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1.
J Fr Ophtalmol ; 38(9): 855-60, 2015 Nov.
Artigo em Francês | MEDLINE | ID: mdl-26363923

RESUMO

PURPOSE: To compare intraocular pressure (IOP) at one year with the InnFocus MicroShunt(®) with or without cataract surgery with according to placement and concentration of mitomycin C (MMC) DESIGN: A retrospective two-center, two-surgeon study (France and Dominican Republic). PATIENTS AND METHODS: Adults with POAG requiring filtering surgery. One MicroShunt(®) was placed in one eye of each patient. The effect of concentration and site of application of MMC was assessed by IOP and medication reduction at one year. RESULTS: Eighty-seven eyes were studied with one-year follow-up. Twenty-three eyes treated with 0.4 mg/mL MMC close to the limbus demonstrated a 55% reduction in IOP from 23.8 ± 5.3 at baseline to 10.7 ± 2.8 mmHg at one year. Topical glaucoma medication/patient was reduced 85% from 2.4 ± 0.9 to 0.3 ± 0.8. Thirty-one eyes treated with 0.2mg/mL MMC close to the limbus demonstrated a 52% reduction in IOP from 27.9 ± 6.7 at baseline to 13.3 ± 3.3 mmHg at one year. Topical glaucoma medication/patient was reduced 88% from 2.5 ± 1.4 to 0.5 ± 1.0. Thirty-three eyes treated with 0.4 mg/mL MMC deep in the pocket demonstrated a 38% reduction in IOP from 25.4 ± 7.9 at baseline to 15.7 ± 4.6 mmHg at one year. Topical glaucoma medication/patient was reduced 72% from 2.9 ± 1.0 to 0.8 ± 1.3. There were no sight-threatening long-term adverse events. CONCLUSION: The InnFocus MicroShunt(®) is a filtering surgery whose efficacy is related to the location of application and concentration of MMC used.


Assuntos
Cirurgia Filtrante , Glaucoma/cirurgia , Mitomicina/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Cirurgia Filtrante/instrumentação , Humanos , Pressão Intraocular , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Tonometria Ocular , Resultado do Tratamento , Adulto Jovem
2.
Diabetologia ; 54(5): 1121-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21360190

RESUMO

AIMS/HYPOTHESIS: The aim of this study was to provide evidence that the anterior chamber of the eye serves as a novel clinical islet implantation site. METHODS: In a preclinical model, allogeneic pancreatic islets were transplanted into the anterior chamber of the eye of a baboon model for diabetes, and metabolic and ophthalmological outcomes were assessed. RESULTS: Islets readily engrafted on the iris and there was a decrease in exogenous insulin requirements due to insulin secretion from the intraocular grafts. No major adverse effects on eye structure and function could be observed during the transplantation period. CONCLUSIONS/INTERPRETATION: Our study demonstrates the long-term survival and function of allogeneic islets after transplantation into the anterior chamber of the eye. The safety and simplicity of this procedure provides support for further studies aimed at translating this technology into the clinic.


Assuntos
Câmara Anterior/cirurgia , Diabetes Mellitus Experimental/terapia , Transplante das Ilhotas Pancreáticas/métodos , Animais , Papio
3.
Jpn J Ophthalmol ; 46(4): 419-25, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12225821

RESUMO

PURPOSE: To determine whether measurements of the a-wave latency of the electroretinogram (ERG) can be made as reliably as that of the implicit time (IT) in rats. In addition, to determine the relationship between the potential level selected for the latency and the baseline potential level. METHODS: ERGs, elicited by different stimulus intensities, were recorded from Long-Evans rats. The a-wave latency was determined by measuring the time between the stimulus onset and the beginning of the negative-going a-wave, and the IT was measured as the time between the stimulus onset and the peak of the a-wave. To test the reliability of the measurements of the latency, the a-wave latency and the IT were measured by three independent observers for the same 15 ERGs. RESULTS: The mean a-wave latency was approximately 14 milliseconds, and the mean a-wave implicit time was approximately 36 milliseconds. The mean of the a-wave latency and the IT, as measured by the three observers, were within 1 millisecond of each other. The coefficient of variation was as good for the latency as for the IT of the a-wave. The potential level selected for the latency was lower than the mean baseline potential level by 1 to 2 standard deviations. CONCLUSIONS: Selection of the a-wave latencies can be made as reliably as that for the IT. Because the a-wave latency is not affected by the activity of the second order neurons, the latency is a better measure than the IT of the time course of the a-wave.


