in laser software and hardware as well as surgeon experience, with over 250 articles published in the peer-reviewed literature. This review examines the published evidence relating to the LenSx platform and discusses surgical techniques, indications, safety, and clinical results.

High Rate of Early Posterior Capsule Opacification following Femtosecond Laser-Assisted Cataract Surgery

Purpose

To compare the rates of rapid posterior capsule opacification (PCO) formation in the first 3 months following femtosecond laser-assisted cataract surgery (FLACS) to manual anterior capsulorhexis.

Methods

Retrospective review of 29 cases of FLACS, comparing the rates of PCO in the first 3 months following surgery to 50 consecutive cases of manual anterior capsulorhexis.

Results

Seven of the 29 FLACS cases developed PCO requiring capsulotomy at 3 months, while none of the control cases required a capsulotomy over the same time period (p < 0.05).

Conclusion

There is an increased incidence of early-onset PCO following the use of femtosecond laser in cataract surgery that is otherwise unfounded in manual capsulorhexis. This suggests that the use of a femtosecond laser could increase the risk of this novel postoperative complication.

Initial experience using a femtosecond laser cataract surgery system at a UK National Health Service cataract surgery day care centre

OBJECTIVES

To describe the initial outcomes following installation of a cataract surgery laser system.

SETTING

National Health Service cataract surgery day care unit in North London, UK.

PARTICIPANTS

158 eyes of 150 patients undergoing laser-assisted cataract surgery.

INTERVENTIONS

Laser cataract surgery using the AMO Catalys femtosecond laser platform.

PRIMARY OUTCOME MEASURE

intraoperative complications including anterior and posterior capsule tears.

SECONDARY OUTCOME MEASURES

docking to the laser platform, successful treatment delivery, postoperative visual acuities.

RESULTS

Mean case age was 67.7±10.8 years (range 29-88 years). Docking was successful in 94% (148/158 cases), and in 4% (6/148 cases) of these, the laser delivery was aborted part way during delivery due to patient movement. A total of 32 surgeons, of grades from junior trainee to consultant, performed the surgeries. Median case number per surgeon was 3 (range from 1-20). The anterior capsulotomy was complete in 99.3% of cases, there were no anterior capsule tears (0%). There were 3 cases with posterior capsule rupture requiring anterior vitrectomy, and 1 with zonular dialysis requiring anterior vitrectomy (4/148 eyes, 2.7%). These 4 cases were performed by trainee surgeons, and were either their first laser cataract surgery (2 surgeons) or their first and second laser cataract surgeries (1 surgeon).

CONCLUSIONS

Despite the learning curve, docking and laser delivery were successfully performed in almost all cases, and surgical complication rates and visual outcomes were similar to those expected based on national data. Complications were predominately confined to trainee surgeons, and with the exception of intraoperative pupil constriction appeared unrelated to the laser-performed steps.

Advances in femtosecond laser technology

Femtosecond laser technology has become widely adopted by ophthalmic surgeons. The purpose of this study is to discuss applications and advantages of femtosecond lasers over traditional manual techniques, and related unique complications in cataract surgery and corneal refractive surgical procedures, including: LASIK flap creation, intracorneal ring segment implantation, presbyopic treatments, keratoplasty, astigmatic keratotomy, and intrastromal lenticule procedures.

Determinants of Visual Outcomes in Femtosecond Laser Assisted Cataract Surgery and Phacoemulsification: A Nested Case Control Study

PURPOSE

We present the visual outcomes 6 weeks following Femtosecond laser assisted cataract surgery (FLACS) and conventional phacoemulsification cataract extraction (CE) cataract surgeries in 2013.

MATERIALS AND METHODS

This was a review of health record type of study. Eyes operated by FLACS and an equal number of conventional phacoemulsification (CE) on the same day by same surgeon were included in the study. Demographics, preoperative status, operative details and the best-corrected visual acuity (BCVA) at 6-8 weeks following surgery were noted. BCVA of >20/60 was considered as excellent. The rate and determinants of excellent vision were calculated.

