Femtosecond laser–assisted pediatric cataract surgery: Bochum formula

Femtosecond laser-assisted cataract surgery for complex cataracts - A review

Since its inception in 2009, femtosecond laser-assisted cataract surgery (FLACS) has become an alternative to conventional phacoemulsification cataract surgery (CPCS). Clinical studies were unable to demonstrate superior visual outcomes, but revealed reduced endothelial cell loss. More recently, the cost-effectiveness of FLACS over CPCS in routine cataract surgeries has been challenged. However, the unique abilities of FLACS to customize anterior capsulotomies precisely, soften and fragment the nucleus without capsular bag stress, and create corneal incisions may have special utility in complex cataract and less-common scenarios. In this article, we review the unique role of FLACS in complex cataract surgeries and how it could play a role to improve the safety and predictability of nonroutine cataract surgery.

Efficacy of a new fragmentation pattern in femtosecond laser-assisted cataract surgery with the Ziemer FEMTO LDV Z8

PURPOSE

To determine the efficacy of different fragmentation patterns in femtosecond laser-assisted cataract surgery (FLACS) using Ziemer FEMTO LDV Z8.

METHODS

We compared three different types of surgery: conventional cataract surgery (CCS), FLACS with conventional radial slices (named No-Spiderweb), and FLACS with a novel fragmentation pattern (radial slices combined with one or two rings) called "Spiderweb." Visual acuity (VA), nuclear opacity (NO) according to the Lens Opacities Classification System (LOCS lll), effective phacoemulsification time (EPT) and vacuum time were obtained for 845 eyes.

RESULTS

Using FLACS (Spiderweb + No-Spiderweb), EPT was significantly reduced by 26% compared to CCS (FLACS: 2.46 ± 2.60 s; CCS: 3.34 ± 2.89 s; ΔM = - 0.88 s, p < .001). Furthermore, EPT as a function of progression of lens opacity was found to be not only lower in Spiderweb compared to CCS, but also in comparison with No-Spiderweb. At NO3, a significant reduction of 65% in EPT was observed by using Spiderweb compared to CCS (Spiderweb: 0.68 ± 1.23 s; CCS: 1.96 ± 1.53 s; ΔM = - 1.28 s, p <.001). Interestingly, EPT at NO3 was also significantly reduced by 57% in Spiderweb compared to No-Spiderweb (Spiderweb: 0.68 ± 1.23 s; No-Spiderweb: 1.57 ± 1 .59 s; ΔM  = - 0.90 s, p <.001). The use of Spiderweb only marginally extends the vacuum time compared to No-Spiderweb by 11 s (Spiderweb: 209.13 ± 35.83 s; No-Spiderweb: 198.35 ± 36.84 s; p = .003) and the postoperative improved VA showed no significant difference among the different types of surgery (all ps ≥ .05).

CONCLUSION

FLACS significantly reduces EPT compared to CCS. Furthermore, the novel Spiderweb pattern significantly reduces EPT in patients with a cataract of NO3 compared to CCS, but also to FLACS with the existing radial pattern (No-Spiderweb).

Multiple linear regression model for improving accuracy of capsulorhexis size calculation in femtosecond laser-assisted cataract surgery for adults: a retrospective single-center study

BACKGROUND

Differences between programmed capsulorhexis diameter and actual resulting capsulorhexis diameter (ARCD) are commonly encountered in femtosecond laser-assisted cataract surgery (FLACS). The purpose of this study was to identify the preoperative ophthalmic variables influencing capsulorhexis diameter index (CDI) in FLACS for adults and create a multiple linear regression model for obtaining a more accurate capsulorhexis diameter.