Assuntos
Eletrorretinografia , Retina/fisiologia , Animais , Adaptação à Escuridão , Ratos , Ratos Long-Evans , Tempo de Reação , Reprodutibilidade dos Testes , Fatores de Tempo
4.
Exp Eye Res ; 74(1): 51-9, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11878818

RESUMO

The major problems associated with the use of corticosteroids for the treatment of ocular diseases are their poor intraocular penetration to the posterior segment when administered locally and their secondary side effects when given systemically. To circumvent these problems more efficient methods and techniques of local delivery are being developed. The purposes of this study were: (1) to investigate the pharmacokinetics of intraocular penetration of hemisuccinate methyl prednisolone (HMP) after its delivery using the transscleral Coulomb controlled iontophoresis (CCI) system applied to the eye or after intravenous (i.v.) injection in the rabbit, (2) to test the safety of the CCI system for the treated eyes and (3) to compare the pharmacokinetic profiles of HMP intraocular distribution after CCI delivery to i.v. injection. For each parameter evaluated, six rabbit eyes were used. For the CCI system, two concentrations of HMP (62.5 and 150mg ml(-1)), various intensities of current and duration of treatment were analyzed. In rabbits serving as controls the HMP was infused in the CCI device but without applied electric current. For the i.v. delivery, HMP at 10mg kg(-1)as a 62.5mg ml(-1)solution was used. The rabbits were observed clinically for evidence of ocular toxicity. At various time points after the administration of drug, rabbits were killed and intraocular fluids and tissues were sampled for methylprednisolone (MP) concentrations by high pressure liquid chromatography (HPLC). Histology examinations were performed on six eyes of each group. Among groups that received CCI, the concentrations of MP increased in all ocular tissues and fluids in relation to the intensities of current used (0.4, 1.0 and 2.0mA/0.5cm(2)) and its duration (4 and 10min). Sustained and highest levels of MP were achieved in the choroid and the retina of rabbit eyes treated with the highest current and 10min duration of CCI. No clinical toxicity or histological lesions were observed following CCI. Negligible amounts of MP were found in ocular tissues in the CCI control group without application of current. Compared to i.v. administration, CCI achieved higher and more sustained tissue concentrations with negligible systemic absorption. These data demonstrate that high levels of MP can be safely achieved in intraocular tissues and fluids of the rabbit eye, using CCI. With this system, intraocular tissues levels of MP are higher than those achieved after i.v. injection. Furthermore, if needed, the drug levels achieved with CCI can be modulated as a function of current intensity and duration of treatment. CCI could therefore be used as an alternative method for the delivery of high levels of MP to the intraocular tissues of both the anterior and posterior segments.


Assuntos
Anti-Inflamatórios/farmacocinética , Sistemas de Liberação de Medicamentos , Olho/metabolismo , Glucocorticoides/farmacocinética , Iontoforese/métodos , Hemissuccinato de Metilprednisolona/farmacocinética , Animais , Anti-Inflamatórios/sangue , Humor Aquoso/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Relação Dose-Resposta a Droga , Esquema de Medicação , Olho/anatomia & histologia , Olho/efeitos dos fármacos , Feminino , Glucocorticoides/sangue , Injeções Intravenosas , Hemissuccinato de Metilprednisolona/sangue , Coelhos , Corpo Vítreo/metabolismo
5.
Retina ; 21(5): 513-20, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11642382

