Influence of the dilution method on the intraocular duration of C3F8 in vitrectomy for macular hole: a randomized clinical trial

ABSTRACT Purpose: To compare the injection of small amounts of undiluted C3F8 with the traditional gas injection in vitrectomy for macular hole treatment. Methods: This clinical trial included 26 individuals divided into two groups. Group 1 received an intravitreal injection of 0.9-1.0 mL of 100% C3F8, and Group 2 received 15-20 mL of 20% C3F8. Results: The median intraocular gas duration was 31 days in Group 1 and 34 in Group 2. The median letter gains in corrected distance visual acuity for the 26th postoperative week were 20 letters in Group 1 and 12.5 in Group 2. The median intraocular pressure was normal in both groups. Primary anatomical success was 11/13 in both groups. Conclusions: The use of C3F8 gas in a small undiluted volume is an alternative that slightly reduces the duration of the gas without negatively affecting the anatomical and visual response.

Gas tamponade followed by laser treatment for macular retinal detachment secondary to optic pit / Tamponamento com gás seguido de laser para descolamento de retina secundário à fosseta de disco óptico

ABSTRACT Purpose: The study aimed to describe anatomic and visual outcomes associated with perfluoropropane intravitreal injection followed by laser treatment for macular retinal detachment secondary to optic disc pit. Methods: A single-center, retrospective study. Medical records of all patients treated at a tertiary retina referral center were evaluated between 2011 and 2018 for congenital optic disc pit-associated macular detachment with 0.3 ml 100% perfluoropropane intravitreal injection followed by retinal laser photocoagulation along the temporal optic disc margin as the initial treatment. Results: Six patients with optic disc pit-associated macular detachment were identified, with postoperative follow-up ranging from 13 to 52 months (mean: 28 months). Spectral domain optical coherence tomography (SD-OCT) showed complete fluid resolution without recurrence in five of the six cases. Four cases showed complete reabsorption after Intravitreal perfluoropropane plus laser, one patient needed an extra procedure (pars plana vitrectomy with inner limiting membrane peeling and pedicle flap inversion over the temporal optic disc margin) to achieve complete fluid reabsorption, and one patient had persistent intraretinal fluid and denied additional surgeries. The time between the initial procedure and total fluid reabsorption varied from 6.5 to 41 months (mean: 19.5 months). Best-corrected visual acuity improved after surgery on the last follow-up visit in all cases. Conclusion: 100% perfluoropropane intravitreal injection followed by photocoagulation along temporal optic disc margin was associated with anatomic and visual improvement in most cases, representing an alternative treatment approach for optic disc pit-associated macular detachment.

RESUMO Objetivo: Descrever os resultados anatômicos e visuais associados à injeção intravítrea de perfluoropropano seguida de tratamento a laser para descolamento de retina macular secundário à fosseta do disco óptico. Métodos: Estudo retrospectivo em um único centro. Foram revisados os prontuários médicos dos pacientes com descolamento macular associado a fosseta do disco óptico congênito em um centro de referência terciário de retina entre 2011 e 2018. Todos receberam como estratégia de tratamento inicial injeção intravítrea de perfluoropropano 100% seguido por fotocoagulação a laser ao longo da margem temporal do disco óptico. Resultados: Foram identificados seis pacientes com descolamento macular associado a fosseta do disco óptico durante o período do estudo. O seguimento pós-operatório variou de 13 a 52 meses, com média de 28 meses. SD-OCT demonstrou resolução completa do fluido em cindo dos seis casos, sem recorrência. Quatro casos apresentaram reabsorção completa após perfluoropropano intravítreo associado a laser, e um paciente necessitou de procedimento adicional (vitrectomia via pars plana com peeling da membrana limitante interna e inversão do retalho do pedículo sobre a margem temporal do disco óptico) para obter reabsorção completa de fluidos. Um paciente apresentou fluido intrarretiniano persistente e negou tratamentos adicionais. O tempo entre o procedimento inicial e a resolução completa do fluido variou entre 6,5 a 41 meses, com média de 19,5 meses. A acuidade visual corrigida melhorou após a cirurgia, considerando a última consulta de acompanhamento em todos os casos. Conclusão: A injeção intravítrea de perfluoropropano 100% seguida de fotocoagulação ao longo da margem temporal da margem do disco óptico foi associada à melhora anatômica e visual na maioria dos casos e representa uma abordagem terapêutica alternativa para o descolamento macular associado a fosseta do disco óptico.