METHODS

This retrospective study involved sixty-seven eyes of 44 patients who received FLACS and intraocular lens implantation. The ARCD was measured using anterior segment swept-source optical coherence tomography (CASIA 2). Keratometry (K1, K2 and average K), anterior chamber depth (ACD), lens thickness (LT), anterior chamber width (ACW), white-to-white (WTW), curvature radius of anterior lens capsule (Front R) and axial length (AL) were all measured preoperatively. Based on the derived data, LT/ACW, LT/AL, LT/ACD and LT/ACW/Front R were calculated. The ratio of the programmed capsulorhexis diameter and ARCD was defined as the CDI. Correlation analysis was conducted to examine the relationship between preoperative variables listed above and the CDI. Multiple linear regression analysis was applied to select the most influential preoperative variables on CDI.

RESULTS

ACD, LT, ACW, Front R, AL, LT/ACW, LT/AL, LT/ACD, and LT/ACW/Front R showed significant correlation with CDI. Front R and LT/ACW/Front R were selected as constants in the multiple linear regression model using stepwise variable selection. The following equation represents the multiple linear regression model: CDI = 1.306-4.516 × LT/ACW/FrontR-0.011 × Front R, when P < 0.0001, adjusted R-squared = 0.919, variance inflation factor = 8.389, and Durbin-Watson ratio = 1.846. Predicted postoperative capsulorhexis diameter (PPCD) equation was created based on CDI equation as follows: PPCD = programmed capsulorhexis diameter × 1.306-4.516 × LT/ACW/FrontR-0.011 × Front R.

CONCLUSION

Front R and LT/ACW/Front R were found to be the most significant influencing factors of capsulorhexis size. CDI and PPCD calculation equations presented in this study may be useful in setting up more accurate programmed capsulorhexis diameter for FLACS in adults, resulting in a precise ARCD.

Pediatric cataract surgery: considerations and updates in diagnosis and management

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of updates in the diagnosis and management of pediatric cataracts, with an emphasis on recent discoveries in the last two years.

RECENT FINDINGS

Pediatric cataracts remain an infrequent but significant disease with vision threatening consequences. Although much of the management has not changed historically, more recent updates, particularly borrowed from adult cataract management, have influenced the field of cataract management in children. Even these studies emphasize that pediatric cataracts are a distinct clinical entity from adult-onset cataracts, and further research is needed to optimize the diagnosis and management of cataracts in childhood.

SUMMARY

This is an overview of the recent advancements in the diagnosis of management of pediatric cataracts, with advancements that originate from the adult cataract surgery field in addition to studies that challenge classical surgical techniques to make cataract surgery safer and to promote amblyopia therapy.

Femtosecond laser-assisted cataract surgery: Update and perspectives

Cataract surgery is among the most frequently performed surgical procedures worldwide and has a tremendous impact on patients' quality of life. Phacoemulsification (PCS) is accepted as a standard of care; its technique has continuously evolved and already achieved good anatomical, visual, and refractive outcomes. Lasers in ophthalmology are widely used in clinical practice, femtosecond lasers (FSLs) for corneal surgery in particular. It was natural to assess the usefulness of FSL in cataract surgery as this technology was within reach. Indeed, precise and reproducible cuttings provided by FSL platforms could improve standardization of care and limit the risk associated with the human element in surgery and provide a step toward robot-assisted surgery. After docking and planning the procedure, femtosecond lasers are used to perform corneal incisions, capsulorhexis, lens fragmentation, and arcuate incisions in an automated manner. A well-constructed corneal incision is primordial as it offers safety during the procedure, self-seals afterward, and influences the refractive outcome. Capsulorhexis size, centration, and resistance to shearing influence the surgery, intraocular lens (IOL) centration and stability, and posterior capsular opacification formation. Lens fragmentation is where most of the energy is delivered into the eye, and its amount influences endothelial cell damage and potential damage to other ocular structures. The arcuate incisions offer an additional opportunity to influence postoperative astigmatism. Femtosecond laser-assisted cataract surgery (FLACS) has been a topic of research in many studies and clinical trials that attempted to assess its potential benefits and cost-effectiveness over PCS and is the subject of this mini-review.