RESUMO

PURPOSE: To assess in vitro the potential of silicone oil as a delivery system for acetylsalicylic acid (ASA) and to evaluate in vivo the pharmacokinetic distribution of salicylic acid (SA) in the eye. METHODS: In an experimental model ASA/silicone oil suspension mixed to a concentration of 1.67 mg/mL was investigated for release rate of ASA and SA. In vivo vitrectomy and intravitreal injection of two different ASA/silicone oil suspensions, both mixed to a concentration of 1.67 mg/mL, was performed on two groups, A and B, of New Zealand white rabbits. Salicylic acid concentrations in ocular tissues, aqueous, vitreous, and blood plasma were evaluated at 6 hours, 24 hours, and 5 days using high performance liquid chromatography. RESULTS: Salicylic acid was detected in all tissues. The highest levels were obtained in the vitreous: 745.4 microg/mL (A) and 640.0 microg/mL (B) at 6 hours. The retina followed with 332.9 ng/mg (A) and 281.3 ng/mg (B) at 6 hours and 31.6 ng/mg (A) and 48.1 ng/mg (B) at day 5. The maximum blood plasma levels were 5.2 microg/mL. CONCLUSION: Silicone oil is an efficacious delivery system of ASA in vitro and in vivo. Higher concentrations of SA were found in all ocular tissues and fluids when compared to intravenous administration of maximum doses.


Assuntos
Anti-Inflamatórios/administração & dosagem , Aspirina/administração & dosagem , Dimetilpolisiloxanos/administração & dosagem , Sistemas de Liberação de Medicamentos , Fibrinolíticos/administração & dosagem , Silicones/administração & dosagem , Animais , Anti-Inflamatórios/farmacocinética , Aspirina/farmacocinética , Cromatografia Líquida de Alta Pressão , Dimetilpolisiloxanos/farmacocinética , Olho/metabolismo , Fibrinolíticos/farmacocinética , Projetos Piloto , Coelhos , Silicones/farmacocinética , Esteroides , Distribuição Tecidual , Vitrectomia
6.
Optom Vis Sci ; 78(6): 405-10, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11444629

RESUMO

Phaco-Ersatz is a surgical procedure for restoring accommodation in which the presbyopic crystalline lens is replaced by a flexible polymer gel in the lens capsule. We assessed the feasibility of simultaneously correcting ametropia while restoring accommodation using Phaco-Ersatz by utilizing polymer gel of the appropriate refractive index. Computation results using paraxial equations and ray tracing on two model eyes indicate that although this approach might be feasible for the hypermetrope, its usefulness for correcting myopia is limited, principally due to significant reductions in the resultant amplitude of accommodation.


Assuntos
Acomodação Ocular/fisiologia , Facoemulsificação/métodos , Procedimentos Cirúrgicos Refrativos , Capsulorrexe/métodos , Cristalino/cirurgia , Modelos Biológicos , Polímeros , Presbiopia/fisiopatologia , Próteses e Implantes , Implantação de Prótese
7.
Graefes Arch Clin Exp Ophthalmol ; 239(3): 208-16, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11405070

RESUMO

BACKGROUND: A new method of intravitreal drug delivery of acetylsalicyclic acid (AS) in silicone oil was investigated for safety and for its pharmacokinetics in the posterior pole of the eye. METHODS: The AS was mixed in silicone oil to a concentration of 1.67 mg/ml. After vitrectomy, 15 NZW rabbits received an intravitreal injection of AS/silicone oil suspension. Clinical examination, pre- and postoperative electroretinography (ERG) and histology were performed. The pharmacokinetics of the distribution of salicylic acid was determined by HPLC analysis at 6 h, 24 h and 5 days in optic nerve, retina, choroid, vitreous, and blood. RESULTS: Clinical examination and histology revealed no adverse effects or signs of toxicity. The ERGs showed no significant difference between the pre- and postoperative results. The salicylic acid concentrations demonstrated peak values in the residual vitreous (640.0 micrograms/ml), choroid (446.0 ng/mg) and retina (281.3 ng/mg) at 6 h. At 24 h, the salicylic acid concentration decreased to 20.9 micrograms/ml in the residual vitreous and to 38.5 ng/mg in the retina. At 5 days the retinal level was still 48.1 ng/mg. CONCLUSIONS: AS delivery by intravitreal administration of loaded silicone oil is a safe method and results in high concentrations of salicylic acid in the posterior segment of the eye while maintaining low blood levels.


