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

PURPOSE: To compare 3 capsulotomy centration methods. SETTING: Private clinic, Zlin, Czech Republic. DESIGN: Prospective, consecutive case series. METHODS: 180 eyes undergoing cataract surgery had anterior capsule staining with microfiltered 0.4% trypan blue solution before selective laser capsulotomy. The first 60 eyes (Group 1) had mydriatic dilated pupil centered capsulotomies. The next 60 eyes (Group 2) were centered on the trypan blue central landmark (TCL). The final 60 capsulotomies (Group 3) were centered on the patient fixated coaxial Purkinje reflex (CPR). Measurements between key anatomical landmarks and the TCL, CPR capsulotomies, and implanted intraocular lens (IOL) center were made. RESULTS: The TCL, observed in >94% of eyes in the study, coincided with the CPR with a displacement of <0.1 ± 0.1 mm. Group 1 capsulotomies were noticeably decentered on the IOLs by 0.3 ± 0.2 mm. The Group 2 symmetrical IOL relationship was maintained with a decentration of 0.15 ± 0.1 mm. Group 3 had a similar decentration with the IOLs with 0.15 ± 0.1 mm. Verification with IOLMaster 700 data and CALLISTO Eye System showed that the CPR and the TCL were coincident with the measured visual axis. CONCLUSIONS: The clearly visible TCL served as an alternate landmark to the patient fixated CPR, and being on the anterior capsule was not sensitive to tilt. Further patient compliance was not required. Both were superior to dilated pupil centration, to achieve symmetric IOL coverage. This has application for both capsulotomies and capsulorhexes.

Anterior lens capsule: Biological drape.

Small perforations are often managed with cyanoacrylate glue - bandage contact lens (BCL). An additional layer with substances like sterile drape often enhances the strength of the glue. Herein, we describe a novel method of using anterior lens capsule as biological drape to secure perforation. The anterior capsule was secured from femtosecond laser-assisted cataract surgery (FLACS) and placed over the perforation after folding it twice. The area was dried and a small aliquot of cyanoacrylate glue was applied over it. The BCL was applied over it after the glue was dry. In our series of five patients, none of them needed repeat surgery and all cases healed by three months without vascularization. It is a unique technique to secure small corneal perforations.

Selective laser capsulotomy complications: Management and prevention.

PURPOSE: To report how to manage and prevent the incomplete laser cut and following uncut tags of anterior capsular lens, performed using the selective laser capsulotomy. METHODS: We describe three possible approaches: peeling the anterior capsulotomy disc with forceps, breaking the tags using the cystotomy needle tip, or cutting them using a 23-G vitrectomy scissors. RESULTS: Using the 23-G vitrectomy scissors resulted in no complication. Peeling the anterior capsulotomy using the forceps instead caused zonular stress with subsequent risks of zonular dialysis, whereas using the cystotomy needle tip resulted in irregular capsulotomy rim and weakness all along the capsulotomy edge where micro tears caused a tear during the rest of cataract surgery. CONCLUSION: Incomplete laser cut and subsequent discontinuous capsulotomy results in the presence of multiple tags which create strong adherence between the central capsulotomy disc and the peripheral capsule. Key steps of the procedure to prevent an incomplete laser cut, which are the anterior lens capsule staining and laser beam focusing, and how to correctly manage them, which may shorten the learning curve and enhance the outcomes.

Lente multifocal de tres piezas con captura de la óptica, como manejo de ruptura de la cápsula posterior en paciente sometida a cirugía facorrefractiva / Three-piece multifocal intraocular lens with optic capture as management of posterior capsule rupture in a patient undergoing refractive lens exchange

Se presenta el caso de una paciente sometida a cirugía facorrefractiva que sufre una ruptura de la cápsula posterior en la cirugía del primer ojo. Ante la imposibilidad de usar un lente trifocal de una pieza como inicialmente se tenía planteado, se realiza implante de lente multifocal de tres piezas en el sulcus con captura pupilar. Se reportan las imágenes de Scheimpflug y de retroiluminación del lente de tres piezas de un ojo y el lente de una pieza del ojo contralatera

We present the case of a female patient who suffered a posterior capsule rupture while undergoing refractive lens exchange. In view of the impossibility of using a single piece intraocular lens as was initially planned, a three-piece multifocal intraocular lens with an optic capture was positioned. Scheimpflug and retro-illumination images are presented.

