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Li SY, Xue RY, Wu H, Pu N, Wei D, Zhao N, Song ZM, Tao Y. Novel Role of Molecular Hydrogen: The End of Ophthalmic Diseases? Pharmaceuticals (Basel) 2023; 16:1567. [PMID: 38004433 PMCID: PMC10674431 DOI: 10.3390/ph16111567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/03/2023] [Accepted: 10/06/2023] [Indexed: 11/26/2023] Open
Abstract
Molecular hydrogen (H2) is a colorless, odorless, and tasteless gas which displays non-toxic features at high concentrations. H2 can alleviate oxidative damage, reduce inflammatory reactions and inhibit apoptosis cascades, thereby inducing protective and repairing effects on cells. H2 can be transported into the body in the form of H2 gas, hydrogen-rich water (HRW), hydrogen-rich saline (HRS) or H2 produced by intestinal bacteria. Accumulating evidence suggest that H2 is protective against multiple ophthalmic diseases, including cataracts, dry eye disease, diabetic retinopathy (DR) and other fields. In particular, H2 has been tested in the treatment of dry eye disease and corneal endothelial injury in clinical practice. This medical gas has brought hope to patients suffering from blindness. Although H2 has demonstrated promising therapeutic potentials and broad application prospects, further large-scale studies involving more patients are still needed to determine its optimal application mode and dosage. In this paper, we have reviewed the basic characteristics of H2, and its therapeutic effects in ophthalmic diseases. We also focus on the latest progress in the administration approaches and mechanisms underlying these benefits.
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Affiliation(s)
| | | | | | | | | | | | - Zong-Ming Song
- Henan Eye Institute, Henan Eye Hospital, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou 450003, China
| | - Ye Tao
- Henan Eye Institute, Henan Eye Hospital, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou 450003, China
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2
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Chen K, Xu WY, Sun SS, Zhou HW. Corneal endothelial cells and acoustic cavitation in phacoemulsification. World J Clin Cases 2023; 11:1712-1718. [PMID: 36969995 PMCID: PMC10037277 DOI: 10.12998/wjcc.v11.i8.1712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/14/2023] [Accepted: 02/22/2023] [Indexed: 03/07/2023] Open
Abstract
Postoperative complications of phacoemulsification, such as corneal edema caused by human corneal endothelial cell (CEC) injury, are still a matter of concern. Although several factors are known to cause CEC damage, the influence of ultrasound on the formation of free radicals during surgery should be considered. Ultrasound in aqueous humor induces cavitation and promotes the formation of hydroxyl radicals or reactive oxygen species (ROS). ROS-induced apoptosis and autophagy in phacoemulsification have been suggested to significantly promote CEC injury. CEC cannot regenerate after injury, and measures must be taken to prevent the loss of CEC after phacoemulsification or other CEC injuries. Antioxidants can reduce the oxidative stress injury of CEC during phacoemulsification. Evidence from rabbit eye studies shows that ascorbic acid infusion during operation or local application of ascorbic acid during phacoemulsification has a protective effect by scavenging free radicals or reducing oxidative stress. Both in experiments and clinical practice, hydrogen dissolved in the irrigating solution can also prevent CEC damage during phacoemulsification surgery. Astaxanthin (AST) can inhibit oxidative damage, thereby protecting different cells from most pathological conditions, such as myocardial cells, luteinized granulosa cells of the ovary, umbilical vascular endothelial cells, and human retina pigment epithelium cell line (ARPE-19). However, existing research has not focused on the application of AST to prevent oxidative stress during phacoemulsification, and the related mechanisms need to be studied. The Rho related helical coil kinase inhibitor Y-27632 can inhibit CEC apoptosis after phacoemulsification. Rigorous experiments are required to confirm whether its effect is realized through improving the ROS clearance ability of CEC.
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Affiliation(s)
- Kai Chen
- Department of Ophthalmology, Lianshui County People's Hospital, Huai’an 223400, Jiangsu Province, China
| | - Wen-Ya Xu
- Department of Ophthalmology, Lianshui County People's Hospital, Huai’an 223400, Jiangsu Province, China
| | - Si-Si Sun
- Department of Ophthalmology, Lianshui County People's Hospital, Huai’an 223400, Jiangsu Province, China
| | - Hong-Wei Zhou
- Department of Ophthalmology, Huai’an 82 Hospital, Huai'an 223001, Jiangsu Province, China
- Department of Industrial Engineering, Tsinghua University, Beijing 100084, China
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Evaluation of the Corneal Endothelium Following Cataract Surgery in Diabetic and Non-Diabetic Patients. Diagnostics (Basel) 2023; 13:diagnostics13061115. [PMID: 36980422 PMCID: PMC10047116 DOI: 10.3390/diagnostics13061115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/09/2023] [Accepted: 03/14/2023] [Indexed: 03/17/2023] Open
Abstract
The aim of this study was to evaluate the influence of phacoemulsification cataract surgery on the state of the corneal endothelium in diabetic versus non-diabetic patients. We compared the corneal cell morphology in 48 diabetics with good glycemic control and 72 non-diabetic patients before and after uneventful phacoemulsification. Corneal cell density, central corneal thickness, and hexagonality were measured preoperatively and post-surgery (at 1 and 4 weeks) by specular microscopy. The effect of age, gender, axial length, and anterior chamber depth on the parameters of the corneal endothelium were evaluated. We noticed a drop in the endothelial density in both groups postoperatively: a mean endothelial cell loss of 472.7 ± 369.1 in the diabetic group was recorded versus 165.7 ± 214.6 mean loss in the non-diabetic group after the first week. A significant increase in central corneal thickness was also noticed in both groups one week after phacoemulsification, but no statistical significance after 4 weeks in the diabetic group. In terms of cell hexagonality, statistically significant differences were noticed after 4 weeks in both groups. Overall, a significant difference between diabetic and non-diabetic population was noticed in terms of corneal endothelial cell loss after uneventful phacoemulsification cataract surgery. Routine specular microscopy and HbA1c evaluation is recommended before cataract surgery, while intraoperative precautions and high monitorisation in terms of pacho power intensity and ultrasound energy, along with a proper application of the dispersive viscoelastic substances are essential to reduce the risk of endothelial damage.
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Li N, Wang T, Yang X, Qu J, Wang N, Wang L, Yu D, Han C. Effect of high-intensity ultrasonic treatment on the emulsion of hemp seed oil stabilized with hemp seed protein. ULTRASONICS SONOCHEMISTRY 2022; 86:106021. [PMID: 35512585 PMCID: PMC9077534 DOI: 10.1016/j.ultsonch.2022.106021] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/10/2022] [Accepted: 04/28/2022] [Indexed: 05/27/2023]
Abstract
In this study, hemp seed oil (HSO) emulsions stabilized with hemp seed protein (HPI) were prepared and treated with high intensity ultrasonic (HIU). The effects of different treatment powers (0, 150, 300, 450, 600 W) on the properties, microstructure and stability of emulsions were investigated. HIU-treated emulsions showed improved emulsifying activity index and emulsifying stability index, reduced particle size, and increased absolute values of ζ-potential, with the extreme points of these indices occurring at a treatment power of 450 W. Here, the emulsion showed the best dispersion and the smallest particle size in fluorescence microscopy observation, with the highest adsorbed protein content (30.12%), and the highest tetrahydrocannabinol (THC) retention rate (87.64%). The best thermal and oxidative stability of the emulsions were obtained under HIU treatment with a power of 450 W. The D43 and the peroxide values (POV) values after 30 d storage were the smallest at 985.74 ± 64.89 nm and 4.6 μmol/L, respectively. Therefore, 450 W was optimal HIU power to effectively improve the properties of HPI-stabilized HSO emulsion and promote the application of HSO and its derivatives in food processing production.
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Affiliation(s)
- Na Li
- School of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Tong Wang
- School of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Xinrun Yang
- School of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Jiayao Qu
- School of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Ning Wang
- School of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Liqi Wang
- School of Computer and Information Engineering, Harbin University of Commerce, Harbin 150028, China
| | - Dianyu Yu
- School of Food Science, Northeast Agricultural University, Harbin 150030, China.
| | - Cuiping Han
- School of Food Science, Northeast Agricultural University, Harbin 150030, China.
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Dewan T, Malik PK, Tomar P. Comparison of effective phacoemulsification time and corneal endothelial cell loss using three different ultrasound frequencies: A randomized controlled trial. Indian J Ophthalmol 2022; 70:1180-1185. [PMID: 35326010 PMCID: PMC9240574 DOI: 10.4103/ijo.ijo_2163_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Purpose Comparison of three ultrasound (US) frequencies for phacoemulsification of hard cataracts to determine a frequency that makes phacoemulsification more efficacious and safer. Methods A randomized controlled trial was undertaken at a medical college and hospital. In total, 207 patients with grade 5.6-6.9 (LOCS III) senile cataract were randomized into three groups. Group I underwent phacoemulsification with 28-kHz frequency, group II with 42-kHz frequency, and group III with 53-kHz frequency. The effective phacoemulsification time (EPT) and estimated fluid usage (EFU) were compared intraoperatively. The endothelial cell parameters were analyzed for 6 months. Results The groups were matched for age (P = 0.467), gender (P = 0.497), nuclear grade (P = 0.321), and anterior chamber depth (P = 0.635). The EPT and EFU were significantly lower in group III, compared to group II and group I, with P < 0.0001 and P < 0.0001, respectively. Postoperatively, the endothelial cell density (ECD) was significantly higher in group III at 1 month (P < 0.0001), 3 months (P < 0.0001), and 6 months (P < 0.0001). The percentages of ECD loss were also significantly lower in group III; the difference was statistically significant (P < 0.0001) up to 6 months postoperatively. Conclusion Higher frequency ultrasound was associated with a lower EPT and EFU as well as better endothelial preservation than lower frequencies in hard cataracts.
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Affiliation(s)
- Taru Dewan
- Department of Ophthalmology, Atal Bihari Vajpayee Institute of Medical Sciences and Dr Ram Manohar Lohia Hospital, New Delhi, India
| | - Praveen K Malik
- Department of Ophthalmology, Atal Bihari Vajpayee Institute of Medical Sciences and Dr Ram Manohar Lohia Hospital, New Delhi, India
| | - Preeti Tomar
- Department of Ophthalmology, Atal Bihari Vajpayee Institute of Medical Sciences and Dr Ram Manohar Lohia Hospital, New Delhi, India
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The safety and effectiveness of a new ophthalmic viscosurgical device-a randomized, controlled study. J Cataract Refract Surg 2022; 48:1050-1056. [PMID: 35137696 PMCID: PMC9415196 DOI: 10.1097/j.jcrs.0000000000000904] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/01/2022] [Indexed: 11/26/2022]
Abstract
ClearVisc was significantly noninferior to Viscoat in the mean percentage of ECD loss from baseline to 3 months and proportion of patients with postoperative IOP ≥30 mm Hg at any follow-up. To evaluate the safety and effectiveness of a new dispersive ophthalmic viscosurgical device (OVD) (ClearVisc) compared with an approved dispersive OVD (Viscoat) when used in cataract surgery.
