Anterior Lens Capsule Research Articles

Ease of Hydrodissection during Phacoemulsification: A Comparison between Patients with and Those without Exfoliation Syndrome

Background: Exfoliation syndrome (XFS), which is associated with increased surgical complications during phacoemulsification, has a relatively high incidence in Greece. Multiannual surgical experience in XFS patients has led to the clinical observation that hydrodissection occurs more easily in XFS patients. Objective: To compare the ease of hydrodissection between cataract patients with and those without XFS. Methods: One hundred and fifteen patients with senile cataract were included in the study. Forty-two of them had XFS. All patients underwent uneventful phacoemulsification by the same surgeon. For hydrodissection, three 1-mL insulin syringes were filled with 0.5 mL balanced salt solution (BSS). Sequentially, each one was quickly and continuously injected underneath the 3, 6, and 9 o’clock positions of the anterior lens capsule. If lens mobilization was achieved with this procedure, hydrodissection was characterized as “easy.” Results: The two groups were matched for age, gender, the biomicroscopic type of cataract, and the presence of diabetes mellitus. Glaucoma occurred more often among the XFS patients (p = 0.002). In 39 of the 42 exfoliation patients (92.8%), “easy” hydrodissection was recorded. In the control group, the corresponding number was 47 out of 73 (64.3%). The two groups differed significantly (p = 0.001). Conclusions: Hydrodissection was more easily performed on the XFS patients than on the controls. This finding could be related to the extensive ultrastructural subepithelial alterations of the anterior lens capsule in XFS, as recently described in electron microscopy studies. We suggest that less BSS can be used for hydrodissection in XFS patients during phacoemulsification.

In Vitro Evaluation and Transplantation of Human Corneal Endothelial Cells Cultured on Biocompatible Carriers

Corneal transplantation is currently the only effective treatment option for dysfunctional corneal endothelial cells (CEC). In this study, we test in vitro the surgical potential of cultivated human corneal endothelial cells (hCEC) on human anterior lens capsule (HALC), LinkCell™ bioengineered collagen sheets of 20-µm thickness (LK20), and denuded Descemet membrane (dDM) as tissue-engineered grafts for Descemet membrane (DM) endothelial keratoplasty (DMEK) to bypass the problem of donor tissue availability. Primary hCEC cultured on all carriers formed a monolayer of tightly packed cells with a high cell viability rate (96% ± 4%). hCEC on HALC and LK20 showed unremarkable expression of zonula occludens-1 (ZO-1) and Na+/K+-adenosine triphosphatase (ATPase), while Na+/K+-ATPase expression of cells seeded on dDM was mainly cytoplasmic. All hCEC–carrier constructs were evaluated by simulating DMEK surgery in vitro using a human donor cornea without DM mounted on an artificial anterior chamber (AC) and a regular DMEK-graft used as a surgical reference model. During in vitro surgery, hCEC–HALC constructs behaved most similarly to a DMEK-graft during implantation and unfolding, showing good adhesion to the bare stroma. On the other hand, hCEC–LK20 and hCEC–dDM constructs required some additional handling because of challenges related to the surgical procedure, although they were both successfully unfolded and implanted in the artificial AC. The hCEC–dDM constructs showed similar graft adherence as hCEC–HALC constructs, while adherence of hCEC–LK20 constructs was less effective. After the in vitro surgery, the estimated area populated by viable cells on the hCEC–HALC and hCEC–LK20 constructs was ∼83% and ∼67%, respectively. Overall, hCEC–HALC constructs behaved most similarly to a DMEK-graft during in vitro DMEK surgery, while graft adhesion and surgical handling, respectively, are parameters still requiring optimization for hCEC–LK20 and hCEC–dDM constructs.

Surgical removal of cataract in an Asiatic black bear (Ursus thibetanus) by phacoemulsification and aspiration.

