Lens Capsule Research Articles

Ex vivo evaluation of anterior lens capsule staining in horses with three concentrations of gentian violet for surgical training

Resumo O objetivo deste estudo foi avaliar e comparar a eficácia de três concentrações de violeta genciana (0,5%, 0,1% e 0,05%) na coloração da cápsula anterior da lente em equinos. Trinta e seis olhos de equinos post-morten foram utilizados. De acordo com a concentração de violeta genciana utilizada, os olhos foram subdivididos em três grupos compostos por 12 olhos cada. A avaliação da eficácia em coloração da cápsula anterior da lente com diferentes concentrações de violeta de genciana foi realizada por meio de um sistema empírico de avaliação da coloração adequada ou inadequada de retalhos capsulares. Com base na avaliação dos examinadores, as concentrações de 0,1% e 0,05% de violeta de genciana permitiram a visualização adequada da cápsula anterior para o treinamento da capsulotomia curvilínea contínua enquanto a concentração de 0,5% produziu uma coloração capsular forte e inadequada. O modelo desenvolvido com violeta genciana, nas concentrações de 0,1% e 0,05%, permitiu a visualização nítida do retalho capsular, o que o torna viável como modelo para treinamento da etapa de capsulotomia curvilínea contínua em cirurgia de catarata em equinos.

Delayed Presentation and Surgical Management of Traumatic Cataract with Fibrotic Lens Capsule

Delayed Presentation and Surgical Management of Traumatic Cataract with Fibrotic Lens Capsule

Upregulation of histone H3 caused by CRYAA may contribute to the development of age-related cataract

Objective: Age-relate cataract (ARC) is a disease of the eyes with no effective drugs to prevent or treat patients. The aim of the present study is to determine whether histone H3, αA-crystallin (CRYAA), β-galactosidase (GLB1), and p53 are involved in the pathogenesis of ARC. Methods: A total of 99 anterior lens capsules (ALCs) of patients with ARC of various nuclear grades, ultraviolet models of ALCs, and two human lens epithelial cell lines (FHL-124 and SRA01/04) were used, and the expression of histone H3, CRYAA, GLB1, and p53 were detected by immunoblotting and reverse transcription and real time-quantitative polymerase chain reaction. The association between CRYAA with histone H3, GLB1, and p53 was assessed in FHL-124 and SRA01/04 cells following CRYAA overexpression. Results: Histone H3 and p53 in ALCs of patients with ARC were up-regulated in a grade-dependent manner, and the expression of CRYAA showed a positive association with histone H3, p53, and GLB1. In UV models of ALCs and human lens epithelial cell lines, the expression levels of histone H3, cell apoptosis factors (Bax/Bcl-2, cleaved caspase-3), and inflammation factors (interleukin-6, tumor necrosis factor-α) were all up-regulated. Furthermore, transfection of CRYAA in FHL-124 cells induced overexpression of histone H3. Conclusion: CRYAA-mediated upregulation of histone H3 may be involved in the pathogenesis of ARC. p53 may also have a role in ARC development, but not via the CRYAA-histone H3 axis. The results of the present study may assist in improving our understanding of the pathogenesis of ARC and in identifying potential targets for treatment.

Current possibilities of laser surgery on anterior eye segment

The article summarizes the experience of recent years in the development and implementation of novel original laser technologies used in surgery of the anterior segment of the eye. The presented technology of laser activation of scleral hydropermeability (LASH) in glaucoma is based on the effect of enhanced transscleral filtration and has been shown as effective and safe, which was confirmed by the results of a comprehensive clinical and experimental study. Development of another technique was associated with the need to improve the safety of laser interventions in anterior capsule contraction syndrome in pseudophakia, and resulted in a proposition to change the configuration of the anterior lens capsule incision from the usual linear-radial to T-shaped laser anterior capsulorhexis. The proposed technology of laser photomydriasis based on near-infrared radiation of the diode laser (0.810 μm) has shown its effectiveness and gentle nature (absence of atrophy of the iris stroma and post-burn pigmentation) in ectopias and pupil deformity.