Surgical results regarding the correction of macular hole with and without face-down posturing using 25% SF6 gas: a retrospective case series / Resultados cirúrgicos para correção de buraco macular com gás SF6 a 25% com e sem orientação postural: Série retrospectiva de casos

ABSTRACT Purpose: This study aims to compare the anatomical success rates of vitrectomy and SF6 gas tamponade for macular hole surgery with and without postoperative face-down posturing. Methods: This was an observational, longitudinal, and retrospective case series analysis. The study included 52 eyes from 52 patients who underwent pars plana vitrectomy with trypan blue-assisted internal limiting membrane peeling and 25% SF6 tamponade for stages 2, 3, and 4 macular holes. After surgery, all patients were provided with a postoperative postural regimen: 31 patients were instructed not to maintain face-down posturing, whereas 21 were instructed to maintain face-down posturing for 7 days. The primary outcome measure was the macular hole closure rate. Statistical analysis was performed using Epi Info 7.1. Results: A total of 47 (90.3%) patients achieved hole closure. The nonface-down posturing group and face-down posturing group obtained closure rates of 90.3% and 90.4%, respectively; these rates were not significantly different. Statistical analysis revealed that no significant differences existed in sex, age, hole duration, hole stage, preoperative visual acuity, or postoperative visual acuity between the two groups. Conclusion: Our results suggest that macular hole surgery with the use of short duration gas (SF6) is safe and effective and that maintaining a postural orientation of nonface-down posturing is also safe. However, these recommendations should be assessed further in a prospective and randomized study to comprehensively delineate the associated benefits and risks.

RESUMO Objetivos: Comparar as taxas de sucesso anatômico da vitrectomia e tamponamento de gás SF6 na cirurgia de buraco macular com e sem a postura pronada pós-operatória. Métodos: Foi realizado um estudo observacional, longitudinal e retrospectivo de séries de casos. O estudo incluiu 52 olhos de 52 pacientes submetidos à vitrectomia posterior via pars-plana com peeling de membrana limitante interna auxiliada por azul trypan e tamponamento com gás SF6 a 25% para os estágios 2, 3 e 4 dos buracos maculares. Após a cirurgia, todos os pacientes foram orientados a manter um regime postural pós-operatório: 31 pacientes foram orientados a não realizar posição pronada de cabeça, enquanto 21 foram orientados a manter uma pronada pós-operatória por 7 dias. O objetivo principal foi a análise da taxa de fechamento do buraco macular. A análise estatística foi realizada usando Epi-Info 7.1. Resultados: Um total de 47 (90,3%) pacientes obtiveram fechamento do buraco macular. O grupo de postura não pronada e o grupo de postura pronada obtiveram taxas de fechamento de 90,3%, e 90,4%, respectivamente; essas taxas não foram significativamente diferentes. A análise estatística revelou que não houve diferenças significativas relacionadas ao gênero, idade, duração do buraco macular, estágio do buraco macular, acuidade visual corrigida pré e pós-operatória entre os dois grupos. Conclusão: Nossos resultados sugerem que a cirurgia para buraco macular com o uso de gás de curta duração (SF6) é segura e eficaz e que a manutenção de uma orientação pós-operatória de não-pronada também é segura. No entanto, essas recomendações devem ser avaliadas em um estudo prospectivo e randomizado para delinear de forma abrangente os riscos e benefícios associados.