Assuntos
Aspirina/farmacocinética , Inibidores de Ciclo-Oxigenase/farmacocinética , Sistemas de Liberação de Medicamentos , Fibrinolíticos/farmacocinética , Óleos de Silicone , Corpo Vítreo/metabolismo , Animais , Disponibilidade Biológica , Corioide/metabolismo , Corioide/patologia , Cromatografia Líquida de Alta Pressão , Eletrorretinografia , Feminino , Masculino , Coelhos , Retina/metabolismo , Retina/patologia , Segurança , Vitrectomia , Corpo Vítreo/patologia
8.
Biomaterials ; 22(10): 1125-36, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11352092

RESUMO

Axonal growth and myelination in a SC graft contained in a resorbable tubular scaffold made of poly(D,L-lactic acid) (PLA50) or high molecular weight poly(L-lactic acid) mixed with 10% poly(L-lactic acid) oligomers (PLA(100/10)) were studied for up to 4 months after implantation in the completely transected adult rat thoracic spinal cord. The PLA50 tubes collapsed soon after implantation and, consequently, compressed the graft inside, leading to only occasional thin cables with SCs and a low number of myelinated axons: 17 +/- 6 at 1 and 158 +/- 11 at 2 months post-grafting. The cable contained 32 +/- 23 blood vessels at 2 weeks, 55 +/- 33 at 1 month and 46 +/- 30 at 2 months after implantation. PLA(100/10) tubes, on the other hand, were found to break up into large pieces, which compressed and sometimes protruded into the tissue cable inside. At all time points studied, however, cables contained SCs and were well vascularized with 414 +/- 47 blood vessels at 2 weeks, 437 +/- 139 at 1, 609 +/- 134 at 2 and 396 +/- 95 at 4 months post-grafting. The number of myelinated axons was 712 +/- 509 at 1 month, 1819 +/- 837 at 2 months and 609 +/- 132 at 4 months post implantation. These results demonstrated that fiber growth and myelination into a SC graft contained in a resorbable PLA(100/10) tube increases over the first 2 months post-implantation but decreases thereafter. Changes in geometry of both types of polymer tubes were detrimental to axonal regeneration. Future research should explore the use of polymers that better retain the appropriate mechanical, geometrical and permeability properties over time.


Assuntos
Axônios/fisiologia , Materiais Biocompatíveis , Ácido Láctico , Regeneração Nervosa/fisiologia , Polímeros , Células de Schwann/transplante , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/terapia , Animais , Feminino , Teste de Materiais , Bainha de Mielina/patologia , Neovascularização Patológica , Poliésteres , Ratos , Ratos Endogâmicos F344 , Traumatismos da Medula Espinal/patologia , Fatores de Tempo
9.
Cornea ; 20(3): 317-20, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11322423

RESUMO

PURPOSE: To evaluate the efficacy of dextran in balanced salt solution (BSS) as a preparation of eye bank corneas for experimental surgeries. METHODS: We used 12 eye bank eyes that were unsuitable for transplant. The corneas were removed from the globe and affixed to a Hanna artificial anterior chamber. Four concentrations of dextran-BSS (10%, 15%, 20%, and 30% [+/-0.56%]) were used to dehydrate the corneas, and corneal thickness was assessed with an ultrasonic pachymeter (+/-5 microm) at varying time-intervals over 3 hours. RESULTS: The corneas were thinned to an average thickness of 477+/-54 microm, 430+/-54 microm, 406+/-61 microm, and 391+/-52 microm at average times of 75+/-0 minutes, 85+/-23 minutes, 60+/-12 minutes, and 45+/-0 minutes for the 10%, 15%, 20%, and 30% concentrations, respectively. Corneal thickness was stabilized in both a 15% and a 20% solution. The data was fit to exponential curves until a minimum value was reached, after which linear regression analysis was used to determine the slopes of the data. The slopes for the 15% and 20% concentrations were not significantly different from 0 (p = 0.5 and p = 0.4, respectively). The slopes for each set of data from the 10% and 30% concentrations were significantly different from each other (p = 0.010 and p = 0.001, respectively). CONCLUSIONS: A solution of 20% dextran in BSS is effective for dehydrating eye bank corneas to a quasi-normal physiologic thickness and for maintaining the thickness for a sufficient amount of time. Both the posterior and anterior sides of the cornea should be exposed to the solution for 60 minutes.


