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Li Y, Zhang W, Ke H, Wang Y, Duan C, Zhu Q, Liu H. Rs1894720 polymorphism is associated with the risk of age-related cataract by regulating the proliferation of epithelial cells in the lens via the signalling pathway of MIAT/miR-26b/BCL2L2. Arch Med Sci 2022; 18:223-236. [PMID: 35154542 PMCID: PMC8826737 DOI: 10.5114/aoms.2020.91533] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 01/08/2019] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Cataracts caused by old age are one of the most frequent causes for blindness and poor vision worldwide. In this study, we aimed to clarify the possible role of rs1894720 polymorphism in the pathogenesis of age-related cataract. MATERIAL AND METHODS Rs1894720 polymorphism genotype was detected by TaqMan. Bioinformatics analysis, luciferase assay, real-time PCR, western blot, and protein density analysis were conducted to establish the correlations between MIAT and miR-26b as well as between BCL2L2 and miR-26b. Flow cytometry and MTT assay were also performed to observe the effect of MIAT/miR-26b/BCL2L2 signalling pathway on the status of cell apoptosis and viability. RESULTS MIAT functioned as an endogenous competing RNA to sponge miR-26b. In addition, BCL2L2 was identified as a target of miR-26b. Therefore, the expression of miR-26b was obviously suppressed by MIAT or anti-miR-26b, while the mRNA and protein expression of BCL2L2 was up-regulated in the presence of MIAT or anti-miR-26b. Moreover, the positive effect of MIAT on BCL2L2 expression was exerted via inhibition of the expression of miR-26b. In addition, the cells transfected with MIAT or anti-miR-26b showed suppressed expression of caspase-3 and reduced apoptosis index but higher cell viability, indicating that MIAT could suppress cell apoptosis via inhibition of miR-26b expression. Furthermore, the subjects carrying the GT and TT genotypes of single-nucleotide polymorphism (SNP) rs1894720 were associated with a higher risk of age-related cataracts, as indicated by their odds ratio (OR) and p-values. CONCLUSIONS Rs1894720 SNP could down-regulate the expression of MIAT, thus leading to reduced BCL2L2 expression and enhanced epithelial cell apoptosis in the lens, eventually increasing the incidence of age-related cataract.
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Affiliation(s)
- Yan Li
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, Yunnan Province, China
| | - Wenjia Zhang
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, Yunnan Province, China
| | - Hongqin Ke
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, Yunnan Province, China
| | - Yingting Wang
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, Yunnan Province, China
| | - Cong Duan
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, Yunnan Province, China
| | - Qin Zhu
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, Yunnan Province, China
| | - Hai Liu
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, Yunnan Province, China
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Tekin K, Erol YO, Inanc M, Sargon MF, Can CU, Polat S, Yilmazbas P. Electron microscopic evaluation of anterior lens epithelium in patients with idiopathic congenital cataract. Int Ophthalmol 2017; 38:2127-2132. [PMID: 28942547 DOI: 10.1007/s10792-017-0713-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 09/16/2017] [Indexed: 12/14/2022]
Abstract
PURPOSE To investigate the ultrastructure of the lens epithelial cells (LECs) in patients with idiopathic congenital cataract. METHODS This is a prospective interventional study. The anterior lens capsules (aLC: basement membrane and associated LECs) were taken from 16 eyes of 12 consecutive patients who were diagnosed as having idiopathic congenital cataracts. The aLCs were obtained from cataract surgery and prepared for transmission electron microscopy (TEM). RESULTS Some significant ultrastructural changes were observed in all aLCs of the participants. The anterior LECs showed alterations in different areas which were partly cuboidal and partly squamous in shape. The LECs had euchromatic nucleus and included some vacuoles in the cytoplasms as a remarkable alteration. The sizes of these intraepithelial cell vacuoles were changeable. CONCLUSIONS We identified remarkable changes in LECs of the eyes with idiopathic congenital cataract by TEM. It can be assumed that oxidative damage may be associated with these ultrastructural changes in LECs of the eyes with idiopathic congenital cataracts.