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Chalimeswamy A, Thanuja MY, Ranganath SH, Pandya K, Kompella UB, Srinivas SP. Oxidative Stress Induces a Breakdown of the Cytoskeleton and Tight Junctions of the Corneal Endothelial Cells. J Ocul Pharmacol Ther 2021; 38:74-84. [PMID: 34818079 DOI: 10.1089/jop.2021.0037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose: To investigate the impact of oxidative stress, which is a hallmark of Fuchs dystrophy, on the barrier function of the corneal endothelial cells. Methods: Experiments were carried out with cultured bovine and porcine corneal endothelial cells. For oxidative stress, cells were supplemented with riboflavin (Rf) and exposed to UV-A (15-30 min) to induce Type-1 photochemical reactions that release H2O2. The effect of the stress on the barrier function was assayed by transendothelial electrical resistance (TER) measurement. In addition, the associated changes in the organization of the microtubules, perijunctional actomyosin ring (PAMR), and ZO-1 were evaluated by immunocytochemistry, which was also repeated after direct exposure to H2O2 (100 μM, 1 h). Results: Exposure to H2O2 led to the disassembly of microtubules and the destruction of PAMR. In parallel, the contiguous locus of ZO-1 was disrupted, marking a loss of barrier integrity. Accordingly, a sustained loss in TER was induced when cells in the Rf-supplemented medium were exposed to UV-A. However, the addition of catalase (7,000 U/mL) to rapidly decompose H2O2 limited the loss in TER. Furthermore, the adverse effects on microtubules, PAMR, and ZO-1 were suppressed by including catalase, ascorbic acid (1 mM; 30 min), or pretreatment with p38 MAP kinase inhibitor (SB-203580; 10 μM, 1 h). Conclusions: Acute oxidative stress induces microtubule disassembly by a p38 MAP kinase-dependent mechanism, leading to the destruction of PAMR and loss of barrier function. The response to oxidative stress is reminiscent of the (TNF-α)-induced breakdown of barrier failure in the corneal endothelium.
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Affiliation(s)
- Anupama Chalimeswamy
- Department of Biotechnology, Siddaganga Institute of Technology, Tumakuru, India.,Bio-INvENT Lab, Department of Chemical Engineering, Siddaganga Institute of Technology, Tumakuru, India
| | | | - Sudhir H Ranganath
- Bio-INvENT Lab, Department of Chemical Engineering, Siddaganga Institute of Technology, Tumakuru, India
| | - Kaveet Pandya
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Uday B Kompella
- Pharmaceutical Sciences, University of Colorado, Aurora, Colorado, USA
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Coco G, Cremonesi P, Menassa N, Pagano L, Gadhvi KA, Semeraro F, Kaye SB, Romano V. Changes in pupillometry associated with dissipated energy during phacoemulsification. Eur J Ophthalmol 2020; 31:2962-2968. [PMID: 33372549 DOI: 10.1177/1120672120984377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To investigate the effect of ultrasound level during phacoemulsification on pupil dynamics. METHODS Comparative retrospective study on patients who underwent routine cataract surgery at the Royal Liverpool University Hospital. Clinical parameters, anterior chamber measurements, axial length, surgeon grade, time of surgery, level of ultrasound used (cumulative dissipated energy, CDE), intra- and post-operative complications were collected. Pupil diameters were collected before and 4 ± 1 weeks after surgery in static scotopic, mesopic, photopic pupil conditions. Also, pupil dynamic measurements after luminous stimulus were recorded. Changes in static pupil diameters, relative dilation at 3.5 s after luminous stimulus, and time to reach 75% and 95% of maximum dilation were measured. RESULTS Forty-eight eyes of 24 patients (13 males) were included with a mean age of 73.1 ± 14.6 years. Mean CDE value was 18.11 ± 10.56. Mean scotopic pupil diameters decreased by 0.24 ± 0.48 mm (p = 0.021) in the operated eye. Significant correlation was found between reduction in scotopic pupil diameter and CDE (p = 0.05). A generalized linear model confirmed that the level of CDE was significantly associated with reduction in scotopic pupil diameter (p = 0.026). Patients who underwent surgeries with lower CDE (0 < CDE ⩽ 10 and 10 < CDE ⩽ 20) did not experience significant changes in scotopic pupil diameter after surgery (p = 0.28 and p = 0.79, respectively) as opposed to those with higher CDE (CDE > 20; p = 0.03). CONCLUSION Phacoemulsification cataract surgery and the cumulative dissipated energy may be associated with changes in pupil behaviour.
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Affiliation(s)
- Giulia Coco
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Clinical Science and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Pierluca Cremonesi
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Medical and Surgical Specialties, Radiological Specialties and Public Health, University of Brescia, Brescia, Italy
| | - Nardine Menassa
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | - Luca Pagano
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | - Kunal A Gadhvi
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | - Francesco Semeraro
- Department of Medical and Surgical Specialties, Radiological Specialties and Public Health, University of Brescia, Brescia, Italy
| | - Stephen B Kaye
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Vito Romano
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
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Comparison of effective phacoemulsification time and corneal endothelial cell loss using 2 ultrasound frequencies. J Cataract Refract Surg 2019; 45:1285-1293. [PMID: 31371150 DOI: 10.1016/j.jcrs.2019.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 03/19/2019] [Accepted: 04/15/2019] [Indexed: 11/22/2022]
Abstract
PURPOSE To compare 2 ultrasound (US) frequencies for phacoemulsification for moderate to hard cataract to determine a frequency that makes phacoemulsification safer and more efficacious. SETTING Post Graduate Institute of Medical Education and Research, New Delhi, India. DESIGN Randomized controlled trial. METHODS Patients with grade 4.0 to 6.9 senile cataract were randomized to 2 groups. Group A had lower frequency (28 kHz) phacoemulsification, and Group B had higher frequency (42 kHz) phacoemulsification. The effective phacoemulsification time (EPT) and estimated fluid usage (EFU) were compared intraoperatively. The endothelial parameters were assessed over 1 year. RESULTS Both groups comprised 80 patients. The groups were matched for age (P = .533), sex (P = .263), and nuclear grade (nuclear color, P = .496; nuclear opalescence, P = .622). Group B had significant reductions in EPT (P = .008) and EFU (P = .004) compared with Group A. Postoperatively, the endothelial cell density (ECD) was significantly higher in Group B at 1 month (P = .004), 3 months (P = .003), 6 months (P = .004), 9 months (P = .002), and 1 year (P = .003). The percentages of ECD loss were also significantly lower in Group B; the difference was statistically significant up to 1 year postoperatively even after adjustments for age, grade of cataract, EPT, and EFU. CONCLUSION Higher frequency phacoemulsification was associated with a lower EPT and EFU as well as better endothelial preservation than a lower frequency.
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M Padua IR, P Valdetaro G, B Lima T, K Kobashigawa K, E S Silva P, Aldrovani M, M Padua PP, Laus JL. Effects of intracameral ascorbic acid on the corneal endothelium of dogs undergoing phacoemulsification. Vet Ophthalmol 2017; 21:151-159. [PMID: 28714237 DOI: 10.1111/vop.12490] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Cataracts are the most common ocular disorder in dogs. Phacoemulsification is the preferred treatment method among ophthalmologists, but the cellularity of the endothelium must be considered for its success, as endothelial lesions may produce permanent corneal decompensation. The objective of this study was to evaluate the effects of intracameral ascorbic acid, a known antioxidant, on the corneal endothelium of dogs undergoing phacoemulsification. ANIMAL STUDIED In all, 40 eyes from 20 dogs, males and females from 7 to 12 years of age, were assessed for mature cataracts. PROCEDURES Two groups were formed (n = 20): Group 1 (G1) received a balanced salt solution (BSS), whereas Group 2 (G2) received sterile ascorbic acid diluted in a BSS, at a final concentration of 0.001 m ascorbic acid. The corneal endothelium was assessed via non-contact specular microscopy at multiple time points before and after phacoemulsification. Cell density (cells/mm2 ) and area (mm2 ), corneal thickness (mm), hexagonality, and the coefficient of variation of cell size were all assessed. P values equal to or less than 0.05 were considered significant. RESULTS With respect to the density of endothelial cells, both groups showed losses, but they were less severe in G2. There were no differences in corneal thickness. Hexagonality decreased significantly in the postoperative period in G1. Also in G1, the coefficient of variation of cell size increased significantly. CONCLUSION According to the results obtained, ascorbic acid minimizes cellular losses in the corneal endothelium.
