The local wound environment is a key determinant of the outcome of TGFß signaling on the fibrotic response of CD44+ leader cells in an ex vivo post-cataract-surgery model.

The cytokine transforming growth factor beta (TGFß) has a role in regulating the normal and pathological response to wound healing, yet how it shifts from a pro-repair to a pro-fibrotic function within the wound environment is still unclear. Using a clinically relevant ex vivo post-cataract surgery model that mimics the lens fibrotic disease posterior capsule opacification (PCO), we investigated the influence of two distinct wound environments on shaping the TGFß-mediated injury response of CD44+ vimentin-rich leader cells. The substantial fibrotic response of this cell population occurred within a rigid wound environment under the control of endogenous TGFß. However, TGFß was dispensable for the role of leader cells in wound healing on the endogenous basement membrane wound environment, where repair occurs in the absence of a major fibrotic outcome. A difference between leader cell function in these distinct environments was their cell surface expression of the latent TGFß activator, αvß3 integrin. This receptor is exclusively found on this CD44+ cell population when they localize to the leading edge of the rigid wound environment. Providing exogenous TGFß to bypass any differences in the ability of the leader cells to sustain activation of TGFß in different environments revealed their inherent ability to induce pro-fibrotic reactions on the basement membrane wound environment. Furthermore, exposure of the leader cells in the rigid wound environment to TGFß led to an accelerated fibrotic response including the earlier appearance of pro-collagen + cells, alpha smooth muscle actin (αSMA)+ myofibroblasts, and increased fibrotic matrix production. Collectively, these findings show the influence of the local wound environment on the extent and severity of TGFß-induced fibrotic responses. These findings have important implications for understanding the development of the lens fibrotic disease PCO in response to cataract surgery wounding.

Metformin attenuates the epithelial-mesenchymal transition of lens epithelial cells through the AMPK/TGF-ß/Smad2/3 signalling pathway.

Posterior capsule opacification (PCO) is a common ocular fibrosis disease related to the epithelial-mesenchymal transition (EMT) of human lens epithelial cells (HLECs). However, safe and effective drugs that prevent or treat PCO are lacking. Metformin (Mtf) has been used to treat fibrosis-related diseases affecting many organs and tissues, but its effect on ocular fibrosis-related diseases is unclear. We investigated whether Mtf can inhibit EMT and fibrosis in HLECs to prevent and treat PCO and elucidated the potential molecular mechanism. Here, we established an HLEC model of TGF-ß-induced EMT and found that 400 µM Mtf inhibited vertical and lateral migration and EMT-related gene and protein expression in HLECs. Smad2/3 are downstream molecules of TGF-ß that enter the nucleus to regulate EMT-related gene expression during the occurrence and development of PCO. We revealed that Mtf suppressed TGF-ß-induced Smad2/3 phosphorylation and nuclear translocation. Mtf induces AMP-activated protein kinase (AMPK) phosphorylation. In this study, we found that Mtf induced the activation of AMPK phosphorylation in HLECs. To further explore the mechanism of Mtf, we pretreated HLECs with Compound C (an AMPK inhibitor) to repeat the above experiments and found that Compound C abolished the inhibitory effect of Mtf on HLEC EMT and the TGF-ß/Smad2/3 signalling pathway. Thus, Mtf targets AMPK phosphorylation to inhibit the TGF-ß/Smad2/3 signalling pathway and prevent HLEC EMT. Notably, we first illustrated the AMPK/TGF-ß/Smad2/3 signalling pathway in HLECs, which may provide a new therapeutic strategy for PCO.

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.

Exosome-transmitted circ-CARD6 facilitates posterior capsule opacification development by miR-31/FGF7 axis.