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Affiliation(s)
- Kemal Tekin
- Ankara Ulucanlar Eye Training and Research Hospital, 06240, Ankara, Turkey.
| | | | - Merve Inanc
- Ankara Ulucanlar Eye Training and Research Hospital, 06240, Ankara, Turkey
| | | | - Cigdem Ulku Can
- Ankara Ulucanlar Eye Training and Research Hospital, 06240, Ankara, Turkey
| | - Sibel Polat
- Ankara Ulucanlar Eye Training and Research Hospital, 06240, Ankara, Turkey
| | - Pelin Yilmazbas
- Ankara Ulucanlar Eye Training and Research Hospital, 06240, Ankara, Turkey
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Cytomorphometric study of epithelial cells in normal and cataractous human lenses in relation with hyperglycemia. Int Ophthalmol 2015; 36:147-58. [PMID: 26073139 DOI: 10.1007/s10792-015-0082-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 05/06/2015] [Indexed: 10/23/2022]
Abstract
The aim of the study is to evaluate and correlate the morphology and cell density of epithelial cells adhering to lens capsule surgically removed from the anterior central region with lens clarity and type of cataract present in patients with or without type 2 diabetes. Capsulorhexis specimens were obtained from patients who had undergone phacoemulsification cataract surgery. All the samples were centrifuged and stained by the aid of Papanicolaou technique and were observed under light microscope. We determinated the mean cell density, the degree of epithelial damage, and morphological indicators of cells such as cell area and the nucleus-plasma ratio. Patients with cataract demonstrated a statistical significant decrease in cell density and an heterogeneous cell picture in which enlarged cells dominated. In addition, type 2 diabetics with cataract had a significantly even lower mean epithelial cell density by the presence of larger cell area with smaller nucleus-plasma ratio. More pronounced alterations in the lens epithelium were correlated not only with the presence of cortical cataract, increased fasting blood sugar, and increased HbA1c but also with the prolonged duration of diabetes and the co-existence of diabetic retinopathy. It seems that density and morphology of the anterior lens epithelial cells determine the lens epithelium damage which is more profound in hyperglycemia and in cortical cataracts. The changes in lens epithelium seem to play an important role in cataractogenesis.
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Protective effect of tea polyphenol ophthalmic gel on lens epithelial cells in rabbits with silicone oil tamponade after vitrectomy. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:832381. [PMID: 25505926 PMCID: PMC4258369 DOI: 10.1155/2014/832381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 10/23/2014] [Accepted: 11/06/2014] [Indexed: 11/18/2022]
Abstract
Purpose. The aim of this study was to investigate the effect of tea polyphenols (TP) ophthalmic gel on lens epithelial cells (LECs) in rabbits with silicone oil tamponade after vitrectomy. Methods. In this study, unilateral vitrectomy with silicone oil tamponade was performed using 2-month-old New Zealand white rabbits (n = 72); meanwhile, age-matched nonoperated rabbits (n = 18) were used as controls. The TP ophthalmic gel was administered topically in the surgical eyes till they were sacrificed. On days 45 and 90 after operation, the levels of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), and apoptosis of LECs were analyzed, respectively. Meanwhile, caspase-3 mRNA and protein levels were also determined. Results. The results indicate that the levels of ROS and apoptosis were elevated for LECs in rabbits after operation, whereas ΔΨm was decreased. Caspase-3 was apparently increased at both mRNA and protein levels. Treatment of TP ophthalmic gel could reduce the generation of ROS, maintain ΔΨm, inhibit the overexpression of caspase-3, and thus decrease the apoptosis of LECs of rabbits after operation. Conclusions. TP ophthalmic gel can efficiently inhibit caspase-3 overexpression, reduce the apoptosis of LECs, and prevent LECs from damage. Our result provides a new approach to prevent the development of complicated cataract after vitrectomy.