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Affiliation(s)
- Ivan R M Padua
- Ophthalmology Unit, Department of Small Animal Medicine and Surgery, Faculty of Agrarian and Veterinary Sciences, FCAV, UNESP, Jaboticabal, SP, Brazil
| | - Gisele P Valdetaro
- Ophthalmology Unit, Department of Small Animal Medicine and Surgery, Faculty of Agrarian and Veterinary Sciences, FCAV, UNESP, Jaboticabal, SP, Brazil
| | - Tiago B Lima
- Ophthalmology Unit, Department of Small Animal Medicine and Surgery, Faculty of Agrarian and Veterinary Sciences, FCAV, UNESP, Jaboticabal, SP, Brazil
| | - Karina K Kobashigawa
- Ophthalmology Unit, Department of Small Animal Medicine and Surgery, Faculty of Agrarian and Veterinary Sciences, FCAV, UNESP, Jaboticabal, SP, Brazil
| | - Paloma E S Silva
- Anesthesiology Unit, Department of Small Animal Medicine and Animal Reproduction, Faculty of Agrarian and Veterinary Sciences, FCAV, UNESP, Jaboticabal, SP, Brazil
| | - Marcela Aldrovani
- Ophthalmology Unit, Department of Small Animal Medicine and Surgery, Faculty of Agrarian and Veterinary Sciences, FCAV, UNESP, Jaboticabal, SP, Brazil
| | - Pedro P M Padua
- Department of Small Animal Medicine, Clinica Protectora de Animales, Bogota, Colombia
| | - Jose L Laus
- Ophthalmology Unit, Department of Small Animal Medicine and Surgery, Faculty of Agrarian and Veterinary Sciences, FCAV, UNESP, Jaboticabal, SP, Brazil
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Kam AW, Chen TS, Wang SB, Jain NS, Goh AYJ, Douglas CP, McKelvie PA, Agar A, Osher RH, Francis IC. Materials in the vitreous during cataract surgery: nature and incidence, with two cases of histological confirmation. Clin Exp Ophthalmol 2016; 44:797-802. [DOI: 10.1111/ceo.12791] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/04/2016] [Accepted: 06/07/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew W Kam
- Department of Ophthalmology; Prince of Wales Hospital; Sydney New South Wales Australia
- The University of New South Wales; Sydney New South Wales Australia
| | - Tony S Chen
- Department of Ophthalmology; Prince of Wales Hospital; Sydney New South Wales Australia
- The University of New South Wales; Sydney New South Wales Australia
| | - Sarah B Wang
- The University of Sydney; Sydney New South Wales Australia
| | - Neeranjali S Jain
- Department of Ophthalmology; Prince of Wales Hospital; Sydney New South Wales Australia
- The University of New South Wales; Sydney New South Wales Australia
| | - Aaron YJ Goh
- Department of Ophthalmology; Prince of Wales Hospital; Sydney New South Wales Australia
- The University of New South Wales; Sydney New South Wales Australia
| | | | - Penny A McKelvie
- The University of Melbourne; Melbourne Victoria Australia
- St Vincent's Hospital; Melbourne Victoria Australia
| | - Ashish Agar
- Department of Ophthalmology; Prince of Wales Hospital; Sydney New South Wales Australia
- The University of New South Wales; Sydney New South Wales Australia
| | | | - Ian C Francis
- Department of Ophthalmology; Prince of Wales Hospital; Sydney New South Wales Australia
- The University of New South Wales; Sydney New South Wales Australia
- Ophthalmic Surgery Centre; Sydney New South Wales Australia
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Suzuki H, Igarashi T, Shiwa T, Takahashi H. Efficacy of Ophthalmic Viscosurgical Devices in Preventing Temperature Rise at the Corneal Endothelium during Phacoemulsification. Curr Eye Res 2016; 41:1548-1552. [DOI: 10.3109/02713683.2015.1136420] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Hisaharu Suzuki
- Department of Ophthalmology, Nippon Medical School Musashikosugi Hospital, Nakahara-ku, Kawasaki City, Kanagawa, Japan
| | - Tsutomu Igarashi
- Department of Ophthalmology, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Toshihiko Shiwa
- Department of Ophthalmology, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Hiroshi Takahashi
- Department of Ophthalmology, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
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13
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Buschschlüter S, von Eicken J, Koch C, Höh H. Experimental and Numerical Determination of the Local Temperature Distribution during Phacoemulsification and Comparison of Different Surgery Situations within Enucleated Porcine Eyes. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:2161-2172. [PMID: 25944286 DOI: 10.1016/j.ultrasmedbio.2015.03.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 03/07/2015] [Accepted: 03/27/2015] [Indexed: 06/04/2023]
Abstract
Phacoemulsification, a common treatment for cataract, is accompanied by cell damage at the corneal endothelium. Thermal exposure during treatment has been considered a reason for this damage, but a thorough experimental and theoretical assessment of the local temperature distribution inside the eye had not yet been conducted. Measurements in porcine eyes and a finite-element simulation enabled such an assessment and localized the highest temperature rise very close to the probe. The results described in this study indicate that a distance of 1 mm between the probe and the endothelium should be maintained during treatment as a safety margin, especially when fluid flow is blocked. The highest measured temperature rise with surgically reasonable system settings and unblocked fluid flow was 1.11°C. The finite-element simulation described here is able to calculate the temperature rise at the endothelium and could serve as a tool for comparing arbitrary surgical situations with respect to thermal exposure of the endothelium.
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Affiliation(s)
| | - Jörn von Eicken
- Klinik für Augenheilkunde, Dietrich-Bonhoeffer-Klinikum, Neubrandenburg, Germany
| | - Christian Koch
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
| | - Helmut Höh
- Klinik für Augenheilkunde, Dietrich-Bonhoeffer-Klinikum, Neubrandenburg, Germany
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Tovedal T, Thelin S, Lennmyr F. Cerebral oxygen saturation during pulsatile and non-pulsatile cardiopulmonary bypass in patients with carotid stenosis. Perfusion 2015; 31:72-7. [PMID: 25948696 DOI: 10.1177/0267659115586280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pulsatile and non-pulsatile cardiopulmonary bypass (CPB) flows may have different impact on cerebral oxygen saturation in patients with restricted cerebral arterial blood supply. Twenty patients, ten diagnosed with carotid stenosis (CS, n = 10) and ten without known carotid disease (Controls, n = 10), were subjected to one period of pulsatile and one period of non-pulsatile flow (6-8 min each) during CPB at 32°C. Cerebral oxygen saturation was registered by near-infrared light spectroscopy (NIRS).The mean arterial pressure (MAP) was significantly lowered by pulsatile CPB flow. The NIRS tissue oxygenation index (TOI) tended to decrease in the CS group and increase in the Controls during pulsatile flow compared with non-pulsatile; however, the changes were not statistically significant.No significant correlations were seen between the changes in MAP and TOI across the observation periods.In conclusion, pulsatile CPB flow caused slightly decreased mean arterial pressure while the effect on cerebral oxygenation was unclear. Pulsatile flow was not found superior to non-pulsatile flow in patients with or without carotid stenosis.
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Affiliation(s)
- T Tovedal
- Department of Surgical Sciences, Section for Anaesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
| | - S Thelin
- Department of Surgical Sciences, Section for Thoracic Surgery, Uppsala University, Uppsala, Sweden
| | - F Lennmyr
- Department of Surgical Sciences, Section for Anaesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
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Kim E, Yoon SY, Shin YJ. Oxidative Stress in Cornea. OXIDATIVE STRESS IN APPLIED BASIC RESEARCH AND CLINICAL PRACTICE 2015. [DOI: 10.1007/978-1-4939-1935-2_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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16
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Fluid dynamics, cavitation, and tip-to-tissue interaction of longitudinal and torsional ultrasound modes during phacoemulsification. J Cataract Refract Surg 2013; 39:611-6. [DOI: 10.1016/j.jcrs.2012.10.050] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 10/16/2012] [Accepted: 10/21/2012] [Indexed: 11/20/2022]
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Higashide T, Sugiyama K. Use of viscoelastic substance in ophthalmic surgery - focus on sodium hyaluronate. Clin Ophthalmol 2011; 2:21-30. [PMID: 19668386 PMCID: PMC2698691 DOI: 10.2147/opth.s1439] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Among viscoelastic substances, sodium hyaluronate has become the most popular for intraocular surgeries since the introduction of Healon® (sodium hyaluronate 1%, 4 × 106 daltons) in 1979. This review focuses on the recent development of a new generation of sodium hyaluronate agents with new rheologic properties and the relevant new techniques used in cataract, glaucoma, corneal, and vitreoretinal surgeries. The introduction of sodium hyaluronate agents with different rheologic properties has improved the safety and reliability of intraocular surgeries. Although there have been numerous studies reporting the effectiveness of viscoelastic substances in intraocular surgeries, rigorous validation by multi-center randomized control trials is lacking in many cases. At present, no single viscoelastic agent is most suitable to all of the various intraocular surgical techniques. Therefore, ophthalmologic surgeons should keep up with recent developments of viscoelastic agents and relevant surgical techniques for better patient care.
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Affiliation(s)
- Tomomi Higashide
- Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
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Quantification of hydroxyl radical produced during phacoemulsification. J Cataract Refract Surg 2010; 35:2149-53. [PMID: 19969222 DOI: 10.1016/j.jcrs.2009.06.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 06/24/2009] [Accepted: 06/26/2009] [Indexed: 11/21/2022]
Abstract
PURPOSE To quantitate hydroxyl radicals produced during phacoemulsification with various irrigating solutions and conditions used in cataract surgery. SETTING Chemistry and Biochemistry Department, Utah State University, Logan, Utah, USA. METHODS All experiments were performed using an Infiniti Vision System phacoemulsifier with irrigation and aspiration. Hydroxyl radicals were quantitated using electron spin resonance spectroscopy and a spectrophotometric assay for malondialdehyde, which is formed by the oxidation of deoxyribose by the hydroxyl radical. RESULTS Hydroxyl radical production increased during longitudinal-stroking phacoemulsification as power levels were increased in a nonlinear, nonexponential fashion. The detection of hydroxyl radical was reduced in irrigating solutions containing organic molecules (eg, citrate, acetate, glutathione, dextrose) and further reduced in Navstel, an irrigating solution containing a viscosity-modifying agent, hydroxypropyl methylcellulose. CONCLUSIONS Hydroxyl radicals produced in settings representative of those used in phacoemulsification cataract surgery were quantitated using the deoxyribose method. Hydroxyl radical production was dependent on the level of ultrasound power applied and the irrigating solution used. Oxidative stress on the eye during phacoemulsification may be minimized by using irrigating solutions that contain organic molecules, including the viscosity-modifying agent hydroxypropyl methylcellulose, that can compete for reaction with hydroxyl radicals.
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Suzuki H, Oki K, Shiwa T, Oharazawa H, Takahashi H. Effect of bottle height on the corneal endothelium during phacoemulsification. J Cataract Refract Surg 2009; 35:2014-7. [DOI: 10.1016/j.jcrs.2009.05.057] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 05/15/2009] [Accepted: 05/17/2009] [Indexed: 10/20/2022]
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20
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Maugeri F, Maltese A, Ward KW, Bucolo C. Hydroxyl Radical Scavenging Activity of a New Ophthalmic Viscosurgical Device. Curr Eye Res 2009; 32:105-11. [PMID: 17364743 DOI: 10.1080/02713680601147716] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To quantify the hydroxyl radical scavenging activity of a new ophthalmic viscosurgical device (OVD) based on sodium hyaluronate and hydroxypropylmethylcellulose (named VISC28) in comparison with Viscoat, Healon, and Amvisc Plus. METHODS The hydroxyl radicals that represent the principal free-radical species generated during phacoemulsification were produced by the Fenton reaction, and the scavenging activity of the tested viscoelastic substances was evaluated in vitro by the 2-deoxy-D-ribose (2-DR) oxidation method that produces the thiobarbituric acid-malondialdehyde (TBA-MDA), complex. An aliquot of viscosurgical formulation was added to phosphate buffer and mixed with 2-DR, Fe2 +/ethylenediaminetetraacetic acid (EDTA), and H2O2. The sample mix was incubated and thiobarbituric acid-trichloroacetic acid solution was added. The sample was then incubated for 30 min, and a chromatographic analysis was performed to quantify the TBA-MDA complex. The data were expressed as micromoles of MDA per milliliter of sample. RESULTS All tested OVDs showed a marked hydroxyl radical scavenging activity. The MDA level was significantly lower in VISC28 (0.045 +/- 0.007 micromol/ml) compared with Viscoat (0.070 +/- 0.012 micromol/ ml, p < 0.05), Amvisc Plus (0.111 +/- 0.008 micromol/ml, p < 0.001), and Healon (0.175 +/- 0.016 micromol/ml, p < 0.001). A reduced scavenging activity was shown by VISC28 phosphate-buffered solution (PBS) (no TRIS and no sorbitol) compared with VISC28 (p < 0.001). CONCLUSIONS The new OVD, VISC28, showed significantly higher hydroxyl radical inhibition compared with the other viscosurgical formulations. The following rank order for the scavenging activity was established: VISC28 > Viscoat > Amvisc Plus > Healon.