Subfoveal perfluorocarbon liquid removal by peeling of internal limiting membrane, without retinotomy / Remoção de perfluorocarbono líquido subfoveal, sem retinotomia, através do peeling da membrana limitante interna

ABSTRACT Perfluorocarbon liquid has been widely used during vitreoretinal operations. Subretinal retention is a rare intraoperative complication, but even small quantities can damage the macular structure and function, and no standard treatment has been established. We encountered a 43-year-old woman who presented a retained subfoveal bubble after a vitreoretinal operation due to primary rhegmatogenous retinal detachment. Herein, we describe the procedure we used to remove the perfluorocarbon liquid without retinotomy using internal limiting membrane peeling.

RESUMO O perfluorocarbono líquido tem sido amplamente durante cirurgias vitreorretinianas. A retenção subretiniana, é uma complicação intraoperatória rara, mas mesmo pequenas quantidades podem danificar a estrutura e função macular, e nenhum tratamento padrão foi estabelecido. Encontramos uma mulher de 43 anos que apresentou bolha subfoveal retida após uma cirurgia vitreorretiniana devido a descolamento de retina regmatogênico. Aqui, descrevemos o procedimento que usamos para remover o líquido perfluorocarbono sem retinotomia usando peeling da membrana limitante interna.

Effect of vaporized perfluorocarbon on oxidative stress during the cold ischemia phase of lung graft preservation / Efeito do perfluorocarbono vaporizado sobre o estresse oxidativo no período de isquemia fria durante a preservação pulmonar

ABSTRACT Liquid perfluorocarbon (PFC) instillation has been studied experimentally as an adjuvant therapy in the preservation of lung grafts during cold ischemia. The objective of this study was to evaluate whether vaporized PFC is also protective of lung grafts at different cold ischemia times. We performed histological analysis of and measured oxidative stress in the lungs of animals that received only preservation solution with low-potassium dextran (LPD) or vaporized PFC together with LPD. We conclude that vaporized PFC reduces the production of free radicals and the number of pulmonary structural changes resulting from cold ischemia.

RESUMO O perfluorocarbono (PFC) líquido tem sido estudado experimentalmente como uma substância adjuvante na preservação de enxertos pulmonares durante o período de isquemia fria. O objetivo deste estudo foi avaliar se o PFC vaporizado (e não instilado) também atuaria como protetor de enxertos pulmonares em diferentes tempos de isquemia fria. Realizamos análise histológica e dosamos o estresse oxidativo em pulmões de animais que receberam somente uma solução de preservação com low-potassium dextran (LPD, dextrana com baixa concentração de potássio) ou PFC vaporizado associado a LPD. Concluímos que o PFC vaporizado reduziu a produção de radicais livres e provocou menor número de alterações estruturais pulmonares decorrentes do período de isquemia fria que o uso de LPD isoladamente.

Protective effect of perfluorocarbon emulsions on rat donor lung / 中华麻醉学杂志

Objective To evaluate the protective effect of perfluorocarbon emulsions (FCE) on donor lung of rats during storage.Methods Twenty-four healthy male Sprague-Dawley rats,weighing 350-400 g,were equally and randomly divided into 2 groups using a random number table:University of Wisconsin (UW) solution group (UW group) and FCE group (FCE group).After the model of lung perfusion was established according to the method described by Fischer et al,the lung and heart were removed and perfused with 4 ℃ UW or FCE preservation solutions.The lung was taken out when stored for 6 h for determination of SOD activity (by WST assay),malondialdehyde (MDA) content (by TBA assay),and activity of myeloperoxidase (MPO) and content of interleukin1 β (IL-1β),IL-6,tumor necrosis factor-apha (TNF-α) (using ELISA) in lung tissues and for microscopic examination of pathologic changes.Results MPO activity was significantly lower in UW group than in FCE group (P ＜0.05).There were no significant differences in the SOD activity and content of MDA,IL-1β,IL-6,TNF-α between the two groups (P ＞ 0.05).Conclusion FCE can reduce the neutrophil infiltration in lung tissues,indicating that FCE is more superior to UW solution in reduction of injury to the donor lung of rats.

