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1.
Clin Ophthalmol ; 10: 277-83, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26917950

RESUMO

PURPOSE: To evaluate the anatomic and functional outcomes of pars plana vitrectomy combined with internal limiting membrane peeling for recurrent macular edema (ME) due to branch retinal vein occlusion (BRVO) after intravitreal injections of antivascular endothelial growth factor (anti-VEGF) agents. METHODS: Twenty-four eyes of 24 patients with treatment-naive ME from BRVO were treated with intravitreal injections of anti-VEGF agents. Recurred ME was treated with pars plana vitrectomy combined with internal limiting membrane peeling. RESULTS: After the surgery, ME was significantly reduced at 1 month (P=0.031) and the reduction increased with time (P=0.007 at the final visit). With the reduction in ME, treated eyes showed a slow improvement in visual acuity (VA). At the final visit, improvement in VA was statistically significant compared with baseline (P=0.048). The initial presence of cystoid spaces, serous retinal detachment, or subretinal hemorrhage under the fovea, as well as retinal perfusion status, showed no association with VA improvement. However, the presence of epiretinal membrane showed a significant association with the visual recovery. Although eyes without epiretinal membrane showed visual improvement (-0.10±0.32 in logarithm of the minimum angle of resolution [logMAR]), eyes with epiretinal membrane showed greater visual improvement (-0.38±0.12 in logMAR, P=0.012). CONCLUSION: For recurrent ME due to BRVO after anti-VEGF treatment, particularly when accompanied by epiretinal membrane, pars plana vitrectomy combined with internal limiting membrane peeling might be a possible treatment option.

2.
Ophthalmic Surg Lasers Imaging Retina ; 46(3): 362-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25856824

RESUMO

BACKGROUND AND OBJECTIVE: To characterize the cellular, immunological, and inflammatory response to retinal photocoagulation of intense rupture laser lesions as a model of retinal degenerative diseases. MATERIALS AND METHODS: Seven C57BL/6 mice were irradiated using a 532-nm laser to induce 10 retinal burns per eye that ruptured Bruch's membrane. Blood was drawn from the saphenous vein before and 2 months after laser treatment. The serum was run on antigen microarrays with 85 molecular markers associated with retinal degenerative diseases. RESULTS: Rupture laser resulted in dramatic changes in the immunoglobulin reactivity of most inflammatory markers 2 months after laser injury. Approximately two-thirds increased expression and one-third decreased expression. Notable markers that were increased included complement C3, CRP, PKM2, and aldolase. CONCLUSION: Rupture laser injury causes a change in the serum inflammatory markers after 2 months similar to macular degeneration, diabetic retinopathy, and cancer-associated retinopathy. This animal model could be used as a biomarker for disease stage and activity in retinal degenerations.


Assuntos
Biomarcadores/sangue , Lâmina Basilar da Corioide/lesões , Modelos Animais de Doenças , Fotocoagulação a Laser/efeitos adversos , Degeneração Retiniana/sangue , Animais , Proteína C-Reativa/metabolismo , Complemento C3/metabolismo , Frutose-Bifosfato Aldolase/sangue , Imunoglobulina G/sangue , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Piruvato Quinase/sangue , Degeneração Retiniana/etiologia , Degeneração Retiniana/patologia , Ruptura , Veia Safena
3.
J Neurosci ; 33(16): 6800-8, 2013 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-23595739

RESUMO

CNS neurons change their connectivity to accommodate a changing environment, form memories, or respond to injury. Plasticity in the adult mammalian retina after injury or disease was thought to be limited to restructuring resulting in abnormal retinal anatomy and function. Here we report that neurons in the mammalian retina change their connectivity and restore normal retinal anatomy and function after injury. Patches of photoreceptors in the rabbit retina were destroyed by selective laser photocoagulation, leaving retinal inner neurons (bipolar, amacrine, horizontal, ganglion cells) intact. Photoreceptors located outside of the damaged zone migrated to make new functional connections with deafferented bipolar cells located inside the lesion. The new connections restored ON and OFF responses in deafferented ganglion cells. This finding extends the previously perceived limits of restorative plasticity in the adult retina and allows for new approaches to retinal laser therapy free of current detrimental side effects such as scotomata and scarring.