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21
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Phacoemulsification-induced injury in corneal endothelial cells mediated by apoptosis: In vitro model. J Cataract Refract Surg 2008; 34:2146-52. [DOI: 10.1016/j.jcrs.2008.08.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Accepted: 08/29/2008] [Indexed: 11/19/2022]
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22
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Evaluation of Endothelial Mucin Layer Thickness After Phacoemulsification With Next Generation Ophthalmic Irrigating Solution. Cornea 2008; 27:1050-6. [DOI: 10.1097/ico.0b013e31817313cb] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Zacharias J. Role of cavitation in the phacoemulsification process. J Cataract Refract Surg 2008; 34:846-52. [DOI: 10.1016/j.jcrs.2008.01.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 01/28/2008] [Indexed: 11/26/2022]
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24
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Sato M, Sakata C, Yabe M, Oshika T. Soft-shell technique using Viscoat and Healon 5: a prospective, randomized comparison between a dispersive-viscoadaptive and a dispersive-cohesive soft-shell technique. Acta Ophthalmol 2008; 86:65-70. [PMID: 17908256 DOI: 10.1111/j.1600-0420.2007.01018.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To compare the efficacy of the dispersive-viscoadaptive soft-shell technique using Viscoat and Healon 5 to the dispersive-cohesive soft-shell technique in reducing corneal endothelial cell damage during cataract surgery. METHODS In this prospective randomized study, 207 eyes of 171 cataract patients underwent phacoemulsification using the dispersive-viscoadaptive soft-shell technique (V-group, 102 eyes) with Viscoat and Healon5 or the dispersive-cohesive soft-shell technique (C-group, 105 eyes) with Viscoat and a cohesive agent (Opegan-Hi). Each group was divided into two subgroups depending on the amount of ultrasound (%Min) used during phacoemulsification. Corneal endothelial cell density was examined preoperatively and 3 months postoperatively. The endothelial cell loss was compared between the two groups, and also between the subgroups. RESULTS The mean endothelial cell loss 3 months after surgery was 8.4 +/- 5.6% standard deviation (SD) in the V-group and 8.2 +/- 6.2% in the C-group (P = 0.787). In the subgroups with ultrasound of 10 %Min or less, the mean endothelial cell loss 3 months after surgery was 6.6 +/- 4.6% in the V-group and 5.5 +/- 5.0% in the C-group (P = 0.104). In the subgroups with ultrasound of over 10 %Min, this value was 10.6 +/- 6.3% in the V-group and 11.9 +/- 5.7% in the C-group (P = 0.413). The correlation coefficient of the endothelial cell loss rate and %Min was 0.245 (P = 0.0129) in the V-group and 0.501 (P < 0.0001) in the C-group. CONCLUSION The dispersive-viscoadaptive soft-shell technique is as effective as the dispersive-cohesive soft-shell technique in protecting corneal endothelial cells during phacoemulsification regardless of the amount of ultrasound energy used.
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Affiliation(s)
- Masaki Sato
- Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
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25
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Miranda M, Bosch-Morell F, Belda JI, García-Manzanares MD, Barcia J, Alió JL, Romero FJ. Protective Effect of Viscoelastics against Retina Lipid Peroxidation. Ophthalmic Res 2007; 39:260-4. [PMID: 17851266 DOI: 10.1159/000108119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 04/08/2007] [Indexed: 11/19/2022]
Abstract
Viscoelastics or ophthalmic viscosurgical devices are routinely used during anterior segment surgery and also in posterior segment surgery. Studies of the harmful effects of phacoemulsification on corneal endothelial cells suggest that much of this damage is mediated by free radicals. In this study, we compare the possible effects against lipid peroxidation in the retina of three different viscoelastic substances: Viscoat, Healon and Visiol. Herein we demonstrate for the first time that viscoelastics are effective to protect the retina against lipid peroxidation, as can be seen by the slight increase of malondialdehyde in the homogenates incubated with viscoelastic exposed to light and to a temperature of 37 degrees C when compared with the control homogenates.
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Affiliation(s)
- M Miranda
- Universidad Cardenal Herrera - CEU, Valencia, España
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26
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Storr-Paulsen A, Nørregaard JC, Farik G, Tårnhøj J. The influence of viscoelastic substances on the corneal endothelial cell population during cataract surgery: a prospective study of cohesive and dispersive viscoelastics. ACTA ACUST UNITED AC 2007; 85:183-7. [PMID: 17305732 DOI: 10.1111/j.1600-0420.2006.00784.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To compare the ability of cohesive and dispersive ophthalmic viscoelastic devices (OVDs) to protect the corneal endothelium following in-the-bag phacoemulsification with implantation of a foldable posterior chamber intraocular lens (IOL). METHODS In a prospective single-masked randomized study, 60 eyes of 60 cataract patients were assigned to three groups of 20 patients each, according to which OVD was used: Celoftal, Vitrax or Healon. The corneal response to surgery was evaluated by measuring the endothelial cell loss, the variation in mean cell area of the endothelial cells (CV), the frequency of hexagonal cells, and the central corneal thickness. Data were recorded preoperatively and 3 months postoperatively. RESULTS Preoperatively, no significant difference was observed in cell count, CV, hexagonal pattern or pachymetry among groups. Postoperatively, all three groups had a significant decrease in cell count, but the decrease was significantly less in the Vitrax group (6.97%) than in the Celoftal (18.03%) and Healon groups (18.46%). No changes in CV, hexagonality or corneal thickness were observed within any of the three groups or among the groups. There was an equal and significant increase in visual acuity. CONCLUSIONS Phacoemulsification with implantation of a posterior chamber lens is known to affect the density and morphology of corneal endothelial cells. Viscoelastics facilitate cataract surgery and protect the corneal endothelium during the procedure. Choosing a dispersive hyaluronate OVD during the phaco procedure may allow for protection of the endothelial cells while suppressing the formation of free radicals. This may be the reason for the superior protective effect on the corneal endothelial cells of Vitrax compared with Celoftal and Healon.
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Affiliation(s)
- Allan Storr-Paulsen
- Department of Ophthalmology, Frederiksberg University Hospital, Frederiksberg, Denmark.
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27
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Nemet AY, Assia EI, Meyerstein D, Meyerstein N, Gedanken A, Topaz M. Protective effect of free-radical scavengers on corneal endothelial damage in phacoemulsification. J Cataract Refract Surg 2007; 33:310-5. [PMID: 17276276 DOI: 10.1016/j.jcrs.2006.10.031] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Accepted: 10/06/2006] [Indexed: 01/01/2023]
Abstract
PURPOSE To examine the role of the water-soluble antioxidants glutathione and ascorbic acid in the irrigating solution on corneal endothelial cells following exposure to high-intensity ultrasound energy. SETTING Goldschleger Eye Research Institute, Sheba Medical Center, Tel-Aviv University, Tel Aviv, Israel. METHODS Thirty-two rabbit eyes were subjected to prolonged exposure to the phacoemulsification device in the anterior chamber. The eyes were divided into 4 groups that differed only in the composition of the irrigating solution applied to the eyes: balanced salt solution (BSS) BSS Plus BSS containing additional soluble components including glutathione, BSS with 10(-3) M of oxidized glutathione (GSSG), and BSS with 10(-2) M of ascorbic acid. Specular microscopy was performed preoperatively and 1 week after surgery. RESULTS The BSS group exhibited the highest endothelial cell loss (19.3%), followed by the BSS Plus group (10.6%), the GSSG group (5.2%), and the ascorbic acid group (0.9%). An overall difference was found between the groups (F = 11.046, P<.0001), and all groups demonstrated a statistically significant difference from the control BSS group (P<.02, P = .001, and P<.0001, respectively). CONCLUSIONS Damage to the cornea is largely due to the free radicals generated by high-intensity ultrasound energy during phacoemulsification. Adding the antioxidants ascorbic acid and GSSG to the irrigation solution significantly reduced the endothelial corneal cell damage. Ascorbic acid in the concentration of 10(-2) M had the highest protective effect; thus, it should be evaluated for clinical use.
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Affiliation(s)
- Arie Y Nemet
- Department of Ophthalmology, Meir Hospital, Sapir Medical Center, Kfar-Saba, Israel.
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Davison JA. Comparison of Ultrasonic Energy Expenditures and Corneal Endothelial Cell Density Reductions During Modulated and Non-Modulated Phacoemulsification. Ophthalmic Surg Lasers Imaging Retina 2007; 38:209-18. [PMID: 17552387 DOI: 10.3928/15428877-20070501-05] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE To compare the Legacy 20000 Advantec continuous and Infiniti hyperpulse modes (Alcon Laboratories, Fort Worth, TX) with respect to average power, machine-measured phacoemulsification time, total stopwatch real time spent within the phacoemulsification process, balanced salt solution (BSS) volume, and corneal endothelial cell density losses. PATIENTS AND METHODS A background study was done of consecutive patients operated on with the Legacy (n = 60) and Infiniti (n = 40) machines programmed with identical parameters and using the continuous mode only. A primary study of another set of consecutive cases was operated on using the Legacy (n = 87) and Infiniti (n = 94) with the same parameters, but using the hyperpulse mode during quadrant removal with the Infiniti. Measurements for each set included average power and phacoemulsification time with corneal endothelial cell densities, BSS volume, and time spent in the phacoemulsification process. RESULTS Similarities were found in the background study for average power percent and average minutes of phacoemulsification time. In the primary study, similarities were found for total minutes in the phacoemulsification process, BSS usage, and ECD losses, and differences were found for average power percent (P< .001) and machine-measured phacoemulsification minutes (P< .001). CONCLUSIONS The Legacy and Infiniti performed similarly in continuous mode. With the Infiniti hyperpulse mode, a total ultrasonic energy reduction of 66% was noted. The machines required the same amount of total stopwatch measured time to accomplish phacoemulsification and produced the same 5% corneal endothelial cell loss. Therefore, clinically, these two machines behave in a comparable manner relative to safety and effectiveness.