Клиническое наблюдение больного после комбинированного хирургического лечения макулярного разрыва большого размера при осложненной катаракте

The only effective treatment for macular holes (MH) is surgery. Published data demonstrate that surgery (vitrectomy, internal limiting membrane/ILM peeling, and vitreous tamponade) of small and medium MHs is usually highly effective. Meanwhile, good outcomes and a high recurrence rate of large MHs postoperatively remain challenges. The authors propose a surgical technique for MHs in complicated cataracts (patent of the RF No. 2731794 dated 09/08/2020) that involves vitrectomy, posterior hyaloid removal, ILM staining, ILM peeling, formation of a flap from the anterior lens capsule to close MH, and air tamponade. This paper describes a woman who underwent combined surgery for cataract and MH as described. The technique provided a complete and stable anatomical outcome. After 1 month (i.e., after complete resorption of air), the best-corrected visual acuity of the right eye increased to 20/40. IOP was 19.0 mm Hg. KEYWORDS: vision, idiopathic macular hole, retina, anterior les capsule, surgery, postoperative follow-up. FOR CITATION: Bikbov M.M., Orenburkina O.I., Zinnatullin A.A., Yarmukhametova A.L., Babushkin A.E., Kalanov M.R. Combined surgery for large macular hole in complicated cataract: case report. Russian Journal of Clinical Ophthalmology. 2023;23(3):152–156 (in Russ.). DOI: 10.32364/2311-7729-2023-23-3-7.

Features of accumulation of chemical elements in the volume of the lens in senile cataract

This study provides a detailed analysis of the bioinorganic chemical composition of lens substance in patients with senile cataract using classical and spatial statistics methods. The study included 30 isolated human lenses. The light scattering ability (LSA) of the lens substance was evaluated using an original method. Additionally, distribution of chemical elements in the lens substance was analyzed using a scanning electron microscope with energy dispersive spectrometer (SEM/EDS). Measurements by all methods were carried out in a single coordinate space, which made it possible to compare the spatial correlation of different parameters. Small-angle light scattering of the lens substance has been quantitatively characterized for the first time. In contrast to the conventional norm, in senile cataract the accumulation fields of the majority of ion-forming elements (including Na, P, K, Cl) are distributed along the lines repeating the geometry of the lens capsule. At the same time, the light scattering ability of certain areas of the lens is significantly correlated with changes in the concentrations of Na, P, K, Ca in these areas. In particular, one ion-forming element can be distinguished - Na: spatial change of its concentration in senile cataract is strongly associated with a local change in LSA of the lens with opacities clustering of any degree. Thus, a change in the nature of the Na accumulation in the lens volume can be considered the main marker of senile cataract formation. The distribution pattern of ion-forming elements indicates that the loss of barrier properties in the capsule plays a significant role in the development of senile cataract.

Nd:YAG Laser Capsulotomy Rates in the Netherlands; Practice Variation and Association with Physician Practice Styles.

To determine the practice variation in rate of Nd:YAG laser capsulotomy within one year after cataract surgery and to identify possible associations with physician practice styles. All hospitals and private clinics in The Netherlands. Retrospective observational study. In the national medical claims database, we identified all laser capsulotomies performed in the Netherlands within a year after cataract surgery in the years 2016 and 2017. Centres with the lowest and highest percentages of Nd:YAG laser capsulotomies were interviewed on their physician practice styles related to the development of posterior capsule opacification. The incidence of Nd:YAG laser capsulotomy varied between 1.2% and 26.0% in 2016 (median 5.0%) and between 0.9% and 22.7% in 2017 (median 5.0%). The rate of capsulotomy was highly consistent over time for each centre (Pearson correlation coefficient, 0.89, P < 0.001). In general, ophthalmology centres with a high rate of Nd:YAG laser capsulotomy more often did not (routinely) polish the posterior lens capsule, performed cortex removal with coaxial irrigation/aspiration (instead of bimanual), and more often used hydrophilic IOLs (compared to only using hydrophobic IOLs). We found a significant practice variation in performing Nd:YAG laser capsulotomy within one year after cataract surgery in the Netherlands. Routinely polishing the posterior capsule, using bimanual I/A, and the use of hydrophobic IOLs are associated with a lower incidence in Nd:YAG laser capsulotomy. Incorporating these practice styles may lower the practice variation and thus prevent added medical burden for the patient and decrease costs.