BACKGROUND: Posterior capsular opacification (PCO) is the major vision-disrupting complication arising after cataract surgery. Circular RNAs (circRNAs) are biological active RNAs which were involved in various physiological functions. So far, the role of circRNA caspase recruitment domain family member 6 (circ-CARD6) in PCO is still unclear. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the expression of circ-CARD6, microRNA 31 (miR-31) and fibroblast growth factor 7 (FGF7) message RNA (mRNA). Western blot was used to analyze the protein expression. Transmission electron microscopy (TEM) was employed to capture the exosome image. The proliferation and metastasis were analyzed by cell counting kit-8 (CCK8), transwell and wound healing assays. The potential binding sequences between miR-31 and circ-CARD6 or FGF7 were respectively predicted by Circinteractome and Targetscan online tool, and verified by dual-luciferase reporter and RNA binding protein immunoprecipitation (RIP) assays. RESULTS: Exosome-transmitted circ-CARD6 was highly expressed in PCO tissues and TGF-ß2-treated SRA01/04 cells. Circ-CARD6 deletion repressed the proliferation, metastasis, EMT process and MAPK pathway, which was reversed by anti-miR-31 in TGF-ß2-treated SRA01/04 cells. Meanwhile, circ-CARD6 sponged miR-31 which directly targeted FGF7 in TGF-ß2-treated SRA01/04 cells. FGF7 overexpression allayed miR-31 overexpression-induced suppression in proliferation, metastasis, EMT process and MAPK pathway. Besides, circ-CARD6 regulated FGF7 expression by sponging miR-31. CONCLUSION: Circ-CARD6 promoted PCO development via miR-31/FGF7 axis. This finding might contribute to the development of the targeted therapy for PCO.

Lens opacity prevalence among the residents in high natural background radiation area in Yangjiang, China.

The aim of the study was to evaluate the risk and threshold doses of lens opacity among residents exposed to low-dose radiation. Residents aged ≥45 years were recruited from a high natural background radiation (HNBR) area in Yangjiang City and a control area selected from nearby Enping City. Lens opacities (LOPs) were classified according to the Lens Opacities Classification System (LOCS) III system. Face-to-face interviews were conducted to collect information on lifestyles, migration and medical history. Life-time cumulative doses were estimated using gender, age, occupancy factors and environmental radiation doses received indoors and outdoors. Logistic regression analyses were conducted to estimate the dose response and determine thresholds. In the HNBR area, among 479 study participants, 101 (21.1%), 245(51.1%) and 23 cases (4.8%), respectively, of cortical, nuclear and posterior subcapsular (PSC) LOPs were found. In the control area, those types of LOPs were identified among 58 cases (12.6%), 206 cases (51.2%) and 6 cases (1.3%) of 462 examinees, respectively. Cumulative eye lens dose was estimated to be 189.5 ± 36.5 mGy in the HNBR area. Logistic analyses gave odds ratios at 100 mGy of 1.26 [95% confidence interval (CI) 1.00-1.60], 0.81 (95% CI 0.64-1.01) and 1.73 (95% CI 1.05-2.85) for cortical, nuclear and PSC LOPs, respectively. For cortical LOPs, a logistic analysis with a threshold dose gave a threshold estimate of 140 mGy (90% CI 110-160 mGy). The results indicated that population exposed to life-time, low-dose-rate environmental radiation was at an elevated risk of cortical and PSC LOPs. A statistically significant threshold dose was obtained for cortical LOPs and no threshold dose for PSC LOPs.

Evaluation of posterior capsule opacification of the Alcon Clareon IOL vs the Alcon Acrysof IOL using a human capsular bag model.

BACKGROUND: Posterior capsule opacification (PCO) after cataract surgery is influenced by intraocular lens (IOL) design and material. The following is an ex vivo comparison of PCO between the Clareon vs. the AcrySof IOL in human capsular bags. METHODS: Twenty cadaver capsular bags from 10 human donors were used, with the novel hydrophobic IOL (Clareon, CNA0T0) being implanted in one eye and the other eye of the same donor receiving the AcrySof IOL (SN60WF) following phacoemulsification cataract surgery. Five capsular bags of 3 donors served as controls without IOL. Cellular growth of lens epithelial cells was photo-documented daily. The primary endpoint was the time until full coverage of the posterior capsule by cells. Furthermore, immunofluorescence staining of capsular bags for the fibrotic markers f-actin, fibronectin, alpha smooth muscle actin, and collagen type 1 were performed. RESULTS: The new Clareon IOL did not show any disadvantages in terms of days until full cell coverage of the posterior capsule in comparison to the AcrySof (p > 0.99). Both, the Clareon (p = 0.01, 14.8 days) and the AcrySof IOL (p = 0.005, 15.7 days) showed a slower PCO development in comparison to the control (8.6 days). The fibrotic markers f-actin, fibronectin, alpha smooth muscle actin, and collagen type 1 were equally distributed between the two IOLs and differed from the control. CONCLUSIONS: A comparable performance has been found in the ex vivo formation of PCO between the two IOLs. Long-term clinical studies are necessary to reach final conclusions.