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Affiliation(s)
- James A Davison
- Wolfe Eye Clinic, 309 East Church Street, Marshalltown, IA 50158, USA
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29
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Takahashi H, Suzuki H, Shiwa T, Sakamoto A. Alteration of free radical development by ophthalmic viscosurgical devices in phacoemulsification. J Cataract Refract Surg 2006; 32:1545-8. [PMID: 16931270 DOI: 10.1016/j.jcrs.2006.04.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 04/06/2006] [Indexed: 11/18/2022]
Abstract
PURPOSE To determine the effect of ophthalmic viscosurgical devices (OVDs) and irrigation/aspiration (I/A) settings on free radical development during phacoemulsification. SETTING Department of Ophthalmology, Nippon Medical School, Tokyo, Japan. METHODS Free radicals were detected by the electron spin resonance (ESR) spin-trap method. After a spin-trapping agent, 5,5-dimethyl-1-pyrroline N-oxide 1%, was mixed with the irrigating solution, phacoemulsification simulation was performed in an eye model at 100% ultrasound power levels for 10, 20, and 30 seconds. A high I/A setting (35 mL/min with 250 mm Hg vacuum) and a low I/A setting (15 mL/min with 60 mm Hg vacuum) were used in combination with no OVD, sodium hyaluronate 1% (Healon), sodium hyaluronate 2.3% (Healon5), sodium hyaluronate 3%-chondroitin sulfate 4% (Viscoat), or sodium hyaluronate 1% (Opegan). Immediately after phacoemulsification, the solution in the anterior chamber was collected and signals from the spin adduct were measured using an ESR spectrometer. RESULTS With the low setting, all OVDs significantly suppressed the signals for up to 20 seconds. At 30 seconds, the signals were still significantly smaller in all OVD groups, except Healon, than those in the no-OVD. With the high setting, the effect was not significant in the Healon and Opegan groups at 10 seconds; by 20 seconds and after, only Viscoat showed significant suppression. CONCLUSIONS Free radical development in phacoemulsification can be altered by OVD properties and I/A settings. To reduce oxidative stress to the corneal endothelium, attention should be paid to the retention of OVDs in the anterior chamber during phacoemulsification.
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De Biaggi CP, Barros PSM, Silva VV, Brooks DE, Barros SBM. Ascorbic acid levels of aqueous humor of dogs after experimental phacoemulsification. Vet Ophthalmol 2006; 9:299-302. [PMID: 16939457 DOI: 10.1111/j.1463-5224.2006.00462.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Phacoemulsification has been successfully employed in humans and animals for lens extraction. This ultrasonic extracapsular surgical technique induces hydroxyl radical formation in the anterior chamber, which accumulates despite irrigation and aspiration. In this paper we determined the total antioxidant status of aqueous humor after phacoemulsification by measuring aqueous humor ascorbic acid levels. Mixed-breed dogs (n = 11; weighing about 10 kg) with normal eyes as determined by slit-lamp biomicroscopy, applanation tonometry, and indirect ophthalmoscopy had phacoemulsification performed in one eye with the other eye used as a control. Samples of aqueous humor were obtained by anterior chamber paracentesis before surgery and at days 1, 2, 3, 7, and 15 after surgery. Total aqueous humor antioxidant status was inferred from the capacity of aqueous humor to inhibit free radical generation by 2,2-azobis (2-amidopropane) chlorine. Ascorbic acid concentrations were measured by high-pressure liquid chromatography with UV detection. Protein content was determined with the biuret reagent. Statistical analysis was performed by anova followed by the paired t-test. Total antioxidant capacity was reduced from 48 to 27 min during the first 24 h with a gradual increase thereafter, remaining statistically lower than the control eye until 7 days postoperatively. Reduced levels of ascorbic acid followed this reduction in antioxidant capacity (from 211 to 99 microm after 24 h), remaining lower than the control eye until 15 days postoperatively. Protein concentration in aqueous humor increased from 0.62 mg/mL to 30.8 mg/mL 24 h after surgery, remaining statistically lower than the control eye until 15 days postoperatively. Paracentesis alone did not significantly alter the parameters measured. These results indicate that after phacoemulsification, the aqueous humor ascorbic acid levels and antioxidant defenses in aqueous humor are reduced, indirectly corroborating free radical production in the anterior chamber as a result of phacoemulsification. The inflammatory process consequent to the surgical procedure demonstrated by increased protein content in aqueous humor can also contribute to free radical production and ascorbic acid consumption.
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Affiliation(s)
- Christianni P De Biaggi
- Laboratory of Investigation in Comparative Ophthalmology, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil
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Lynch GL, Brinkis JL. The effect of elective phacofragmentation on central corneal thickness in the dog. Vet Ophthalmol 2006; 9:303-10. [PMID: 16939458 DOI: 10.1111/j.1463-5224.2006.00459.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To characterize the short- and intermediate-term effects of elective phacofragmentation on central corneal thickness (CCT) in the dog. METHODS Forty-three dogs (66 eyes) undergoing elective phacofragmentation cataract surgery over an 8-month period at a single private ophthalmology referral clinic were enrolled in the study. Central corneal thickness was measured by ultrasonic pachymetry just prior to surgery, 1 day following surgery, 1 week postoperatively, 1 month postoperatively, and more than 2 months postoperatively. Statistical comparisons were made using descriptive and inferential statistical methods with a level of significance set at P < 0.05. RESULTS The initial mean CCT of 611 microm increased dramatically to 741 microm 1 day postphacofragmentation. Mean CCT remained slightly elevated (666 microm) at 1 week postoperatively, but became indistinguishable from preoperative measurements by 1 month postsurgery (626 microm) and remained so at the > 2-month time period (618 microm). The change over time and trends remained statistically significant and remarkably similar, even when adjusted separately for age, gender, surgeon status, diabetic status, cataract type, and total surgery time (all P < 0.0001). Corneas of diabetic dogs were thicker than those of nondiabetic dogs at all time periods, and the overall effect of diabetic status was significant (P = 0.016). There was a sharper increase from the preoperative to 1-day postoperative CCT in the diabetic group compared to the nondiabetic group. The mean CCT of the pseudophakic group took longer to return to baseline than the aphakic group. The mean CCT of the foldable intraocular lens (IOL) group took longer to return to baseline than both the rigid IOL and aphakic groups. Dogs with documented in-hospital postoperative intraocular pressure spikes (> 25 mmHg) developed a greater 1-day postsurgical increase in CCT. It appears that there was a sharper decrease in mean CCT from 1 month to more than 2 months postoperatively in the postoperative hypertension group. CONCLUSIONS Elective phacofragmentation cataract surgery results in an increase in CCT in dogs, but this increase is transient. Particular care may be indicated to protect the endothelium of diabetic patients undergoing phacofragmentation. These data do not clearly support an advantage of the small-incision cataract surgery made possible by the use of foldable IOLs.
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Affiliation(s)
- Gwendolyn L Lynch
- Eye Care for Animals at City of Angels Veterinary Specialty Center, 9599 Jefferson Blvd., Culver City, CA 90401, USA.
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Barbara A, Shehadeh-Masha'our R, Sartani G, Garzozi HJ. Reactivation of Ocular Toxoplasmosis After LASIK. J Refract Surg 2005; 21:759-61. [PMID: 16329371 DOI: 10.3928/1081-597x-20051101-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To report a reactivation of ocular toxoplasmosis after LASIK. METHODS Case report of a 34-year-old man who underwent bilateral LASIK. The posterior segment examination revealed an old toxoplasmosis scar in the retinal periphery of the right eye. RESULTS Uncorrected visual acuity improved postoperatively, and the patient was satisfied. However, 52 days after the procedure, he complained of loss of visual acuity in his right eye. Examination revealed signs of anterior uveitis, vitreitis, and active chorioretinal lesion satellite of the old toxoplasmosis scar. The patient was treated with a multidrug regiment with resolution of the vitreous and lesion activity. CONCLUSIONS Toxoplasmosis reactivation may develop after LASIK.
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Topaz M, Shuster V, Assia EI, Meyerstein D, Meyerstein N, Mazor D, Gedanken A. Acoustic cavitation in phacoemulsification and the role of antioxidants. ULTRASOUND IN MEDICINE & BIOLOGY 2005; 31:1123-9. [PMID: 16085102 DOI: 10.1016/j.ultrasmedbio.2005.02.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2004] [Revised: 02/14/2005] [Accepted: 02/25/2005] [Indexed: 05/03/2023]
Abstract
Cataract surgery by phacoemulsification generates acoustic cavitation, resulting in formation of reactive oxygen species. The aim of this study was to establish the mechanism of damage by phacoemulsification in an in vitro setting simulating cataract surgery and to assess the protective effects of water-soluble antioxidants. Electron paramagnetic resonance spectroscopy was used to analyze generation of radicals in an intraocular irrigating solution by phacoemulsification instrumentation, operating at an ultrasonic frequency range of 40--60 kHz. Hydroxyl radicals were generated by phacoemulsification under conditions simulating cataract surgery. The effects of water-soluble antioxidants in the irrigating solution on the amounts of radicals were evaluated by electron paramagnetic resonance spectroscopy. The water-soluble antioxidant glutathione, applied in either oxidized or reduced form, decreased hydroxyl radicals concentration measured in the sonicated medium. The effective concentrations of oxidized and reduced glutathione in irrigating solution that significantly eliminate the hydroxyl radical signal were determined in the range of 10(-3)-10(-2) M. Antioxidants should be applied clinically to reduce damage to the corneal endothelium induced by phacoemulsification, thereby improving biosafety.
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Affiliation(s)
- Moris Topaz
- Hillel Yaffe Medical Center, Hadera, Israel.