Assuntos
Lasers/efeitos adversos , Fotocoagulação/métodos , Recuperação de Função Fisiológica/fisiologia , Retina/patologia , Doenças Retinianas/cirurgia , Animais , Modelos Animais de Doenças , Estimulação Elétrica , Ácido Glutâmico/metabolismo , Técnicas In Vitro , Masculino , Técnicas de Patch-Clamp , Estimulação Luminosa , Células Fotorreceptoras/patologia , Células Fotorreceptoras/ultraestrutura , Coelhos , Retina/metabolismo , Retina/ultraestrutura , Doenças Retinianas/etiologia , Células Ganglionares da Retina/fisiologia , Sinapses/patologia , Sinapses/ultraestrutura , Fatores de Tempo , Tomografia Computadorizada por Raios X , Visão Ocular/fisiologia , Vias Visuais/patologia , Vias Visuais/fisiologia , Ácido gama-Aminobutírico/metabolismo
4.
J Cataract Refract Surg ; 39(5): 686-93, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23489916

RESUMO

PURPOSE: To evaluate the stability of axis rotation, astigmatism correction, and improvement in uncorrected distance visual acuity (UDVA) up to 6 months postoperatively using an astigmatism-correcting intraocular lens (IOL) in a 25-gauge transconjunctival sutureless vitrectomy combined with cataract surgery. SETTING: Department of Ophthalmology, Kagawa University Faculty of Medicine, Kagawa, Japan. DESIGN: Prospective nonrandomized interventional study. METHOD: Eyes with a preoperative corneal cylinder of more than 0.75 diopter (D) had a triple procedure for idiopathic epiretinal membrane (ERM) using an Acrysof IQ toric IOL. Outcome measures were the amount of IOL axis rotation up to 3 months postoperatively, UDVA, corrected distance visual acuity, and corneal and refractive astigmatism up to 6 months postoperatively. A comparison was performed between patients with a target postoperative spherical refraction of emmetropia (toric emmetropic group) and patients who previously had a triple procedure for idiopathic ERM using a nontoric IOL (control group). RESULTS: The mean IOL axis rotation from the end of surgery until 3 months postoperatively was 3.67 degrees ± 3.13 (SD). Six months postoperatively, the mean corneal and refractive cylinders were 1.32 ± 0.61 D and 0.51 ± 0.31 D, respectively, showing a significant difference (P<.0001, paired t test). In addition, the mean UDVA was significantly improved 6 months postoperatively in the control and toric emmetropic group (0.57 logMAR versus 0.35 logMAR) (P=.028), although the toric group was more improved than the control group. CONCLUSION: In vitrectomy (triple procedure) for idiopathic ERM with a toric IOL, postoperative IOL axis stability was similar to that reported for cataract surgery alone. Furthermore, the UDVA was better than with implantation of a spherical IOL.


Assuntos
Astigmatismo/cirurgia , Membrana Epirretiniana/cirurgia , Lentes Intraoculares , Microcirurgia/métodos , Facoemulsificação/métodos , Vitrectomia/métodos , Idoso , Idoso de 80 Anos ou mais , Astigmatismo/fisiopatologia , Catarata/fisiopatologia , Membrana Epirretiniana/diagnóstico , Membrana Epirretiniana/fisiopatologia , Feminino , Humanos , Implante de Lente Intraocular , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Técnicas de Sutura , Tomografia de Coerência Óptica , Resultado do Tratamento , Transtornos da Visão/fisiopatologia , Acuidade Visual/fisiologia
5.
Invest Ophthalmol Vis Sci ; 54(1): 444-53, 2013 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-23154457