Assuntos
Córnea/cirurgia , Bancos de Olhos , Procedimentos Cirúrgicos Oftalmológicos , Manejo de Espécimes/métodos , Acetatos/farmacologia , Idoso , Idoso de 80 Anos ou mais , Córnea/efeitos dos fármacos , Dessecação , Dextranos/farmacologia , Combinação de Medicamentos , Humanos , Pessoa de Meia-Idade , Minerais/farmacologia , Cloreto de Sódio/farmacologia , Doadores de Tecidos
11.
Retina ; 21(1): 48-53, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11217929

RESUMO

PURPOSE: Intravenous (i.v.) pulse of corticosteroids has been used to treat severe eye inflammation from different origins. Whether such large doses result in vitreous levels that differ either in magnitude or duration from more conventional corticotherapy remain unsolved issues. The authors therefore determined levels of methylprednisolone hemisuccinate and methylprednisolone in the vitreous and serum of patients at different times after a single i.v. perfusion of methylprednisolone hemisuccinate. METHODS: Fifty patients scheduled for a first vitrectomy received an i.v. injection of 500 mg hemisuccinate methylprednisolone at different times before surgery (from 15-24 hours). Patients were divided into two groups: those with (n = 21) and without (n = 29) retinal detachment (RD). Pure vitreous samples were analyzed by high-pressure liquid chromatography. RESULTS: Both the ester and the nonester methylprednisolone forms were sampled in the vitreous, showing a slower rate of hydrolysis compared to the serum. On average, the highest concentration of total methylprednisolone in the vitreous was found at 2.5 hours and rapidly decreased for the group of patients with RD. In the group of patients without RD, the highest concentration was reached at 6 hours and then slowly decreased. The antiinflammatory potency in the nondetached retina eyes was approximately 500 times more than in the physiologic vitreous, but despite the route of administration (i.v. or oral), only 1/10 of the corticosteroid serum concentration was measured in the vitreous. CONCLUSION: High concentration of methylprednisolone is achieved by i.v. pulse therapy without changing the kinetic of entry in the vitreous of nondetached retina eyes when compared to conventional oral corticotherapy. Hydrolysis occurs in the vitreous resulting in high rate of active form. Pulse therapy could be considered in cases of severe ocular inflammation involving the posterior segment of the eye.


Assuntos
Glucocorticoides/farmacocinética , Hemissuccinato de Metilprednisolona/farmacocinética , Corpo Vítreo/metabolismo , Adolescente , Adulto , Idoso , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Feminino , Glucocorticoides/administração & dosagem , Humanos , Injeções Intravenosas , Masculino , Hemissuccinato de Metilprednisolona/administração & dosagem , Pessoa de Meia-Idade , Pulsoterapia , Distribuição Tecidual , Vitrectomia
12.
Arch Ophthalmol ; 118(7): 965-8, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10900111

RESUMO

BACKGROUND: Partial thickness sclerectomy is the most commonly employed scleral shortening technique used in conjunction with pars plana vitrectomy in the repair of myopia-associated macular holes in patients with staphyloma. Recently, scleral shortening induced through scleral invagination has been advocated as an adjunct in retinal translocation surgery. OBJECTIVE: To determine whether a correlation exists between the amount of sclera infolding and the posttreatment reduction in axial length (AL) as a result of lamellar scleral resectioning or full-thickness scleral invagination. METHODS: Three groups of 10 eyes each underwent lamellar scleral resection with dissection of 6, 8, and 10 mm in height, and 1 group of 10 eyes underwent a 10-mm invagination. Presurgical and postsurgical external AL of globes with stabilized intraocular pressure was measured to +/-0.022-mm precision. RESULTS: Average (+/-SD) AL shortening following lamellar resections for 6-, 8-, and 10-mm groups were 1.50+/-0.24, 2.10+/-0.13, and 2.65+/-0.24 mm, respectively, and 2.50+/-0.23 mm for the 10-mm invagination group. Differences in AL before and after scleral shortening were found to be significantly different between dissections of different heights (P<.05), and not significantly different between the 10-mm resection and invagination groups (P>.17). The AL of each group was shortened by approximately 25% of the resection-invagination height. The relation was quasilinear. CONCLUSIONS: Lamellar scleral resection and nonresected scleral invagination reduce the ocular AL. The extent of the reduction significantly correlates to the amount of removed or invaginated sclera. CLINICAL RELEVANCE: Surgical shortening of the sclera is useful in the management of several retinal disorders, but causes significant changes in AL. Arch Ophthalmol. 2000;118:965-968


