Evaluation of mechanical resistance to tearing of the anterior lens capsule after staining with different concentrations of trypan blue.

PURPOSE: To evaluate and compare the mechanical resistance to tearing of the anterior lens capsule opening after staining with different concentrations of trypan blue in ex vivo porcine eyes. SETTING: Semmelweis University, and Budapest University of Technology and Economics, Budapest, Hungary. DESIGN: Experimental study. METHODS: The study comprised 75 porcine eyes. The capsule was unstained in the Control Group (n = 25 eyes), 0.06% trypan blue was used to stain the capsule in Stained 1 Group (n = 25 eyes), and 0.1% trypan blue was used to stain the capsule in Stained 2 Group (n = 25 eyes). After capsulorhexis, the capsule openings were stretched with custom-designed testing equipment until they ruptured. The rupture force (RF), circumference stretching ratio (CSR), and secant modulus at 10 mN (SM10mN) and 50 mN (SM50mN) were evaluated. RESULTS: In total, 75 eyes were enrolled. There were no statistically significant differences in the RF (P = .8924) or CSR (P = .3876) among the groups. There were no statistically significant differences in the SM10mN (P = .8215) or SM50mN (P = .4184) among the groups. CONCLUSIONS: In this porcine eye model, the trypan blue concentrations that are routinely used in cataract surgery had no effect on capsular rim stability.

MicroRNA-26a and -26b inhibit lens fibrosis and cataract by negatively regulating Jagged-1/Notch signaling pathway.

Fibrosis is a chronic process involving development and progression of multiple diseases in various organs and is responsible for almost half of all known deaths. Epithelial-mesenchymal transition (EMT) is the vital process in organ fibrosis. Lens is an elegant biological tool to investigate the fibrosis process because of its unique biological properties. Using gain- and loss-of-function assays, and different lens fibrosis models, here we demonstrated that microRNA (miR)-26a and miR-26b, members of the miR-26 family have key roles in EMT and fibrosis. They can significantly inhibit proliferation, migration, EMT of lens epithelial cells and lens fibrosis in vitro and in vivo. Interestingly, we revealed that the mechanisms of anti-EMT effects of miR-26a and -26b are via directly targeting Jagged-1 and suppressing Jagged-1/Notch signaling. Furthermore, we provided in vitro and in vivo evidence that Jagged-1/Notch signaling is activated in TGFß2-stimulated EMT, and blockade of Notch signaling can reverse lens epithelial cells (LECs) EMT and lens fibrosis. Given the general involvement of EMT in most fibrotic diseases, cancer metastasis and recurrence, miR-26 family and Notch pathway may have therapeutic uses in treating fibrotic diseases and cancers.

Intraoperative management of anterior capsular tear.

PURPOSE OF REVIEW: The article reviews the current literature on intraoperative techniques to properly manage anterior capsular tears during cataract surgery. RECENT FINDINGS: Femtosecond laser-assisted cataract surgery creates a more consistent capsulorhexis than traditional capsulotomies, but can also present with new challenges. Irregularities, like microadhesions and tags, can lead to anterior tears if not properly treated. New technology, like the Zepto (Mynosys, Fremont, CA, USA) pulse precision capsulotomy, may produce a smoother edge and reduce the incidence of capsular tears. However, there are novel rescue techniques in the case that a tear-out does occur. SUMMARY: Anterior capsular tears can occur at any stage of cataract surgery. The proper management of these tears will prevent them from extending into the posterior capsule and compromising the structural integrity of the capsular bag. This is essential for endocapsular placement of artificial lenses and for optimal visual outcomes for the patient.

Histologic evaluation of in vivo femtosecond laser-generated capsulotomies reveals a potential cause for radial capsular tears.