RESUMO

PURPOSE: Müller glia respond to retinal injury by a reactive gliosis, but only rarely do mammalian glial cells re-enter the cell cycle and generate new neurons. In the nonmammalian retina, however, Müller glia act as stem/progenitor cells. Here, we tested the function of Wnt signaling in the postinjury retina, focusing on its ability to influence mammalian Müller cell dedifferentiation, proliferation, and neurogenesis. METHODS: A 532 nm frequency doubled neodymium-doped yttrium aluminum garnet (ND:YAG) laser was used to create light burns on the retina of Axin2(LacZ/+) Wnt reporter mice. At various time points after injury, retinas were analyzed for evidence of Wnt signaling as well as glial cell response, proliferation, and apoptosis. Laser injuries also were created in Axin2(LacZ/LacZ) mice, and the effect of potentiated Wnt signaling on retinal repair was assessed. RESULTS: A subpopulation of mammalian Müller cells are Wnt responsive and, when Wnt signaling is increased, these cells showed enhanced proliferation in response to injury. In an environment of heightened Wnt signaling, caused by the loss of the Wnt negative regulator Axin2, Müller cells proliferated after injury and adopted the expression patterns of retinal progenitor cells (RPCs). The Wnt-responsive Müller cells also exhibited long-term survival and, in some cases, expressed the rod photoreceptor marker, rhodopsin. CONCLUSIONS: The Wnt pathway is activated by retinal injury, and prolonging the endogenous Wnt signal causes a subset of Müller cells to proliferate and dedifferentiate into RPCs. These data raised the possibility that transient amplification of Wnt signaling after retinal damage may unlock the latent regenerative capacity long speculated to reside in mammalian neural tissues.


Assuntos
Neuroglia/metabolismo , Retina/lesões , Proteínas Wnt/metabolismo , Animais , Apoptose , Ciclo Celular , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Modelos Animais de Doenças , Queimaduras Oculares/metabolismo , Queimaduras Oculares/patologia , Lasers de Estado Sólido/efeitos adversos , Camundongos , Camundongos Endogâmicos C57BL , Neuroglia/patologia , Retina/metabolismo , Retina/patologia , Transdução de Sinais
6.
Retina ; 33(1): 63-70, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23026846

RESUMO

PURPOSE: To evaluate the effect of intravitreal triamcinolone acetonide (TA) on healing of retinal photocoagulation lesions using drug and laser dosing typically employed in clinical practice. METHODS: Laser burns with a 267-µm retinal beam size at 532-nm wavelength were applied to 40 eyes of Dutch belted rabbits. Barely visible to intense lesions were produced with pulses of 5, 10, 20, and 50 milliseconds and power of 175 mW. Eyes received intravitreal injections of either 2 mg TA/50 µL or balanced salt solution administered either 1 week before or immediately after laser treatment. Lesion grades were assessed acutely ophthalmoscopically and by a masked observer histologically at 1, 3, 7, 30, and 60 days. RESULTS: Both TA groups demonstrated significant reduction in retinal thickness throughout follow-up compared with balanced salt solution groups (P < 0.001). The width of the lesions at 1 day after injection was not significantly different between groups. However, by 7 days, the lesions in balanced salt solution groups contracted much more than in the TA groups, especially the more intense burns, and this difference persisted to 2 months. The healing rate of the barely visible burns was not significantly affected by TA compared with the balanced salt solution control eyes. CONCLUSION: Triamcinolone acetonide injection previously or concurrently with photocoagulation significantly decreases laser-induced edema but interferes with lesions healing, thereby leaving wider residual scarring, especially persistent in more intense burns.


Assuntos
Glucocorticoides/uso terapêutico , Fotocoagulação a Laser/efeitos adversos , Papiledema/tratamento farmacológico , Retina/cirurgia , Triancinolona Acetonida/uso terapêutico , Cicatrização/efeitos dos fármacos , Acetatos/uso terapêutico , Animais , Combinação de Medicamentos , Injeções Intravítreas , Minerais/uso terapêutico , Papiledema/etiologia , Papiledema/patologia , Coelhos , Retina/fisiologia , Cloreto de Sódio/uso terapêutico
7.
Nippon Ganka Gakkai Zasshi ; 116(11): 1080-5, 2012 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-23316656