Clinical profile and surgical outcome of patients with pseudo-exfoliation syndrome undergoing cataract surgery - A retrospective study

Pseudoexfoliation (PXF) syndrome is an age-related process of unknown etiology characterized by the deposition of distinctive fibrillar material in the anterior segment of the eye. The material is commonly deposited in the anterior chamber, angle of the eye, iris, trabecular meshwork, anterior capsule of the lens, and also the cornea. It is associated with open and narrow angle glaucoma, the formation of cataracts and the corneal endothelial decompensation.PXF deposition in the lens zonules leads to disintegration of the lens zonules resulting in lens subluxation and dislocation. PXF deposition on the iris causes poor pupillary dilatation. Both zonular dehiscence and poor pupillary dilatation pose a great challenge to the cataract surgeon during surgery. Intra operatively, the chances of lens subluxation / dislocation, posterior capsular rupture, vitreous loss is high in the presence of pseudoexfoliation. In the immediate post-operative period, intra ocular pressure spikes, increased and prolonged iritis and corneal decompensation can affect the visual outcome of the surgery. This study will retrospectively analyze the clinical profile of the patients with pseudoexfoliation and to evaluate the occurrence of intra and immediate post-op complications of cataract surgery. In this way, the surgeon can plan his/her surgical technique to help avoid complications during cataract surgery and be prepared to manage the potential intraoperative and postoperative complications that can occur in pseudoexfoliation eyes.

Complications and visual outcome of cataract surgery in pseudoexfoliation patients

Pseudoexfoliation syndrome is a multifactorial diffuse disease and is diagnosed clinically on slit lamp examination of the eye by the deposition of white, dandruff like material on different structures in anterior segment i:e corneal endothelium, iris, pupillary margin, anterior lens capsule, zonules and trabecular meshwork. The aim of study was to study demographic features, intraoperative and postoperative complications and the visual outcome of cataract surgery in pseudoexfoliation patients. 93 eyes of 93 patients with pseudoexfoliation posted for cataract surgery were included in the study. 79.56% patients were of more than 60 years of age group.43 patients were male and 50 patients were female. 44 patients had pseudoexfoliation syndrome in both eyes and 49 patients had either right eye or left eye involvement. Intraoperative problems encountered were poor pupillary dilatation, capsular bag prolapse, zonular dehiscence, posterior capsular rent, residual cortical matter and positive vitreous pressure. Postoperative complications reported were corneal edema, raised intraocular pressure, significant anterior chamber cell reaction, left cortical matter and exudative membrane. Best corrected visual acuity was more than 6/18 in 67 eyes, between 6/60-6/24 in 16 eyes, and less than 6/60 in 10 eyes. At 1 month, best corrected visual acuity was more than 6/18 in 92 eyes. Cataract surgery in pseudoexfoliation patients is associated with high risk of complications. Use of iris hooks and capsule tension rings where required during the surgery can decrease the intraoperative complications and thus will give better visual outcome.

ОПТИМИЗАЦИЯ ЭНЕРГЕТИЧЕСКИХ ПАРАМЕТРОВ ФЕМТОЛАЗЕРНОЙ ПЕРЕДНЕЙ КАПСУЛОТОМИИ В ХИРУРГИИ НАБУХАЮЩИХ ПЕРЕЗРЕЛЫХ КАТАРАКТ

The study included 40 patients (40 eyes) with swellingovermature cataract. These patients were divided into groups. The first group included 10 patients (10 eyes) with fibrotic changes in the anterior lens capsule, where the power offemtolaser energy exposure during anterior femtocapsulotomy was 100 %. The second group consisted of 10 patients (10 eyes) with thinning of the anterior lens capsule, where the power of femtolaser energy exposure was 60 %. The third and fourth groups were controls, 10 patients each (10 eyes) with fibrotic changes and thinning of the anterior capsule, respectively, where the power of femtolaser energy exposure was 80% (recommended by the manufacturer of the laser unit). In the first and second groups, in contrast to the control, the absence of tissue bridges was achieved in almostall cases.The carved disc stood out freely, without additional traction, leaving no burrs. These burrs cause radialization of the anterior capsule during manipulation during cataract surgery.As a result of the study, the optimal values of the power of femtolaser exposure were selected for anterior femtocapsulotomy in case of detection of fibrosis or thinning of the anterior lens capsule in case of swelling overmature cataract.