Comparison of the actual diameter of capsulotomy and predicted diameter of capsulotomy after femtosecond laser-assisted capsulotomy

PURPOSE

To compare the consistency between the actual diameter of capsulotomy (ADC) and the predicted diameter of capsulotomy (PDC) in femtosecond laser-assisted cataract surgery (FLACS) and analyze the factors that influence the deviation of the diameter of capsulotomy (DDC) between the actual and predicted.

SETTING

Aier Eye Hospital of Wuhan University, China.

DESIGN

Retrospective observational case series.

METHODS

Patients who underwent FLACS from March 2020 to March 2021 were reviewed. The ADC in FLACS was measured and compared with the PDC. The effects of age, sex, and biometrics on DDC were analyzed.

RESULTS

412 eyes of 336 patients were included. The mean age was 53.0 ± 0.91 years (range 3 to 91 years). When the PDC was set to 4.50 mm, the results showed that the ADC was 5.21 ± 0.21 mm with a significant difference between them ( P &amp;lt; .05). However, when the PDC was set to 5.2 mm, the ADC was 5.10 ± 0.38 mm without a significant difference between them ( P &amp;gt; .05). No correlation ( P &amp;gt; .05) was found between the DDC and the axial length, the DDC and the anterior chamber depth (ACD), and the DDC and the mean keratometry (Km), but a negative correlation was found between the DDC and the lens thickness (LT) ( r = -0.21; P &amp;lt; .05) and the DDC with age ( r = -0.70; P &amp;lt; .05). Using curvilinear regression analysis, a development of an age-depending correction formula was predicted: ADC = PDC + 1.23 - 0.30 ln (x) (x = age ≥3) ( R2 = 0.65; F = 752.39; P = .00).

CONCLUSIONS

The consistency of the ADC and PDC was influenced by age and LT. For patients aged 40 years or younger, the younger the patient, the wider the DDC; for patients older than 40 years, the DDC was small. The thicker the LT, the smaller the DDC.

Portable femtosecond laser assisted cataract surgery in a child with bilateral ectopia lentis with microspherophakia

Purpose

The purpose of this case report is to describe the utility of portable femtosecond laser platform in a child with bilateral isolated microspherophakia and ectopia lentis performed under general anesthesia.

Observation

An appropriately sized and well centered capsulotomy with well centered PCIOL could be achieved in both eyes of the patient.

Conclusion & Importance

The advent of mobile femtosecond laser assisted cataract surgery might prove a useful and convenient platform for surgeries in pediatric patients with subluxated cataracts even under general anesthesia. It may circumvent the need for an additional laser suite and reduce surgical time by eliminating the need for patient movement.

Femtosecond laser-assisted anterior capsulotomy in children undergoing cataract surgery: a large case series

Objective

To evaluate safety and postoperative visual outcomes of low-energy femtosecond laser-assisted (FLA) anterior capsulotomy in paediatric cataract surgery.

Methods and analysis

We report a retrospective single-centre consecutive case series of 51 eyes of 33 paediatric cataract patients with a mean age of 3.22 years (range: 2 months to 13 years) who underwent cataract surgery with FLA anterior capsulotomy, using FEMTO LDV Z8 femtosecond laser (Ziemer Ophthalmic Systems). Anterior laser capsulotomy, phacoaspiration and intraocular lens implantation were performed in all eyes. Both intraoperative and long-term postoperative complications, along with long-term monocular corrected distance visual acuity (CDVA), were assessed during average follow-up period of 32.96 months (range: 13–69 months).

Results

In 48 out of 51 eyes, a well-sized and well-located anterior capsulotomy was achieved without intraoperative complications. Anterior capsule tears occurred in three eyes; however, they did not extend posteriorly and the intraocular lens were placed in the bags without any further complications. Posterior capsular opacification developed in 45.10% of eyes (23 out of 51) and was subsequently treated with neodymium:yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy. Mean CDVA at final follow-up was 20/40 (range: 20/63 to 20/32) in unilateral cases younger than 12 months, 20/40 (range: 20/1000 to 20/25) in unilateral cases older than 12 months, 20/66 (range: 20/400 to 20/32) in bilateral cases younger than 12 months and 20/40 (range: 20/200 to 20/20) in bilateral cases older than 12 months.