RESUMO

PURPOSE: To evaluate the subfoveal choroidal thickness (SCT) of the epiretinal membrane (ERM) and macular hole (MH) both before and after microincision vitrectomy surgery. SUBJECTS AND METHODS: A total of 104 eyes of 104 subjects (64 ERM, 40 MH, mean age 68.9 years) were evaluated. All subjects underwent vitrectomy with internal limiting membrane peeling. SCT was measured before vitrectomy and 1 week, 1 month and 3 months postoperatively. SCT was measured by enhanced depth imaging OCT (EDI-OCT) using a Heiderberg Spectralis. RESULTS: The SCT of ERM was 202.6 microm before vitrectomy, and 201.8 microm at 1 week, 198.8 microm at 1 month, and 196.4 microm at 3 months postoperatively. There were no significant differences between the times of measurement. MH was 182.5 microm before vitrectomy, and 186.7 microm at 1 week, 189.4 microm at 1 month, and 187.4 microm at 3 months. There were also no significant differences between any other factors. The SCT between the ERM and MH was not significantly different at any time. We examined the correlation between the changes in SCT and the changes in age, refractive error and intraocular pressure (IOP), but found no significant correlation. CONCLUSION: The SCT hat not changed either before or after microincision vitrectomy surgery, and there was no siginificant correlation between SCT and any other factor.


Assuntos
Membrana Epirretiniana/patologia , Perfurações Retinianas/patologia , Vitrectomia/métodos , Idoso , Idoso de 80 Anos ou mais , Membrana Epirretiniana/cirurgia , Olho/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Perfurações Retinianas/cirurgia , Tomografia de Coerência Óptica/métodos , Resultado do Tratamento , Acuidade Visual/fisiologia
10.
Retina ; 31(2): 380-8, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20930656

RESUMO

PURPOSE: To evaluate the safety, selectivity, and healing of retinal lesions created using a continuous line scanning laser. METHODS: A 532-nm Nd:YAG laser (PASCAL) with retinal beam diameters of 40 µm and 66 µm was applied to 60 eyes of 30 Dutch-belted rabbits. Retinal exposure duration varied from 15 µs to 60 µs. Lesions were acutely assessed by ophthalmoscopy and fluorescein angiography. Retinal pigment epithelial (RPE) flatmounts were evaluated with live-dead fluorescent assay. Histological analysis was performed at 7 time points from 1 hour to 2 months. RESULTS: The ratios of the threshold of rupture and of ophthalmoscopic visibility to fluorescein angiography visibility (measures of safety and selectivity) increased with decreasing duration and beam diameter. Fluorescein angiography and live-dead fluorescent assay yielded similar thresholds of RPE damage. Above the ophthalmoscopic visibility threshold, histology showed focal RPE damage and photoreceptor loss at 1 day, without inner retinal effects. By 1 week, photoreceptor and RPE continuity was restored. By 1 month, photoreceptors appeared normal. CONCLUSION: : Retinal therapy with a fast scanning continuous laser achieves selective targeting of the RPE and, at higher power, of the photoreceptors without permanent scarring or inner retinal damage. Continuous scanning laser can treat large retinal areas within standard eye fixation time.


Assuntos
Fotocoagulação a Laser/instrumentação , Fotocoagulação a Laser/métodos , Lasers de Estado Sólido , Retina/cirurgia , Epitélio Pigmentado da Retina/cirurgia , Animais , Angiofluoresceinografia , Oftalmoscopia , Coelhos , Retina/patologia , Epitélio Pigmentado da Retina/patologia , Cicatrização
11.
Invest Ophthalmol Vis Sci ; 52(3): 1780-7, 2011 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-21087969

RESUMO

PURPOSE: Subthreshold retinal phototherapy demonstrated clinical efficacy for the treatment of diabetic macular edema without visible signs of retinal damage. To assess the range of cellular responses to sublethal hyperthermia, expression of the gene encoding a 70 kDa heat shock protein (HSP70) was evaluated after laser irradiation using a transgenic reporter mouse. METHODS: One hundred millisecond, 532 nm laser exposures with 400 µm beam diameter were applied to the retina surrounding the optic nerve in 32 mice. Transcription from the HSP70 promoter was assessed relative to the control eye using a bioluminescence assay at 7 hours after laser application. The retinal pigmented epithelium (RPE) viability threshold was determined with a fluorescence assay. A computational model was developed to estimate temperature and the extent of cell damage. RESULTS: A significant increase in HSP70 transcription was found at exposures over 20 mW, half the threshold power for RPE cell death. Computational modeling estimated peak temperature T = 49°C at HSP70 expression threshold. At RPE viability threshold, T = 57°C. Similar temperatures and damage indices were calculated for clinical subvisible retinal treatment parameters. CONCLUSIONS: Beneficial effects of laser therapy have been previously shown to extend beyond those resulting from destruction of tissue. One hundred millisecond laser exposures at approximately half the threshold power of RPE damage induced transcription of HSP70, an indication of cellular response to sublethal thermal stress. A computational model of retinal hyperthermia can guide further optimization of laser parameters for nondamaging phototherapy.