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Abstract
Phacoemulsification and aspiration (PEA) has become the most popular cataract surgery, due to the establishment of safe surgical techniques and development of associated instruments. However, corneal endothelial damage still represents a serious complication, as excessive damage can lead to irreversible bullous keratopathy. In addition to causes such as mechanical or heat injuries, free radical formation due to ultrasound has been posited as another cause of corneal endothelium damage in PEA. Ultrasound in aqueous solution induces cavitation, directly causing water molecule disintegration and resulting in the formation of hydroxylradicals, the most potent of the reactive oxygen species. Considering the oxidative insult to endothelial cells caused by free radicals, their presence in the anterior chamber may represent one of the most harmful factors during these procedures. Indeed, some researchers have recently started to evaluate PEA from the perspective of oxidative stress. Conversely, the major ingredient in ophthalmic viscosurgical devices (OVDs), which are indispensable for maintaining the anterior chamber in PEA surgery, is sodium hyaluronate, a known free radical scavenger. OVDs can thus be expected to provide some anti-free radical effect during PEA procedures. In addition, since commercially available OVDs display different properties regarding retention in the anterior chamber during PEA, the anti-free radical effect of OVDs is likely to depend on behavior during irrigation and aspiration. The present study followed standard PEA procedures in an eye model and measured hydroxylradicals in the anterior chamber using electron spin resonance. The kinetics of free radical intensity and effects of several OVDs during clinical PEA were also demonstrated. These studies may be of significance in re-evaluating OVDs as a chemical protectant for corneal endothelium, since the OVD has thus far only been regarded as a physical barrier. In addition, many reports about corneal endothelium damage during PEA have been published, but objective evaluation of various damaging factors has been difficult. The present assay of free radicals in a simulation of clinical PEA offers the first method to quantitatively assess stress on the corneal endothelium.
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Affiliation(s)
- Hiroshi Takahashi
- Department of Ophthalmology, Nippon Medical School, Bunkyo-ku, Tokyo 113-8603, Japan.
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Belda JI, Artola A, García-Manzanares MD, Ferrer C, Haroun HE, Hassanein A, Baeyens V, Munoz G, Alió JL. Hyaluronic acid combined with mannitol to improve protection against free-radical endothelial damage: Experimental Model. J Cataract Refract Surg 2005; 31:1213-8. [PMID: 16039500 DOI: 10.1016/j.jcrs.2004.11.055] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2004] [Indexed: 12/01/2022]
Abstract
PURPOSE To evaluate the protective properties of combined sodium hyaluronate 2% and mannitol 0.5% (Visiol) on the corneal endothelium in the presence of oxidative stress induced by hydrogen peroxide (H(2)O(2)). SETTING Instituto Oftalmológico de Alicante, Universidad Miguel Hernández, Alicante, Spain. METHODS This was an exploratory randomized controlled parallel-group, masked-assessor study of 3 sodium hyaluronate-based ophthalmic viscosurgical devices (OVDs): Visiol, Healon (sodium hyaluronate 1%), and Viscoat (sodium hyaluronate 3%-chondroitin sodium 4%). The OVDs were tested for protective effects on the endothelium following oxidative stress induced by H(2)O(2) at increased concentrations: control (lactated Ringer's solution), 1 mM, 10 mM, and 100 mM. Groups without OVD were used as controls at the same concentrations of peroxide. Each animal received the same treatment in both eyes (10 eyes per group). Endothelial cell lesion was assessed using the Janus green photometry absorbance technique. RESULTS At 10 mM peroxide concentration, the value of endothelial cell lesion was significantly lower in the Visiol (16.8%, P=.0056), Healon (22.2%, P=.0302), and Viscoat (21.6%, P=.0336) groups than in the control group (29.4%, no OVD). There was a trend in favor of Visiol to more efficiently reduce cell lesions of the endothelium, than Healon (P=.055) and Viscoat (P=.1013). Values of endothelial cell lesion at peroxide concentrations of 1 mM and 100 mM showed the same trends than those observed at 10 mM. CONCLUSIONS All of the OVDs tested efficiently reduced endothelial lesions against free radicals compared with the control group in which no OVD was used. The following sequence for the efficacy of endothelial cell protection was established: Visiol>Viscoat>Healon>no OVD.
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Affiliation(s)
- José I Belda
- Vissum-Instituto Oftalmológico de Alicante, 03016 Alicante, Spain.
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Davison JA. Ultrasonic power reduction during phacoemulsification using adjunctive NeoSoniX technology. J Cataract Refract Surg 2005; 31:1015-9. [PMID: 15975472 DOI: 10.1016/j.jcrs.2004.09.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Accepted: 07/20/2004] [Indexed: 11/28/2022]
Abstract
PURPOSE To compare the phacoemulsification times and powers used in 3 phacoemulsification machine configurations. SETTING Wolfe Eye Clinic, Marshalltown, Iowa, USA. METHODS A randomized prospective study of 410 consecutive cases was conducted. All cases were performed using the Alcon Legacy 20000 phacoemulsification machine. Configurations were the Standard Legacy 20000 machine (n=165), Advantec upgraded Legacy 20000 (n=112), and Advantec upgraded Legacy 20000 with NeoSoniX (n=133). Preoperative measurements included the patient's age and cataract grade using the nuclear color (NC) scale of the Lens Opacities Classification System III (LOCS III). Intraoperative measurements included machine-measured phacoemulsification time and average percentage of maximum power expenditure. An independent statistician performed analysis of covariance on NC for each of the machine configurations. RESULTS The mean age in years and the NC value were similar in each group. There was no significant difference in phacoemulsification time in minutes among the 3 machines: Standard=1.17, Advantec=1.12, NeoSoniX=1.16. The average percentage of maximum power consumption was similar for Standard Legacy 20000 at 38.00% and Advantec Legacy 20000 at 37.97% but significantly less for Advantec Legacy 20000 with NeoSoniX at 27.56% (P<.001). With the NeoSoniX-incorporated machine, compared with Standard and Advantec, a 27.5% reduction in ultrasonic energy power expenditure was observed all grades of nuclear density. CONCLUSIONS The addition of 15% amplitude NeoSoniX rotational energy reduced total ultrasonic power expenditure by 27.5% for all cataract nuclear densities.
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Affiliation(s)
- James A Davison
- Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA.
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Packer M, Fishkind WJ, Fine IH, Seibel BS, Hoffman RS. The physics of phaco: a review. J Cataract Refract Surg 2005; 31:424-31. [PMID: 15767168 DOI: 10.1016/j.jcrs.2004.11.027] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2004] [Indexed: 11/29/2022]
Abstract
Despite its unparalleled success in the field of surgery, the precise mechanism of ultrasonic phacoemulsification cataract extraction remains controversial. We review the relevant peer-reviewed literature on the subject of power generation and tip-tissue interactions to clarify the current status of our knowledge. We conclude that phacoemulsification most likely operates by a combination of mechanisms, including direct action of the vibrating tip against tissue and indirect cavitational effects. Surgeons will benefit from understanding the physical principles underlying phacoemulsification because they will be better able to evaluate the performance of various parameters and different machine settings.
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Tognetto D, Sanguinetti G, Sirotti P, Brezar E, Ravalico G. Visualization of fluid turbulence and acoustic cavitation during phacoemulsification. J Cataract Refract Surg 2005; 31:406-11. [PMID: 15767166 DOI: 10.1016/j.jcrs.2004.04.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2004] [Indexed: 11/20/2022]
Abstract
PURPOSE To describe a technique for visualizing fluid turbulence and cavitational energy created by ultrasonic phaco tips. SETTING University Eye Clinic of Trieste, Trieste, Italy. METHODS Generation of cavitational energy by the phaco tip was visualized using an optical test bench comprising several components. The technique uses a telescope system to expand a laser light source into a coherent, collimated beam of light with a diameter of approximately 50.0 mm. The expanded laser beam shines on the test tube containing the tip activated in a medium of water or ophthalmic viscosurgical device (OVD). Two precision optical collimators complete the optical test bench and form the system used to focus data onto a charge-coupled device television camera connected to a recorder. RESULTS Images of irrigation, irrigation combined with aspiration, irrigation/aspiration, and phacosonication were obtained with the tip immersed in a tube containing water or OVD. CONCLUSIONS Optical image processing enabled acoustic cavitation to be visualized during phacosonication. The system is a possible means of evaluating a single phaco apparatus power setting and comparing phaco machines and techniques.
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Vasavada AR, Raj SM, Lee YC. NeoSoniX ultrasound versus ultrasound alone for phacoemulsification: randomized clinical trial. J Cataract Refract Surg 2005; 30:2332-5. [PMID: 15519084 DOI: 10.1016/j.jcrs.2004.02.077] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2004] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate the difference in consumption of ultrasound (US) energy required with NeoSoniX (Alcon) in conjunction with US (NeoSonix US) versus US alone. SETTING Iladevi Cataract & IOL Research Center, Ahmedabad, India. METHODS This prospective randomized study comprised 120 consecutive eyes having phacoemulsification with the Alcon Legacy 20000 series at Iladevi Cataract & IOL Research Centre. Two groups of 60 eyes each were formed based on cataract grade according to the Emery classification: grade 2 and 3 nuclear sclerosis (Group A) and grade 4 and 5 nuclear sclerosis (Group B). In each group, 30 eyes had phacoemulsification using NeoSoniX US and 30 eyes, using US alone. The main parameters were intraoperative US time and mean US power. Effective phaco time (EPT) was calculated by multiplying the US time and mean US power and dividing the product by 100. The unpaired Student t test was used to evaluate the differences between NeoSoniX US and US alone. The corresponding 95% confidence intervals were calculated. RESULTS In Group A, the mean US time was 106 seconds with NeoSoniX US and 144.30 seconds with US alone (P = .002), the mean US power was 13.50% and 15.83%, respectively (P = .059), and the mean EPT was 15.17 seconds and 22.94 seconds, respectively (P = .006). In Group B, the mean US time was 193.67 seconds with NeoSoniX US and 255.17 seconds with US alone (P = .000), the mean US power was 18.31% and 22.76%, respectively (P = .000), and the mean EPT was 35.67 seconds and 59.15 seconds, respectively (P = .000). The EPT was 33.5% and 39.6% less with NeoSoniX US than with US alone in Group A and Group B, respectively. CONCLUSIONS Ultrasound energy consumption with NeoSoniX was significantly less than with US alone, indicating the value of NeoSoniX in emulsifying cataracts of optimum density and dense hard cataracts. Combining NeoSoniX and US significantly reduced the consumption of US energy.