Phacoemulsification of cataract in the case of capsular bag damage

Purpose: to analyze the results of complicated cataract phacoemulsification with implantation of various types of intraocular lenses and fixation techniques. Material and methods. 48 patients (51 eyes) with complicated cataracts and weakened ligamentous apparatus of the lens or intraoperative rupture of the posterior lens capsule were divided into two groups: the study group I consisted of 21 patients (23 eyes, aged 71.4 ± 4.5 years) who had cataract phacoemulsification with an implantation of RSP-III IOL which was performed through a 2.4 mm small self-sealing incision using an injector and the control group II consisting of 27 patients (28 eyes, aged 73.6 ± 4.1 years) who had. Cataract phacoemulsification with an anterior chamber IOL implantation using an incision widened to 6.0 mm. Results. By the end of 1-year follow-up period, uncorrected visual acuity was 0.8 ± 0.1 in group 1 and 0.5 ± 0.1 in group II. In 100% of the patients of group 1 the correct position of the IOL was achieved in the early postoperative period (1–3 days) and maintained in the late period (1 year), whereas in group II, two eyes of 28 operated (7.14 %) showed a forward displacement of the anterior chamber IOL, which involved a contact with corneal endothelium. IOP stayed within the normal range in 21 eyes of group I patients (91.3 %), albeit two eyes (8.7 %) revealed transitory hypertension. In group II, 21 eyes (75 %) had normal IOP in the first three postoperative days, while 7 eyes (25 %) revealed an IOP increased to 29–30 mm Hg. In contrast to group I, group II patients showed induced corneal astigmatism which was decreasing during the follow-up period. Conclusion. In the case of a rupture of the posterior capsule during cataract phacoemulsification, or failure of the ligamentous apparatus of the lens of various origins, the implantation of the RSP-III IOL through a small self-sealing incision using an injector is the method of choice, which allows achieving a stable position of the IOL in the early and long-term follow-up periods, and high visual acuity with the minimal values of corneal astigmatism.

Novel clinical presentation and PAX6 mutation in families with congenital aniridia.

To explore the clinical phenotype and genetic defects of families with congenital aniridia. Four Chinese families with aniridia were enrolled in this study. The detailed ocular presentations of the patients were recorded. Whole exome sequencing (BGI MGIEasy V4 chip) was used to detect the gene mutation. Sanger sequencing was performed to validate the potential pathogenic variants, and segregation analysis was performed on all available family members. By whole exome sequencing and Sanger sequencing, three recurrent mutations (c.112del, p.Arg38Glyfs*16; c.299G > A, p.Trp100* and c.718C > T, p.Arg240*) and one novel mutation (c.278_281del, p.Glu93Alafs*30) of PAX6 were identified. All the mutations were co-segregated with the phenotype in the families. We also observed spontaneous anterior lens capsule rupture in aniridia for the first time. We report spontaneous anterior lens capsule rupture as a novel phenotype of aniridia and three recurrent mutations and one novel mutation of PAX6 in families with aniridia. Our results expanded the phenotype and genotype spectra of aniridia and can help us better understand the disease.