PURPOSE: To compare histologically the size and appearance of capsule disks after femtosecond laser-assisted cataract surgery and conventional cataract surgery. METHODS: In 100 eyes of 100 patients with visually significant cataracts, a femtosecond laser capsulotomy or a capsulorhexis with an aimed diameter of 5.0 mm was performed by one experienced surgeon. The diameter, area, circularity, and cut quality was histologically examined with light microscopy and scanning electron microscopy. RESULTS: The mean diameter of the manual and the femtosecond laser capsule disk group were not statistically significantly different (manual 4.91 ± 0.34; femtosecond: 4.93 ± 0.03; p = 0.58). The mean area of the capsule disks was 18.85 ± 2.69 mm2 in the manual and 19.03 ± 0.26 mm2 in the femtosecond group (p = 0.64). The capsules of the femtosecond group (0.95 ± 0.02) were significantly more circular than the ones of the manual group (0.81 ± 0.07; p<0.0001). The femtosecond laser capsule disks displayed a more saw blade-like structure created through the single laser spots. The histologic examination combined with prospective video analysis revealed respiratory movement of the eye during the capsulotomy as a potential risk factor for redial tears. CONCLUSIONS: Femtosecond laser can perform a capsulotomy with high reliability. In comparison to a highly experienced cataract surgeon, the achieved results in size are similar. In terms of circularity, the femtosecond laser was superior the manual procedure. Better refractive outcomes based on a 360°-degree optic overlap seem to be possible, especially for less experienced surgeons.

Intraocular femtosecond laser use in traumatic cataract.

PURPOSE: To report the use of femtosecond laser cataract surgery in a traumatic case. METHODS: A 38-year-old man had a penetrating eye injury while working with wire. The corneal laceration was sutured first. In the postoperative period, cortical cataract appeared in the crystalline lens; therefore, in the second session, cataract surgery was performed using a femtosecond laser system (Alcon-LenSx Lasers Inc.). RESULTS: Corneal incisions, an intact 4.5 mm capsulorhexis, and nucleus liquefaction were performed with the femtosecond laser. Corrected distance visual acuity was 0.9 1 month after surgery. CONCLUSIONS: Femtosecond laser is an effective method in traumatic cataract cases after penetrating eye injury. Corneal incisions, capsulorhexis, and nucleus liquefaction can be performed precisely and safety.

Femtosecond laser-assisted capsulotomy after penetrating injury of the cornea and lens capsule.

We present a 39-year-old patient with a penetrating injury of the cornea and anterior lens capsule containing an intralenticular foreign body. One week after the accident, the patient consulted our emergency unit. Clinical examination showed no Seidel II phenomenon. A femtosecond laser-assisted capsulotomy was performed followed by lens removal and intraocular lens implantation. The capsulotomy diameter was increased to 6.7 mm to include the foreign-body area and the break in the anterior capsule. The procedure was uneventful, and the capsule leaf, including the foreign body, was extracted safely.

Anterior capsulotomy integrity after femtosecond laser-assisted cataract surgery.

OBJECTIVE: To compare the incidence of anterior capsular tears after femtosecond laser-assisted cataract surgery (FLACS) versus phacoemulsification cataract surgery (PCS) and to assess the ultrastructural features of anterior capsulotomy specimens (FLACS and PCS) using electron microscopy. DESIGN: Prospective, multicenter, comparative cohort case series. PARTICIPANTS: Consecutive patients undergoing FLACS or PCS. METHODS: A prospective cohort study of all patients (n = 1626) undergoing FLACS or PCS by 2 surgeons from centers A and B was undertaken to compare the incidence of anterior capsule tears. Anterior lens capsules were collected by 4 surgeons from centers A, B, C, and D using 3 different commercially available femtosecond platforms, each with latest version upgrades. Lens capsule tissue was prepared for scanning electron microscopy (SEM) using a total of 10 samples for patients undergoing PCS, and 40 samples for patients undergoing FLACS. MAIN OUTCOME MEASURES: Incidence of anterior capsule tear and comparative ultrastructural features of capsular samples from both PCS and FLACS cases. RESULTS: There was a significantly increased rate of anterior capsule tears in the FLACS group (15/804 [1.87%]) when compared with the PCS group (1/822 [0.12%]; P = 0.0002, Fisher exact test). In 7 cases, the anterior capsule tear extended to the posterior capsule. Because all cases had occurred in complete capsulotomy, the integrity of the anterior capsule was questioned in the FLACS group. Subsequent SEM sampling showed irregularity at the capsule margin, as well as multiple apparently misplaced laser pits in normal parts of the tissue. Aberrant pits were approximately 2 to 4 µm apart and occurred at a range of 10 to 100 µm radially from the capsule edge. CONCLUSIONS: Laser anterior capsulotomy integrity seems to be compromised by postage-stamp perforations and additional aberrant pulses, possibly because of fixational eye movements. This can lead to an increased rate of anterior capsule tears, and extra care should be taken during surgery after femtosecond laser pretreatment has been performed. A learning curve may account for some of the increased complication rate with FLACS. However, the SEM features raise safety concerns for capsular integrity after FLACS and warrant further investigation.