A twenty-year-old male Asiatic black bear (Ursus thibetanus) presented at the Rakuno Gakuen University Animal Medical Center with a 10-year history of bilateral blindness and cataracts. Surgical treatment of bilateral cataracts by extracapsular lensextraction using phacoemulsification and aspiration (PEA) was performed under general anesthesia. An anterior capsulectomy was performed using micro iris scissors and micro anterior lens capsule forceps. The cataract was removed with PEA using the two-handed technique. After surgery, systemic corticosteroids, anti-inflammatory drugs and antibiotics were administered. After cataract removal, the bear had recovered vision, and good quality vision has been maintained to date (15 months). PEA can be a safe and effective treatment for cataracts that impair vision in bears.

The effects of vıtal dyes on mechanıcal propertıes of the human anterıor lens capsule.

Purpose:The purpose of this study was to evaluate the mechanical effects of vital dyes on the anterior lens capsule via the nanoindentation method.Methods:Twenty anterior lens capsules of 20 different patients were dissected into four equal fragments. Each fragment was stained separately with dyes for intraocular surgeries, such as trypan blue 0.06% (TB), brilliant blue 0.025% (BB), and indocyanine green 0.05% (ICG), for 1 min. The remaining fragment was assessed as an untreated control group. The alterations on the mechanical characteristics of the anterior lens capsule were evaluated using a nanoindentation testing device with Oliver–Pharr and Martens hardness methods.Results:The mean values of elasticity were 7.842 ± 0.55 GPa for capsules fragments stained with TB (P < 0.05), 8.407 ± 0.82 GPa for capsules fragments stained with BB (P < 0.05), 8.557 ± 0.60 GPa for ICG (P < 0.05), and 6.09 ± 0.57 GPa for the untreated control group. The mean values of stiffness were 299.7 ± 47 MPa for TB (P < 0.05), 317.9 ± 34 MPa for BB (P < 0.05), 331.8 ± 48 MPa for ICG (P < 0.05), and 229.85 ± 44 MPa for the untreated control group. The elasticity of the capsules statistically decreased in comparison to the control group, and the capsule stiffness showed a statistically significant increase in comparison to the untreated controls.Conclusion:The mechanical characteristics of the human anterior lens capsule were affected in association with the alterations in the elasticity and stiffness properties of the capsule as a result of exposure to three different dyes.

Ultrastructural Analysis of the Anterior Lens Epithelium in Cataracts Associated with Uveitis

Purpose: To investigate the transmission electron microscopic findings of lens epithelial cells (LECs) in patients with different subtypes of uveitis and to compare the findings with those in age-matched controls. Methods: In this prospective case-control study, the anterior lens capsules were taken from 47 eyes of 47 patients with uveitis of different subtypes (17 with Fuchs uveitis syndrome [FUS], 13 with ­Behçet’s uveitis, 10 with idiopathic uveitis, and 7 with herpetic keratouveitis) and from 15 eyes of 15 control patients. Results: In the FUS group, the LECs had homogeneous thickening and irregularity, with some small vacuoles and widespread, oval-shaped pigment clusters in some areas. In the Behçet uveitis group, there was evident thinning in the lens epithelium. The subepithelial tissue under the epithelium was thickened, and edematous areas were detected. In the idiopathic uveitis group, the LECs were thinner with small vacuoles, and the cubic structure of the LECs was transformed into a squamous one. Moreover, the LECs included some small vacuoles, similar to those in the FUS group. In the herpetic keratouveitis group, two prominent cell types were observed: (1) completely normal LECs and (2) degenerated-type LECs with pyknotic nuclei, condensation of chromatin, swelling in the cytoplasm, membrane ruptures, and intra­cytoplasmic inclusion bodies. In the control group, the LECs and all of their elements occurred in normal ultrastructural patterns, with the exception of a few small intraepithelial vacuoles, which were fewer in number and smaller than those in the FUS and idiopathic uveitis groups. Conclusion: The electron microscopic analysis of LECs of patients with different subtypes of uveitis revealed significant ultrastructural alterations, which may be related to the summation of oxidative stress and intraocular inflammation.