Posterior capsule opacification prevention by an intraocular lens incorporating a micropatterned membrane on the posterior surface.

PURPOSE: To evaluate posterior capsule opacification (PCO) with a new hydrophobic acrylic intraocular lens (IOL) featuring a new micropatterned membrane, in comparison with a commercially available 1-piece hydrophobic acrylic IOL. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. STUDY DESIGN: Experimental study. METHODS: Twelve New Zealand rabbits had bilateral phacoemulsification and implantation of a ClearSight unpatterned IOL (Group 1), a ClearSight Sharklet-patterned IOL (Group 2), or a control, commercially available IOL (Group 3) (8 IOLs in each group). Slit-lamp examination was performed weekly for 4 weeks. The rabbits were then killed humanely, and their globes enucleated. Capsular bag opacification was assessed from the Miyake-Apple view, and the eyes underwent histopathology. RESULTS: The mean postmortem central PCO was 1.87 ± 1.35 in Group 1, 1.06 ± 1.23 in Group 2, and 3.14 ± 0.89 in Group 3. Peripheral PCO was 2.18 ± 1.36 in Group 1, 1.5 ± 1.03 in Group 2, and 3.57 ± 0.53 in Group 3. When comparing central and peripheral PCO between Groups 1 and 3, the difference was not statistically significant, but it was statistically significant between Groups 2 and 3 (P = .003 and P = .0003, t test with Bonferroni correction). CONCLUSIONS: Unique discontinuous features comprising the micropattern allow for focal adhesions to be precisely guided and therefore controlling cell migration. The patterned membrane incorporated on the posterior surface of the IOL significantly reduced capsular bag opacification compared with a commercially available control IOL.

Uveal and capsular biocompatibility of a new hydrophobic acrylic microincision intraocular lens.

PURPOSE: To evaluate uveal biocompatibility and capsular bag opacification of a new hydrophobic acrylic microincision intraocular lens (IOL) in comparison with a commercially available 1-piece hydrophobic acrylic IOL. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Eight New Zealand rabbits underwent bilateral phacoemulsification and implantation of the preloaded Nanex multiSert IOL in one eye and a commercially available preloaded lens (AcrySof IQ in UltraSert, model AU00T0) in the contralateral eye. A slitlamp examination was performed weekly for 4 weeks. The rabbits were then killed humanely and their globes enucleated. Capsular bag opacification was assessed from the Miyake-Apple view, and the eyes were subjected to histopathologic evaluation. RESULTS: Postoperative inflammatory reactions were similar between the test and control eyes in the 8 New Zealand rabbits. The mean postmortem central posterior capsule opacification (PCO) was 0.93 ± 0.73 in the test group and 1.19 ± 0.53 in the control group. The mean postmortem peripheral PCO was 1.75 ± 0.92 in the test group and 2.06 ± 0.77 in the control group. Central and peripheral PCO scores were not statistically different between the test and control groups (P = .41 and P = .35, respectively, 2-tailed t test: paired 2-sample for means). CONCLUSIONS: A new 1-piece hydrophobic acrylic microincision IOL incorporating an ultraviolet-ozone treatment on the posterior surface performed similarly to a commercially available 1-piece hydrophobic acrylic IOL in terms of uveal and capsular biocompatibility in the rabbit model. To our knowledge, this is the first hydrophobic acrylic microincision IOL to demonstrate similar PCO performance when compared with a conventional, commercially available IOL.