Posterior lens capsule rupture in non‐diabetic canine cataracts: Pre‐operative, intra‐operative, and post‐operative findings

To describe clinical features of non-diabetic canine cataracts with presumed pre-existing posterior capsule rupture (PLCR) and their surgical outcomes. Clinical records of 497 non-diabetic canines that underwent elective cataract surgery were reviewed. Twelve canines met the inclusion criteria indicative of PLCR pre-dating surgery. The incidence of presumed pre-existing PLCR was 12/497 (2.4%). Cataracts included were unilateral in 10 out of 12 canines (83.3%) and bilateral in the remaining two (16.7%). Four eyes (28.6%) had clinically detectable pre-operative lens-induced uveitis. The mean age at cataract diagnosis for cases included was 6.6 years, and golden retrievers were the most common breed affected (28.6%). Phacoemulsification surgery was performed at a median time of 110 days (range 17-403 days) after presentation. Pre-existing PLCR was found intra-operatively as a large ellipse spanning the posterior capsule from equator to equator centrally in 12 eyes and peripherally in two eyes. The capsular defect in all eyes with PLCR incorporated a distinct "pseudo-capsule" preventing vitreal presentation and ruling out intraoperative surgeon rupture. Ten eyes (71.4%) received an intraocular lens implant (IOL), and 13 eyes (92.9%) maintained vision throughout a mean follow-up period of 12 months. Posterior lens capsule rupture of blunt trauma origin and associated cataract formation, as reported in humans, may also be an infrequent but distinct cause of some cases of non-diabetic canine cataracts. Medical management of phacolytic uveitis and delayed phacoemulsification surgery may be beneficial by allowing time for "pseudo-capsule" development, increasing the likelihood of IOL placement and improved visual outcomes.

Wide-spread enhancer effect of SNP rs2279590 on regulating epoxide hydrolase-2 and protein tyrosine kinase 2-beta gene expression

Polymorphisms in the PTK2B-CLU locus have been associated with various neurodegenerative disorders including pseudoexfoliation glaucoma, Alzheimer’s and Parkinson’s. Many of these genomic variants are within enhancer elements and modulate genes associated with the disease pathogenesis. However, mechanisms by which they control the gene expression is unknown. Previously, we have shown that clusterin enhancer element surrounding rs2279590 intronic variant, a risk factor in the pathogenesis of pseudoexfoliation glaucoma modulates gene expression of clusterin (CLU), protein tyrosine kinase 2 beta (PTK2B) and epoxide hydrolase 2 (EPHX2). Here, we explored the mechanism by which rs2279590 enhancer regulates their gene expression through chromosome conformation capture assays. 3C assays revealed a strong enhancer-promoter chromatin interaction between rs2279590 enhancer and promoters of genes CLU, PTK2B and EPHX2 in the HEK293 wild type cells. Moreover, genomic knockout of rs2279590 element significantly decreases the chromatin-chromatin cross-linking frequency suggesting gene regulation at transcriptional level through formation of chromatin loop. In addition, molecular assays showed a significantly decreased expression of EPHX2 but not PTK2B at both mRNA and protein level in the lens capsule of pseudoexfoliation affected patients in comparison to control subjects implying a role of EPHX2 in the pathogenesis of pseudoexfoliation.

The ciliary zonules provide a pathway for immune cells to populate the avascular lens during eye development.

The eye is an immune-privileged site, with both vasculature and lymphatics absent from the central light path. Unique adaptations have made it possible for immune cells to be recruited to this region of the eye in response to ocular injuries and pathogenic insults. The induction of such immune responses is typically activated by tissue resident immune cells, considered the sentinels of the immune system. We discovered that, despite the absence of an embedded vasculature, the embryonic lens becomes populated by resident immune cells. The paths by which they travel to the lens during development were not known. However, our previous studies show that in response to corneal wounding immune cells travel to the lens from the vascular-rich ciliary body across the zonules that link these two tissues. We now examined whether the zonule fibers provide a path for immune cells to the embryonic lens, and the zonule-associated matrix molecules that could promote immune cell migration. The vitreous also was examined as a potential source of lens resident immune cells. This matrix-rich site in the posterior of the eye harbors hyalocytes, an immune cell type with macrophage-like properties. We found that both the zonules and the vitreous of the embryonic eye contained fibrillin-2-based networks and that migration-promoting matrix proteins like fibronectin and tenascin-C were linked to these fibrils. Immune cells were seen emerging from the ciliary body, migrating along the ciliary zonules to the lens, and invading through the lens capsule at its equator. This is just adjacent to where immune cells take up residence in the embryonic lens. In contrast, the immune cells of the vitreous were not detected in the region of the lens. These results strongly suggest that the ciliary zonules are a primary path of immune cell delivery to the developing lens.