RESULT

Study population comprised of 154 eyes. Both FLACS and CL groups had 77 eyes. Visual acuity at 6-8 weeks was excellent in 44 (60%) eyes of FLACS group and 36 (40%) eyes of CE. Visual outcome following FLACS and conventional surgery was not different (Odd's ratio [OR] 1.5 [95% confidence intervals [CI]: 0.8-2.9]). Operating surgeon did not significantly influence the visual outcomes following FLACS (OR = 1.6) and CE (OR = 0.4). Association of the grade of lens opacities to the visual outcome was not affected by type of surgery (χ(2) = 0.5, P = 0.2). The duration of surgery in CE and FLACS groups was not significantly different (-3.2 min [95% CI: -13; 6.6]).

CONCLUSION

Visual outcomes at 6-8 weeks following CE were not different from FLACS. Visual outcomes following FLACS and CE were not influenced by the operating surgeon or severity of the cataract. The time required for FLACS was greater than that required for CE.

New device for creating a continuous curvilinear capsulorhexis

PURPOSE

To describe the evolution of a new device to facilitate continuous curvilinear capsulorhexis (CCC) creation.

SETTING

Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado, USA.

DESIGN

Experimental study.

METHODS

Bench-side ex vivo testing of unique prototypes for guidance and assistance of CCC in bovine and human eyes was performed. Five designs were sequentially tested as follows: a flexible circular blade of nickel-titanium alloy (nitinol), a flexible nitinol guide wire, a flexible elastomeric suction device, a combination approach of a nitinol guide wire and flexible silicone ring, and a freestanding micropatterned silicone ring.

RESULTS

The first 3 designs were not amenable to insertion through a sub-2.4 mm corneal incision and failed to maintain adequate downward force to cut the capsule and/or prevent radial tears. The fourth design was successfully inserted through a 2.4 mm incision and maintained adequate downward pressure and contact to guide a manual CCC without radial tears. The final design was insertable through a 2.4 mm incision and exhibited self-adhesive characteristics after placement on the anterior capsule of an ophthalmic viscosurgical device-filled anterior chamber.

CONCLUSIONS

Given the steep learning curve of manual capsulorhexis and the high cost of capsulotomy-assistive devices, such as the femtosecond laser, an alternative approach for creating a CCC is desirable. Performance of a highly precise manual CCC through a small incision using a medical-grade silicone device with an adhesive micropatterned design is a viable and cost-effective option for use in cataract surgery across a wide range of user experience.

FINANCIAL DISCLOSURE

All authors are named as the inventors in a patent filed by the University of Colorado covering the details in this report.

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.

A Comparison of Different Operating Systems for Femtosecond Lasers in Cataract Surgery

The introduction of femtosecond lasers is potentially a major shift in the way we approach cataract surgery. The development of increasingly sophisticated intraocular lenses (IOLs), coupled with heightened patient expectation of high quality postsurgical visual outcomes, has generated the need for a more precise, highly reproducible and standardized method to carry out cataract operations. As femtosecond laser-assisted cataract surgery (FLACS) becomes more commonplace in surgical centers, further evaluation of the potential risks and benefits needs to be established, particularly in the medium/long term effects. Healthcare administrators will also have to weigh and balance out the financial costs of these lasers relative to the advantages they put forth. In this review, we provide an operational overview of three of five femtosecond laser platforms that are currently commercially available: the Catalys (USA), the Victus (USA), and the LDV Z8 (Switzerland).

The evolution of corneal and refractive surgery with the femtosecond laser

The use of femtosecond lasers has created an evolution in modern corneal and refractive surgery. With accuracy, safety, and repeatability, eye surgeons can utilize the femtosecond laser in almost all anterior refractive procedures; laser in situ keratomileusis (LASIK), small incision lenticule extraction (SMILE), penetrating keratoplasty (PKP), insertion of intracorneal ring segments, anterior and posterior lamellar keratoplasty (Deep anterior lamellar keratoplasty (DALK) and Descemet's stripping endothelial keratoplasty (DSEK)), insertion of corneal inlays and cataract surgery. As the technology matures, it will push surgical limits and open new avenues for ophthalmic intervention in areas not yet explored. As we witness the transition from femto-LASIK to femto-cataract surgery it becomes obvious that this innovation is here to stay. This article presents some of the most relevant advances of femtosecond lasers to modern corneal and refractive surgery.

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.

Introducing a New Surgical Technology: Controversies in Femtosecond Laser-assisted Cataract Surgery and Impact on Resident Surgical Training

Femtosecond laser-assisted cataract surgery is becoming more widely available as an option for patients considering cataract surgery. Controversies exist around determining the best platform for LCS, the potential global role and cost to the health care system of LCS, as well as the future of LCS in resident surgical training.