Conclusions

Paediatric cataract surgery with low-energy FLA anterior capsulotomy is a procedure with long-term safety, resulting in significant improvement in CDVA.

Study on the enlargement index of femtosecond laser-assisted capsulorhexis in 2-6-year-old patients with congenital cataract

Background

To identify the capsule enlargement index after femtosecond laser-assisted anterior capsulorhexis in 2–6-year-old children who underwent congenital cataract surgery.

Methods

In this prospective case series study, femtosecond laser-assisted anterior capsulorhexis was performed in patients with congenital cataract, aged 2–6 years. The actual achieved capsulorhexis diameters were measured with Digimizer version 4.2.6. Correlation coefficient (r) and multiple linear regression analysis were used to evaluate the variables that could potentially influence anterior capsulorhexis enlargement index (E).

Results

This prospective study enrolled 28 eyes of 22 patients with congenital cataract. The mean age of the patients at surgery was 4.67 years ±1.54 (standard deviation [SD]). “E” of the 28 cases was 1.211 ± 0.039 (SD). Correlation analysis showed that “E” correlated significantly with the anterior chamber depth (ACD) (r = − 0.469, p = 0.021) and axial length (AL) (r = 0.452, p = 0.027). The following formula was developed by using multivariable linear regression analysis: Predicted E = 1.177–0.052 × ACD + 0.009 × AL, R² = 0.346 (F = 4.396, p = 0.046).

Conclusions

The anterior capsulorhexis enlargement index and its calculation formula could help to set up an accurate programmed capsulorhexis diameter for femtosecond laser-assisted congenital cataract surgery in children aged 2–6 years. Thus, an appropriate actual capsulorhexis diameter could be achieved.

Management of the subluxated crystalline lens: A review

Cataract surgery for the subluxated crystalline lens is challenging. A thorough preoperative evaluation is important to determine the appropriate surgical approach for lens removal and the subsequent technique of intraocular lens placement. Important considerations include the extent and location of zonular weakness, and whether the zonular deficiency is caused by a static or progressive disease. The capsular bag should be preserved where possible. Creating a good-sized and centred continuous curvilinear capsulorhexis is crucial to facilitate the use of capsular retractors and capsular tension devices, which provide capsular stability. Nucleus sculpting and rotation should be minimised to reduce zonular stress. Being cognisant of the possible intraoperative complications that may occur at each stage of the surgery and knowing how to reduce the risk of these complications occurring will enable surgeons to perform safe cataract surgery in these complex cases.

Femtosecond laser - Assisted cataract surgery in pediatric pyramidal anterior polar cataract

PURPOSE

The purpose of this report is to describe the successful utilization of femtosecond laser assisted cataract surgery (FLACS) in a rare case of pyramidal anterior polar cataract in a female child.

OBSERVATIONS

The patient is a 6 years old girl that presented to the cornea clinic with a unilateral pyramidal cataract that was deemed to be visually significant, and therefore required cataract extraction and intraocular lens implantation surgery. FLACS was proposed and mother consented to proceed with the surgery. The femtosecond laser technology enabled precise completion of a central capsulotomy around the protruding pyramidal capsular lesion.

CONCLUSIONS AND IMPORTANCECONCLUSION

Various capsulorhexis techniques have been described and are used in pediatric cataracts including manual, can opener, vitrectorhexis, and laser, but none has become a standard. We propose the use of femtosecond laser for cataract extraction in cases of pediatric pyramidal cataracts, and hereby provide the first case report of such. The laser is a safe method for capsulorhexis construction and offers an additional advantage of intraoperative anterior segment OCT image guidance with visualization of the pyramidal lesion.

[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.