Assuntos
Regulação da Expressão Gênica/fisiologia , Proteínas de Choque Térmico HSP70/genética , Fotocoagulação a Laser/efeitos adversos , Lasers de Estado Sólido/efeitos adversos , Retina/lesões , Animais , Sobrevivência Celular , Simulação por Computador , Análise de Elementos Finitos , Perfilação da Expressão Gênica , Genes Reporter , Medições Luminescentes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Animais , Retina/metabolismo , Epitélio Pigmentado da Retina/metabolismo
12.
Connect Tissue Res ; 52(2): 147-56, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20672978

RESUMO

The distribution of the collagen chains from α1(IV) to α6(IV) could serve as a basis for the characterization of type IV collagen. In this study, immunohistochemistry of the ocular anterior segment of adult mice was performed using specific monoclonal antibodies against each chain in the series from α1(IV) to α6(IV). The results show that the components of type IV collagen in vascular basement membranes are α1(IV) and α2(IV) with or without α5(IV) and α6(IV) chains and those in epithelium and muscle basement membranes are α1(IV), α2(IV), α5(IV), and α6(IV) chains. In corneal endothelium, pigmented epithelium of iris and ciliary body, and trabecular meshwork, α3(IV) and α4(IV) chains are also expressed in addition to α1(IV), α2(IV), α5(IV), and α6(IV) chains. Moreover, we investigated the change in molecular composition in ciliary body during postnatal development. α3(IV) and α4(IV) chains were also expressed in addition to α1(IV), α2(IV), α5(IV), and α6(IV) chains in ciliary pigmented epithelium basement membrane from 7 days after birth. This result suggests that the basement membranes gradually change their biochemical features owing to temporal regulation. Taken together, these findings suggest that the different distribution and the developmental expression of α1(IV) to α6(IV) chains are associated with the tissue-specific function of type IV collagen in basement membranes.


Assuntos
Membrana Basal/metabolismo , Colágeno Tipo IV/metabolismo , Olho/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Corpo Ciliar/metabolismo , Endotélio/metabolismo , Ensaio de Imunoadsorção Enzimática , Epitélio/metabolismo , Olho/crescimento & desenvolvimento , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Peptídeos/genética
13.
J Cataract Refract Surg ; 36(1): 127-32, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20117716

RESUMO

PURPOSE: To evaluate a new pulsed-electron avalanche knife design for creating a continuous curvilinear capsulotomy (CCC) and compare the CCC with a mechanical capsulorhexis. SETTING: Department of Ophthalmology, Stanford University, Stanford, California, USA. METHODS: In this study, CCCs were created in freshly enucleated bovine eyes and in rabbit eyes in vivo. The cutting velocity was adjusted by controlling the burst repetition rate, voltage amplitude, and burst duration. Tissue samples were fixed and processed for histology and scanning electron microscopy (SEM) immediately after surgery. RESULTS: The study included 50 bovine eyes and 10 rabbit eyes. By adjusting the electrosurgical waveforms, gas-bubble formation was minimized to permit good surgical visualization. The optimum voltage level was determined to be +/-410 V with a burst duration of 20 mus. Burst repetition rate, continuously adjustable from 20 to 200 Hz with footpedal control, allowed the surgeon to vary linear cutting velocity up to 2.0 mm/s. Histology and SEM showed that the pulsed-electron avalanche knife produced sharp-edged capsule cutting without radial nicks or tears. CONCLUSIONS: The probe of the pulsed-electron avalanche knife duplicated the surgical feel of a 25-gauge cystotome and created a histologically smooth capsule cut. It may improve precision and reproducibility of creating a CCC, as well as improve its proper sizing and centration, especially in the face of surgical risk factors, such as weak zonules or poor visibility. FINANCIAL DISCLOSURES: Drs. Palanker and Vankov hold patents to the pulsed electron avalanche knife technology, which are licensed to PEAK Surgical by Stanford University. Drs. Palanker and Chang are consultants to PEAK Surgical. Dr. Vankov is an employee of PEAK Surgical. Neither of the other authors has a financial or proprietary interest in any material or method mentioned.