Reduced NGF Level Promotes Epithelial–Mesenchymal Transition in Human Lens Epithelial Cells Exposed to High Dexamethasone Concentrations

ABSTRACTPurpose: To investigate the protective effects of nerve growth factor (NGF) against steroid-induced cataract formation in dexamethasone (Dex)-treated human lens epithelial B-3 (HLE-B3) cells and the possible molecular mechanisms underlying this protection.Materials and Methods: HLE-B3 cells were treated with Dex, and cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay. The levels of expression of NGF, fibronectin, α-smooth muscle actin (α-SMA), and E-cadherin mRNAs were measured by real-time quantitative polymerase chain reaction (qPCR), and the levels of NGF, fibronectin, α-SMA, E-cadherin, tropomyosin receptor kinase A (TrkA), and Akt proteins were measured by Western blot analysis. Gene expression profiles of growth factors in Dex-treated HLE-B3 cells were determined by PCR arrays. In addition, anterior capsule tissue was obtained during cataract surgery, and the specimens were also examined expressions of NGF.Results: NGF was expressed in HLE-B3 cells and also in lens epithelial cells of anterior lens capsules. Dex treatment of HLE-B3 cells increased their expression of epithelial–mesenchymal transition (EMT) markers and migration activity, while markedly downregulating the expression of NGF. NGF treatment significantly reduced the expression of α-SMA and fibronectin, as well as cell proliferation. The decreased phosphorylation of p38 MAPK and Akt induced by Dex treatment was significantly reversed by treatment with NGF.Conclusion: NGF/TrkA may repress EMT by targeting the p38 MAPK and pAkt pathways in Dex-treated HLE-B3 cells. NGF may be a novel therapeutic target for patients with steroid-induced cataract.

Intraoperative capsular marking for toric intraocular lens placement

Preoperatively, the surgeon instills two drops of 0.5% proparacaine and then marks the 0° and 180° points at the limbus using a Gentian violet marker and 26G needle edge. Intraoperatively, after phacoemulsification and irrigation and aspiration of the cortex are complete, the surgeon inspects the previously marked 0°–180° points on the limbus. In case the steeper astigmatic meridian needs to be marked, a Mendez Ring is used and the meridian is marked using a Gentian violet marker and 26G needle edge. The desired markings (2 mm in length only) on the anterior lens capsule can be made using 26G needle bent at the bevel or using micro-vitreoretinal scissors. The toric intraocular lens (IOL) is then rotated in the bag in the desired meridian (customized-toric IOL in 0°–180° meridian and noncustomized toric IOL in steeper marked meridian), viscoelastic substance is aspirated and corneal wounds are hydrated.

Characterization of cataract patients’ lens epithelial cells by using synchrotron based FTIR

AbstractPurposeThe mechanisms involved in the process of cataract formation are not yet fully understood. Lens epithelial cells (LECs) are important for the maintenance of lens transparency as they control energy production, antioxidative mechanisms and biochemical transport for the whole lens. The purpose of this study is to characterize LECs compounds of two different cataract types, nuclear (N) and cortical (C), by using the high resolution synchrotron radiation‐based Fourier Transform Infrared (SR‐FTIR) microspectroscopy.MethodsThe anterior lens capsule (basement membrane and associated LECs) were obtained from cataract surgery and prepared by desiccation for FTIR. Measurements were set to achieve single cell resolution. Data obtained by SR‐FTIR have been analysed by comparing all spectra of N type and C type LECs. The average spectra of each group have been calculated and principal component analysis (PCA) has been performed.ResultsThe first component of the PCA in Amide I area of spectra showed the most prominent contribution at 1625 cm‐1 which is associated with beta sheet organisation in protein aggregates in N cataract type. In the C type we found proteins organized more in the turn and loops conformation (~1670 cm‐1). The markers of oxidative stress: ratios of the asymmetric vibration CH2 and CH3, as well as C=O/lipids showed an increase in C cataract type LECs that pointed out to an increase in lipid peroxidation in this type of LECs. The region corresponds to the P=O asymmetric bands indicate possible difference in protein phosphorylation in C and N types LECs.ConclusionsHere we evaluated the proteins conformation changes, as well as lipids and phosphates bands in LECs of two different cataract types. The oxidative stress and the lipids peroxidation were more pronounced in C type, while protein aggregation is associated with N type. These spectral changes can be assigned to specific biochemical processes occur in two different cataract types LECs.