Integrin-linked kinase deletion in the developing lens leads to capsule rupture, impaired fiber migration and non-apoptotic epithelial cell death.

PURPOSE: The lens is a powerful model system to study integrin-mediated cell-matrix interaction in an in vivo context, as it is surrounded by a true basement membrane, the lens capsule. To characterize better the function of integrin-linked kinase (ILK), we examined the phenotypic consequences of its deletion in the developing mouse lens. METHODS: ILK was deleted from the embryonic lens either at the time of placode invagination using the Le-Cre line or after initial lens formation using the Nestin-Cre line. RESULTS: Early deletion of ILK leads to defects in extracellular matrix deposition that result in lens capsule rupture at the lens vesicle stage (E13.5). If ILK was deleted at a later time-point after initial establishment of the lens capsule, rupture was prevented. Instead, ILK deletion resulted in secondary fiber migration defects and, most notably, in cell death of the anterior epithelium (E18.5-P0). Remarkably, dying cells did not stain positively for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) or activated-caspase 3, suggesting that they were dying from a non-apoptotic mechanism. Moreover, cross to a Bax(fl/fl)/Bak⁻/⁻ mouse line that is resistant to most forms of apoptosis failed to promote cell survival in the ILK-deleted lens epithelium. Electron microscopy revealed the presence of numerous membranous vacuoles containing degrading cellular material. CONCLUSIONS. Our study reveals a role for ILK in extracellular matrix organization, fiber migration, and cell survival. Furthermore, to our knowledge we show for the first time that ILK disruption results in non-apoptotic cell death in vivo.

A capsulotomia descontínua durante a facoemulsificação / Discontinuous capsulotomy during phacoemulsification

OBJETIVO: Descrever a prevalência, localização e causas da capsulotomia descontínua durante a cirurgia de catarata por facoemulsificação. MÉTODOS: Estudo retrospectivo, consecutivo, não comparativo de 971 cirurgias de catarata com capsulotomia descontínua no per-cirúrgico entre janeiro de 2009 a junho de 2010. RESULTADOS: Observou-se uma prevalência de 0,02 por cento e a descontinuação da cápsula ocorreu em 100 por cento das vezes durante o tratamento do núcleo. Em 58.33 por cento dos olhos o implante foi realizado no saco capsular e em 41.67 por cento no sulco ciliar. A AV > 20/30 em 100 por cento dos olhos. CONCLUSÃO: apesar de ser uma intercorrência pouco frequente, pode comprometer o resultado final.

OBJECTIVE: To describe the prevalence, location and causes of discontinuous capsulotomy during phacoemulsification cataract surgery. METHODS: Retrospective, consecutive, non-comparative study of 971 cataract surgeries - with discontinuous capsulotomy during surgery - performed from January 2009 to June 2010. RESULTS: it was observed a prevalence of 0.02 percent and capsule discontinuation occurring 100 percent of the time during the treatment of the nucleus. In 58.33 percent of the eyes the implant was done in the capsular bag and in 41.67 percent in the ciliary sulcus. VA > 20/30 in 100 percent of the eyes. CONCLUSION: despite the fact that it is a not too frequent event, it may compromise the final result.