Deslocamento espontâneo do núcleo do cristalino para câmara anterior / Spontaneous displacement of the lens nucleus into the anterior chamber

RESUMO Ao longo da vida, o cristalino produz novas fibras dispostas de forma concêntrica, que aumentam seu diâmetro anteroposterior e peso, tornando seu núcleo mais compacto e endurecido. A catarata hipermadura é uma forma de progressão avançada dessa proliferação de fibras, que pode desencadear uma variedade de complicações. A ruptura espontânea da cápsula anterior do cristalino, evoluindo com deslocamento anterior do núcleo, é uma complicação rara e com poucos casos publicados na literatura. Descrevemos o caso de uma paciente do sexo feminino, 68 anos, que apresentou ruptura espontânea da cápsula anterior do cristalino com deslocamento anterior do núcleo em olho esquerdo sem histórico de trauma ocular. A paciente foi submetida à facoemulsificação do cristalino e ao controle da pressão intraocular, evoluindo com melhora do quadro clínico.

ABSTRACT Throughout life, the lens produces new fibers arranged concentrically, which increase its anteroposterior diameter and weight, making its nucleus more compact and hardened. Hypermature cataract is an advanced stage of this fiber proliferation, which can trigger a variety of complications. Spontaneous rupture of the anterior lens capsule evolving with anterior displacement of the nucleus is a rare complication, with few cases published in the literature. We describe the case of a 68-year-old female patient, who presented spontaneous rupture of the anterior lens capsule with anterior displacement of the nucleus in the left eye, without a history of ocular trauma. The patient underwent phacoemulsification and clinical control of intraocular pressure, improving her condition.

Star CanVac-continuous curvilinear capsulorhexis - A novel, safe rhexis technique in intumescent total cataracts.

Achieving a complete uniform capsulorhexis in an intumescent cataract is perhaps the most crucial and challenging step for surgeons. Star CanVac CCC is a new manual technique for creating a continuous curvilinear capsulorhexis (CCC) in intumescent total cataracts. Small centripetal tears in the shape of a star are created in the center of the anterior lens capsule by using a 26-G cystotome. This allows equal distribution of forces secondary to increased intralenticular pressure, thereby avoiding unidirectional or bidirectional tear extension. Subsequently, a 25-G flat-tipped fine cannula connected to a syringe is used to hold the free capsular flap. The piston of the syringe is withdrawn to create a stable suction pressure, and the rhexis is completed without withdrawing the instrument from the anterior chamber. Our technique is safe, affordable, and an alternative method to routine CCC or expensive techniques such as Femto or Zepto capsulotomy for white intumescent cataracts.

Age-related appearance of lamellar structures in lens capsule of cataractous eyes and its pathological significance.

PURPOSE: To determine morphological changes in the lens capsule with aging. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. DESIGN: Cross-sectional study. METHODS: 25 eyes from the older patient group (aged 80 years or older) and 25 eyes from the younger patient group (aged 65 years or younger) who were diagnosed with cataract and indicated for surgery were included in the study. After continuous curvilinear capsulorhexis, the anterior lens capsule was collected, immediately fixed, and processed for electron microscopy analysis. Backscattered electron images of the cross-section of the anterior lens capsule were observed under a scanning electron microscope. The ultrastructure of the anterior lens capsule was observed and compared between the groups. Factors associated with the occurrence of the lamellar structure were also identified, with the presence or absence of a lamellar structure as an objective variable and preoperative clinical characteristics as the explanatory variables. RESULTS: 50 eyes of 50 patients were included. In the younger patient group, 20 eyes (80%) had a homogeneous lens capsule, whereas 5 eyes had lamellar structures. By contrast, in the older patient group, 5 eyes had homogeneous structures, while the remaining 20 eyes (80%) had lamellar structures. 1 eye showed capsular delamination. The only significant factor for the occurrence of lamellar structures was age group ( P < .01, nominal logistic regression analysis). CONCLUSIONS: Lamellar structures appear in the anterior capsule during aging. The appearance of lamellar structures indicates fragility of the lens capsule, which may, in turn, lead to capsular delamination or lens dislocation in some cases.