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Oh SY, Park HJ, Kim SJ. A Case of Unilateral Electric Cataract with Optic Neuropathy after Electric Injury. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2013. [DOI: 10.3341/jkos.2013.54.4.680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Shin Yeop Oh
- Department of Ophthalmology, Maryknoll Hospital, Busan, Korea
| | - Hong Jae Park
- Department of Ophthalmology, Haeundae Paek Hospital, Inje University College of Medicine, Busan, Korea
| | - Soo Jin Kim
- Department of Ophthalmology, Maryknoll Hospital, Busan, Korea
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Stunf S, Hvala A, Vidovič Valentinčič N, Kraut A, Hawlina M. Ultrastructure of the anterior lens capsule and epithelium in cataracts associated with uveitis. Ophthalmic Res 2012; 48:12-21. [PMID: 22222715 DOI: 10.1159/000333219] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 08/19/2011] [Indexed: 12/14/2022]
Abstract
AIMS To study the ultrastructure of the anterior lens capsule and epithelium, and capsular thickness in uveitic cataracts. METHODS Capsulorhexis samples from 20 uveitic cataracts were compared to 20 nuclear cataracts using the semi- and ultra-thin techniques. RESULTS Extensive epithelial and capsular-epithelial border changes and epithelial-mesenchymal transition in some fibrotic capsules were found only in the uveitic group. All these changes were observed predominately in white uveitic cataracts. Mild and moderate ultrastructural changes were seen in both groups. Surface deposition of amorphous material was also found only in uveitic cataracts. Capsular thickness was not different between the two groups. CONCLUSIONS Uveitic capsules showed more extensive and different ultrastructural changes that probably occurred because of inflammation in the eye and epithelial-mesenchymal transition. These changes might be an additional reason for altered behavior of the lens capsule at capsulorhexis.
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Affiliation(s)
- Spela Stunf
- Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia.
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Zablocki GJ, Ruzycki PA, Overturf MA, Palla S, Reddy GB, Petrash JM. Aldose reductase-mediated induction of epithelium-to-mesenchymal transition (EMT) in lens. Chem Biol Interact 2011; 191:351-6. [PMID: 21329682 DOI: 10.1016/j.cbi.2011.02.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 02/01/2011] [Accepted: 02/01/2011] [Indexed: 12/14/2022]
Abstract
Cataract is a key factor in the morbidity associated with diabetes. While the pathogenesis of diabetic cataract formation is poorly understood, previous research has identified aldose reductase (ALR2) as a key player. To elucidate a potential role for this enzyme in diabetic cataract formation, we created a series of transgenic mice designed for expression of human ALR2 (AKR1B1) in epithelial and outer cortical fiber cells of the lens. One of the founder lines, designated PAR39, developed an early onset cataract that involved formation of a plaque of cells at the anterior aspect of the lens. These cells appear to separate from the anterior epithelium and undergo a dramatic change that is reminiscent of the epithelial to mesenchymal transition (EMT). We characterized this phenotype in the PAR39 strain by examining rates of cell proliferation and by immunostaining for markers of EMT. Incorporation of the thymidine analog bromodeoxyuridine (BrdU) was used to estimate cell proliferation in two functional areas of the lens epithelium: the mitotically active germinative zone (GZ) and the less proliferative center zone (CZ). Staining cell nuclei with diamido 4',6-diamidino-2-phenylindole (DAPI) was used to establish a total cell count in the demarcated areas. Lens epithelium in PAR39 transgenic mice demonstrated a decrease in the percentage of BrdU/DAPI staining within the GZ as compared to nontransgenic littermate controls (8.1% vs. 10.9%). A similar decrease in BrdU/DAPI was observed in the CZ (0.6% compared to 3.3%). However, cell density was greater within the GZ of PAR39 mice as compared with nontransgenic controls, while it was not significantly different in the CZ among the two groups. Furthermore, cells associated with the epithelial plaque did not stain positive for BrdU, but were strongly positive for alpha-smooth muscle actin, a classical marker for EMT. These findings suggest that ALR2 over-expression is associated with an alteration in the balance between proliferation and apoptosis of epithelial cells in the mouse lens, and that cells associated with epithelial plaques in the PAR39 lens have features in common with cells undergoing EMT.
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Affiliation(s)
- Gregory J Zablocki
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045, United States
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Yuasa M, Kobayashi A, Yokogawa H, Sugiyama K. In vivo laser confocal microscopic analysis of murine cornea and lens microstructures. Ophthalmic Surg Lasers Imaging Retina 2008; 39:391-6. [PMID: 18831421 DOI: 10.3928/15428877-20080901-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE The purpose of the current study is to investigate in vivo microstructures of anterior segments of normal murine eyes by new-generation in vivo laser confocal microscopy. MATERIALS AND METHODS Twenty-six corneas and lenses from 13 mice were analyzed by in vivo laser confocal microscopy. RESULTS Murine corneal superficial cells formed a polygonal cell pattern, with a mean cell density of 577 +/- 115 cells/mm2 (mean +/- standard deviation). Corneal basal epithelial cells had dark cytoplasm and were closely organized (9,312 +/- 1,777 cells/mm2). Sub-basal nerve fiber bundles were arranged in a whorl pattern, with both clockwise and counter-clockwise patterns. In the stroma, keratocytes were observed as numerous reflective stellate structures. The endothelial cells were organized in a honeycomb pattern (2,463 +/- 292 cells/mm2). Deeper inside the eye, murine lens epithelial cells were organized in a regular pattern (4,168 +/- 636 cells/mm2) and numerous lens fibers were observed. CONCLUSION In vivo laser confocal microscopy can provide high-resolution images of all corneal layers and lens structures of mice without sacrificing animals or tissue preparation.