Assuntos
Capsulorrexe/instrumentação , Eletrocirurgia/instrumentação , Cápsula do Cristalino/cirurgia , Animais , Capsulorrexe/métodos , Bovinos , Desenho de Equipamento , Cápsula do Cristalino/ultraestrutura , Microscopia Eletrônica de Varredura , Coelhos , Suínos
14.
Chemistry ; 15(38): 9824-35, 2009 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-19681069

RESUMO

Glutamine derivative 1 with two-photon absorbing units has been synthesized and was found to show gelation ability in some solvents. Its self-assembly in the gel phase could be controlled by the solvent and speed of gelation. For example, in DMSO the organogelator self-assembled into H-aggregates with weak exciton coupling between the aromatic moieties. On the other hand, in DMSO/diphenyl ether (1:9, v/v) the molecules formed 1D aggregates, but with strong exciton coupling due to the small distance between the chromophores. Moreover, the formation of these two kinds of aggregates could be adjusted by the ratio of DMSO to diphenyl ether. In DMSO/toluene, DMSO/butanol, DMSO/butyl acetate, and DMSO/acetic acid systems similar results were observed. Therefore, conversion of the packing model occurs irrespective of the nature of the solvent. Notably, a unique sign inversion in the CD spectra could be realized by controlling the speed of gelation in the DMSO/diphenyl ether (1:9, v/v) system. It was found that a low speed of gelation induces the gelator to adopt a packing model with strong pi-pi interactions between the aromatic units. Moreover, the gels, when excited at 800 nm, emit strong green fluorescence and the quantum chemical calculations suggest that intramolecular charge transfer leads to two-photon absorption of the gelator molecule.


Assuntos
Géis/química , Glutamina/química , Solventes/química , Dimetil Sulfóxido/química , Cinética , Espectrofotometria Ultravioleta , Estereoisomerismo , Temperatura
15.
J Biomed Opt ; 14(3): 034007, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19566300

RESUMO

In laser retinal photocoagulation, short (<20 ms) pulses have been found to reduce thermal damage to the inner retina, decrease treatment time, and minimize pain. However, the safe therapeutic window (defined as the ratio of power for producing a rupture to that of mild coagulation) decreases with shorter exposures. To quantify the extent of retinal heating and maximize the therapeutic window, a computational model of millisecond retinal photocoagulation and rupture was developed. Optical attenuation of 532-nm laser light in ocular tissues was measured, including retinal pigment epithelial (RPE) pigmentation and cell-size variability. Threshold powers for vaporization and RPE damage were measured with pulse durations ranging from 1 to 200 ms. A finite element model of retinal heating inferred that vaporization (rupture) takes place at 180-190 degrees C. RPE damage was accurately described by the Arrhenius model with activation energy of 340 kJ/mol. Computed photocoagulation lesion width increased logarithmically with pulse duration, in agreement with histological findings. The model will allow for the optimization of beam parameters to increase the width of the therapeutic window for short exposures.


Assuntos
Fotocoagulação a Laser/métodos , Modelos Biológicos , Retina/diagnóstico por imagem , Doenças Retinianas/cirurgia , Animais , Sobrevivência Celular , Simulação por Computador , Análise de Elementos Finitos , Temperatura Alta , Fotocoagulação a Laser/efeitos adversos , Terapia a Laser , Coelhos , Retina/lesões , Epitélio Pigmentado da Retina/lesões , Epitélio Pigmentado da Retina/patologia , Suínos , Termodinâmica , Ultrassonografia
16.
Retina ; 29(5): 689-98, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19373129