[Future perspectives of the femtosecond laser in anterior segment surgery]

Around 12 years after its introduction laser cataract surgery (LCS) has enabled remarkable progress, such as extremely precise capsulotomy and lens fragmentation with reduced or no ultrasound energy at all (zero phako); however, another innovation push is necessary to bring this technology to its full potential. Among the many benefits that have not yet been fully explored are primary posterior laser capsulotomy (PPLC) and the use of the femtosecond laser in pediatric cataract patients. In the present collective of patients in whom a PPLC was carried out at the end of the operation, a clearly reduced prevalence of secondary cataract could be observed, whereas the short additional intervention was not associated with notable complications. The LCS in infants is best carried out as an off-label procedure, which has been rendered more precise by the Bochum formula. In the near future, postoperative laser fine tuning will enable the target refraction to be achieved in most patients. Laser-induced refractive index change (LIRIC) will enable very exact refraction alterations on an already implanted intraocular lens (IOL), on a contact lens and on a treatment native cornea. A new version of the Scheimpflug camera will be used just prior to surgery to analyze the morphology and kernel density of the lens opacity and to carry out a real-time grading of lens hardness. Based on this categorization, where the system classifies the results into five different density grades, the surgeon is automatically provided with an individualized fragmentation pattern defined preoperatively by the operator. A further innovation of the same system involves microcorneal incisions for fine tuning of residual refractive deficits.

Femtosecond laser-assisted anterior and posterior capsulotomies in children with persistent hyperplastic primary vitreous

Anterior and posterior capsulotomies were performed in 12 eyes of 12 patients (age range 3 months to 6 years) with congenital cataracts and primary persistent hyperplastic primary vitreous (PHPV) syndrome using a femtosecond laser. The procedure was performed in 8 eyes with PHPV severity level 1 and 4 eyes with severity level 2 (Sudovsky classification). Surgeries were performed at the Kaluga branch of the S. Fyodorov Eye Microsurgery Federal State Institution, Russia. Postoperative follow-up was between 8 months and 36 months. The use of a low-energy femtosecond laser-assisted posterior capsulotomy in this pediatric population provided safe and predictable results with a reduced number of intraocular manipulations, and reduced the risk for complications.

Postoperative outcomes of intraocular lens implantation in the bag versus posterior optic capture in pediatric cataract surgery

PURPOSE

To compare complications in children up to 4 years old having cataract surgery with intraocular lens (IOL) implantation using 2 techniques: in-the-bag IOL with anterior vitrectomy or optic capture of IOL with no anterior vitrectomy.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

DESIGN

Prospective randomized control clinical trial.

METHODS

The study included children having cataract surgery with IOL implantation. Patients were randomized to Group 1 (in-the-bag 3-piece hydrophobic acrylic IOL [Acrysof MA60AC] with anterior vitrectomy) or Group 2 (optic capture of the same IOL without anterior vitrectomy). Intraoperative complications were documented. Postoperative visual axis obscuration (VAO), glaucoma, cell deposits on the IOL, and posterior synechiae were compared at 1, 3, 6, and 12 months.

RESULTS

The study comprised 61 children (61 eyes). The mean ages were 14.8 months ±11.47 (SD) in Group 1 (n = 30) and 18.2 ± 11.47 months in Group 2 (n = 31). Overall, only 1 eye in Group 1 developed a VAO requiring membranectomy 4 months postoperatively, and 2 eyes in Group 1 developed glaucoma over 12 months (P = .49). Intraocular lens cell deposits and posterior synechiae were comparable between groups. The IOL could not be captured in 5 eyes (16.1%); no complications occurred in these eyes.

CONCLUSIONS

Optic capture of 3-piece hydrophobic acrylic IOLs could be achieved in most eyes. The VAO, glaucoma, and inflammation were comparable 12 months postoperatively. Thus, optic capture of an IOL is an alternative surgical technique that can be used to avoid vitrectomy, even in children younger than 4 years.