Measurement of tear resistance after manual capsulorhexis and femtosecond laser-assisted capsulotomy of crystalline lenses.

BACKGROUND: In this study, the tear resistance of porcine lens capsules after continuous curvilinear capsulorhexis (CCC) and femtosecond (fs)-laser-assisted capsulotomy for cataract surgery (FLC) with different laser parameters is measured with a custom-made testing setup. METHODS: Forty-five fresh porcine lenses were randomly chosen for CCC (n = 15) or FLC 1 (n = 15) and FLC 2 (n = 15). The FLC 1-group was treated with smaller spot distances than the FLC 2-group. The force necessary to break the opening of the anterior capsule and the maximum displacement were measured. RESULTS: The mean tear resistance of the CCC-group (150 ± 70 mN) was higher than that of the FLC 1-group (60 ± 20 mN) and the FLC 2-group (30 ± 20 mN). CONCLUSION: It could be shown that CCC leads to a significantly higher tear resistance of the opening than FLC in porcine lenses. The femtosecond laser group demonstrated that smaller spot distances lead to a higher tear resistance.

Electron microscopy analysis of femtosecond laser-assisted capsulotomy before and after lens fragmentation.

Studying anterior lens capsule cutting edge profiles from femtosecond laser-assisted capsulotomy procedures performed before and after lens fragmentation. Twenty eyes (10 patients) with age-related cataract underwent femtosecond laser-assisted surgery (FLACS) using the Ziemer Z8 platform. First step of laser surgery was either capsulotomy (group first) or fragmentation (group second). One eye of each patient was assigned randomly, the second eye treated with the different sequence of procedures. After anterior capsule removal, tissue was fixed in cacodylate-buffered solution and cutting-edge profiles were analysed using scanning electron microscopy (SEM). All cases had cataract grade 2 and 3 based on LOCS III grading. SEM analysis showed more smooth edges in the first group, especially in cases with pseudoexfoliation (P = 0.037); more tags and bridges and a significant number of staggered cutting patterns (7 out of 10 cases) in the second group. All cases evolved the same microgroves with "valleys and mountains " as signs of the photodisruption process. Femtosecond laser capsulotomy should be performed before lens fragmentation minimizing the rate of cutting errors. Especially in eyes with advanced cataract, as intracapsular pressure may increase due to lens fragmentation without anterior capsular opening.

Ex-Vivo Method to Quantifiably Evaluate the Staining Effectiveness of Anterior Lens Capsule Dyes.

Purpose: High frequency of cataracts and the requirements of new European Union regulations for medical devices require the availability of preclinical models to adequately evaluate anterior lens capsule dyes before their use in patients. Herein, we describe an ex vivo method to quantifiably evaluate the macroscopic and microscopic staining effectiveness of anterior lens capsule dyes using porcine eyes. Methods: Commercially available trypan blue-based products or physiological saline solution (negative control) was injected into porcine eyes. Anterior pole and lens (after extraction) were macroscopically photographed, and the images were quantitatively analyzed. Lenses were histologically processed, and the staining intensity microscopically was semiquantified. Results: Macroscopic evaluation of the anterior pole revealed bluish staining of the anterior capsule; however, this coloring cannot be macroscopically discerned after lens extraction. Quantitative image analyses showed significant (P < 0.01) staining of the lens capsule compared to the negative control, but not significant (P > 0.05) between the products tested. Quantitative analysis of dying on lens images could not be performed. Microscopic semiquantification of the capsule staining intensity allows us to appreciate differences between products. Conclusions: The described method is a quick and useful tool for macroscopic evaluation by surgeons to choose an anterior capsule staining for use during everyday surgeries, and a more specific microscopic evaluation also allows us to determine the effectiveness and usefulness of these products. Translational Relevance: This method satisfies preclinical effectiveness evaluations required by European Union regulations and complements the safety and toxicity evaluations that new products must guarantee before they enter the market and are used in clinical practice.

A study for lens capsule tearing during capsulotomy by finite element simulation.