Anti-inflammatory Medication After Cataract Surgery and Posterior Capsular Opacification.

PURPOSE: To assess the role of anti-inflammatory medication following cataract surgery on the formation of posterior capsular opacification. DESIGN: Cohort study. METHODS: A retrospective registry analysis of 25,818 consecutive patients who underwent cataract surgery between the years 2014 and 2018 at Helsinki University Hospital in Finland. Nd:YAG laser capsulotomy rates were compared between patients treated postoperatively with topical steroids, nonsteroidal anti-inflammatory medications (NSAIDs), or their combination. Kaplan-Meier and Cox regression analyses were used. A single eye of each patient was included. Main outcomes were confirmed against a second independent dataset. RESULTS: A total of 13,368 patients were included in the analysis, with a mean age of 73.2 ± 9.7 years; 61.7% were female. Pseudoexfoliation was noted in 10.1% of cases. The mean follow-up time was 22.8 ± 15.7 months. Patients were treated with steroid monotherapy (28.9% of cases), NSAID monotherapy (62.2%), or a combination of both (8.9%). Treatment with steroids resulted in significantly lower Nd:YAG capsulotomy rates compared to NSAIDs (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.62-0.93, P = .009). Treatment with combination therapy of steroids and NSAIDs showed no added benefit over steroid monotherapy (HR 1.11, 95% CI 0.68-1.80, P = .674). Cox regression analysis adjusted for patients' age, sex, pseudoexfoliation, and risk stratification remained significantly predictive for lower capsulotomy rates with steroid treatment over NSAIDs (HR 0.70, 95% CI 0.52-0.88, P = .001). CONCLUSIONS: Postoperative treatment with steroids among patients undergoing uncomplicated cataract surgery was associated with lower rates of clinically significant posterior capsule opacification compared to treatment with NSAIDs alone. Combination therapy of steroids and NSAIDs had no added benefit over steroids alone.

Evaluation of quality of life and visual acuity after posterior capsulotomy with neodymium: YAG laser in adults / Avaliação da qualidade de vida e da acuidade visual após capsulotomia com Neodymium: YAG laser em adultos

Abstract Purpose: To determine the impact of neodymium:YAG (Nd:YAG) laser posterior capsulotomy on quality of life and visual acuity in adults. Methods: A prospective study that included patients over 65 years old with clinical indications for Nd: YAG laser capsulotomy. On the day of the procedure, corrected distance visual acuity tests, slit-lamp examination and posterior capsule opacification (PCO) photo documentation were performed, followed by application of the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). The PCO rate was evaluated with Evaluation of Posterior Capsule opacification (EPCO 2000) software. Four weeks after the posterior capsulotomy, corrected distance visual acuity was measured, and the NEI-VFQ-25 was applied again. Complications were also reported. Results : Sixty eyes from 45 patients were enrolled in the study. The mean age was 71.51 ± 6.38 years (65 to 93). Comparing the results before and after the Nd:YAG laser capsulotomy, there was a statistically significant improvement in quality of life according to the NEI-VFQ-25 (p<0.001) and in visual acuity (p=0.0). The mean score in NEI-VFQ-25 Questionnaire before capsulotomy was 62.07 ± 20.90 (16.81-95.90) and after was 83.95±19.49 (20.68 - 100.0). The mean CDVA before the procedure was 0.75 ± 0.35 LogMAR (0.1-1.3) and after was 0.21 ± 0.20 LogMAR (0.0-1.3). The mean PCO rate measured by the EPCO software was 0.688 ± 0.449. There was a positive correlation between the EPCO score and the total score of quality of life after Nd: YAG laser capsulotomy (r=0.845, p=0.00). Damage to intraocular lens was the only complication observed in six eyes (10%). Conclusion: Nd: YAG laser capsulotomy, in addition to improving visual acuity, is able to improve quality of life.