Precision pulse capsulotomy: an automated alternative to manual capsulorhexis in paediatric cataract

Objective

To report our operative experience with precision pulse capsulotomy (PPC) for anterior capsulotomy in a paediatric cataract series.

Methods and analysis

This study is a retrospective interventional, descriptive series of consecutive paediatric eyes (≤16 years) undergoing cataract surgery using PPC. Surgical time and the time required to perform PPC was recorded. Any intraoperative and postoperative adverse events were noted. Postoperatively, visual acuity, anterior segment examination and intraocular pressure (IOP) were recorded for all children at day 1, 1 week and 1 month.

Results

21 eyes of 14 patients were included in the study, with the median age at surgery of 6.0 years (IQR; 5-7.75, range=1–16 years). Male to female ratio was 11:3. 13 eyes had lamellar cataract, 3 eyes had total cataract, 2 had posterior subcapsular cataract, 2 had traumatic cataract, while 1 eye had sutural cataract. Median surgical time was 26 min (IQR 21-32) and median PPC time was 75.0 secs (IQR 56-86.5). The anterior capsulotomy was round and complete in most cases, except in one case due to faulty suction. All patients underwent a successful in the bag implantation of intraocular lens with capsulotomy margins overlapping the optic edges in 19 eyes (90%). Median PPC size was 5.54 mm (n=9, IQR 5.39 -5.75) which was slightly larger than expected. None of the cases had any intraoperative or postoperative adverse events with no radial tears of capsulotomy. Postoperatively, the mean final follow-up was 5.71+3.20 weeks.

Conclusion

To conclude PPC can be used as an alternative to manual continuous curvilinear capsulorhexis in paediatric cataract surgery producing round well- centred and strong capsulotomy with an easier learning curve.

[Morphological and clinical aspects of anterior capsulotomy in femtosecond laser-assisted cataract surgery]

The review covers morphological and clinical aspects of femtosecond laser-assisted anterior capsulotomy in cataract surgery. Literature data suggests that femtosecond laser-assisted capsulotomy is more accurate in size, shape, and centration than manual. Femtosecond laser-assisted anterior capsulotomy improves the accuracy of IOL positioning within the capsular bag.

Femtosecond laser-assisted cataract surgery in pediatric patients

Pediatric cataract surgery poses a significant challenge for the cataract surgeon, in part because an elastic anterior capsule can make capsulorhexis difficult. With the use of femtosecond laser-assisted cataract surgery (FLACS), however, the continuous curvilinear capsulorhexis can be made with predictable size, circular shape, centration, and accuracy. In addition, topical anesthesia can be used for the FLACS docking procedure in cooperative children above 6 years of age, using transparent adhesive polyurethane film segments.

[Mechanical dilation of the pupil and its possible applications in femtosecond laser-assisted cataract surgery]

In certain cases intraoperative pupil dilation during cataract surgery may be necessary to improve the visualization of intraocular structures and assure the atraumatic nature of surgical manipulations. The article reviews a wide range of pupil expanders, their historical aspects and possibilities of their application in modern cataract surgery.

Mobile femtosecond laser platform for pediatric cataract surgery

PURPOSE

To describe the use of a mobile femtosecond laser platform in assisting paediatric cataract surgery.

METHODS

A mobile femtosecond laser was brought into the operating room and calibrated on the day of the surgery. After general anesthesia is induced, the femtosecond laser was docked onto the eyes with a liquid-filled interface, without any perioperative adaptations or additional surgical procedures. An anterior capsulotomy was created with the femtosecond laser, followed by conventional cataract extraction and intraocular lens implantation.

RESULTS

Five eyes of 3 children with congenital cataracts were treated with this technique. Docking and capsulorhexis were successful in all cases. No perioperative or intraoperative complications were noted in any of the cases. At median follow-up of 15 months (range 6-18 months), all patients had improved best-corrected visual acuity.

CONCLUSIONS

Using the mobile femtosecond laser platform, a perfectly sized anterior capsulotomy could be created with high precision and accuracy in paediatric cataract cases, while ensuring that perioperative care for the children undergoing the procedure was not compromised.