Perfluoroctano em cavidade orbitária após vitrectomia posterior e sutura de perfurante ocular: relato de caso / Perfluoro-n-octane in orbital cavity after posterior vitrectomy and suture of eye perforating injury: case report

O objetivo é relatar, pela primeira vez, o caso de um paciente submetido à vitrectomia posterior e sutura de perfurante ocular que evoluiu com extravasamento de perfluoroctano para cavidade orbitária. Paciente do sexo masculino, 39 anos, hígido, encaminhado para avaliação oftalmológica após ter sofrido trauma no olho direito com pedaço de metal há um dia. Ao exame, apresentava redução súbita da acuidade visual à direita com ferimento perfurante ocular córneo-escleral, corpo estranho intraocular e descolamento de retina. O paciente foi submetido à sutura de perfurante, introflexão escleral e vitrectomia posterior com utilização de perfluoroctano, quando foi constatada transfixação do globo ocular. No pós-operatório, evoluiu com proptose e presença de imagens hiperdensas à tomografia computadorizada de órbitas, sugerindo tratar-se de extravasamento de perfluoroctano para a cavidade orbitária. Dessa forma, diante de ferimento perfurante ocular, deve--se sempre atentar para a possibilidade de existência de corpo estranho intraocular, bem como para possível ocorrência de transfixação do globo ocular, no momento de se realizar a programação cirúrgica destes casos.

A case of a perfluoro-n-octane leakage into the orbital cavity after corneoscleral suture, scleral buckling and pars plana vitrectomy in an eye with perforating injury after trauma is reported for the first time. A previously healthy 39-year-old man was sent for ophthalmic evaluation one day after suffering a penetrating ocular trauma in his right eye while hammering a nail. On the initial evaluation, the patient presented sudden reduction of visual acuity on his right eye with a perforating corneoscleral injury, intraocular foreign body and retinal detachment. The patient was submitted to corneoscleral suture, pars plana vitrectomy with perfluoro-n-octane administration to flatten the retina and scleral buckling, when it was found transfixation of the globe by the intraocular foreign body. Postoperatively, computed tomography scans of the orbit were ordered due to proptosis, which showed the presence of hyperdense images, suggesting leakage of perfluoro-n-octane into the orbital cavity. Thus, in cases of perforating eye injury, one should be suspicious about the possibility of intraocular foreign body, as well as possible occurrence of transfixation of the globe when scheduling the surgery.

Injeção intravítrea de bevacizumab e gás C3F8 para tratamento da hemorragia submacular secundária a degeneração macular relacionada à idade: relato de casos / Intravitreous injection of bevacizumab and C3F8 gas for the treatment of submacular hemorrhage due to age-related macular degeneration: case reports

O objetivo desta série de casos foi demonstrar se a aplicação de bevacizumab e gás perfluoropropano (C3F8) intravítreos beneficiariam o deslocamento da hemorragia sub-retiniana dos pacientes com degeneração macular relacionada à idade. Foi realizada uma série retrospectiva de 5 olhos que tinham recebido injeção intravítrea simultânea de bevacizumab e C3F8. Os resultados foram medidos pelo grau de deslocamento de sangue sob a fóvea, pela acuidade visual final e pelas complicações intraoperatórias. Na apresentação inicial, a idade média dos pacientes foi de 72,6 ± 8,9 anos e a duração média dos sintomas foi de 13 ± 9,7 dias. Dos 5 pacientes do estudo, 3 (60 por cento) eram homens e 2 (40 por cento) mulheres. O sucesso do deslocamento da hemorragia submacular foi alcançado em 4 pacientes. A média de acuidade visual pré-operatória foi de 1,12 ± 0,34 logMAR e pós-operatório foi de 0,92 ± 0,4 logMAR. Não foram observados nenhum caso de descolamento da retina, endoftalmite, hemorragia vítrea, uveíte, catarata e hipertensão ocular. A injeção intravítrea bevacizumab e C3F8, juntamente com a posição pronada pode ser uma valiosa opção terapêutica nos olhos com degeneração macular relacionada à idade neovascular e hemorragia sub-retiniana a fim de deslocar o sangue para fora da área foveal.