Resumo Objetivo: Determinar o impacto da capsulotomia posterior com laser de neodímio: YAG (Nd: YAG) na qualidade de vida e na acuidade visual em adultos. Métodos: Estudo prospectivo que incluiu pacientes acima de 65 anos com indicação clínica para capsulotomia com laser de Nd: YAG. No dia do procedimento, foram realizados testes de acuidade visual corrigida, exame com lâmpada de fenda e fotodocumentação da opacificação da cápsula posterior (OCP), seguido da aplicação do National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). A taxa de OCP foi avaliada utilizando o software de avaliação de opacificação de cápsula posterior (EPCO 2000). Quatro semanas após a capsulotomia posterior, a acuidade visual corrigida foi medida, e o NEI-VFQ-25 foi aplicado novamente. Complicações também foram relatadas. Resultados: Sessenta olhos de 45 pacientes foram incluídos no estudo. A idade média foi de 71,51±6,38 anos (65 to 93). Comparando os resultados antes e após a capsulotomia com laser Nd: YAG, houve melhora estatisticamente significante na qualidade de vida de acordo com o NEI-VFQ-25 (p <0,001) e na acuidade visual (p = 0,0). A média do escore total do questionário NEI-VFQ-25 pré capsulotomia foi de 62.07 ± 20.90 (16.81-95.90) e pós foi de 83.95 ±19.49 (20.68 - 100.0). A AVCC antes do procedimento foi 0.75 ± 0.35 LogMAR (0.1-1.3) e após foi 0.21 ± 0.20 LogMAR (0.0-1.3). A taxa média de OCP medida pelo software EPCO foi de 0,688 ± 0,449. Houve correlação positiva entre o escore EPCO e o escore total de qualidade de vida após a capsulotomia com laser de Nd: YAG (r = 0,845, p = 0,00). O dano à lente intraocular foi a única complicação observada em seis olhos (10%). Conclusão: A capsulotomia com laser Nd: YAG, além de melhorar a acuidade visual, é capaz de melhorar a qualidade de vida.

Anti-Adhesive And Antiproliferative Synergistic Surface Modification Of Intraocular Lens For Reduced Posterior Capsular Opacification.

BACKGROUND: Posterior capsular opacification (PCO) is the main complication after intraocular lens (IOL) implantation in cataract surgery, which is the result of lens epithelial cell (LEC) adhesion, proliferation and migration on the IOL and at the lens capsule interface. Hydrophilic surface modification, such as surface heparinization, decreases the cell adhesion, which has been commercialized and used clinically. However, clinical long-term observation results show no significant difference between the pristine and heparinized IOLs. METHODS: To prevent PCO over the long time span, we modified the IOLs with an antiproliferative drug-loaded hydrophilic coating. The antiproliferative drug doxorubicin (DOX)-incorporated chitosan (CHI) nanoparticle was fabricated by sodium tripolyphosphate (TPP) gelation. Such antiproliferative drug-loaded CHI-TPP-DOX nanoparticles (CTDNP) were used as one of the building blocks to prepare polyelectrolyte multilayer with heparin (HEP) via layer-by-layer assembly, obtaining (HEP/CTDNP)n multilayers. The assembly process was characterized by quartz crystal microbalance with dissipation (QCM-D). The drug release behavior of the coating was investigated by ultra-HPLC (UPLC). In vitro cell experiments were carried out to monitor the effects of multifunctional coatings on cellular adhesion, proliferation and migration. And the intraocular implantation was performed on rabbits to evaluate the in vivo PCO inhibitory effect of such surface-functionalized IOLs. RESULTS: The positively charged CTDNP was successfully prepared by ionic gelation. The QCM-D results indicate the successful preparation of the (HEP/CTDNP)n multilayer film. Drug release profiles showed that surface-multifunctionalized IOL had drug-sustained release properties. In vitro cell culture results showed significant inhibition of adhesion, proliferation and migration of LECs after surface modification. The in vivo results showed that the IOLs with multifunctionalized surface can effectively reduce the posterior hyperplasia and Soemmering's ring (SR) formation. CONCLUSION: These findings suggested that such multifunctionalized drug-eluting IOLs can effectively reduce the posterior hyperplasia and SR formation when intraocular implantation has a major impact on reducing PCO incidence. Thus they have a great potential in improving patient vision recovery and maintenance.