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Affiliation(s)
- Masashi Yuasa
- Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
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Kumamoto Y, Takamura Y, Kubo E, Tsuzuki S, Akagi Y. Epithelial cell density in cataractous lenses of patients with diabetes: association with erythrocyte aldose reductase. Exp Eye Res 2007; 85:393-9. [PMID: 17655844 DOI: 10.1016/j.exer.2007.06.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 05/30/2007] [Accepted: 06/05/2007] [Indexed: 01/02/2023]
Abstract
In the present study we evaluated the cell density of lens epithelium and its relation to the degree of erythrocyte aldose reductase (AR) in patients with type 2 diabetes. This prospective clinical study included 46 eyes of patients with type 2 diabetes and 48 eyes of patients without diabetes mellitus (DM). Flat preparations of lens epithelial cells (LECs) attached to the anterior capsule were studied. Multiple regression analysis was performed to evaluate the association between lens cell density and age, gender, type of cataract, duration of diabetes, diabetic retinopathy (DR), the levels of glycosylated hemoglobin (HbA1c) and erythrocyte AR. The mean density of LECs of patients with type 2 diabetes was 4,141+/-508cells/mm(2), which was significantly lower than that of patients without DM (4,560+/-458cells/mm(2); p<0.0001). Multiple regression analysis revealed that the level of erythrocyte AR was correlated with the reduction of LECs in the eyes of patients with type 2 diabetes. The correlation between the density of LECs and the amount of erythrocyte AR was significant in the diabetic group with a high value of HbA1c (>6.5%) or with DR. These results suggest that the polyol pathway via AR may be associated with the reduction of epithelial cell density in the eyes of patients with DM.
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Affiliation(s)
- Yuko Kumamoto
- Department of Ophthalmology, Faculty of Medical Sciences, University of Fukui, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan
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Johar SRK, Rawal UM, Jain NK, Vasavada AR. Sequential Effects of Ultraviolet Radiation on the Histomorphology, Cell Density and Antioxidative Status of the Lens Epithelium-An In Vivo Study ¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2003)0780306seouro2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tkachov SI, Lautenschläger C, Ehrich D, Struck HG. Changes in the lens epithelium with respect to cataractogenesis—light microscopic and Scheimpflug densitometric analysis of the cataractous and the clear lens of diabetics and non-diabetics. Graefes Arch Clin Exp Ophthalmol 2005; 244:596-602. [PMID: 16175371 DOI: 10.1007/s00417-005-0091-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Revised: 05/13/2005] [Accepted: 07/07/2005] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND We compared the human lens documented, using the Scheimpflug densitometry, with the light microscopic changes in the epithelium of the anterior central lens in patients with age-related cataract and diabetes mellitus type II and verified the findings on the control tissue of the clear eye lens. We wanted to determine the relevance of the lens epithelium in cataract formation in type II diabetics compared to non-diabetics. MATERIALS AND METHODS One hundred fifty central lens capsules (138 cataract and 12 clear lenses) of type II diabetics (n=77, 45 female, 32 male) and non-diabetics (n=73, 41 female, 32 male) were examined by light microscope, regarding defined histomorphological parameters. Further criteria were duration of diabetes, diabetic retinopathy, cataract (PENTACAM, scheimpflug densitometric definition), protein content in the aqueous humour (laser flare meter 500 KOWA, tyndallometry), different blood parameters and glucose content in the aqueous humour. RESULTS The mean cell density in the cataractous lens in type II diabetics was 3,951+/-528 cells/mm(2) and in non-diabetics 4,329+/-580 cells/mm(2) (P<0.001); in the clear lens it corresponded to 4,593+/-409 cells/mm(2) (type II diabetics) and 4,894+/-333 cells/mm(2) (non-diabetics, P=0.207). The cell density of the cataractous lens in type II diabetics (P=0.005) and in non-diabetics (P=0.035) is smaller than that of the clear lens. The cell area of the lens epithelium in the cataractous diabetic lens is larger (P<0.001) and the nucleus-plasma ratio is lower (P<0.001) than those of the clear non-diabetic lens. The increase in damage of the lens epithelium correlates with the decrease of cell density (P< 0.001), the increase of nucleus area and volume (P< 0.001), and the decrease of nucleus-plasma ratio (P< 0.001). Risk factors for the decrease of cell density are advanced age (P=0.015), type II diabetes (P=0.01), increase in glucose content in the aqueous humour (P=0.014), increase in blood sugar (P=0.003) and increase in glycosylated haemoglobin (P=0.039). CONCLUSIONS The lens epithelium is primarily damaged in type II diabetics who develop age-related cataract. This might play an important role in cataract formation.