Histopathological findings of anterior lens capsule in paediatric cataract patients

AbstractPurpose: To investigate the histopathological findings of the anterior lens capsule in patients with paediatric cataracts.Methods: This study is a prospective interventional study. Anterior capsule tissue samples which were obtained by anterior capsulotomy method during phaco surgery were fixed in 0.1 M phosphate buffered 2.5% glutaraldehyde at +4°C for 2–4 h and after passing through other stages, thin sections were taken and stained. It was then examined and visualized under HITACHI HT7800 transmission electron microscope.Results: Twenty‐three eyes of 19 patients were included. Three patients had unilateral cataract and remaining 16 had bilateral cataract. Four patients had concomitant systemic disease including hydrocephalus, cerebral palsy, juvenile myelomonocytic leukaemia and Down syndrome. Except for one patient, common findings were single‐layered epithelium under the capsule, degenerated organelles with round‐oval and prismatic‐oval nuclei in some regions, enlarged mitochondria and heterochromatin cells. In the case with cerebral palsy, unlike the normal lens structure, collagen fibrils of the connective tissue and fibroblast‐like cells were observed in the epithelial area that should be located under the capsule, in both eyes. Disorganized distribution of collagen fibrils and vacuole structures in the cytoplasm of fibroblast‐like cells were observed.Conclusions: Similar histopathological findings were found in paediatric cataracts with or without systemic disease. Due to the presence of increased inflammation and gliosis in cerebral palsy, the absence of lens epithelium may have developed as a result of degeneration in this patient. The absence of lens epithelium and inflammation are thought to play a role in the development of dense subcapsular fibrosis.

RARE CASE OF ISOLATED ANTERIOR LENTICONUS

Lenticonus is a bulging of the lens capsule and the underlying cortex. The diagnosis of lenticonus is essentially a clinical diagnosis which is made by biomicroscopic examination. According to the localization of the conus a distinction is made between lenticonus anterior and lenticonus posterior. Sometimes isolated, it may be an ocular manifestation of Alport syndrome, a hereditary nephritis accompanied by deafness and other ocular signs such as ecked retinopathy or posterior polymorphous corneal dystrophy. All these manifestations are a result of a genetic defect in type IV collagen, a major component of basal membranes in the human body. The clinical aspects and therapy of anterior lenticonus and Alport syndrome are described, as well as the exploration that must begin when anterior lenticonus is discovered. Preconical lenses are less commonly reported and are ［ ］ more common in Alport syndrome (AS) If a patient with a conical 2 lens in front of eye is observed clinically, the possibility of being an AS patient should be ruled out rst. AS,typically manifested as renal injury (hematuria, proteinuria and progressive renal insufciency), neurosensorineural deafness and eye injury triad, more common in women, but male patients are more seriously ill, and most of them have renal failure before the age of 40. 11%~92% of AS patients have eye injury, of which anterior conus lens and spotted retinopathy are characteristic changes, mostly involving both eyes, usually only when renal failure occurs. Reference to the Flinter standard or the new Gregory standard ,For the family history and eye, ear, and kidneyrelated examinations of patients with suspected AS, clinical diagnosis can usually be established, and combined with pathological examination and collagen molecular immunopathological examination, clinicopathological diagnosis can be established in most cases .

Capsular bag distension syndrome after uneventful DMEK for Fuchs corneal endothelial dystrophy