The purpose of this case series is to describe if the intravitreal use of bevacizumab and perfluoropropane gas (C3F8) would be beneficial to the displacement of subretinal hemorrhage in patients with age-related macular degeneration (AMD). A retrospective study of 5 eyes that received concurrent intravitreal injection of bevacizumab and C3F8 was performed. The results were graded according to blood displacement under the fovea, best final visual acuity and intraoperative complications. At the initial presentation, mean age of patients was 72.6 ± 8.9 years-old and duration of symptoms was 13 ± 9.7 days. From the 5 patients, 3 (60 percent) were male and 2 (40 percent) female. The success of submacular hemorrhage full displacement was achieved in 4 patients. The mean preoperative visual acuity (VA) was 1.12 ± 0.34 logMAR and the mean postoperative VA was 0.92 ± 0.4 logMAR. No cases of retinal detachment, endophthalmitis, vitreous hemorrhage, uveitis, cataracts and increased intraocular pressure were noted during the follow-up period. Intravitreal bevacizumab and C3F8 injection, associated to prone position can be a valuable therapeutic option for eyes with neovascular age-related macular degeneration and subretinal hemorrhage to the blood displacement out of the foveal area.

Experimental study on preparation and in vivo enhanced effect of a novel lipid perfluorooctylbromide nanoparticles / 中华超声影像学杂志

Objective To prepare a kind of new lipid perfluorooctylbromide(PFOB) nanoparticles and to explore its potential application as an ultrasound contrast agent. Methods Lipid PFOB nanoparticles were prepared by microfluidization techniques. The morphology and distribution were observed with optical microscope and transmission electron microscope. Particle size and electric potential were determined with Malvern laser light scattering analyzer. Twelve normal Wistar rats were performed directly contrast imaging after injection of PFOB nanoparticles via caudal vein. Vital signs of the rats were monitored during the whole study. And eehogenie intensity of the liver was dynamically quantified through DFY ultrasound quantified analysis system. The mechanism of enhancement was studied by the frozen sections of rat's liver and spleen. Results The nanoparticles size and distribution were highly uniformed. The grey scale ultrasound imaging of the rat's liver and spleen were enhanced by PFOB nanoparticles. Ten seconds after PFOB nanoparticles injected,enhancement of liver began, the peak time was approximately 3 - 4 min, the duration of contrast enhancement was nearly up to 1 h, The enhancement of spleen was more significant and the duration was much longer. No abnormal changes of the rat's vital signs appeared during the study. Frozen sections suggested that PFOB nanoparticles accumulated in the liver and spleen was the potential mechanism of enhancement. Conclusions This novel and safe lipid PFOB nanoparticles could make prolonged enhancement of rat's liver and spleen,which has a good potency for ultrasound application.

Perfluoroctano líquido como tamponante vitreorretiniano de curta duração no pós-operatório de portadores de descolamento de retina por ruptura gigante / Perfluoroctane liquid as a short-term vitreous-retinal tamponade in the postoperative period in patients with retinal detachment due to giant tears