Assuntos
Oftalmopatias/etiologia , Olho/patologia , Esclera/cirurgia , Esclerostomia/efeitos adversos , Oftalmopatias/patologia , Humanos
13.
Lasers Surg Med ; 26(1): 67-75, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10637005

RESUMO

BACKGROUND AND OBJECTIVE: The size (0.5-1.0 cm) of early nonpalpable breast tumors currently detected by mammography and confirmed by stereotactic core biopsy is of the order of the penetration depth of near infrared photons in breast tissue. In principle, stereotactically biopsied tumors, therefore, could be safely and efficiently treated with laser thermotherapy. The aim of the current study is to confirm the controlled heating produced by clinically relevant power levels delivered with an interstitial laser fiber optic probe adapted for use with stereotactic mammography and biopsy procedures. STUDY DESIGN/MATERIALS AND METHODS: Temperature increases and the resultant thermal field produced by the irradiation of ex vivo (porcine and human) and in vivo (porcine) tissue models appropriate to the treatment of human breast tissue by using cw Nd:YAG laser radiation delivered with a interstitial fiber optic probe with a quartz diffusing tip, were recorded with an array of fifteen 23-gauge needle thermocouple probes connected to a laboratory computer-based data acquisition system. RESULTS: By using a stepwise decreasing power cycle to avoid tissue charring, acceptably symmetric thermal fields of repeatable volumetric dimensions were obtained. Reproducible thermal gradients and predictable tissue necrosis without carbonization could be induced in a 3-cm-diameter region around the fiber probe during a single treatment lasting only 3 minutes. The time-dependences of the temperature rise of the thermocouples surrounding the LITT probe were quantitatively modeled with simple linear functions during the applied laser heating cycles. CONCLUSION: Analysis of our experimental results show that reproducible, symmetric and predictable volumetric temperature increases in time can be reliably produced by interstitial laser thermotherapy.


Assuntos
Tecido Adiposo/efeitos da radiação , Neoplasias da Mama/terapia , Hipertermia Induzida/métodos , Terapia a Laser , Animais , Humanos , Suínos
14.
J Biomed Mater Res ; 47(2): 260-9, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10449638

RESUMO

A novel drainage implant for glaucoma filtering surgery (MESH) is proposed. After various expanded poly(tetrafluoroethylene) (e-PFTE) materials were evaluated, the feasibility and the short-term safety of the technique were assessed in this first pilot study in the rabbit. The porous structure and the in vitro resistance to aqueous flow of seven different e-PTFE membranes (5-80 microm average pore size) were compared. Eight Dutch pigmented rabbits were implanted with the T-shaped MESH implants made from either 20- or 50-microm average pore size e-PTFE membranes. Clinical examination, intraocular pressure (IOP) measurements, and histology analyses were performed over a period of 3 months. The contralateral nonoperated eyes served as controls. MESH implantation took less than 7 min. No postoperative hypotony, migration, or extrusion of the implant and no intraocular inflammation or infection occurred. A significant IOP reduction in the implanted eyes was obtained past postoperative day 21 with the 20-microm material implant. The drainage efficacy was correlated with the degree of colonization of the porous materials and the inner spacing of the implant as observed by histology. With a filtering patency 3 times longer than conventional trabeculectomy and laser sclerectomy, MESH surgery is a promising technique for glaucoma treatment. Further studies are underway to enhance the device efficacy and understand the mechanism of filtration.