Ultrasound biomicroscopy of the anterior segment of the eyeball after implantation of a phakic IOL in patients with different refractive errors

AbstractPurposeTo study the changes in of the anterior segment of the eyeball in the early and late postoperative periods after implantation of a phakic intraocular lens (PhIOL) in patients with different refractive errors using ultrasound biomicroscopy data.Material and methods32 patients (64 eyes) with moderate and high degree myopia (56 eyes) and hyperopia (8 eyes) without concomitant pathology were operated. The average age of the patients was 30 ± 5 years. Observation period: 1 day, 1 and 6 months after surgery. Complementary to standard diagnostic examination, ultrasound biomicroscopy was performed in all patients before and after surgery. The following parameters were estimated: anterior chamber depth (ACD), anterior chamber angle (ACA); iris profile; the position of the PhIOL, the distance between the PhIOL and the lens, the state of the Zinn’s zonules, the ciliary apparatus and the lens. Bilateral implantation of PhIOL was performed through 2.2 mm incision.ResultsOn day 1, in 31 patients (96.8%): ACD decreased by 0.67 ± 0.1 mm, ACA was open, iris profile–straight, PhIOL position‐in ciliary sulcus, distance between PhIOL and the lens‐0.57 ± 0.2 mm, Zinn’s zonules were saved, ciliary body‐within normal limits, lens‐transparent; in 1 patient with high hyperopia (preoperative data: ACD‐open, ACA‐3.17 mm (OD), 3.23 mm (OS)) anterior chamber was shallow (1.05 mm), ACA was covered with iris, 1/3 of the iris root was in contact with corneal endothelium, PhIOL dislocated in the frontal plane, distance between PhIOL and the lens was uneven. After 1 and 6 months in 31 patients, the state of anterior and posterior chambers’ structures remained satisfactory.ConclusionUltrasound biomicroscopy data of the anterior segment of the eyeball showed that implantation of PhIOL in patients with different refractive errors in early and late postoperative periods changes ACA, slightly decreases ACD, does not have contact with the anterior lens capsule.

In vitro expanded corneal endothelial cell sheets: towards a new therapeutic approach

AbstractCorneal transplantation is currently the only effective treatment solution to restore corneal clarity in patients with endothelial disorders. Descemet membrane endothelial keratoplasty (DMEK) is the most recent corneal transplantation technique that selectively replaces only Descemet membrane (DM) and endothelium with the same layers of a healthy donor. However, its application is limited by shortage of high‐quality healthy donor tissue. In order to increase the pool of endothelial grafts, new strategies have been developed, which include surgical‐based and tissue‐engineering based approaches.Tissue‐engineered approaches such as endothelial cell sheet transplantation and cell injection rely on the in‐vitro expansion of cultured corneal endothelial cells (CEC). For endothelial cell sheet transplantation suitable cell carriers are required, which could either be natural carriers (e.g. human anterior lens capsules (HALC)) or bioengineered matrices (e.g. 20 µm thick collagen‐based carriers (LK20)).Within the ARREST BLINDNESS project, CEC were cultured on different carriers and the suitability of the cell‐carrier sheets as tissue‐engineered grafts for DMEK‐like procedures was evaluated by performing in‐vitro surgeries. Upon in‐vitro DMEK surgery, CEC‐HALC sheets behaved similarly to a standard DMEK‐graft on all scored aspects such as graft implantation, unfolding and adherence to bare stroma, whereas graft adhesion and surgical handling, respectively, are issues that still need to be addressed for CEC‐LK20 and CEC‐‘denuded DM’ sheets. First results of in‐vivo tests in an animal model will be presented as well as measures to approach legislative issues.