OBJETIVOS: Relatar os resultados de vitrectomia via pars plana com utilização de perfluocarbono líquido (Perfluoroctano-Ophtalmos®), como tamponante vítreo-retiniano de curta duração, no pós-operatório de portadores de descolamento de retina, por ruptura gigante. MÉTODOS: Estudaram-se dez desses pacientes. Todos os casos eram complicados por vitreorretinopatia proliferativa grau B ou pior com rupturas que variavam em extensão de 90° a 210°. O perfluorocarbono líquido foi introduzido, por via pars plana, com o volume necessário para ultrapassar o limite posterior da ruptura, permanecendo no pós-operatório por cinco dias, estando os pacientes em decúbito dorsal. Após esse período submetiam-se a segunda intervenção para troca do perfluorocarbono líquido para gás ou óleo de silicone. RESULTADOS: Após período de acompanhamento médio de 16,2 ± 12,4 meses (2 a 43 meses), 80 por cento das retinas estavam aplicadas, sendo necessária a repetição desta técnica em 1 caso (10 por cento) caso e em 2 casos (20 por cento) não houve reaplicação da retina por vitreorretinopatia avançada. Houve melhora da acuidade visual em 5 casos (50 por cento). CONCLUSÃO: Observaram-se bons resultados quanto à aplicação da retina (80 por cento) e melhora da acuidade visual (50 por cento) quando do uso do perfluorocarbono líquido como tamponante vitreorretiniano de curta duração no pós-operatório de cirurgias de descolamento de retina por rupturas gigantes.

PURPOSE: To report pars plana vitrectomy results of intravitreous use of liquid perfluorocarbon as a short-term postoperative tamponade in retinal detachment due to giant tears in a series of patients. METHODS: Ten of those patients, all of them complicated by proliferative vitreoretinopathy grade B or worse, with tear extension varying from 90° to 210° were studied. Perfluorocarbon liquid was injected via pars plana until the posterior tear limit, remaining in the postoperative period during five days, with the patients in supine position. After this period, the patients underwent a second surgical procedure to exchange the liquid perfluorocarbon for gas or silicone oil. RESULTS: The retinas of eight patients were attached (80 percent) after a mean follow-up of 16.2 ± 12.4 months (from 2 to 43 months). It was necessary to repeat this technique in one (10 percent) case, and there was no attachment of the retina in two (20 percent) cases due to advanced proliferative vitreoretinopathy. Visual acuity improved in five (50 percent) cases. CONCLUSION: Good results (80 percent) and improvement of the visual acuity (50 percent) were observed with the use of intravitreous liquid perfluorocarbon as short-term tamponade in the postoperative period in patients with retinal detachments due to giant tears.

Combined Effect of Low-dose Nitric Oxide Gas Inhalation with Partial Liquid Ventilation on Hemodynamics, Pulmonary Function, and Gas Exchange in Acute Lung Injury of Newborn Piglets

We conducted a randomized animal study to determine whether there is a cumulative effect on hemodynamics, pulmonary function, and gas exchange when low dose nitric oxide (NO) is added to partial liquid ventilation (PLV) in acute lung injury. ighteen newborn piglets were saline-lavaged repeatedly, and randomly divided into two groups: PLV with perfluorocarbon group (n=8) and lavage only (control) group (n=10). Perfluorodecalin (30 mL/kg) was instilled into the endotracheal tube for 30 min, followed by 5-10 mL/kg/hr. Fifteen minutes after the completion of perfluorodecalin dosing, NO (10 ppm) was added to the inspiratory gas in an "on/off" manner. Perfluorodecalin instillation produced a significant improvement in gas exchange, pulmonary mechanics, shunt, and pulmonary arterial pressure (PAP). The addition of NO produced a further significant improvement in PaO2 and PAP. The "on/off" response to NO was seen apparently in PAP, PaO2, dynamic compliance, and shunt. All the variables in control group were remained at near the after-lavage levels without significant improvements until the end of the experiment. We concluded that NO might have a cumulative effect on gas exchange when combined with PLV, and this might be attributable to deceased PAP and V/Q mismatching.

