Neodymium:YAG capsulotomy rates associated with femtosecond laser–assisted versus manual cataract surgery

Comparison of clinical outcomes between cystotome-assisted prechop phacoemulsification surgery and femtosecond laser-assisted cataract surgery for hard nucleus cataracts

BACKGROUND/OBJECTIVES

To compare the safety and efficacy of cystotome-assisted prechop phacoemulsification surgery (CAPPS) and femtosecond laser-assisted cataract surgery (FLACS) in patients with hard nucleus cataract.

SUBJECTS/METHODS

Ninety-six eyes of 64 patients with grade IV hard nucleus cataract were assigned to 1 of the 2 groups (49 CAPPS and 47 FLACS). Follow-up visits were performed at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year, and the outcome measures comprised ultrasound power, effective phacoemulsification time (EPT), corrected distance visual acuity (CDVA), endothelial cell density (ECD), corneal endothelium cell loss rate (ECL), central corneal thickness (CCT), and intraoperative and postoperative complications.

RESULTS

The ultrasound power and EPT were lower in the CAPPS group (p = 0.03 and <0.0001, respectively). Patients in both groups gained better CDVA postoperatively. The ECD value decreased at each follow-up visit and did not return to the preoperative level; FLACS resulted in greater endothelial cell loss compared to CAPPS. CCT increased immediately after the surgery and decreased thereafter. The mean CCT value returned to the preoperative level 3 months postoperatively in the CAPPS group, while in the FLACS group, CCT value took 6 months to return to the preoperative level. Miosis was more likely to occur in the FLACS group.

CONCLUSIONS

Due to its efficacy and cost-effectiveness, CAPPS is worth promoting and applying to clinical work in the future.

The Protective Effect of Metformin Use on Early Nd:YAG Laser Capsulotomy

Purpose

To determine the effect of metformin on early Nd:YAG laser treatment for posterior capsule opacification (PCO) and to explore a molecular mechanism to explain a possible protective effect of metformin against PCO.

Methods

We conducted: 1) a retrospective cohort study of patient eyes undergoing phacoemulsification at our institution; and 2) laboratory investigation of the effect of metformin on the behavior of lens epithelial cells in the context of an animal model for PCO. Population-averaged Cox proportional hazards modeling was used to estimate risk for time to Nd:YAG. For laboratory studies, expression of markers for epithelial-to-mesenchymal transition (EMT) implicated in PCO pathogenesis was measured in tissue culture and following extracapsular lens extraction in a mouse model.

Results

The rate of Nd:YAG laser capsulotomy was 13.1% among the 9798 eyes. Both metformin use and diabetes were protective factors for Nd:YAG laser capsulotomy in univariate analysis. However, in multivariable analysis with nondiabetics as the reference group, only metformin use among diabetics was significantly protective of Nd:YAG (hazard ratio: 0.68, 95% CI: 0.54–0.85, P = 0.0008), while eyes of patients with diabetes without metformin use did not significantly differ (P = 0.5026). Treatment of lens epithelial cells with metformin reduced the level of the EMT markers ⍺-SMA and pERK induced by TGF-β2. Similarly, metformin treatment reduced ⍺-SMA expression in lens epithelial cells following extracapsular lens extraction in a mouse model.

Conclusions

The protective effect of metformin against early Nd:YAG may relate to its ability to downregulate EMT in residual lens epithelial cells that otherwise trend toward myofibroblast development and PCO.

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.

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

PURPOSE

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

DESIGN

Retrospective case-control study.

METHODS

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

RESULTS

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

CONCLUSION

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

Intraocular lens tilt and decentration after Nd:YAG laser posterior capsulotomy: Femtosecond laser capsulorhexis versus manual capsulorhexis

PURPOSE

To compare intraocular lens (IOL) tilt and decentration after Nd:YAG laser posterior capsulotomy in eyes that had femtosecond laser-assisted capsulotomy versus manual capsulorhexis.

SETTING

Ekol Eye Hospital, Izmir, Turkey.

DESIGN

Retrospective case series.

METHODS

Intraocular lens decentration and angle of tilt were measured using a Scheimpflug camera before and 1 month after Nd:YAG capsulotomy.

RESULTS

Eighteen eyes had a femtosecond laser-assisted capsulotomy and 25 eyes a manual capsulorhexis. The mean age was 58.2 years ± 10.2 (SD) (range 44 to 69 years) and 60.6 ± 8.3 years (range 45 to 70 years), respectively. Before capsulotomy, the angle of tilt and decentration at both meridians did not differ significantly between the 2 groups (P > .05). After capsulotomy, the angle of tilt was significantly decreased in both groups (femtosecond: vertical 1.5 degrees and horizontal 1.2 degrees; manual: vertical 1.1 degrees and horizontal) and decentration was significantly increased (femtosecond: vertical 0.085 mm and horizontal 0.096 mm; manual: vertical 0.2 mm and horizontal 0.2 mm) at both meridians (P < .05). After capsulotomy, all tilt and decentration parameters were significantly different between the 2 groups (P < .05) except decentration on the horizontal meridian (P = .669).