The use of femtosecond lasers in cataract surgery: review of the published results with the LenSx system

PURPOSE

To review the published literature describing the use of the LenSx femtosecond laser technology (Alcon Laboratories, Inc., Fort Worth, TX) in cataract surgery.

METHODS

Literature review.

RESULTS

The LenSx system has been used in more than 200,000 cataract surgery procedures to date. Pre-clinical evaluations have shown that this system produces accurate and reproducible capsulorhexes, and that both the energy required for phacoemulsification and total phacoemulsification time are less than with conventional phacoemulsification. In comparative studies, femtosecond lasers have been shown to produce more precise and reproducible capsulorhexes than manual procedures, and better intraocular lens placement; capsule overlap, circularity of capsulotomy, and centration of the intraocular lens are consistently better with femtosecond lasers than with manual procedures. The improved quality of capsulorhexis and intraocular lens positioning are reflected in favorable visual and refractive outcomes. As with any new technology, there is a significant learning curve: prospective cohort studies have shown that the incidence of intraoperative complications such as suction breaks or anterior capsular tears or tags decreases with experience. In general, the incidence of such complications is within the range (< 2%) considered in recent evidence-based guidelines to be feasible and desirable.

CONCLUSIONS

Although femtosecond laser cataract surgery is in its infancy, the technology is evolving rapidly and offers the potential for more consistent and predictable results after cataract surgery.

Cortex removal after laser cataract surgery and standard phacoemulsification: a critical analysis of 800 consecutive cases

PURPOSE

To evaluate the ease of anterior cortex removal and hydrodissection of the lens in femtosecond laser-assisted cataract surgery compared with standard phacoemulsification.

METHODS

In the femtosecond laser-assisted cataract surgery group (400 eyes), a femtosecond laser was used for capsulotomy and followed by lens fragmentation. In the standard group, the capsulorhexis was performed manually. In both groups, a normal hydrodissection was set, the nucleus was aspirated with or without ultrasound phacoemulsification energy, and residual cortex removal and posterior capsule polishing were performed using bimanual irrigation/aspiration. The primary end point was the time (in seconds) required for the removal of the cortex from instrument insertion in the eye until aspiration tip removal. Secondary end points were the effective phacoemulsification time, quality of the anterior capsule, and anterior or posterior capsule ruptures.

RESULTS

Cortex removal time measured 30 ± 13 seconds (range: 10 to 76 seconds) for the standard group and 27 ± 10 seconds (range: 9 to 72 seconds) for the femtosecond laser-assisted cataract surgery group (P < .005). After laser-assisted capsulotomy, one capsule was still adherent following removal by forceps. No anterior or posterior capsular tears were observed in either group.

CONCLUSIONS

In femtosecond laser-assisted cataract surgery, the biaxial cortex removal time was comparable with the time in standard phacoemulsification.

[Posterior capsule opacification, capsular bag distension syndrome, and anterior capsular phimosis: A retrospective cohort study]

OBJECTIVE

To determine the incidence and the risk factors involved in the development of the three main postoperative capsular complications: posterior capsule opacification (PCO), capsular bag distension syndrome (CBDS), and anterior capsular phimosis syndrome (ACP).

SUBJECTS, MATERIAL AND METHODS

A retrospective cohort study was conducted on 801 patients submitted to cataract surgery in the ophthalmology unit of Hospital del Henares (Madrid) from March 2, 2009 to February 28, 2010. Computerized clinical charts were reviewed during July 2012. PCO was studied using the Kaplan-Meier method (log rank test).

RESULTS

A total of 167 patients developed PCO. No association could be demonstrated between PCO and age, sex, diabetes mellitus, phaco technique, IOL model, tamsulosin intake, glaucoma, and age-related macular degeneration. Three patients developed CBDS, all of them have received and Akreos Adapt AO(®) (Bausch & Lomb). Two of them were young men who had received surgery for posterior subcapsular cataracts. Three patients developed ACP, 2 of whom had received a MicroSlim(®) IOL (PhysIOL).

CONCLUSIONS

No association was found between PCO and any of the studied variables. Male gender, young age, subcapsular cataract and large non-angulated lens such as Akreos Adapt AO(®) could be associated with CBDS. ACP could be more frequent when microincision IOLs (like MicroSlim(®)) are implanted.