BACKGROUND AND OBJECTIVE: During capsulotomy, the force applied to the anterior capsule is a crucial parameter controlling capsule tears, that affects the clinical performance. This study aims to investigate the tear force in capsulotomy and analyze the effects of different tearing conditions on the tear force. METHODS: A three-dimensional model of the human lens was constructed based on published clinical data using the finite element (FE) method. The lens model consisted of four layers: the anterior and posterior lens capsule, the cortex, and the nucleus. Distortion energy failure criterion combined with the bilinear interface law was used to express the crack propagation process at the edge of the anterior lens capsule. At the clamping position, a local coordinate system was established to parameterize the capsule tearing. The simulation results were then validated by conducting a capsulorhexis experiment using isolated porcine eyes with force-sensing forceps. RESULTS: The simulation results showed a good agreement with the experimental data of two porcine specimens (No. 6 and 9) during a stable tearing process (p-values = 0.76 and 0.10). The mean force differences between the experimental data and the simulation were 3.10 ± 2.24 mN and 2.14 ± 1.73 mN, respectively. The tear direction with a minimum mean tear force was at θ1 = 0° and θ2 = 30°. The tear velocity was not significantly different to the variation in the tear force. However, an appropriate capsulorhexis diameter was found to contribute to the reduction of tear force. CONCLUSIONS: The outcome of this paper demonstrates that our FE model could be used in modeling lens capsule tearing and the theoretical study of tear mechanism.

MicroRNA Let-7c-5p-Mediated Regulation of ERCC6 Disrupts Autophagic Flux in Age-Related Cataract via the Binding to VCP.

Purpose: DNA damage contributes to the pathogenesis of age-related cataract (ARC) and is repaired through the nucleotide excision repair (NER) pathway, which includes ERCC6. Evidence has demonstrated that defective autophagy leads to lens organelle degradation and cataract. This study aimed to investigate the effects of ERCC6 on autophagy and determine its mechanisms in ARC.Methods: The clinical case-control study comprised 30 patients with ARC and 30 age-matched controls who received transparent lens extraction. Transmission electron microscopy was used to assess the ultrastructure of autophagic vesicles in lens anterior capsule tissues and lens epithelial cell line (SRA01/04). Real-time polymerase chain reaction and western blot analyses were performed to measure relative gene expression levels. Gene expression levels and localization were assessed by immunofluorescence. A coimmunoprecipitation assay was used to investigate the relationship between CSB which encoded by ERCC6 and VCP. ERCC6-siRNA and let-7 c-5p mimic were used to alter the expression of ERCC6 and let-7 c-5p.Results: Autophagy induction occurred in lens anterior capsule tissues of patients with ARC and in UVB-induced SRA01/04 cells, where the number of LC3B puncta was increased. Consistent with this result, the expression of beclin1 (BECN1) and LC3B, in addition to that of p62, was increased. Additionally, ERCC6 expression decreased, and silencing ERCC6 induced increases in the expression of BECN1, LC3B and p62. Moreover, CSB interacted with VCP, and let-7 c-5p induced dysregulation of autophagy by targeting ERCC6.Conclusion: In ARC, Let-7 c-5p-mediated downregulation of ERCC6 might prevent the degradation of autophagic vacuoles. CSB binds to VCP, inducing autophagosomes to combine with lysosomes and be degraded.

Stability and Visual Outcomes of the Capsulotomy-Fixated FEMTIS-IOL After Automated Femtosecond Laser-Assisted Anterior Capsulotomy.