Assuntos
Materiais Biocompatíveis , Implantes para Drenagem de Glaucoma , Glaucoma/cirurgia , Politetrafluoretileno , Animais , Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Humanos , Politetrafluoretileno/efeitos adversos , Politetrafluoretileno/química , Coelhos
15.
Acta Ophthalmol Scand ; 77(3): 279-85, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10406146

RESUMO

PURPOSE: To investigate scleral and episcleral histological alterations induced by encircling explants used in scleral buckling procedures. METHODS: We performed a histopathological study of 20 enucleated eyes after failure of retinal detachment surgery including encircling scleral buckle. RESULTS: Nonabsorbable materials were encapsulated and often gave rise to a limited scleral invagination. The inner capsular surface was regular in 10 silicone explants, it was partially covered with hydrogel fragments and a granulomatous foreign body giant cell reaction in 8 hydrogel explants. One Arruga thread was encased in fibrosis and a catgut circle showed no encapsulation. Other changes were mostly related to the long-standing retinal detachment: peripheral anterior synechiae, anterior uveal effusion, persistent retinal detachment, retinal gliosis, retinal atrophy, retinal breaks, and silicone oil droplets. CONCLUSION: All nonabsorbable explants underwent encapsulation and prompted scleral invagination. A granulomatous reaction accompanied hydrogel fragmentation. The long term fragmentation impact on implanted eyes remains unknown.


Assuntos
Granuloma de Corpo Estranho/patologia , Esclera/patologia , Recurvamento da Esclera/efeitos adversos , Doenças da Esclera/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Materiais Biocompatíveis/efeitos adversos , Categute/efeitos adversos , Feminino , Fibrose , Seguimentos , Granuloma de Corpo Estranho/etiologia , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/efeitos adversos , Masculino , Pessoa de Meia-Idade , Descolamento Retiniano/cirurgia , Estudos Retrospectivos , Doenças da Esclera/etiologia , Elastômeros de Silicone/efeitos adversos
16.
J Cataract Refract Surg ; 25(6): 744-7, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10374151

RESUMO

Cataract surgery is routinely performed using an anterior continuous curvilinear capsulorhexis (CCC). A manual surgical technique is described for performing a small (less than 1.5 mm diameter) anterior CCC. This technique's applications extend from Phaco-Ersatz, a cataract surgical technique designed to restore accommodation to pediatric cataract surgery. An experimental rabbit study was conducted to determine the feasibility of the technique. Up to 9 small peripheral anterior CCCs were made in the same lens capsule without the capsule tearing. The mean diameter of the CCCs was 1.1 mm +/- 0.3 (SD). A 30 gauge needle and Utrata capsulorhexis forceps were used to construct the CCC. This technique shows promise for the successful performance of small CCCs in Phaco-Ersatz procedures and pediatric cataract surgery.


Assuntos
Capsulorrexe/métodos , Cápsula do Cristalino/cirurgia , Animais , Estudos de Viabilidade , Coelhos
17.
J Cataract Refract Surg ; 25(3): 332-9, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10079437

RESUMO

PURPOSE: To evaluate experimentally and clinically the tolerance and efficacy of a reticulated hyaluronic acid implant in nonperforating trabecular surgery (NPTS). SETTING: Bascom Palmer Eye Institute, Miami, Florida, USA, and Clinique Sourdille and Clinique Ophtalmologique Universitaire, Nantes, France. METHODS: In experimental surgery, NPTS was performed with and without a hyaluronic acid implant in 25 rabbit eyes. In a pilot study, the results of NPTS with a hyaluronic acid implant in 72 human eyes were retrospectively analyzed in terms of visual acuity, intraocular pressure (IOP), external filtration, postoperative inflammation, and gonioscopy. Mean follow-up was 13.8 months (range 6 to 24 months). RESULTS: In the experimental surgery, the rabbit eyes with the implant showed a different healing process than the eyes without the implant. The implant was slowly bioabsorbed and remnants were seen at the operative site (where the tissue was removed) up to day 56 postoperatively. This site was detectable at all histology study periods. Intraocular pressure reduction was longer in the implant group: greater than 5 months versus 3 weeks (P < .05). In the pilot study, visual acuity remained stable, IOP decreased from a mean preoperative level of 26.3 mm Hg +/- 5.22 (SD) to a mean postoperative level without treatment of 15.4 +/- 3.1 mm Hg (P < .0001). No external filtration was detected in 60 eyes, a slightly elevated conjunctiva was noted in 12 eyes. Postoperative inflammation (laser flare and cell measurements) was low. Gonioscopy consistently demonstrated the persistence of a decompression space behind the trabeculum. CONCLUSION: Comparative experimental surgery results showed excellent tolerance and efficacy in the rabbit eyes with a hyaluronic acid implant. Clinical results, to be confirmed by a randomized comparative study, also showed excellent biocompatibility and encouraging efficacy.