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Affiliation(s)
- Sergey I Tkachov
- Department of Ophthalmology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str 40, 06097, Halle/Saale, Germany
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Johar SR, Rawal UM, Jain NK, Vasavada AR. Sequential effects of ultraviolet radiation on the histomorphology, cell density and antioxidative status of the lens epithelium--an in vivo study. Photochem Photobiol 2003; 78:306-11. [PMID: 14556319 DOI: 10.1562/0031-8655(2003)078<0306:seouro>2.0.co;2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In vivo progressive effects of UV irradiation on the lens epithelium were studied using various histomorphological and biochemical parameters. Fifteen day old rat pups were exposed to 600 mW/m2 of radiation, including UV-A and UV-B, 12 h daily for 90, 120, 150 and 180 days. Biochemical parameters such as protein-bound and non-protein-bound sulfhydryl groups in both soluble and insoluble fractions and enzymes, which play an important role in combating the oxidative stress, were studied. Decreased cell density of lens epithelial cells (LEC) was observed in all three zones along with the decrease in the levels of soluble sulfhydryls (S-SH), glutathione reductase (GR), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT). On the other hand, an increase in insoluble sulfhydryls was observed. Because of the decrease in S-SH and GR activities, the LEC became vulnerable to oxidative stress. Decreased activities of SOD, GPx and CAT suggest elevated oxidative stress. This effect of UV radiation may lead to cell death that may be responsible for the observed decrease in the cell density in all three zones of the lens epithelium.
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Affiliation(s)
- S R Johar
- Iladevi Cataract and IOL Research Centre, Gurukul Road, Memnagar, Ahmedabad 380 052, Gujarat, India.
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Budo C, Goffinet G, Bellotto D, Petroll WM. Effect of ophthalmic viscosurgical devices on lens epithelial cells. J Cataract Refract Surg 2003; 29:2411-8. [PMID: 14709306 DOI: 10.1016/s0886-3350(03)00410-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To investigate the morphological effects of Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%) on lens epithelial cells (LECs). SETTING Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA, and the Laboratory of Ultrastructural Morphology, Zoological Institute, University of Liège, Liège, Belgium. METHODS Human LECs collected via capsulorhexis were examined by light microscopy (LM) and transmission electron microscopy (TEM). Lens epithelial cells from rabbit capsulorhexis samples were studied by LM and TEM following exposure to Provisc (sodium hyaluronate 1.0%) or Viscoat ophthalmic viscoelastic device (OVD). Since Viscoat is hypertonic (340 mOsm), hypertonic, isotonic, and hypotonic solutions were compared to investigate a possible mechanism for the observed effects. The effects of Provisc and Viscoat on rabbit LECs in the intact lens were also compared. RESULTS Human LECs gathered via capsulorhexis following exposure to Viscoat were generally thinner than control samples and often had condensed nuclei and increased intracellular vacuolization. Rabbit capsular tissue exposed in situ to Viscoat demonstrated changes similar to those seen in humans. Cells exposed to Provisc were similar to cells in untreated controls in humans and rabbits. Corneal endothelial cells exposed to either agent were unaffected. Experiments with hypertonic and hypotonic buffers induced some of the changes noted with Viscoat, but the effects were less severe. Lens epithelial cells in intact rabbit lenses exposed to Viscoat appeared similar to LECs in the control samples. CONCLUSIONS Light microscopy and TEM of human lens capsule tissue suggest that Viscoat induces significant morphological changes in LECs during cataract surgery. The changes may underlie the improved visualization of these cells that has been reported during cataract surgery. Corneal endothelial cells were unaffected by exposure to Viscoat. Studies in a rabbit model suggest that the hyperosmolarity of Viscoat may play a partial role in the LEC changes.