PURPOSE: To evaluate stability and performance of a new monofocal anterior capsulotomy-fixated intraocular lens (IOL) (FEMTIS; Teleon Surgical B.V., Spankeren, Netherlands) after femtosecond laser-assisted cataract surgery (FLACS). DESIGN: Prospective, multicenter, interventional, noncomparative case series. METHODS: FLACS with FEMTIS IOL was performed in 336 eyes of 183 cataract patients with fixation of the IOL to the anterior capsulotomy followed up for 12 months. Examination included uncorrected distance visual acuity (UDVA), best-corrected visual acuity (CDVA), subjective refraction, IOL centration, posterior capsule opacification (PCO), and investigators' satisfaction questionnaire. RESULTS: At 12 months, mean IOL rotation was 1.50 ± 1.76 degrees and decentration 0.14 ± 0.14 mm from baseline (day of surgery). Mean horizontal IOL tilt was 0.70 ± 0.60 degrees and vertical 1.15 ± 1.06 degrees relative to the baseline (crystalline lens). Mean distance between IOL and iris was 0.32 mm to 0.36 mm for all measured meridians. Mean UDVA was 0.12 ± 0.14 logMAR (range -0.20 to 0.54 logMAR), mean CDVA -0.01 ± 0.09 logMAR (range -0.30 to 0.20 logMAR). Mean spherical equivalent was 0.35 ± 0.53 diopter (D) and 98% of eyes (n = 235) were within ±1.0 D. Median PCO score was 1 with an Nd:YAG laser rate of 3.1% after 12 months. Most surgeons were very satisfied (median score: 1) with surgery and implanted IOL. CONCLUSIONS: Implantation of FEMTIS IOL provided excellent visual and stable refractive outcomes. IOL decentration was very low compared to other published studies and showed an exceptional high in-the-bag stability over a 12-month period. This lens benefits from femtosecond laser capsulotomies. It can be positioned very predictably and offers an optimal platform for toric and multifocal IOL optics.

Microstructure and Chemical Analysis in Pseudoexfoliation Syndrome.

Purpose: The aim of this study is to show the pseudoexfoliation syndrome (PES) material accumulated in the lens anterior capsule and the trace elements directly with using scanning electron microscopy (SEM) and to investigate the effect of PES materials on aqueous humor by chemical analyses.Methods: The study groups consisted of 30 patients with PES and 30 patients without PES. 0.1-0.3 mL of aqueous humor was aspirated from anterior chamber and anterior capsule sample was obtained by applying continuous curvilinear capsulorhexis. The level of selected elements (Zn, Cu, Se, Fe, Si, Al, Ca, K) were determined from aqueous humor samples via Inductively coupled plasma - optical emission spectrometry (ICP-OES) machine. The morphology and elemental distribution of anterior lens capsules were carried out via a Zeiss Sigma 300 scanning electron microscope with energy dispersive X-ray spectroscopy (semiquantitative EDX).Results: For aqueous humor, the ICP-OES results show that Cu and Zn levels is higher (p < .001, both of them) in PES group than that the obtained from control group. It was noticed that the ratio of Cu/Zn was higher (p = .008) in aqueous humor, while Cu/Se ratio was higher in both aqueous humor (p < .001) and anterior capsule (p < .001) for PES group. The SEM images show that different metal precipitates were obtained from anterior lens capsules with PES. However, there is no obvious element precipitates on the anterior lens capsules without PES.Conclusion: The results observed that the level of selected elements can be obtained at different level in both PES group and control group. Especially, if the oxidative behavior of these elements which is thought to play a role in PES formation can be clarified, new approaches will be done to evaluate the structure of PES.

Comprehensive analysis of transcriptome-wide m6A methylome in the anterior capsule of the lens of high myopia patients.

To assess the m6A methylome in the anterior capsule of the lens of high myopia patients. MeRIP-seq and RNA-seq were performed to identify differences in the m6A methylomes and gene expression between anterior capsule of the lens of simple nuclear cataract patients (N) and nuclear cataract patients with high myopia (G). Expression of m6A-related enzymes was confirmed by quantitative real-time-PCR. ALKBH5 was downregulated in G. The observed m6A peak was identical to the conserved RRACH gmotif and was markedly correlated with two distinct coordinates. Differentially methylated genes were enriched in some pathways regulating the formation of extracellular matrix. These findings suggest that upregulation of m6A methylation may change fundus anatomy by regulating the composition of the extracellular matrix through encoding protein.

Anterior lens capsule: biomechanical properties and biomedical engineering perspectives.

Anterior lens capsule, as the thickest basement membrane in the body, has its unique physiology characteristics. In ophthalmology, many attempts have been made to culture different kinds of cells including iris pigment epithelial cells, retinal pigment epithelial cells, corneal epithelium and endothelium cells, trabecular meshwork cells etc and anterior lens capsule has been confirmed to be served as an excellent scaffold for the growth and expansion of different ocular cells. Furthermore, anterior lens capsule also has unique potential in gestation evaluation and the treatment of various ocular diseases, including corneal ulcer, glaucoma, age-related macular degeneration and macular hole, etc. Here, we provide an overview of the biomechanical properties and biomedical engineering perspectives of anterior lens capsule.