Posterior capsule opacification rate after phacoemulsification in pediatric cataract: Hydrophilic versus hydrophobic intraocular lenses.

PURPOSE: To compare the rate of posterior capsule opacification (PCO) of hydrophilic acrylic intraocular lenses (IOLs) and hydrophobic acrylic IOLs in pediatric cataract surgery. SETTING: Sadguru Netra Chikitsalaya, Chitrakoot, India. DESIGN: Retrospective case series. METHODS: The medical records of children who had uneventful cataract surgery with acrylic IOL implantation from 2010 to 2016 and a follow-up of at least 1-year were reviewed. The patients had implantation of a hydrophilic IOL (Ocuflex ANU6 IOL) or a hydrophobic IOL (AcrySof SA60AT). The main outcome measure was the PCO rate at the last follow-up. RESULTS: The study comprised 103 eyes (80 children). The mean age was 8.2 years ± 4 (SD) in the hydrophilic group (51 eyes) and 6.9 ± 4 years in the (52 eyes) hydrophobic group (P = .1). The mean follow-up was 38.8 months and 39.4 months, respectively. When the posterior capsule was left intact, 39.3% of eyes in the hydrophilic group and 13.4% of eyes in the hydrophobic group developed PCO (P = .03). When primary posterior capsulotomy (PPC) and anterior vitrectomy were performed, 4.3% and 6.8%, respectively, developed PCO (P = .69). Kaplan-Meier survival plots with stratification for type of procedure (ie, PPC and anterior vitrectomy) showed a survival (ie, no PCO formation at 5-year follow-up) rate of 95.4% in the hydrophobic group and 88.8% in the hydrophilic group. CONCLUSION: Hydrophilic acrylic IOLs and hydrophobic acrylic IOLs implanted in the bag had comparable visual and surgical outcome and an equal rate of PCO formation when PPC and anterior vitrectomy were performed.

HSP90 as a novel therapeutic target for posterior capsule opacification.

Posterior capsule opacification (PCO) is a common complication of cataract surgery, resulting from a combination of proliferation, migration, epithelial-mesenchymal transition (EMT) of residual capsular epithelial cells and fibrosis of myofibroblasts. HSP90 is known to regulate the proteostasis of cells under pathophysiological conditions. The role of HSP90 in PCO formation, however, is not clear. To do this, the lens epithelial cell lines and an ex vivo cultured rat capsular bag model were used to study the role of HSP90 in PCO formation. The expression of protein and mRNA was measured by immunoblotting and quantitative RT-PCR, and cell apoptosis was measured by TUNEL(TdT-mediated dUTP nick-end labeling). The cell proliferation was measured by cell viability assays. The results showed that 17-AAG (Tanespimycin), an inhibitor of HSP90, suppresses the proliferation of immortalized lens epithelial cell lines HLE-B3, SRA01/04, and mLEC, with IC50 values of 0.27, 0.27, and 0.49 µM, respectively. In an ex vivo cultured rat capsular model, the capsular residual epithelial cells resisted the stress of the capsulorhexis surgery and took 3-6 days to completely overlay the capsular posterior wall. During this process, heat shock factor 1 and its downstream targets HSP90, HSP25, αB-crystallin, and HSP40 were upregulated. Treatment with 17-AAG inhibited the viability of capsular residual epithelial cells and induced the cells apoptosis, characterized by increases in ROS levels, apoptotic DNA injury, and the activation of caspases 9 and 3. HSP90 participated in regulating both EGF receptor (EGFR) and TGF receptor (TGFR) signaling pathways. HSP90 was found to interact with the EGFR, such that inhibition of HSP90 by 17-AAG destabilized the EGFR protein and suppressed p-ERK1/2 and p-AKT levels. 17-AAG also inhibited the TGF-ß-induced phosphorylation of SMAD2/3 and ERK1/2 and the decrease in E-cadherin and ZO-1 expression. Accordingly, these data suggest that the induction of HSP90 protects capsular residual epithelial cells against capsulorhexis-induced stress and participates in regulating the processes of proliferation, EMT and migration of rat capsular residual epithelial cells, at least partly, through the EGFR and TGFR signaling pathways. Treatment with 17-AAG suppresses PCO formation and is therefore a potential therapeutic candidate for PCO prevention.