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Affiliation(s)
- Camille Budo
- Laboratory of Ultrastructural Morphology, Zoological Institute, University of Liège, Liège, Belgium.
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Vasavada AR, Thampi P, Bhatt DS. Degeneration and Transdifferentiation of Human Lens Epithelial Cells. J Cataract Refract Surg 1999. [DOI: 10.1097/02158034-199910000-00008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ram J, Apple DJ, Peng Q, Visessook N, Auffarth GU, Schoderbek RJ, Ready EL. Update on fixation of rigid and foldable posterior chamber intraocular lenses. Part II: Choosing the correct haptic fixation and intraocular lens design to help eradicate posterior capsule opacification. Ophthalmology 1999; 106:891-900. [PMID: 10328386 DOI: 10.1016/s0161-6420(99)00506-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
PURPOSE Posterior capsule opacification (PCO) is one of the most common complications of cataract surgery, and there is an urgent need to reduce its incidence. Its main treatment, neodymium:YAG (Nd:YAG) laser posterior capsulotomy, may be associated with significant morbidity and is expensive. In this study, the authors ascertain the effect of posterior chamber intraocular lens (PC-IOL) fixation and various IOL designs (rigid polymethyl methacrylate [PMMA] optic and small-incision foldable designs) on the pathogenesis of PCO. DESIGN Prospective analysis of pseudophakic eyes obtained postmortem. PARTICIPANTS A total of 3493 eyes with PC-IOLs obtained postmortem and received between 1984 and 1998. METHODS Miyake-Apple posterior photographic technique. MAIN OUTCOME MEASURES Peripheral Soemmering's ring, central PCO in the visual axis, and eyes that have had Nd:YAG laser posterior capsulotomy were analyzed and scored, and these findings were correlated with the type of fixation and IOL design. RESULTS The degree of formation of peripheral Soemmering's ring was not influenced by IOL fixation. The acrylic design revealed relatively low Soemmering's ring scores. In contrast, central PCO and Nd:YAG laser capsulotomy scores were consistently influenced by fixation. The scores were significantly lower in eyes with in-the-bag fixation. The bag-bag fixated acrylic-PMMA design and the three modern silicone IOL designs analyzed in this study had less central PCO and lower posterior capsulotomy scores than did the PMMA IOLs. CONCLUSIONS The formation of peripheral PCO (the Soemmering's ring), the precursor of clinically significant, vision-threatening PCO, is not significantly influenced by the haptic fixation pattern. It is much more dependent on the quality and thoroughness of surgical cortical cleanup. Reduction of Soemmering's ring is an important goal because the retained regenerative cortical cells within this lesion are the cells of origin of PCO. The acrylic IOL design was associated with a lessor amount of peripheral Soemmering's ring as compared with all other designs. In sharp contrast to peripheral PCO, fixation of the IOL was a highly significant factor affecting the formation and quantity of central PCO-the clinically significant opacity behind the IOL optic, measured in this series either by scoring an intact retro-optical membrane or by documenting the presence of a Nd:YAG laser posterior capsulotomy orifice. The quantity of central PCO was consistently much lower in eyes with in-the-bag fixated IOLs compared with lenses with one or both haptics out of the bag. This is best explained by the fact that secure in-the-bag fixation positions the IOL optic in the best possible position to create a barrier effect. The lowest PCO rates were generally noted with the acrylic and modern silicone IOL designs.
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Affiliation(s)
- J Ram
- Post-Graduate Institute of Medical Education & Research, Chandigarh, India
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Abe T, Sato M, Kuboki J, Kano T, Tamai M. Lens epithelial changes and mutated gene expression in patients with myotonic dystrophy. Br J Ophthalmol 1999; 83:452-7. [PMID: 10434869 PMCID: PMC1722992 DOI: 10.1136/bjo.83.4.452] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS Examination of the expression of the mutated allele of myotonic dystrophy protein kinase gene and lens epithelial cell changes in patients with myotonic dystrophy. METHODS Six eyes from three patients with myotonic dystrophy underwent cataract surgery. The lens epithelium was photographed to examine the morphological changes. mRNAs were extracted to determine myotonic dystrophy protein kinase gene expression in the lens epithelium and peripheral blood. Age matched lens epithelial cells from senile cataracts were used as controls. RESULTS All eyes showed iridescent or posterior subcapsular lens opacity. The expression of the myotonic dystrophy protein kinase gene with trinucleotide repeat expansion was evaluated by reverse transcriptase polymerase chain reaction, Southern blotting, and sequence analysis. Lens epithelial cell densities were extremely reduced in the patients compared with the control group. CONCLUSION To the authors' knowledge, this is the first report to describe the relation between lens epithelial cell changes and mutated gene expression in patients with myotonic dystrophy. The gene may be mitotically unstable in the lens epithelial cells; it may influence cell density and lens epithelial function, and it may lead to the development of typical subcapsular lens opacity.