A Review of Laser-Assisted Versus Traditional Phacoemulsification Cataract Surgery

The use of femtosecond laser surgery improves the precision and reproducibility of corneal incisions and the capsular opening; it also reduces the amount of ultrasound energy required for lens nucleus work-up. The rate of complications reported so far appears to be low. There are a number of contraindications such as a history of cornea and/or glaucoma surgery and certain anatomical features like deep-set eyes, kyphosis, tremor, and obesity. Visual recovery and refractive results of both techniques are excellent. Comparing laser cataract surgery (LCS) with manual cataract surgery (conventional phacoemulsification) based on meta-analysis currently reveals slight differences in refractive and visual outcome. Both methods are extremely successful and safe. LCS is a technique still on the rise, with its full potential not yet tapped.

Current and effective advantages of femto phacoemulsification

PURPOSE OF REVIEW

The purpose is to review the current and effective advantages of femtosecond laser-assisted cataract surgery (FLACS).

RECENT FINDINGS

FLACS has advantages over manual phacoemulsification in its precision, and predictability and may be especially advantageous in difficult situations such as shallow anterior chamber, subluxated cataracts, white cataracts, and so on. However, the femtosecond capsulorhexis may not be as strong as a manual rhexis. Laser-induced miosis is also a potential disadvantage.

SUMMARY

There may be increased surgeon confidence and patient satisfaction with FLACS and it may be friendlier to the internal structures of the eye. However, it is not superior to manual phacoemulsification in terms of primary outcomes such as visual and refractive outcomes or overall complications. Further refinements in technology may be needed to give it distinct advantages over manual phacoemulsification and to make it the norm in cataract surgery.

Safety of femtosecond laser-assisted cataract surgery: assessment of aqueous humour and lens capsule

PURPOSE

To investigate the effect of femtosecond laser-assisted cataract surgery (FLACS) on aqueous humour and lens capsule.

METHODS

This prospective randomized comparative study enrolled 19 eyes that underwent FLACS as the trial group and 20 eyes that underwent conventional phacoemulsification as the control group. The femtosecond laser platform (LLS-fs 3D; LensAR, Orlando, FL, USA) was used to generate capsulotomy (laser energy 8 μJ) and lens fragmentation (laser energy 10 μJ). Morphology of the cutting edge and cells of anterior capsule was assessed by light microscopy. The proteins in the aqueous humour were identified by mass spectrometry (Ultraflex III TOF/TOF; Bruker Dalton, Bremen, Germany). Electrolyte in the aqueous humour was detected by a chemistry analyzer (Aeroset Clinical Chemistry Analyzer; Abbott Laboratories, Abbott Park, IL, USA).

RESULTS

The cutting edge of anterior capsule was saw-tooth-shaped under magnification of 200× and 400× in the trial group, while it was smooth in the control group. Intact cells were found in the boundary area next to the cutting edge of anterior capsule in both groups. β-Crystallin B1, γ-crystallin S and transferrin were detected in the aqueous humour in the trial group. The concentrations of K⁺ , Na⁺ and Cl^- in the aqueous humour in the trial group differed significantly from those in the control group (p = 0.02, 0.03 and 0.04, respectively).

CONCLUSION

Femtosecond laser-assisted cataract surgery (FLACS) causes release of transferrin and crystallin from lens to aqueous humour and results in significant changes in the concentrations of K⁺ , Na⁺ and Cl^- in aqueous humour. However, these changes due to FLACS have no clinical significance or toxicity.

Efficacy and Safety of Femtosecond Laser-Assisted Cataract Surgery Compared with Manual Cataract Surgery: A Meta-Analysis of 14 567 Eyes

TOPIC

To investigate the efficacy and safety of femtosecond laser-assisted cataract surgery (FLACS) relative to manual cataract surgery (MCS).

CLINICAL RELEVANCE

It is unclear whether FLACS is more efficacious and safe relative to MCS.