AbstractPurpose: Capsular bag distension syndrome or capsular block syndrome is a rare complication of cataract surgery characterized by accumulation of fluid between the intraocular lens and the posterior lens capsule, leading to visual deterioration. A small continuous curvilinear capsulorhexis, residual cortical lens material, as well as residual viscoelastic material behind the intraocular lens are associated with increased risk of fluid entrapment. Capsular bag syndrome usually occurs in the early postoperative period, but it has also been described as late as 14 years after cataract surgery. Nd‐YAG laser posterior capsulotomy is the treatment of choice in most cases, facilitating the drainage of the fluid in the vitreous cavity. Late‐onset capsular block syndrome is often associated with Propionibacterium acnes, requiring surgical management.Methods: Hereby we report a case of a 72‐year‐old female patient with Fuchs corneal endothelial dystrophy, who developed a capsular block syndrome after an uneventful endothelial keratoplasty (DMEK).Results: In the early postoperative period after the DMEK, we observed the development of capsular block syndrome OS. The patient was subjected to bilateral cataract surgery 6 years ago. After intensive follow‐up examination for excluding Propionibacterium acnes‐related endophthalmitis, we proceeded with Nd‐YAG capsulotomy, which resulted in drainage of the fluid in the vitreous cavity and immediate visual recovery.Conclusions: To our knowledge this is the first report of capsular bag syndrome after DMEK and therefore anterior segment surgeons should be aware of this rare complication.

TGF-β/Smad Signalling Activation by HTRA1 Regulates the Function of Human Lens Epithelial Cells and Its Mechanism in Posterior Subcapsular Congenital Cataract.

Congenital cataract is the leading cause of blindness among children worldwide. Patients with posterior subcapsular congenital cataract (PSC) in the central visual axis can result in worsening vision and stimulus deprivation amblyopia. However, the pathogenesis of PSC remains unclear. This study aims to explore the functional regulation and mechanism of HTRA1 in human lens epithelial cells (HLECs). HTRA1 was significantly downregulated in the lens capsules of children with PSC compared to normal controls. HTRA1 is a suppression factor of transforming growth factor-β (TGF-β) signalling pathway, which plays a key role in cataract formation. The results showed that the TGF-β/Smad signalling pathway was activated in the lens tissue of PSC. The effect of HTRA1 on cell proliferation, migration and apoptosis was measured in HLECs. In primary HLECs, the downregulation of HTRA1 can promote the proliferation and migration of HLECs by activating the TGF-β/Smad signalling pathway and can significantly upregulate the TGF-β/Smad downstream target genes FN1 and α-SMA. HTRA1 was also knocked out in the eyes of C57BL/6J mice via adeno-associated virus-mediated RNA interference. The results showed that HTRA1 knockout can significantly upregulate p-Smad2/3 and activate the TGF-β/Smad signalling pathway, resulting in abnormal proliferation and irregular arrangement of lens epithelial cells and leading to the occurrence of subcapsular cataract. To conclude, HTRA1 was significantly downregulated in children with PSC, and the downregulation of HTRA1 enhanced the proliferation and migration of HLECs by activating the TGF-β/Smad signalling pathway, which led to the occurrence of PSC.

The Immediate Early Response of Lens Epithelial Cells to Lens Injury.

Cataracts are treated by lens fiber cell removal followed by intraocular lens (IOL) implantation into the lens capsule. While effective, this procedure leaves behind numerous lens epithelial cells (LECs) which undergo a wound healing response that frequently leads to posterior capsular opacification (PCO). In order to elucidate the acute response of LECs to lens fiber cell removal which models cataract surgery (post cataract surgery, PCS), RNA-seq was conducted on LECs derived from wild type mice at 0 and 6 h PCS. This analysis found that LECs upregulate the expression of numerous proinflammatory cytokines and profibrotic regulators by 6 h PCS suggesting rapid priming of pathways leading to inflammation and fibrosis PCS. LECs also highly upregulate the expression of numerous immediate early transcription factors (IETFs) by 6 h PCS and immunolocalization found elevated levels of these proteins by 3 h PCS, and this was preceded by the phosphorylation of ERK1/2 in injured LECs. Egr1 and FosB were among the highest expressed of these factors and qRT-PCR revealed that they also upregulate in explanted mouse lens epithelia suggesting potential roles in the LEC injury response. Analysis of lenses lacking either Egr1 or FosB revealed that both genes may regulate a portion of the acute LEC injury response, although neither gene was essential for expression of either proinflammatory or fibrotic markers at later times PCS suggesting that IETFs may work in concert to mediate the LEC injury response following cataract surgery.