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Affiliation(s)
- T Abe
- Department of Ophthalmology, Tohoku University School of Medicine, Miyagi, Japan
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17
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Abstract
PURPOSE To evaluate the intraoperative difficulties associated with phacoemulsification of white mature cataracts and develop a strategy for consistently achieving continuous curvilinear capsulorhexis (CCC) in these cases. SETTING Raghudeep Eye Clinic, Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS This prospective study comprised 60 eyes of 60 patients with senile white mature cataract. Mean follow-up was 7 months. Detailed preoperative and intraoperative notes were made including intraoperative subjective assessment of the intracapsular pressure and cataract hardness. A small capsulorhexis was attempted initially. Endophacoemulsification was performed using the stop, chop, chop, and stuff technique. The capsulorhexis was enlarged before intraocular lens implantation. An initial cut in the capsulorhexis margin was made with a cystotome needle while a spatula supported the anterior capsule. The capsulorhexis was then enlarged with forceps. RESULTS A CCC was achieved in 57 eyes (95%). Intracapsular pressure was judged to be raised in 24 eyes (40%). Of these, CCC was accomplished in 21 eyes (88%). Statistical analysis confirmed that raised intracapsular pressure was a significant factor. Capsule opacification or plaque was detected at the end of the surgery in 20 eyes (33%); 50% of the nuclei were of grade 5 hardness. CONCLUSION If a CCC can be achieved, the results of white cataract phacoemulsification are comparable to those of routine cataract surgery. When using the two-stage technique, one should be prepared to deal with a hard cataract through a small capsulorhexis.
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Affiliation(s)
- A Vasavada
- Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India
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18
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Vasavada AR, Chauhan H, Shah G. Incidence of posterior capsular plaque in cataract surgery. J Cataract Refract Surg 1997; 23:798-802. [PMID: 9278806 DOI: 10.1016/s0886-3350(97)80294-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To determine the incidence of posterior capsular plaque detected during cataract surgery, its association with age and type of cataract, and its impact on vision. SETTING Raghudeep Eye Clinic and Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS This prospective study comprised 256 consecutive eyes having extracapsular cataract extraction with posterior chamber intraocular lens implantation. The presence of plaque on the posterior capsule was noted and charted. Plaque peeling or posterior capsulorhexis was not done at the time of surgery. Mean patient age was 59 years (range 24 to 83 years). Follow-up was up to 1 year. RESULTS The overall incidence of plaque was 10.16%. The incidence by type of cataract was 5.13%, nuclear sclerotic; 12.50%, posterior subcapsular; 9.68%, mixed; 27.27%, mature (P < .05). The difference in incidence according to cataract type was highly significant between patients older than 50 years and those younger than 50 years (P < .001). At the end of 1 year, 61.54% of patients with plaque maintained a visual acuity of 20/20 to 20/30; 30.77%, 20/40; 7.69%, 20/60 or worse. CONCLUSION The incidence of plaque was higher in eyes with mature cataract at any age and in eyes with posterior subcapsular cataract in younger patients. Its presence was compatible with reasonable vision at the end of 1 year.
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19
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Abstract
British adults who were disabled by defective vision were estimated to number 1.668 million in 1988. Cataract is a most important cause of disability and blindness. Cataract develops earlier in life in populations with low income and inferior education. Cataract was shown to be associated with riboflavin deficiency in animals in the 1930s and subsequently with deficiencies of amino acids, vitamins and some minerals. In Britain and the U.S.A. there is a substantial spread in the intake of these micronutrients, the antioxidants and B vitamins, which have been shown to have low intakes in patients at higher risk of cataract. But there is little reliable information on the comparative importance of different micronutrients in Britain and longitudinal surveys relating diet to progression of cataract are recommended, which should also include non-nutrient risk factors for cataract such as smoking, medication and industrial chemicals.