In vitro evaluation and transplantation of human corneal endothelial cells cultured on biocompatible carriers

AbstractPurposeTo test in vitro the surgical potential of cultivated human corneal endothelial cells (hCEC) on human anterior lens capsule (HALC), bioengineered collagen sheets and denuded Descemet membrane (dDM) as tissue‐engineered grafts for Descemet membrane endothelial keratoplasty (DMEK).MethodsPrimary hCEC were seeded onto HALC, LinkCell™ bioengineered matrices of 20µm thickness (LK20), and dDM. Cell morphology, viability, and proliferation were assessed by light microscopy, cell viability assay, and immunohistochemistry. All hCEC‐carrier constructs were evaluated by simulating DMEK surgery in vitro using an artificial anterior chamber (AC) and a human donor cornea, without DM, with a regular DMEK graft as control.ResultsPrimary hCEC cultured on all carriers formed a monolayer of tightly packed cells with a high cell viability rate (96±4%) and expression of ZO‐1 and Na+/K+‐ATPase. During the in vitro surgery, hCEC‐HALC constructs behaved most similar to the DMEK reference model during implantation and unfolding in the artificial AC, showing good adhesion to the bare stroma. On the other hand, hCEC‐LK20 and hCEC‐dDM constructs required some additional handling because of challenges related to the surgical procedure, although they were both successfully unfolded and implanted in the artificial AC. The hCEC‐dDM constructs showed similar graft adherence as hCEC‐HALC constructs, while adherence of hCEC‐LK20 constructs was less effective.ConclusionsAll analyzed carriers were suitable substrates for cultivating hCEC. During in vitro DMEK surgery, hCEC‐HALC constructs behaved most similar to a standard DMEK‐graft, while graft adhesion and surgical handling, respectively, are parameters still requiring optimization for hCEC‐LK20 and hCEC‐dDM constructs.

A study of clinical spectrum of pseudo exfoliation syndrome

Background: Pseudoexfoliation syndrome (PXS) is the most common identifiable cause of secondary glaucoma, the prevalence of which varies considerably among different (PXF) ethnicities. Pseudoexfoliation is a genetically inherited condition. The prevalence of pseudoexfoliation increases with age. It is a common condition in the elderly population. This study aimed to assess the prevalence of and complications in patients with pseudo-exfoliation. Methods: This is an observational study performed in a sample of 103 patients (112 eyes) with pseudo-exfoliation for one year from October 2017-September-2018. Patients visiting the Ophthalmology department, NRI General Hospital, Chinakakani were enrolled in this study. Detailed evaluation including ophthalmic and general history, slit lamp biomicroscope, intraocular pressure measurement, gonioscopy and detailed eye examination was performed in all patients. Results: A total of 103 patients were analyzed; the major age group was 71-80 (40.78%). Among the Male patients were found to be more (66.02%). Majority of the patients were affected unilaterally (91.26%) and remaining bilaterally (8.24%). On slit-lamp examination degranulation of pupillary ruff and pseudoexfoliation material on the anterior capsule of the lens were present in 59.82% and 52.70% whereas corneal endothelium pigments, iris transillumination defects and pigments on the anterior lens capsule were absent in 82.1%, 91.1% and 68.80% respectively. All the cases were identified with PXF material on pupillary margin of the iris. Majority of the patients (72.32%) had normal intraocular pressure. Glaucoma and ocular hypertension were seen in 20.53% and 7.14% of eyes. On gonioscopy, pseudoexfoliation material in the angle, pigments and sampaolesi’s line were identified in 27.7%, 63.4% and 43.80% respectively. Only 8.69% of eyes had 6/24 or better vision, while 8.69% had perception of light (PL) to No perception of light in PXF Glaucoma patients. Conclusion: The study concluded the need for early diagnosis and various complications involved in pseudoexfoliation.