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Takiura K, Chinzei T, Abe Y, Isoyama T, Saito I, Mochizuki S, Imachi K. A temporal and spatial analysis of cavitation on mechanical heart valves by observing faint light emission. ASAIO J 2004; 50:285-90. [PMID: 15171483 DOI: 10.1097/01.mat.0000123687.91183.21] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Cavitation on mechanical heart valves (MHVs) could cause the mechanical failure of the occluder. A simple and reliable in vitro test method to evaluate cavitation potential must be developed. The bubble implosion damages the MHV material; thus, observing the behavior of the bubble implosion is essential. According to sonoluminescence, the collapsing cavity emits faint light. Therefore, in this study, the bubble collapse was analyzed both temporally and spatially by observing faint light emission. A photon counting system has been developed using a photomultiplier tube (H7360-01, Hamamatsu Photonics, Japan). The highest time resolution of this system is 5 microsec. A quartz optical fiber bundle of 2 mm diameter can be connected to this photomultiplier tube and traversed two-dimensionally over the MHV. The closure of the MHV triggers the photon counter, and the photons through 500 beats are recorded and integrated. A 20 mm Björk-Shiley valve was submerged in a water tank containing 10 L deionized water, and the pressure difference of 120 mm Hg was exerted on the valve at a rate of 60 bpm with a pulse duplicator. Approximately 700 microsec after the valve closure, light emission was detected along the edge of the occluder on the inflow side in the major orifice. Then, approximately 1,000 microsec after the closure, light along the occluder's edge in the minor orifice was recorded as well. Compared with the analysis, using a stroboscope and a high-speed camera, faint light was emitted from the collapsing cavities. In conclusion, sonoluminescnece was successfully observed around the MHV, and the photon counting technique and the traversing mechanism of the optical fiber bundle revealed the temporal and spatial distribution of the cavity collapse on the MHV.
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Affiliation(s)
- Koki Takiura
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
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Augustin AJ, Dick HB. Oxidative tissue damage after phacoemulsification: influence of ophthalmic viscosurgical devices. J Cataract Refract Surg 2004; 30:424-7. [PMID: 15030835 DOI: 10.1016/s0886-3350(03)00577-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2003] [Indexed: 12/31/2022]
Abstract
PURPOSE To quantify the oxidative tissue damage after phacoemulsification, correlate the damage to the energy applied, and investigate the influence of ophthalmic viscosurgical devices (OVDs). SETTING Department of Ophthalmology, University of Mainz, Mainz, Germany. METHODS The study comprised 130 eyes operated on by 1 surgeon using the same phacoemulsification machine. Some eyes received an OVD before phacoemulsification and some did not. Energy values were expressed as phaco time; that is, ultrasound (US) time (seconds) after conversion to 100% phaco power. Patients were grouped as follows: Group 1, phaco time less than 20 seconds and no OVD; Group 2, phaco time 20 to 40 seconds and no OVD; Group 3, phaco time more than 40 seconds and no OVD; Group 4, phaco time 20 to 40 seconds and hydroxypropyl methylcellulose 2% (HPMC); Group 5, phaco time 20 to 40 seconds and sodium hyaluronate 1%. Aqueous humor from pseudophakic eyes served as a control. At the end of surgery, anterior chamber fluid was analyzed for lipid peroxides using the thiobarbituric acid method. RESULTS Lipid peroxides were detected in all groups. The values were significantly higher in Group 2 than in Group 1 (P<.01) and in Group 3 than in Groups 1 and 2 (P<.01). The differences in lipid peroxide values between all phaco groups and the control group were statistically significant. Sodium hyaluronate 1% and HPMC 2% produced significantly lower lipid peroxide values than in the respective phaco groups that did not receive an OVD (both P<.01). CONCLUSIONS Oxidative tissue damage occurred during phacoemulsification. The damage, which correlated with the US energy applied, can be reduced by the use of OVDs.
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Camillieri G, Nastasi A, Gulino P, Bucolo C, Drago F. Effects of Hyaluronan on Free-Radical Formation, Corneal Endothelium Damage, and Inflammation Parameters After Phacoemulsification in Rabbits. J Ocul Pharmacol Ther 2004; 20:151-7. [PMID: 15117571 DOI: 10.1089/108076804773710821] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Free-radical formation may play a role in postoperative complications of phacoemulsification (e.g., corneal endothelium damage from mechanical injury). The present experiments were aimed at investigating whether different molecular weight ranges (2000-2600, 2600-3200, or 3200-3800 kDa) of hyaluronan may influence free radical formation, corneal endothelium damage, and inflammation parameters after phacoemulsification in the rabbit eye. The viscoelastic substance was injected in the anterior chamber of rabbits' eyes before phacoemulsification, at a 2.5% concentration. The formation of free radicals was determined by adding luminol to the irrigation media and measuring the chemoluminescence in eyes. The corneal endothelial damage was evaluated by measuring the corneal central thickness by pachimetry. The inflammation parameters were measured by calculation in aqueous humor of peak levels of leukocytes and prostaglandin E(2) (PGE(2)) and evaluation in uveal tissue of myeloperoxidase activity. Hyaluronan decreased by about 58-60% free-radical formation during phacoemulsification, reduced by about 76-80% modifications in mean corneal thickness and by about 54-61% the corneal endothelial cell loss in all molecular weight ranges used. No difference was found among various molecular weight ranges. The highest molecular weight range showed to be more potent than the lowest range for reduced number of inflammation cells and level of PGE(2) in aqueous humor. Thus, hyaluronan reduces free-radical formation, exerts protection on the corneal endothelium and exerts anti-inflammation properties after phacoemulsification in rabbits. The latter effect seems to depend on the molecular weight of the substance.
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Affiliation(s)
- Giovanni Camillieri
- Department of Experimental and Clinical Pharmacology, Ocular Pharmacology Center, School of Medicine, University of Catania, Catania, Italy
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Takiura K, Chinzei T, Abe Y, Isoyama T, Saito I, Ozeki T, Imachi K. A new approach to detection of the cavitation on mechanical heart valves. ASAIO J 2003; 49:304-8. [PMID: 12790381 DOI: 10.1097/01.mat.0000065470.29806.76] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The cavitation on the mechanical heart valves (MHVs) is thought to be a cause of the mechanical failure of the occluder; also, the free radicals that would be generated when the cavitation bubbles implode might affect the patients chemically. These cavitation effects are attributed to the bubble collapse. Therefore, it is important to detect the bubble implosion behavior to analyze the cavitation on MHVs. The cavitation bubbles induce the generation of free radicals at their implosion, and the excited hydroxyl radicals emit the faint light. Based on this fact, we have tried to observe the faint light emission from a MHV to specifically capture the implosion of the cavitation bubbles. A highly sensitive CCD (charge coupled device) camera (C2400-35 VIM camera, Hamamatsu Photonics, Hamamatsu, Japan) was adopted in this study. This camera can observe low light down to the single photon counting range, and it gives two-dimensional mapping of the light. A 20 mm Björk-Shiley valve was submerged in the water tank of 10 L deionized water with luminol as a light enhancer, and then the pressure difference of 150 mm Hg was exerted on the valve at a rate of 60 bpm with a pulse duplicator. The camera and the water tank were settled in the lightproof configuration. After 2 hours of exposure, faint light images have been obtained successfully. The light emits mostly from the edge of the occluder on the inflow side in the major orifice of the valve. Therefore the results suggest that the bubbles would implode around this region and that free radicals caused by cavitation might be produced on MHV, which has coincided with our preliminary result by an electron spin resonance spectrometry.
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Affiliation(s)
- Koki Takiura
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
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Wang N, Chintala SK, Fini ME, Schuman JS. Ultrasound activates the TM ELAM-1/IL-1/NF-kappaB response: a potential mechanism for intraocular pressure reduction after phacoemulsification. Invest Ophthalmol Vis Sci 2003; 44:1977-81. [PMID: 12714632 PMCID: PMC1950284 DOI: 10.1167/iovs.02-0631] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
PURPOSE Elevated intraocular pressure (IOP), the major causal risk factor for glaucoma, often decreases after cataract removal by phacoemulsification ultrasound. In this study, the hypothesis that ultrasound energy propagated through a fluid medium induces a stress response with the potential to lower IOP was investigated. METHODS Normal and glaucomatous trabecular meshwork (TM) cell culture lines were initiated from tissue isolated from human cadaveric eyes or trabeculectomy specimens. Cultured cells were treated for 60 seconds with a phacoemulsification ultrasound probe set to a power of 70%. Activation of the TM cell-specific stress response was assayed by enzyme-linked immunosorbent assay (ELISA) and immunolocalization. RESULTS Normal TM cell cultures did not release detectable levels of the stress response protein, IL-1alpha, into their culture medium. In contrast, IL-1alpha was easily detected after treatment with ultrasound energy. Consistent with earlier findings, glaucomatous TM cells produced IL-1alpha constitutively, and the level of expression was increased after treatment with phacoemulsification ultrasound. As was previously demonstrated, the stress-regulated transcription factor NF-kappaB was present in the cytoplasm of normal cells, but in the nucleus of glaucomatous cells. After treatment with ultrasound energy, NF-kappaB translocated to the nucleus in the normal cells. Endothelial leukocyte-adhesion molecule (ELAM)-1 was not detected in normal TM cells, but was constitutively present on glaucomatous TM cells, consistent with findings in previous work. ELAM-1 expression was induced in normal cells by ultrasound treatment. CONCLUSIONS A potentially IOP-lowering stress response is induced in TM cells by ultrasound. The findings suggest that this response may be induced clinically during cataract removal by phacoemulsification, and may be one mechanism responsible for the reduction in IOP that often follows this procedure.
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Affiliation(s)
- Nan Wang
- New England Eye Center, Tufts University School of Medicine and the Tufts Center for Vision Research, Boston, Massachusetts
| | - Shravan K. Chintala
- New England Eye Center, Tufts University School of Medicine and the Tufts Center for Vision Research, Boston, Massachusetts
- Eye Research Institute, Oakland University, Rochester, Michigan
| | - M. Elizabeth Fini
- New England Eye Center, Tufts University School of Medicine and the Tufts Center for Vision Research, Boston, Massachusetts
- Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida
| | - Joel S. Schuman
- New England Eye Center, Tufts University School of Medicine and the Tufts Center for Vision Research, Boston, Massachusetts
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Topaz M, Motiei M, Assia E, Meyerstein D, Meyerstein N, Gedanken A. Acoustic cavitation in phacoemulsification: chemical effects, modes of action and cavitation index. ULTRASOUND IN MEDICINE & BIOLOGY 2002; 28:775-784. [PMID: 12113790 DOI: 10.1016/s0301-5629(02)00514-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
High-intensity ultrasound (US) energy (HIUE) has been extensively used in the last 3 decades in a wide range of surgical procedures, including phacoemulsification. The generation of radicals and sonoluminescence (SL) by application of continuous-wave (CW) HIUE to an aqueous medium under conditions simulating cataract phacoemulsification surgery is demonstrated by electron paramagnetic resonance (EPR) spectroscopy and a sensitive photon-detecting system. The findings provide direct evidence for the generation of acoustic cavitation in the simulated intraocular environment, pointing out that generation of acoustic cavitation in clinical phacoemulsification and other surgical applications of US is possible. The findings imply that the effects of acoustic cavitation in aqueous medium may contribute to the endothelial damage observed clinically following phacoemulsification cataract surgery. Saturation of the irrigating solution with various gases modifies the acoustic cavitation. Saturation of the irrigating solution with CO2 practically eliminates acoustic cavitation, with the concomitant elimination of radicals and SonL. CO2 may be utilized clinically to suppress acoustic cavitation in phacoemulsification and other medical applications. A cavitation index (CI) is introduced for the purpose of standardizing phacoemulsification instrumentation and other medical US devices that employ HIUE.