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Li WC, Kuszak JR, Dunn K, Wang RR, Ma W, Wang GM, Spector A, Leib M, Cotliar AM, Weiss M. Lens epithelial cell apoptosis appears to be a common cellular basis for non-congenital cataract development in humans and animals. J Cell Biol 1995; 130:169-81. [PMID: 7790371 PMCID: PMC2120521 DOI: 10.1083/jcb.130.1.169] [Citation(s) in RCA: 273] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Cataract is a major ocular disease that causes blindness in many developing countries of the world. It is well established that various factors such as oxidative stress, UV, and other toxic agents can induce both in vivo and in vitro cataract formation. However, a common cellular basis for this induction has not been previously recognized. The present study of lens epithelial cell viability suggests such a general mechanism. When lens epithelial cells from a group of 20 cataract patients 12 to 94 years old were analyzed by terminal deoxynucleotidyl transferase (TdT) labeling and DNA fragmentation assays, it was found that all of these patients had apoptotic epithelial cells ranging from 4.4 to 41.8%. By contrast, in eight normal human lenses of comparable age, very few apoptotic epithelial cells were observed. We suggest that cataract patients may have deficient defense systems against factors such as oxidative stress and UV at the onset of the disease. Such stress can trigger lens epithelial cell apoptosis that then may initiate cataract development. To test this hypothesis, it is also demonstrated here that hydrogen peroxide at concentrations previously found in some cataract patients induces both lens epithelial cell apoptosis and cortical opacity. Moreover, the temporal and spatial distribution of induced apoptotic lens epithelial cells precedes development of lens opacification. These results suggest that lens epithelial cell apoptosis may be a common cellular basis for initiation of noncongenital cataract formation.
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Affiliation(s)
- W C Li
- Department of Ophthalmology, College of Physicians & Surgeons of Columbia University, New York 10032, USA
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21
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Spector A, Wang GM, Wang RR, Li WC, Kleiman NJ. A brief photochemically induced oxidative insult causes irreversible lens damage and cataract. II. Mechanism of action. Exp Eye Res 1995; 60:483-93. [PMID: 7615014 DOI: 10.1016/s0014-4835(05)80063-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Using photochemically induced oxidative stress and rat lenses in organ culture with 4% O2 and 4 microM riboflavin, it has been found that the observed changes in lens parameters are, in most cases, irreversible. This has made possible the elucidation of the sequence of biological changes leading to cataract. The earliest detectable changes in lens cell biology are observed in the epithelial cell redox set point and at the DNA level in terms of DNA integrity and 3H-thymidine incorporation followed by decreased membrane transport and changes in gene expression. Significant modification in classical cataract parameters such as hydration, steady state non-protein thiol, glyceraldehyde-phosphate-dehydrogenase activity and transparency occur at later times. The data suggest a definitive pattern of lens breakdown resulting in opacity starting at the epithelial cell level and leading to subsequent fibre cell involvement.
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Affiliation(s)
- A Spector
- Department of Ophthalmology, College of Physicians & Surgeons of Columbia University, New York, NY 10032, USA
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22
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Kleiman NJ, Spector A. DNA single strand breaks in human lens epithelial cells from patients with cataract. Curr Eye Res 1993; 12:423-31. [PMID: 8344066 DOI: 10.3109/02713689309024624] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In recent years, there has been renewed interest in the association between DNA damage to the lens epithelium and the development of lens opacities. Although a number of in vitro studies have indicated that lens epithelial cells are susceptible to a variety of DNA damaging insults and that these cells possess the capacity to repair such damage, no previous studies have directly addressed whether DNA damage is associated with human cataract in vivo. Utilizing samples of lens epithelial cells obtained from patients undergoing cataract surgery, the percentage of cells containing DNA single strand breaks was directly determined by the single-cell gel assay (SGA) method. Non-cataractous human Eye Bank lenses of similar ages to the cataractous samples and calf lenses were used as controls. In approximately 50% of the cataractous samples analyzed, the proportion of cells containing DNA single strand breaks was significantly higher than in control lenses. No relationship between age and DNA damage was noted. These findings are consistent with the hypothesis that in some human patients with cataract, DNA damage in the lens epithelial cell population may be related to the development of lens fiber cell opacity.
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Affiliation(s)
- N J Kleiman
- Department of Ophthalmology, Columbia University, New York, NY 10032
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