Clinical, ultrasonographic, and histopathologic findings in seven horses with Descemet's membrane detachment: A case series

ObjectiveTo describe ultrasonography as a diagnostic method of in vivo Descemet's membrane detachment (DMD) in horses. Animals studied: Seven horses (three Icelandic horses, two Dutch Warmblood horses, one Appaloosa, and one Welsh Pony), presenting with moderate‐to‐severe focal or diffuse corneal edema, in whom DMD was suspected on ultrasonographic examination and confirmed with histopathology, were studied.ProcedureA retrospective analysis of case records of horses with suspected DMD was performed.ResultsMedian age at presentation was 14 years (range 11‐24). Clinical signs in eyes with DMD were unilateral in all horses and included blepharospasm and epiphora (6/7), buphthalmos (5/7), moderate‐to‐severe focal or diffuse corneal edema (7/7), corneal epithelial bullae (4/7), corneal neovascularization (4/7), Haab's striae (2/7), corneal endothelial precipitates (1/7), fibrin in the anterior chamber (1/7), focal cataract (2/7), and pigment deposits on the anterior lens capsule (1/7). During transpalpebral ultrasonography, a distinct linear echogenic structure was noted in the anterior chamber, initially diverging from, and later running parallel to, the posterior lining of the cornea in all eyes studied. In all cases, the cornea was severely thickened and echogenic, consistent with edema, and DMD was suspected. In all horses, the clinical signs progressed and the affected eye was eventually enucleated. Histopathology revealed DMD (7/7), spindle cell proliferation (4/7), Descemet's membrane reformation (3/7), and inflammation of the anterior uvea (5/7). Overall incidence was 1.04%.ConclusionsUltrasonography is an adequate tool in diagnosing DMD in horses. Descemet's membrane detachment should be included in the differential diagnosis in horses with dense focal or diffuse corneal edema.

Phacoemulsification vs Manual Small Incision Cataract surgery in eyes affected by pseudo exfoliation syndrome with grade II and III Cataracts

PurposeTo compare the postoperative alteration of central corneal thickness (CCT) and visual outcomes between phacoemulsification (group A) and manual small incision cataract surgery (MSICS) (group B) in grade II and III nuclear cataracts (NS II & III) with pseudoexfoliation syndrome (PXF). MethodsIt is a double masked prospective randomised interventional study. A total of 60 eyes of 60 patients were assigned randomly to either the phacoemulsification (group A) or MSICS (group B) groups. All eyes had nuclear sclerosis grade II and III (LOCS II grading system) with pseudoexfoliation material either over the pupillary margin, anterior lens capsule, or both. All surgeries were done by a single surgeon. Postoperative evaluation was scheduled on the 1st, 30th, 90th, and 180th-day. Statistical analyses were done using appropriate methods. Outcome of the study were measured with changes in central corneal thickness (CCT), Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) and the spherical equivalent in the operated eye up to 6 months post surgery. ResultsThe mean preoperative CCT showed no difference between the groups (0.9659). The mean rise in CCT on the 1st postoperative day (POD) showed a significant difference between the groups {24.65 (SD 9.32) [group A (Phacoemulsification)] and 33.34 (SD11.68) [group B (MSICS)] (p < 0.0023)}. At the 1st, 3rd, and 6th month postoperative visits, there was no significant difference. The mean uncorrected distance visual acuity (UDVA) on the 1st POD was 0.189 (SD 0.118) in Group A and 0.302 (SD 0.121) in group B (p < 0.0005) which was significantly better with the phacoemulsification procedure. At the 1st month it was 0.039 (SD 0.084) in group A and 0.148 (SD 0.089) in group B (p < 0.004), which remained almost stable after that. The mean corrected distance visual acuity (CDVA) at the 1st, 3rd, and 6th-month postoperative visits showed no significant difference (p 0.8). The mean spherical equivalent was 0.29 in group A and 0.8 in group B. ConclusionIn moderately hard nuclear cataracts with PXF, phacoemulsification provides better unaided visual outcomes with less endothelial dysfunction than MSICS in the immediate and subsequent postoperative period.