Histological comparison of in vitro and in vivo development of peripheral posterior capsule opacification in human donor tissue.

In order to study the mechanisms involved in the development of posterior capsule opacification (PCO) we compared in vivo developed PCO with PCO formed in tissue culture with focus on the periphery of the lens capsule to evaluate lens regeneration potential. We studied three human tissue groups: Cultured lens capsules after mock cataract surgery (n = 6, 30 days), lens capsules from donors that had previously undergone cataract surgery (IOL capsules) (n = 12) and intact lenses (n = 6). All samples were stained with Vimentin, alpha Smooth Muscle Actin, Picro Sirius Red (for collagen) and Paired box protein (Pax6). We found that cultured capsules and less developed IOL capsules consisted mainly of monolayers of mesenchymal cells, while more developed IOL capsules, contained lens epithelial cells (LECs), globular cells and lens fiber cells. Many IOL capsule samples expressed collagen I and III in areas where cells were in contact with the IOL. Pax6 had a similar dispersed distribution in less developed IOL capsules and cultured capsules, while more developed IOL capsules and intact lenses, concentrated Pax6 in LECs at the equatorial lens bow. The similarities between cultured capsules and less developed IOL capsules indicate that our in vitro developed PCO is comparable to early in vivo developed PCO. The similar morphology of more developed IOL capsules and intact lenses seems to indicate an attempt at lens regeneration.

Optic shrinkage and retraction in opacified hydrophilic acrylic intraocular lens: an anterior segment optical CT-based observation.

Intraocular lens (IOL) opacification is a rare phenomenon noted with hydrophilic acrylic IOLs. We report a case of advanced IOL opacification appreciated on anterior segment optical CT (ASOCT)as a shrunken biconcave optic retracted away from the posterior capsule (PC), unlike the other eye which had a clear biconvex IOL of similar material abutting the PC. After IOL exchange, the affected eye was noted to have more folds and Elschnig's pearls on the PC when compared with the other eye. Our case points towards rare IOL changes seen in advanced cases of opacification, their association with posterior capsular changes and the aid of ASOCT as a non-invasive tool in diagnosing them correctly.

Rotation versus non-rotation of intraocular lens for prevention of posterior capsular opacification.

Purpose: To study the effect of rotation of intraocular lens (IOL) on posterior capsular opacification (PCO) in eyes with phacoemulsification. Methods: This was a prospective, comparative, randomized case series. One eye of each patient was randomized to one of two groups. The 360-degree rotation of IOL was carried out after its placement in the capsular bag (rotation group). The control group had no rotation of IOL. PCO was analyzed by an independent observer on EPCO computer analysis system at 6, 12, 24, and 36 months. Results: The study included 50 patients (100 eyes) with senile cataracts scheduled for phacoemulsification and IOL implantation. The median age in 2 groups was 66 years. 25% quartile age in both the group was 62 years (P = 0.06). There were 30 males, and 20 females. The median PCO score at 6, 12 and 24 months was significantly low in the rotation group (0.15, 0.13, 0.22) compared to the control group (0.22, 0.23, 0.25). There was no significant difference in PCO score between the two groups from 24-36 months. The median PCO score at 36 months was 0.2 in both the groups. At the end of three years, 4 eyes (8%) in the rotation group, and 10 eyes (20%) in the control group needed Nd:YAG capsulotomy (P = 0.04). Conclusion: Rotation of IOL in the capsular bag decreases PCO and Nd:YAG capsulotomy rate.

MicroRNA-34a inhibits epithelial-mesenchymal transition of lens epithelial cells by targeting Notch1.