Femtosecond laser-assisted cataract surgery versus standard phacoemulsification cataract surgery: outcomes and safety in more than 4000 cases at a single center

PURPOSE

To compare the intraoperative complications and safety of femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery.

SETTING

Single center.

DESIGN

Prospective consecutive comparative cohort case series.

METHODS

Eyes had femtosecond laser-assisted cataract surgery (study group) or phacoemulsification (control group) by 1 of 5 surgeons. The technique comprised manual corneal incisions and capsulorhexis or laser-assisted anterior capsulotomy, lens fragmentation, corneal incisions, phacoemulsification, and intraocular lens implantation.

RESULTS

The study group comprised 1852 eyes and the control group, 2228 eyes. Patient demographics were similar between groups. There was a significant improvement in vacuum/docking attempts, surface recognition adjustments, treatment, and vacuum time during the laser procedure in the study group. Anterior capsule tears occurred in 1.84% of eyes in the study group and 0.22% of eyes in the control group (P < .0001). There was no difference in the incidence of anterior capsule tears between the first half and second half of laser-assisted cases. Anterior capsulotomy tags occurred in 1.62% study group eyes. There was no significant difference in posterior capsule tears between the 2 groups (0.43% versus 0.18%). The incidence of significant intraoperative corneal haze and miosis was higher and the effective phacoemulsification time significantly lower in the study group (P < .001).

CONCLUSIONS

Significant intraoperative complications likely to affect refractive outcomes and patient satisfaction were low overall. The 2 cataract surgery techniques appear to be equally safe. Although anterior capsule tears remain a concern, the safety of femtosecond-assisted cataract surgery in terms of posterior capsule complications was equal to that of phacoemulsification.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Femtosecond-laser assisted cataract surgery: a review

Introduced in 2008, the femtosecond laser is a promising new technological advance which plays an ever increasing role in cataract surgery where it automates the three main surgical steps: corneal incision, capsulotomy and lens fragmentation. The proven advantages over manual surgery are: a better quality of incision with reduced induced astigmatism; increased reliability and reproducibility of the capsulotomy with increased stability of the implanted lens; a reduction in the use of ultrasound. Regarding refractive results or safety, however, no prospective randomized study to date has shown significant superiority compared with standard manual technique. The significant extra cost generated by this laser, undertaken by the patient, is a limiting factor for both its use and study. This review outlines the potential benefits of femtosecond-laser-assisted cataract surgery due to the automation of key steps and the safety of this new technology.

Femtosecond laser cataract surgery: updates on technologies and outcomes

PURPOSE

To describe femtosecond laser cataract surgery and discuss the published peer-reviewed articles to have a fair evaluation of this new technology and its comparisons to conventional phacoemulsification surgery.

METHODS

The technology information released in this article comes from the key individuals in each of the U.S. Food and Drug Administration-approved companies and from the available commercial information. Bibliographic research was performed in PubMed and MEDLINE for the published prospective or retrospective clinical studies.

RESULTS

The femtosecond laser has been reported to be safe intraoperatively and postoperatively, with less cornea and macula effect than conventional phacoemulsification. The incision is integrated, stable, and aberration free. Many studies reported the high precision of the capsulotomy over manual continuous curvilinear capsulorhexis, which favors less intraocular lens tilt, higher optical quality, and more accurate premium intraocular lens centration. The lens fragmentation is effective with significant reduction of the phacoemulsification power and effective phacoemulsification time. The refractive difference between femtosecond laser and standard phacoemulsification is minimal, with no difference in corrected distance visual acuity, but the optical quality and the internal aberrations results are significantly better for femtosecond laser phacoemulsification.

CONCLUSIONS

Femtosecond laser cataract surgery is a good addition to cataract surgery despite its few remarkable advantages among experienced phacoemulsification surgeons.

[Femtosecond laser-assisted cataract surgery]

Employing a femtosecond laser as an initial step in cataract surgery has the clear potential to provide more precise capsulotomies and full lens fragmentation in cases of pre-existing astigmatism in conjunction with relaxing corneal incisions. In the long run femtosecond laser-assisted cataract surgery might replace phacoemulsification which has been the standard in cataract surgery over the last 20 years. Besides precision and predictability, the low rate of complications impresses surgeons working with the technology, particularly those employing a laser with a fluid-filled interface which seems to prevent major complications including increases in intraocular pressure.