CONCLUSIONS

Nd:YAG posterior capsulotomy performed after femtosecond laser-assisted capsulotomy resulted in better mechanical stability of the IOL. This suggests that a femtosecond laser-created capsulotomy better maintains a proper IOL position. Although the differences were statistically significant, the tilt and decentration values were small and might not be clinically significant.

Femtosecond laser-assisted cataract surgery: A review

PURPOSE

Review scientific literature concerning femtosecond laser-assisted cataract surgery.

METHODS

Following databases were searched: CENTRAL (Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 2 of 12, June 2019), Ovid MEDLINE^® without Revisions (1996 to June 2019), Ovid MEDLINE^® (1946 to June 2019), Ovid MEDLINE^® Daily Update June 2019, MEDLINE and MEDLINE Non-Indexed Items, Embase (1980-2019), Embase (1974 to June 2019), Ovid MEDLINE^® and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1946 to June 2019), Web of Science (all years), the metaRegister of Controlled Trials ( www.controlled-trials.com ), ClinicalTrials.gov ( www.clinicaltrial.gov ) and World Health Organization International Clinical Trials Registry Platform ( www.who.int/ictrp/search/en ). Search terms/keywords included 'Femtosecond laser' combined with 'cataract', 'cataract surgery'.

RESULTS

Based on quality of their methodology and their originality, 121 articles were reviewed, including randomised controlled trials, cohort studies, case-controlled studies, case series, case reports and laboratory studies. Each step of the femtosecond laser-assisted cataract surgery procedure (corneal incisions, arcuate keratotomies, capsulotomy and lens fragmentation) has been discussed with relevance to published outcomes, as well as complication rates of femtosecond laser-assisted cataract surgery, and what we can learn from the larger studies/meta-analyses and the economics of femtosecond laser-assisted cataract surgery within different healthcare settings.

CONCLUSION

Studies suggest that the current clinical outcomes of femtosecond laser-assisted cataract surgery are not different to conventional phacoemulsification surgery and it is not cost effective when compared with conventional phacoemulsification surgery. In its current technological form, it is a useful surgical tool in specific complex cataract scenarios, but its usage has not been shown to translate into better clinical outcomes.

Consensus on procedures to include in a simulation-based curriculum in ophthalmology: a national Delphi study

PURPOSE

The number of available simulation-based models for technical skills training in ophthalmology is rapidly increasing, and development of training programmes around these procedures should follow a structured approach. The aim of this study was to identify all technical procedures that should be integrated in a simulation-based curriculum in ophthalmology.

METHODS

Key opinion leaders involved in the education of ophthalmologists in Denmark including heads of departments, heads of clinical education, professors and board members of the society were invited to participate in a three-round Delphi process. Round 1 aimed at identifying technical procedures that physicians should be able to perform competently when completing specialty training; round 2 involved characterization of each procedure including frequency, number of operators, risk and/or discomfort for patients associated with an inexperienced physician, and feasibility of simulation-based training; round 3 included a priority ranking of procedures.

RESULTS

The response rate for each round was 71%, 64% and 64%, respectively. Sixty-five procedures were reduced to 25 prioritized procedures during the three rounds. Two-thirds of the procedures that were identified and highly prioritized were therapeutic procedures such as intravitreal injection therapy, yttrium-aluminium-garnet laser iridotomy/capsulotomy, minor ocular surface procedures and retinal argon laser therapy. The diagnostic procedures that were prioritized were ocular ultrasound, superficial keratectomy and optical coherence tomography (OCT).

CONCLUSION

The Delphi process identified and prioritized 25 procedures that should be practised in a simulation-based environment to achieve competency before working with patients. The list may be used to guide the development of future training programmes for ophthalmologists.

Cyclodextrin-containing hydrogels as an intraocular lens for sustained drug release

To improve the efficacy of anti-inflammatory factors in patients who undergo cataract surgery, poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (p(HEMA-co-MMA)) hydrogels containing β-cyclodextrin (β-CD) (pHEMA/MMA/β-CD) were designed and prepared as intraocular lens (IOLs) biomaterials that could be loaded with and achieve the sustained release of dexamethasone. A series of pHEMA/MMA/β-CD copolymers containing different ratios of β-CD (range, 2.77 to 10.24 wt.%) were obtained using thermal polymerization. The polymers had high transmittance at visible wavelengths and good biocompatibility with mouse connective tissue fibroblasts. Drug loading and release studies demonstrated that introducing β-CD into hydrogels increased loading efficiency and achieved the sustained release of the drug. Administering β-CD via hydrogels increased the equilibrium swelling ratio, elastic modulus and tensile strength. In addition, β-CD increased the hydrophilicity of the hydrogels, resulting in a lower water contact angle and higher cellular adhesion to the hydrogels. In summary, pHEMA/MMA/β-CD hydrogels show great potential as IOL biomaterials that are capable of maintaining the sustained release of anti-inflammatory drugs after cataract surgery.