RESUMO

PURPOSE: To characterize the in vitro behavior of three preparations of triamcinolone acetonide (TA). METHODS: Three preparations of TA were mixed with Balanced Salt Solution Plus: commercially available TA (Kenalog 40, Bristol-Myers Squibb, Princeton, NJ), compounded preservative-free triamcinolone acetonide (PFTA, New England Compounding Center, Framingham, MA), and triamcinolone acetonide injectable suspension (TAIS, TRIESENCE, Alcon, Inc., Fort Worth, TX). We determined the mean number of crystalline aggregates per high-power deconvolution microscopy field, largest aggregate area, and spectroscopic photometric absorption. RESULTS: Preservative-free triamcinolone acetonide had larger mean number of aggregates compared with TA (time 0 P = 0.002, 10 minutes P < 0.001) and TAIS (time 0 P < 0.001, 10 minutes P = 0.003). Aggregate size varied at both 0 and 10 minutes: TAIS > TA > PFTA. Spectroscopic photometric absorption decreased in direct correlation to aggregate size over time for all three preparations. CONCLUSION: In vitro, PFTA in Balanced Salt Solution Plus had more aggregates of smaller size than either TA or TAIS. By contrast, TAIS had much larger aggregate size than both PFTA and TA, and this increased over time. These findings correlate with the clinical observations that PFTA and TA tend to disperse throughout the vitreous, whereas TAIS tends to conglomerate and gravitate toward the most dependent portion of the eye in a globular fashion.


Assuntos
Glucocorticoides/química , Triancinolona Acetonida/química , Cristalização , Processamento de Imagem Assistida por Computador , Técnicas In Vitro , Microscopia , Soluções Oftálmicas/química , Conservantes Farmacêuticos , Espectrofotometria
17.
Invest Ophthalmol Vis Sci ; 50(10): 4807-13, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19324856

RESUMO

PURPOSE: To investigate the pharmacokinetics of bevacizumab in rabbits for three different routes of administrations: intravitreal injection, subconjunctival injection, and eye drops. METHODS: Pigmented rabbits received bevacizumab in one eye by topical eye drops (1.25 mg/0.05 mL six times daily for the first 7 days), single subconjunctival injection (1.25 mg/0.05 mL), or single intravitreal injection (1.25 mg/0.05 mL). Bevacizumab concentrations in plasma and ocular tissues in the treated and fellow eyes were determined by sandwich enzyme-linked immunosorbent assay at 1, 2, 4, and 12 weeks after administration. RESULTS: After intravitreal injection in the treated eye, the mean maximum concentrations (C(max)) of bevacizumab in the iris/ciliary body and retina/choroid were 109,192.6, and 93,990.0 ng/g, respectively, whereas after subconjunctival injection, the C(max) was 1418.7 and 295.8 ng/g, respectively. In the fellow eyes, when the drug was administered by intravitreal injection, the C(max) was 753.6 ng/g in the iris/ciliary body and 224.2 ng/g in the retina/choroid and by subconjunctival injection was 1192.9 and 187.0 ng/g, respectively. With eye drops, only a small level of bevacizumab was detected in the iris/ciliary body and retina/choroid. Systemic exposure to bevacizumab was at the same level when administered by intravitreal or subconjunctival injection. CONCLUSIONS: Intravitreal injection of bevacizumab was the most effective route of administration for intraocular tissue. Also, bevacizumab injected subconjunctivally was transported into the intraocular tissues of the treated eyes at an effective level. Both intravitreal and subconjunctival injections of bevacizumab resulted in high plasma concentrations. Bevacizumab was distributed into the intraocular tissues in fellow eyes via the systemic circulation. This treatment may be effective for blocking vascular endothelial growth factor activity.


Assuntos
Inibidores da Angiogênese/farmacocinética , Anticorpos Monoclonais/farmacocinética , Administração Tópica , Inibidores da Angiogênese/administração & dosagem , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados , Bevacizumab , Disponibilidade Biológica , Túnica Conjuntiva , Vias de Administração de Medicamentos , Ensaio de Imunoadsorção Enzimática , Injeções , Coelhos , Distribuição Tecidual , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Corpo Vítreo
18.
J Nanosci Nanotechnol ; 8(1): 314-20, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18468076