PERSISTENT PUPILLARY MEMBRANE

PERSISTENT PUPILLARY MEMBRANE A 12 years old girl from D.I.Khan city, Pakistan presented with diminished vision. On examination her vision was 6/60 in both eyes, not improving with glasses. The intra-ocular pressure was 15 mmHg in both eyes. Both the corneas were clear and pupils were round, and reactive to light. There was pupillary membrane covering the entire pupil in undilated state. After dilation, we took the picture shown. The persistent pupillary membrane is usually an innocuous finding diagnosed on routine slit-lamp examination but in this case, it was adherent to the anterior lens capsule causing anterior capsular cataract, affecting the visual acquity.

Alteration of Retinal Vessel Diameter of the Patients with Pseudoexfoliation and Optical Coherence Tomography Images

ABSTRACTPurpose: The aim of this study was to measure retinal vessel diameter using spectral domain optical coherence tomography (SD-OCT), and to compare patients with unilateral pseudoexfoliation syndrome (PEX) with controls.Materials and Methods: 40 patients with pseudoexfoliation material (40+) eyes and (40−) eyes and 32 healthy controls was included study. Observation of pseudoexfoliative material on the anterior lens capsule or pupillar margin in one or both eyes was set as the diagnostic criteria for PEX. The diameter of superior temporal vein, inferior temporal vein; superior temporal artery and inferior temporal artery were measured by SD-OCT device.Results: when PEX (+) eyes were compared with PEX (−) eyes, a significant decrease was noted in vertical diameter of the arteries, as in the superior nasal artery. In PEX (+) patients the diameter of vascular structures was significantly decreased.Conclusion: We report a relationship between PEX and retinal vessel diameter. Vascular narrowing in the contralateral eye was also seen. Thus detection of this narrowing in the non-PEX eye vessels might be important for diagnosis and prevention of early glaucoma.

Repressed Wnt Signaling Accelerates the Aging Process in Mouse Eyes.

Purpose Ocular aging is a natural process of functional decline in vision. When the process reaches a point that compromised vision affects normal daily activity, it manifests as age-related ocular diseases, such as age-related macular degeneration, cataracts, glaucoma, and pseudoexfoliation syndrome. We previously reported that repressed Wnt signaling accelerated the maturation of corneal epithelium during tissue development. Here, we explore the hypothesis that repressed Wnt signaling is associated with accelerated aging in mouse eyes. Methods Wnt ligand antagonist secreted frizzled-related protein 1 (sFRP1) was expressed in the corneal stroma by a tissue-specific, inducible, bitransgenic system. Tissue structure was analyzed for signs of aging. Signal transduction analysis was performed to determine the cellular response to sFRP1. Results Mouse eyes with sFRP1 expression showed signs of accelerated aging, resembling those found in pseudoexfoliation (PEX) syndrome, a known age-related disease. Specific findings include granular deposition on the surface of the anterior lens capsule, pigment loss from the anterior surface of the iris, the presence of fibrillary material in the anterior chamber, and changes in cell size (polymegethism) and shape (pleomorphism) of the corneal endothelial cells. In vitro studies demonstrated that sFRP1 did not inhibit Wnt5a function and that cells responded to sFRP1 and Wnt5a in a very similar manner. Conclusion The expression of sFRP1 accelerates the aging process in mouse eyes and future studies are warranted to elucidate the underlying mechanisms.

Opacification of lentoid bodies derived from human induced pluripotent stem cells is accelerated by hydrogen peroxide and involves protein aggregation.

Despite the recent breakthrough in cataract drug development, further improvements have been limited by the lack of human in vitro cataract disease models. This study, therefore, aims to generate a qualified cataract disease model. Mature lentoid bodies (LBs) on Day 25 (D25), which were differentiated from human induced pluripotent stem cells (iPSCs) using the "fried egg" method, were continually culturing (control) or extra treated with either ultraviolet (UV) radiation or hydrogen peroxide (H2 O2 ). The LBs' shape alteration and opacity were examined using light microscopy and mean gray value evaluation. Their structure and crystallin expression were examined using immunofluorescence and transmission electron microscopy (TEM). Real-time polymerase chain reaction and western blot were used to investigate the potential role of autophagy in cloudy LBs. Mature LBs became cloudy with time which was accelerated by H2 O2 . Immunofluorescence examinations and TEM showed that the H2 O2 -treated and control LBs had similar shapes, lens capsule, and monolayer lens epithelial cell (LEC) structures. However, we were unable to do further assessment of the UV-treated LBs as the structures of LBs were easily damaged when treated with UV radiation. Cells containing aggregated protein (αA-crystallin and αB-crystallin) puncta were more abundant in the H2 O2 -treated LBs as compared with control LBs. Moreover, LC3B expression decreased with age in anterior lens capsules obtained from age-related cataracts (ARCs) patients as compared with LC3B levels in primary LECs, which is consistent with that LC3B expression in LBs was lower on D45 than on D25. Our study found that human iPSCs-derived LBs became cloudy with time which was accompanied by protein aggregation, and this phenomenon was accelerated by H2 O2 , suggesting that LBs with extending culture may serve as a human model for in vitro ARCs.