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Affiliation(s)
- Moris Topaz
- Hillel Yaffe Medical Center, Hadera, Israel.
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Cavallini GM, Campi L, Delvecchio G, Lazzerini A, Longanesi L. Comparison of the clinical performance of Healon 5 and Healon in phacoemulsification. Eur J Ophthalmol 2002; 12:205-11. [PMID: 12113566 DOI: 10.1177/112067210201200306] [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: 11/16/2022]
Abstract
PURPOSE Healon 5 is a high-molecular-mass fraction of sodium hyaluronate. Its density endows it with a number of viscoelastic characteristics. In this prospective, randomised clinical study we compared the performance of Healon 5 and Healon in phacoemulsification. SETTING Institute of Ophthalmology, University of Modena and Reggio Emilia, Italy. METHODS Two groups of patients underwent phacoemulsification and intraocular lens (IOL) implantation. In the first 27 patients Healon 5 was used as viscoelastic substance during surgery, and in the second 27 Healon was used. The surgeons subjective comments on the performance of these viscoelastic agents were recorded at the different steps of surgery: injection, capsulorhexis, phacoemulsification, IOL implantation, removal of viscoelastic agent and trasparency throughout the operation. The surgeon's overall impression of the viscoelastics during the whole operation was noted. Tonometry and endothelial cell count were performed in all patients before and after operation. RESULTS There was no statistical difference between the two groups as regards visual acuity, ocular pressure and endothelial damage. Healon 5 showed excellent ability to maintain the anterior chamber during capsulorhexis, phacoemulsification and IOL implantation. Removal time with Healon 5 was not appreciably longer than Healon. CONCLUSIONS Healon 5 emerges as a very interesting viscoelastic substance. Visibility is better if the anterior chamber is filled completely. Removal is easier if it is aspirated while moving the irrigation aspiration tip with circular movements over the top and around the border of the IOL.
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Affiliation(s)
- G M Cavallini
- Institute of Ophthalmology, University of Modena and Reggio Emilia, Italy.
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Bosch-Driessen LH, Plaisier MB, Stilma JS, Van der Lelij A, Rothova A. Reactivations of ocular toxoplasmosis after cataract extraction. Ophthalmology 2002; 109:41-5. [PMID: 11772577 DOI: 10.1016/s0161-6420(01)00845-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
PURPOSE To determine the risk of reactivation of ocular toxoplasmosis following cataract extraction. DESIGN Retrospective case-control study. PARTICIPANTS Out of 154 patients with ocular toxoplasmosis, 14 patients (15 eyes) who had undergone a cataract extraction and 45 age- and sex- matched controls without cataract were selected. INTERVENTION A review of the medical records of 14 patients with ocular toxoplasmosis and cataract and 45 control patients with ocular toxoplasmosis but without cataract. The clinical records of the controls and patients were assessed for an identical 4-month period following the date of the cataract extraction in the index patients. MAIN OUTCOME MEASURES Development of a new active retinal lesion within 4 months after cataract surgery in patients and age -and sex matched-controls. The presence of risk factors such as sex, congenital or postnatal acquisition of ocular toxoplasmosis, age at first clinical manifestation of ocular toxoplasmosis, total number of attacks per affected eye, type of cataract, age at the time of cataract surgery and the intervals between surgery and first clinical manifestation of ocular toxoplasmosis and between surgery and the last recurrence of ocular toxoplasmosis, as well as the use of antiparasitic medication during surgery, type and complications of surgery and optimal visual acuity before and after cataract surgery. RESULTS Reactivations of ocular toxoplasmosis following cataract extraction occurred in 5/14 patients (5/15 eyes), which was higher than the incidence of recurrences in age -and sex-matched controls (p < 0.001). No additional risk factors for the development of recurrences of ocular toxoplasmosis after cataract surgery were found. Incidence of recurrences preceding surgery did not differ between patients and controls. CONCLUSION We identified an increased risk of reactivation of ocular toxoplasmosis following cataract extraction which implies that prophylactic treatment with antiparasitic drugs during and after the cataract surgery might be worthwhile for patients at risk of visual loss.
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Affiliation(s)
- Lotje H Bosch-Driessen
- FC Donders Institute of Ophthalmology, University Medical Center Utrecht, E. 03-136 Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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Manzanas L, Jesús del Nozal M, Marcos MA, Cordero Y, Bernal JL, Goldschmidt P, Pastor JC. Oral flavonoids, chromocarb diethylamine salt and cyaninosides chloride, to eliminate lipoperoxidation postvitrectomy. Exp Eye Res 2002; 74:23-8. [PMID: 11878815 DOI: 10.1006/exer.2001.1069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This study was undertaken to determine the concentration of malondialdehyde, an end product of lipoperoxidation, in lens and retinal tissue postvitrectomy associated with oral administration of antioxidant flavonoids cyaninosides chloride and chromocarb diethylamine salt or N -acetylcysteine. Fifty adult pigmented rabbits were divided into five groups: (1) controls (normal eyes, malondialdehyde concentration in lens and retina); (2) vitrectomy with BSS Plus (malondialdehyde level measured 2hr after vitrectomy); (3) vitrectomy with BSS Plus and pretreatment with oral cyaninosides chloride 100mg kg day(-1)for 3 weeks (malondialdehyde level measured 2hr after surgery); (4) vitrectomy with BSS Plus and pretreatment with oral chromocarb diethylamine salt 100 mg kg day(-1)for 3 weeks (malondialdehyde level measured 2hr after surgery); and (5) vitrectomy with BSS Plus and pretreatment with oral N -acetylcysteine 200 mg kg day(-1)for 3 weeks (malondialdehyde level measured 2hr after surgery). Lens and retina samples were used to determine malondialdehyde levels using ion-pairing high performance liquid chromatography. Statistical analysis was done using analysis of variance (P<0.05). The content of malondialdehyde in the normal lens was 0.036 +/- 0.017 microg g(-1); in the vitrectomized groups the malondialdehyde concentrations were as follows: (2) 0.027 +/- 0.013 microg g(-1); (3) under detection limit (detection limit=1.75x e-3 microg g(-1)); (4) under detection limit; and (5) 0.020 +/- 0.006 microg g(-1). The results showed that the malondialdehyde concentration in the normal retina was 1.160 +/- 0.361 microg g(-1), while in the vitrectomized groups with or without pretreatment (cyaninosides chloride, chromocarb diethylamine salt, and N -acetylcysteine) the malondialdehyde levels were 2.091 +/- 0.982 microg g(-1), 0.069 +/- 0.024 microg g(-1), 0.082 +/- 0.027 microg g(-1), and 0.215 +/- 0.134 microg/g(-1), respectively, all significantly different from the normal eyes (P<0.05). Vitrectomy induced increased malondialdehyde levels in the retina. Oral flavonoids are an effective protective therapy for surgically induced lipoperoxidation, especially in the retina.
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Affiliation(s)
- Lucia Manzanas
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Facultad de Medicina, Universidad de Valladolid, c/Ramón y Cajal, 7, Valladolid 47010, Spain.
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Koralewska-Makár A, Johnsson C, Bruun A, Stenevi U, Ehinger B. Influence of laser irradiation on endogenous hyaluronan in rabbit iris and aqueous humor. ACTA OPHTHALMOLOGICA SCANDINAVICA 2001; 79:493-6. [PMID: 11594986 DOI: 10.1034/j.1600-0420.2001.790513.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE To monitor changes of endogenous hyaluronan in the iris tissue and aqueous humor after an isolated trauma to the iris by argon laser irradiation of the anterior surface of the iris. METHODS Iris and aqueous hyaluronan concentrations in rabbit were measured with a radiometric assay at different time points after laser irradiation. RESULTS Total hyaluronan content in iris tissue increased 3-fold to a peak concentration of 71-72 microg/g at 1 and 2 days after laser treatment. Aqueous hyaluronan increased to a maximum of about 1.6 microg/ml at 2 h and 12 h after laser irradiation of the iris. CONCLUSIONS The iris tissue responds with increased hyluronan synthesis to an isolated iris argon laser irradiation and it seems to be the most important source of aqueous hyaluronan.
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Miller DL, Spooner GJ, Williams AR. Photodisruptive laser nucleation of ultrasonic cavitation for biomedical applications. JOURNAL OF BIOMEDICAL OPTICS 2001; 6:351-358. [PMID: 11516327 DOI: 10.1117/1.1380669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2000] [Revised: 10/27/2000] [Accepted: 02/26/2001] [Indexed: 05/23/2023]
Abstract
Pulses of high intensity laser light, when focused into transparent materials, may produce localized electron-ion plasmas through optical breakdown. By simultaneously incorporating the resulting volume of vaporized material within the focal volume of a high intensity ultrasound source, the photodisruption (1.05 microm wavelength) void served as a nucleation site for ultrasonic cavitation. Dilute suspensions of canine erythrocytes in phosphate buffered saline were exposed in a flow-through exposure chamber and the percentage of lysed cells was used as a measure of the biologically effective cavitation activity produced in the chamber. Brief (about 30 micros) acoustic emissions were detected from the photodisruption alone (indicating laser nucleation of bubbles), but the cell lysis produced was undetectable against the background. However, combined exposure greatly increased both the duration of the acoustic emissions (up to 1.5 ms) and the amount of cell lysis above an ultrasonic pressure amplitude threshold of about 4.3 MPa at 2.5 MHz. The amount of cell lysis (sometimes approaching 100%) increased with increasing ultrasonic intensity, laser pulse energy and laser PRF. Addition of 5% serum albumin enhanced the effect, apparently by stabilizing bubbles and nuclei. Photodisruptive laser nucleation of ultrasonic cavitation can provide controlled and synergistic enhancement of bioeffects.
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Affiliation(s)
- D L Miller
- University of Michigan Medical Center, Department of Radiology, 3315 Kresge III, 200 Zina Pitcher Place, Ann Arbor, Michigan 48109, USA.
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