Posterior capsule opacification (PCO) is a common long-term complication of modern cataract surgery. The epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) is a crucial process in the development of PCO. The purpose of this study is to investigate the role of microRNA-34a (miR-34a) in the regulation of EMT and its target gene. Human LECs were treated with TGFß2 to induce EMT as a model for PCO. The mRNA levels of miR-34a and EMT markers were examined by real-time quantitative polymerase chain reaction (qPCR). The expression level of miR-34a was downregulated, whereas that of Notch1 was upregulated in TGFß2-induced EMT of LECs. Overexpression of miR-34a by transfection with miR-34a inhibited EMT of LECs and reduced the expression of Notch1; while, inhibition of miR-34a upregulated the expression of both Notch1 and its ligand Jagged1 in LECs. Luciferase reporter assays revealed that Notch1 gene was direct target of miR-34a. Moreover, DAPT, a specific inhibitor of Notch signaling pathway, reversed LEC-EMT. In addition, the expression level of miR-34a was downregulated, whereas that of Notch1 was upregulated in capsular opacification from cataract samples. MiR-34a can negatively regulate EMT of LECs by targeting Notch1. Therefore, miR-34a/Notch1 could serve as a potential therapeutic approach for the treatment of PCO.

Depletion of Myo/Nog Cells in the Lens Mitigates Posterior Capsule Opacification in Rabbits.

Purpose: Posterior capsule opacification (PCO) is a vision-impairing disease that occurs in some adults and most children after cataract surgery. Contractile myofibroblasts contribute to PCO by producing wrinkles in the lens capsule that scatter light. Myofibroblasts in the lens originate from Myo/Nog cells named for their expression of the MyoD transcription factor and bone morphogenetic protein inhibitor noggin. In this study we tested the effects of depleting Myo/Nog cells on development of PCO. Methods: Myo/Nog cells were eliminated by injecting the G8 antibody conjugated to 3DNA nanocarriers for the cytotoxin doxorubicin (G8:3DNA:Dox) during cataract surgery in rabbits. The severity of PCO was scored by slit lamp analysis, gross and histologic observation, and immunofluorescence localization of α-smooth muscle actin. Results: G8:3DNA:Dox specifically induced cell death in Myo/Nog cells in the lens. None of the lenses administered G8:3DNA containing 9 to 36 µM doxorubicin developed greater than trace levels of central PCO and few myofibroblasts were present on the capsule. Less than 9% of these lenses exhibited greater than mild levels of peripheral PCO. Doxorubucin itself reduced PCO; however, myofibroblasts and wrinkles were abundant in the lens, and off-target effects were observed in the ciliary processes and cornea. Conclusions: Myo/Nog cells are the primary source of myofibroblasts in the lens after cataract surgery. Targeted depletion of Myo/Nog cells has potential for preventing PCO and preserving vision.

Determination of trypan blue efficacy in the mitigation of ex vivo canine PCO formation.

PURPOSE: To determine whether trypan blue (TB) reduces canine lens epithelial cell (LEC) or corneal endothelial cell (CEC) viability in vitro; if cell death is noted, to subsequently evaluate the molecular mechanism. METHODS: Cellular viability was determined using a lactate dehydrogenase (LDH) assay. In TB-treated LECs, caspase 3/7 activity was assessed to evaluate apoptosis; autophagy was evaluated using immunoblotting against LC3 and p62. To evaluate the effects of TB on ex vivo posterior capsule opacification (PCO), following mock cataract surgery, lens capsules were treated with TB and subsequently maintained in culture to determine LEC migration and proliferation. RESULTS: Following acute exposure, TB did not significantly reduce LEC or CEC viability at any of the concentrations tested. Increased caspase 3/7 activity was found in LEC cultures treated with TB for an extended period of time; no change in LC3 or p62 expression was noted. Ex vivo PCO formation was not significantly altered by TB treatment. CONCLUSIONS: Acute exposure to TB did not reduce LEC or CEC viability, and only longer exposure to TB was able to initiate apoptosis. Treatment with intraocular TB at the time of cataract surgery is likely safe to the CECs but will not prevent PCO formation.