Severe Abnormalities of Lens Epithelial Cells in Exfoliation Syndrome: A Transmission Electron Microscopy Study of Patients with Age-Related Cataract.

Background and objectives: The aim of this study was to examine via electron microscopy the lens epithelial cells in age-related cataracts and compare the findings between patients with and without exfoliation syndrome, in the Greek population. Materials and Methods: Twenty-one patients with age-related cataracts, older than 60 years, were included in the study. Eleven of them also suffered from exfoliation syndrome. Anterior lens capsules, obtained during phacoemulsification, were examined with a transmission electron microscope. Results: In all cases, ultrastructural features of diffuse intracellular and extracellular oedema were noticed to a varying degree and transparent vacuoles were detected. Often, there was more than one layer of cells, giving the impression that healthier cells tried to cover neighboring cells presenting extensive damage. Commonly, cells lost their regular shape and appeared with expanded nuclei carrying dense granules. Apoptotic cells were also detected. The epithelial cells frequently were completely destroyed or absent, exhibiting loose connections amongst them or with the basement membrane. In exfoliation syndrome (XFS) patients the alterations were more severe. Additionally, the lens epithelial cells (LECs) apical cell membrane appeared with varying distances from the basement membrane, due to different cell “heights”, creating an irregular margin of the epithelium (p < 0.05). Conclusion: Transmission electron microscope (TEM) examination revealed ultrastructural abnormalities in all patients’ lens epithelia, more extended and more frequently observed in XFS group. In all cases, the lesions were comparable to those described in severe pathologies, all of which were excluded from the study. Environmental factors such as increased ultraviolet B (UVB) radiation exposure in Mediterranean countries, genetic factors, epigenetic factors, or all of them, could contribute to these alterations. Further epidemiological and molecular biology research is needed, so as to justify these results.

Laminin α4 overexpression in the anterior lens capsule may contribute to the senescence of human lens epithelial cells in age-related cataract.

Senescence is a leading cause of age-related cataract (ARC). The current study indicated that the senescence-associated protein, p53, total laminin (LM), LMα4, and transforming growth factor-beta1 (TGF-β1) in the cataractous anterior lens capsules (ALCs) increase with the grades of ARC. In cataractous ALCs, patient age, total LM, LMα4, TGF-β1, were all positively correlated with p53. In lens epithelial cell (HLE B-3) senescence models, matrix metalloproteinase-9 (MMP-9) alleviated senescence by decreasing the expression of total LM and LMα4; TGF-β1 induced senescence by increasing the expression of total LM and LMα4. Furthermore, MMP-9 silencing increased p-p38 and LMα4 expression; anti-LMα4 globular domain antibody alleviated senescence by decreasing the expression of p-p38 and LMα4; pharmacological inhibition of p38 MAPK signaling alleviated senescence by decreasing the expression of LMα4. Finally, in cataractous ALCs, positive correlations were found between LMα4 and total LM, as well as between LMα4 and TGF-β1. Taken together, our results implied that the elevated LMα4, which was possibly caused by the decreased MMP-9, increased TGF-β1 and activated p38 MAPK signaling during senescence, leading to the development of ARC. LMα4 and its regulatory factors show potential as targets for drug development for prevention and treatment of ARC.