METHODS

A literature search of MEDLINE, EMBASE, and Scopus from 2007 to March 2016 was conducted. Studies containing both FLACS and MCS arms that reported on relevant efficacy and/or safety parameters were included. Weighted mean differences (WMDs) and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated.

RESULTS

From 2802 screened articles, 14 567 eyes from 15 randomized controlled trials and 22 observational cohort studies were included. For primary visual and refractive outcomes, no statistically significant difference was detected between FLACS and MCS in uncorrected distance visual acuity (WMD, -0.02; 95% CI, -0.04 to 0.01; P = 0.19), corrected distance visual acuity (WMD, -0.01; 95% CI, -0.02 to 0.01; P = 0.26), and mean absolute error (WMD, -0.02; 95% CI, -0.07 to 0.04; P = 0.57). In terms of secondary surgical end points, there was a statistically significant difference in favor of FLACS over MCS for effective phacoemulsification time (WMD, -3.03; 95% CI, -3.80 to -2.25; P < 0.001), capsulotomy circularity (WMD, 0.16; 95% CI, 0.11-0.21; P < 0.001), postoperative central corneal thickness (WMD, -6.37; 95% CI, -11.88 to -0.86; P = 0.02), and corneal endothelial cell reduction (WMD, -55.43; 95% CI, -95.18 to -15.69; P = 0.006). There was no statistically significant difference between FLACS and MCS for total surgery time (WMD, 1.25; 95% CI, -0.08 to 2.59; P = 0.07), capsulotomy circularity using a second formula (WMD, 0.05; 95% CI, -0.01 to 0.12; P = 0.10), and corneal endothelial cell count (WMD, 73.39; 95% CI, -6.28 to 153.07; P = 0.07). As well, there was a significantly higher concentration of prostaglandins after FLACS relative to MCS (WMD, 198.34; 95% CI, 129.99-266.69; P < 0.001). Analysis of safety parameters revealed that there were no statistically significant differences in the incidence of overall complications between FLACS and MCS (RR, 2.15; 95% CI, 0.74 to 6.23; P = 0.16); however, posterior capsular tears were significantly more common in FLACS versus MCS (RR, 3.73; 95% CI, 1.50-9.25; P = 0.005).

CONCLUSIONS

There were no statistically significant differences detected between FLACS and MCS in terms of patient-important visual and refractive outcomes and overall complications. Although FLACS did show a statistically significant difference for several secondary surgical outcomes, it was associated with higher prostaglandin concentrations and higher rates of posterior capsular tears.

Capsular Outcomes Differ with Capsulorhexis Sizes after Pediatric Cataract Surgery: A Randomized Controlled Trial

Capsular outcomes of anterior/posterior capsulorhexis opening (ACO/PCO) are essential for performing a secondary in-the-bag intraocular lens implantation. To compare the capsular outcomes with different primary capsulorhexis sizes, Thirty-eight eligible patients (45 eyes) were randomly assigned to three groups by anterior capsulorhexis diameter (Group A: 3.0-3.9, Group B: 4.0-5.0, and Group C: 5.1-6.0 mm). The areas of ACO/PCO and posterior capsule opening opacity (PCOO) as primary outcomes, while, the incidence of visual axis opacity (VAO) as secondary outcome were measured at follow-up visits. Among the thirty eyes included in the final analysis, the mean area of the ACO decreased significantly, whereas the PCO enlarged with time. Group A had the highest anterior capsule constriction and percentage reduction, which increased with time. There were significant differences in the percentage reductions at 6 months and 1 year compared to 1 month in Group A and B. Group C had the highest posterior capsule enlargement. The percentage of PCOO to PCO area and the incidence of VAO was highest in Group A and lowest in Group C. Thus, Capsulorhexis diameter of 4.0-5.0 mm may yield better capsular outcomes, considering moderate contraction of ACO, moderate enlargement of PCO, and lower percentage of PCOO and VAO.

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.