Effects of Perfluorocarbon Associated High Frequency Oscillatory Ventilation on Hemodynamics and Gas Exchange in the Newborn Piglets with Respiratory Distress

We sought to know whether there is a further improvement in gas exchange when partial liquid ventilation (PLV) is added to high-frequency oscillatory ventilation (HFOV) in a piglet model of saline lavage-induced acute lung injury. Seven 7-9 day-old newborn piglets of mixed strain were treated with repeated saline lavage to achieve a uniform degree of acute lung injury. Then, HFOV were applied to the subject. Four animals received two consecutive doses (15 mL/kg) of perfluorodecalin at 30-min interval (PFC+HFOV group). The other three animals remained on HFOV alone (HFOV-only group). Repetitive lung lavage led to a significant acute aggravation in both gas exchange and hemodynamic parameters. Subsequent application of HFOV produced a significant rapid recovery in both gas exchange and hemodynamic parameters to near baseline levels. During and after perfluorodecalin dosing, there were no significant changes in gas exchange or hemodynamic parameters over time in both groups, and no significant differences in gas exchange or hemodynamic parameters between groups. We concluded that the addition of 30 mL/kg of perfluorodecalin to HFOV showed no detrimental effect on hemodynamics, but did not produce a significant improvement in gas exchange over a three-hour period.

Partial liquid ventilation with perfluorocarbon improves gas exchange and decreases inflammatory response in oleic acid-induced lung injury in beagles

The aim of this study was to determine the effect of partial liquid ventilation (PLV) using a perfluorocarbon (PFC) on gas exchange and lung inflammatory response in a canine acute lung injury model. After inducing severe lung injury by oleic acid infusion, beagle dogs were randomized to receive either gas ventilation only (control group, n = 6) or PLV (PLV group, n = 7) by sequential instillation of 10 mL/kg of perfluorodecalin (PFC) at 30 min intervals till functional residual capacity was attained. Measurements were made every 30 min till 210 min. Then the lungs were removed and bronchoalveolar lavage (BAL) (35 mL/kg) was performed on the right lung and the left lung was submitted for histologic analysis. There was significant improvement in PaO2 and PaCO2 in the PLV group compared to the control group (p < 0.05) which was associated with a significant decrease in shunt (p < 0.05). There was no significant difference in parameters of lung mechanics and hemodynamics. There was a significant decrease in cell count and neutrophil percentage in BAL fluid and significantly less inflammation and exudate scores in histology in the PLV group (p < 0.05). We conclude that PLV with perfluorodecalin improves gas exchange and decreases inflammatory response in the acutely-injured lung.

Experimental research of intraocular retention of domestic perfluorocarbon liquid / 中华眼底病杂志

Objective To investigate the effect of long-term intraocular retention of domestic perfluorocarbon liquid (PFCL) on morphology and histology of ocular tissues. Methods A total of 18 New-Zealand rabbits were randomly divided into 3 experimental groups, whose left eyes underwent intraocular injection with 0.3, 0.6, and 1.0 ml PFCL, respectively. All of the right eyes of the rabbits were in the control group. The morphological, electrophysiological and histological changes of the ocular tissue were observed 4, 8, and 12 weeks after the injection. Results No clinically significant retinopathy but only mild morphological changes were found in group 1 and 2, while obvious morphological and histological changes were found in group 3. Mild morphological and histological changes were found in all of the rabbits 4-8 weeks after the injection while significant ones were found 8-12 weeks after the injection. The results of electroretinography indicated a statistically significant decline of amplitude of b wave in group 3. Conclusions Long-term intraocular retention of few PFCL may cause mild histological changes but not affect the clinical function. Plentiful PFCL remains in eyes may lead to toxic reaction to the ocular tissue.