Assuntos
Implantes para Drenagem de Glaucoma , Glaucoma/cirurgia , Ácido Hialurônico , Malha Trabecular/cirurgia , Trabeculectomia/métodos , Idoso , Animais , Feminino , Seguimentos , Glaucoma/patologia , Humanos , Pressão Intraocular , Masculino , Projetos Piloto , Implantação de Prótese , Coelhos , Estudos Retrospectivos , Resultado do Tratamento , Acuidade Visual
18.
J Biomed Mater Res ; 42(4): 642-54, 1998 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9827690

RESUMO

Future surgical strategies to restore neurological function in the damaged human spinal cord may involve replacement of nerve tissue with cultured Schwann cells using biodegradable guiding implants. We have studied the in vitro and in vivo degradability of various aliphatic polyesters as well as their effects on rat Schwann cells in vitro and on spinal cord tissue in vivo. In vitro, cylinders made of poly(D,L-lactic-co-glycolic acid) 50:50 (PLA25GA50) started to degrade at 7 days, compared with 28 days for cylinders made of poly(D,L-lactic acid) (PLA50). This faster degradation of PLA25GA50 was reflected by a much higher absorption of water. In vivo, after implantation of PLA25GA50 or PLA50 cylinders between the stumps of a completely transected adult rat spinal cord, the decrease in molecular weight of both polymers was similar to that found in vitro. In vitro degradation of poly(L-lactic acid) (PLA100) mixed with increasing amounts of PLA100 oligomers also was determined. The degradation rate of PLA100 mixed with 30% oligomers was found to be similar to that of PLA50. In vitro, PLA25GA50 and the breakdown products had no adverse effect on the morphology, survival, and proliferation of cultured rat Schwann cells. In vivo, PLA25GA50 cylinders were integrated into the spinal tissue 2 weeks after implantation, unlike PLA50 cylinders. At all time points after surgery, the glial and inflammatory response near the lesion site was largely similar in both experimental and control animals. At time points later than 1 week, neurofilament-positive fibers were found within PLA25GA50 cylinders or the remains thereof. Growth-associated protein 43, which is indicative of regenerating axons, was observed in fibers in the vicinity of the injury site and in the remains of PLA25GA50 cylinders. The results suggest that poly(alpha-hydroxyacids) are likely candidates for application in spinal cord regeneration paradigms involving Schwann cells.


Assuntos
Materiais Biocompatíveis , Ácido Láctico , Ácido Poliglicólico , Polímeros , Células de Schwann/citologia , Medula Espinal/cirurgia , Animais , Biotransformação , Células Cultivadas , Feminino , Humanos , Inflamação/etiologia , Inflamação/patologia , Ácido Láctico/farmacocinética , Macrófagos/patologia , Monócitos/patologia , Ácido Poliglicólico/farmacocinética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/farmacocinética , Ratos , Ratos Endogâmicos F344 , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Medula Espinal/citologia , Medula Espinal/fisiologia , Traumatismos da Medula Espinal/cirurgia , Fatores de Tempo
19.
Bull Soc Belge Ophtalmol ; 268: 13-7, 1998.
Artigo em Francês | MEDLINE | ID: mdl-9810079

RESUMO

To assess keratometric changes of a new refractive surgical technique (Gel Injection Adjustable Keratoplasty--GIAK) on Eye Bank eyes. The surgery consist of making an intrastromal annular delamination at 80% depth using customized delaminators. The tunnel is then filled with a crosslinked polyethylene oxide gel (PEO).


Assuntos
Ceratoplastia Penetrante/métodos , Materiais Biocompatíveis , Cadáver , Bancos de Olhos , Géis , Humanos , Injeções , Miopia/cirurgia , Polietilenoglicóis
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