RESUMO

To synthesize composite solid materials of metal salt and CdSe nanocrystals by a simple one-step method has been described. These solids can form stable gel in some organic solvent, such as benzene, cyclohexane and 1-butanol, especial in n-decane even below 0.1 wt/vol.%. Furthermore, these gels appear strong fluorescence which can be easily adjusted by the gel concentration. Temperature-dependent fluorescence spectra of composite gels suggested that the CdSe NCs aggregate together in gel state which would induce the energy transfer between nanocrystals and these aggregates could be reversibly disintegrated when gel was heated to form sol. TEM observations provided the further evidence of the energy transfer and suggested that the CdSe NCs were enchased regularly not only on the surface of self assembly of metal salt, but also embedded inside of self assembly in composite gel with small size nanocrystals. In contrast, in composite organogel with large nanocrystals they were only enchased on the edge of self assembly.

19.
Retina ; 28(3): 427-32, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18327134

RESUMO

PURPOSE: To report the 1-year results of macular hole surgery with triamcinolone acetonide (TA)-assisted internal limiting membrane (ILM) peeling and to compare those with results of indocyanine green (ICG)-assisted ILM peeling. METHODS: In a nonrandomized, retrospective, interventional case series, 40 eyes of 39 consecutive patients with idiopathic full-thickness macular holes underwent macular hole surgery with TA-assisted ILM peeling. Surgical results 1 year after surgery, including changes in best-corrected visual acuity (BCVA) and macular hole closure, were evaluated. Moreover, we compared the results for these 40 eyes (TA group) with those for 27 eyes of 27 consecutive patients who had undergone macular hole surgery with 0.25% ICG-assisted ILM peeling (ICG group). RESULTS: In the TA group, macular holes were closed in 39 (98%) of 40 eyes. Mean BCVA +/- SD significantly improved from 0.78 +/- 0.31 logarithm of the minimal angle of resolution (logMAR) preoperatively to 0.20 +/- 0.30 logMAR (P < 0.001). BCVA improved by > or =0.2 logMAR in 37 eyes (93%). BCVA was 20/40 or better in 33 (83%) of 30 eyes. In the ICG group, macular holes were closed in all 27 eyes (100%), and mean BCVA +/- SD significantly improved from 0.81 +/- 0.4 logMAR preoperatively to 0.34 +/- 0.2 logMAR 1 year postoperatively (P < 0.001). BCVA improved by > or =0.2 logMAR in 22 eyes (81%). BCVA was 20/40 or better in 16 (59%) of 27 eyes. Significant differences between groups were seen in mean BCVA 1 year after surgery (P = 0.049) but not in BCVA of 20/40 or better (P = 0.17) or change in BCVA by > or =0.2 logMAR (P = 0.05). CONCLUSION: TA is useful as an adjuvant for ILM peeling in macular hole surgery, and BCVA 1 year after surgery might be more favorable when compared with ICG-assisted ILM peeling.


Assuntos
Glucocorticoides/administração & dosagem , Perfurações Retinianas/cirurgia , Triancinolona Acetonida/administração & dosagem , Adulto , Idoso , Membrana Basal/cirurgia , Corantes , Terapia Combinada , Feminino , Humanos , Verde de Indocianina , Injeções , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Acuidade Visual , Corpo Vítreo
20.
Chemistry ; 13(29): 8231-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17659661

RESUMO

A new organogelator based on a salicylideneaniline derivative with cholesterol moieties was synthesized, and it was proposed that it could gelate various organic solvents, such as 1-butanol, 1-octanol, butyl acetate, tetrachloromethane, benzene, toluene through combination with a gelation test. From the results of analysis by UV/Vis absorption, circular dichroism (CD), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies and semiempirical (AM1) calculations, we believed that the gelator molecules could self-assemble into left-handed helical nanofibers through unimolecular layer packing, which further twisted into the thicker fibers and constructed 3D networks in the gel phase. Interestingly, the organogel exhibited strong fluorescence enhancement relative to a solution of the same concentration because of the formation of J aggregations. Meanwhile, photochromism of the organogel could take place under UV-light irradiation. Both strong fluorescence emission and photochromism properties were concurrent in one system based on a salicylideneaniline derivative. It was suggested that the self-assembly of the functional organogelator could lead to unique photophysical properties.

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