Lens Epithelial Surface Disorders in Exfoliation Syndrome: A Scanning and Transmission Electron Microscopy Study.

BACKGROUND: Hydrodissection was recently reported to occur more easily in patients with exfoliation syndrome (XFS). Transmission electron microscopy (TEM) studies have already revealed alterations of the lens epithelial cells (LECs) and their apical membrane towards the lens fibers. OBJECTIVE: The aim of this work was to examine the three-dimensional appearance of the lens epithelium in patients with XFS. METHODS: Fourteen patients with senile cataract, 7 of whom had XFS, were included. Anterior lens capsules (aLCs) were obtained with continuous curvilinear capsulorrhexis (CCC) during phacoemulsification and were examined with scanning electron microscopy (SEM) and TEM. RESULTS: Exfoliation samples exhibited an overall more irregular apical surface of the lens epithelium compared to control aLCs. The height of LECs varied extensively. On the apical surface of LECs, amorphous, crystalline-like, or microgranular extracellular material and membranous, oval-shaped structures were documented with SEM. All findings were connected to corresponding observations with TEM and were not correlated to the type of cataract. CONCLUSIONS: In XFS patients, the lens epithelial surface exhibited a highly irregular margin, with extracellular material covering the apical membrane of LECs. We suggest that XFS probably causes both epithelial and lens fiber degeneration which, during CCC and mechanical extraction of the aLC from the lens cortex, result in diverse alterations.

Lamellar Dissection Technique for Traumatic Cataract With Corneal Incarceration.

PURPOSE: To describe a technique for traumatic cataract management for cases in which part of the anterior capsule has been incarcerated into a healed corneal laceration. METHODS: This is a single-center retrospective chart review of 3 patients with capsular/corneal incarceration after penetrating injury. Each patient underwent primary globe repair, followed by subsequent cataract surgery with intraocular lens (IOL) and iris prosthesis placement. The main outcome measure was corrected distance visual acuity. RESULTS: At a mean of 19-month postoperative follow-up (range 12-26 mo), corrected distance visual acuity ranged from 20/25 to 20/80 and all patients had improved vision compared with before cataract surgery. At the final follow-up, all IOLs and iris prostheses were in stable position and no eyes required corneal transplantation. CONCLUSIONS: Traumatic cataracts may be complicated by incarceration of the anterior capsule into the cornea. Incorporating the posterior aspect of the cornea into the anterior capsulotomy enables cataract removal and IOL placement in a stable capsular bag complex.

Efficacy of Femtosecond Laser-Assisted Capsulotomy: Experimental Evaluation Using the Zonular Dehiscence Model.

Purpose: The purpose of this study was to evaluate experimentally the efficacy of femtosecond laser (FL)-assisted capsulotomy using an eye model with different degrees of zonular dehiscence (ZD). Methods: An eye model with ZD was created by removing the total iris and including the planned range of the ZD in porcine and human cadaver eyes. FL-assisted capsulotomies (laser group) and manual capsulotomies (manual group) were created for the eye model with 0, 45, 135, 180, and 270 degrees of ZD. The continuity, mean diameter, ellipticity, and decentration of the capsulotomy were evaluated using the captured images. The same evaluation of FL-assisted capsulotomies was done for five human cadaver eyes with 180 degrees of ZD. Results: In the laser group, no differences were seen in the mean diameter, ellipticity, and decentration, although the manual group resulted in significantly larger, ovalized, and decentered capsulotomies with different degrees of ZD (P < 0.001, P < 0.001, and P = 0.0317, respectively). Continuous capsulotomies or capsulotomies with microadhesions were obtained up to 180 degrees of ZD, and incomplete treatment areas were seen in eyes with 270 degrees of ZD. Capsulotomy of the human cadaver eyes with 180 degrees of ZD showed similar results to those of porcine eyes. Conclusions: In this experimental study, FL-assisted capsulotomy showed favorable results in eyes with between 0 and 180 degrees of ZD compared to conventional manual capsulotomy. Translational Relevance: Our experimental model can simulate the capsulotomy in cases with ZD, the results are useful when determining the indication for FL-assisted capsulotomies.