Anti-inflammatory effect of partial liquid ventilation on acute lung injury / 中国病理生理杂志

AIM: To investigate the anti-inflammatory effect of partial liquid ventilation in the piglets with lung lavage-induced acute lung injury. METHODS: 16 piglets were treated by lung lavage to a partial pressure of oxygen in arterial blood (PaO_2) below 100 mmHg for one hour and randomly divided into mechanical ventilation group (MV group) and partial liquid ventilation group (PLV group). Blood-gas analysis, hemodynamics, the contents of TNF-?, MDA, SOD, and MPO activity in lung tissue were measured. RESULTS: (1) Lung W/D, PPI and the count of WBC in the BALF in PLV group were significantly lower than those in MV group. The contents of MDA and MPO in lung tissue in PLV group were significantly lower than those in MV group. However, no evident difference in SOD activity in lung tissue between two groups was observed. (2) The contents of TNF-? in lung tissue in PLV group were significantly lower than those in MV group. CONCLUSION: Partial liquid ventilation with perfluorocarbon has anti-inflammatory effect on lung lavage-induced acute lung injury in the piglets.

Effects of partial liquid ventilation on acute lung injury in piglets / 中国病理生理杂志

AIM: To observe the effect of partial liquid ventilation with perfluorocarbon on gas exchange, hemodynamics and lung histological change in the piglets with surfactant depletion-induced acute lung injury. METHODS: 12 piglets were treated by lung lavage to a partial pressure of oxygen in arterial blood (PaO 2) below 100 mmHg for one hour and randomly divided into gas ventilation group (control group) and partial liquid ventilation (PLV) group, in PLV group, piglets received PFC (FC3280) intratracheally at doses of 15 mL/kg. The parameters of gas exchange and hemodynamics were measured before lung lavage, after lung lavage when the acute lung injury (ALI) was established, and 1 hour, 2 hours after ALI. Animals underwent euthanasia at the end of the study, lung histologic analysis followed. RESULTS: Surfactant depletion by lung lavage induced a stable acute lung injury.Gas exchange increased markedly in the animals that underwent PLV, less hemodynamic damage was observed in PLV group compared with the animals in GV group. Lung histologic analysis demonstrated a less lung damage, including atelectasis, neutrophil excudation, intra-alveolar hemorrhage and interstitial edema in PLV group compared with control group. CONCLUSION: In piglets with surfactant depletion-induced acute lung injury, partial liquid ventilation with perfluorocarbon can improve the gas exchange with less adverse hemodynamic effect and less lung injury compared with conventional gas ventilation.

Surgical management for diabetic retinopathy with diffuse diabetic macular edema and massive subretinal hard exudates / 解放军医学杂志

Objective To evaluate the clinical effects of surgical treatment for diabetic retinopathy (DR) with diffuse diabetic macular edema (DDME) and massive subretinal hard exudates (MSHE) with vitrectomy, endolaser photocoagulation to the retina under perfluorocarbon liquid and long acting gas tamponade. Methods Fifteen eyes of twelve patients with DR complicated with DDME and MSHE admitted from October 2001 to December 2003 were enrolled for study, in whom 9 eyes were in 7 males and 6 eyes in 5 females. The patients were aged from 36~65 years (mean 53.4). The best corrected visual acuity (BCVA), color fundus photography and fundus fluorescein angiography were recorded, and optic coherence tomography was performed preoperatively. Pars plana vitrectomy, posterior hyaloid removal, endolaser retinal photocoagulation under perfluorocarbon liquid and long acting gas tamponade were the therapeutic modalities used to treat the diseased eyes. Results Preoperative BCVA was finger counting to 0.05 in all 15 eyes. Improved vision was observed in eyes during 4~25 months of follow up period (mean 10.26 months), 0.03~0.04 in 2 eyes(13.3%), BCVA ≥0.09 in 13 eyes(86.7%), and 1 eye(6.7%)showed an improved vision from 0.04 to 1.0. Significant decrease in macular edema and retinal thickness were observed, and marlsed to complete absorption of intra-retinal and pre-retinal hemorrhage as well as MSHE was also seen. Conclusions Vitrectomy, posterior hyaloid removal, endolaser retinal photocoagulation under perfluorocarbon liquid and long acting gas tamponade may offer satisfactory effects in the treatment for DDME complicated with MSHE.