Disorder of blood-aqueous barrier following Ahmed Glaucoma Valve implantation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Ahmed Glaucoma Valve implantation (AGVI) is used to treat refractory glaucoma. Breakdown of the blood-aqueous barrier (BAB) has been noted after some surgical techniques. The current study was designed to assess BAB disruption after AGVI.</p><p><b>METHODS</b>Anterior chamber protein content was measured by the laser flare cell photometry in 22 eyes of 22 patients with refractory glaucoma before AGVI and at each postoperative visit up to 1 month.</p><p><b>RESULTS</b>Before AGVI the mean aqueous flare values in all eyes were (15.17 ± 9.84) photon counts/ms. After AGVI, the values significantly increased at day 1, day 3, and week 1 compared to those before AGVI (all P < 0.05) with a peak at day 3. They returned to pre-operative levels at week 2, and were lower than preoperative level at month 1. Eyes with previous intraocular surgery history had greater aqueous flare values than those without previous intraocular surgery history, but there were no significant differences at all time points postoperatively (all P > 0.05). Furthermore, eyes with shallow anterior chambers had greater aqueous flare values at day 3 and week 1 (all P < 0.05). When comparing eyes with other refractory glaucoma conditions, neovascular glaucoma combined with intravitreal bevacizumab injection resulted in lower aqueous flare values after AGVI, but no significant differences were observed at all time points, postoperatively (all P > 0.05).</p><p><b>CONCLUSIONS</b>The BAB was impaired and inflammation was present in the anterior chamber in refractory glaucomatous eyes following AGVI. However, such conditions were resolved within 1 month postoperatively. Intravitreal bevacizumab treatment in neovascular glaucoma eyes before AGVI may prevent BAB breakdown.</p>

Central serous chorioretinopathy mistaken for tuberculous choroiditis

To report a patient erroneously diagnosed with tuberculous choroiditis who was accordingly treated with long term steroids which in turn, worsened the actual disease process that turned out to be central serous chorioretinopathy [CSC]. A 59-year-old Caucasian man developed a chorioretinal disease in his right eye in 1997. Having a positive tuberculin skin test, tuberculous chorioretinitis was suspected and antituberculous therapy was administered for 4 months. In 2005, visual symptoms in the same eye recurred and despite negative interferon gamma release assay, tuberculous choroiditis was considered as the diagnosis and the patient further received massive corticosteroid therapy along with antituberculous agents. Despite a deteriorating clinical picture, therapy was continued. Upon initial examination at our center, no sign of inflammation was observed and a diagnosis of CSC was made, consequently steroid therapy was terminated. In some chorioretinopathies, it is difficult to differentiate inflammatory from non-inflammatory causes. One should observe the course of the disease and question the initial diagnosis when no improvement or deterioration occurs despite therapy

Ocular drug delivery; impact of invitro cell culture models

Normal vision depends on the optimal function of ocular barriers and intact membranes that selectively regulate the environment of ocular tissues. Novel pharmaco-therapeutic modalities have aimed to overcome such biological barriers which impede efficient ocular drug delivery. To determine the impact of ocular barriers on research related to ophthalmic drug delivery and targeting, herein we provide a review of the literature on isolated primary or immortalized cell culture models which can be used for evaluation of ocular barriers. In vitro cell cultures are valuable tools which serve investigations on ocular barriers such as corneal and conjunctival epithelium, retinal pigment epithelium and retinal capillary endothelium, and can provide platforms for further investigations. Ocular barrier-based cell culture systems can be simply set up and used for drug delivery and targeting purposes as well as for pathological and toxicological research

The Steroid Effect on the Blood-Ocular Barrier Change Induced by Triolein Emulsion as seen on Contrast-Enhanced MR Images

OBJECTIVE: The purpose of this study is to evaluate the effect of dexamethasone on the damaged blood-ocular barrier caused by triolein emulsion, using contrast-enhanced MR imaging. MATERIALS AND METHODS: An emulsion of 0.1-mL triolein in 20 mL of saline was infused into the carotid arteries of 32 cats, 12 cats were placed in the treatment group and 18 cats were placed in the Control group. Thirty minutes after the infusion of triolein emulsion, a set of orbital pre- and post-contrast T1-weighted MR images (T1WIs) were obtained. Infusion of 10 mg/kg dexamethasone into the ipsilateral carotid artery of each of the cats in the treatment group cats and 20 mL saline in each of the cats in the control group was given. A second set of pre- and post-contrast orbital T1WIs were obtained three hours following triolein emulsion infusion. Qualitative analysis was performed for the the anterior chamber (AC), the posterior chamber (PC), and in the vitreous humor of the ipsilateral and contralateral eyes. The signal intensity ratios of the ipsilateral eye over the contralateral eye were quantitatively evaluated in the three ocular chambers on the first and second set of T1WIs, and were then statistically compared. RESULTS: Qualitatively, the AC, the PC or the vitreous did not show immediate contrast enhancement on the first and the second set of post-contrast T1WIs. However, the AC and the PC showed delayed contrast enhancement for both groups of cats on the second pre-contrast T1WIs. No enhancement or minimally delayed enhancement was seen for the vitreous humor. Quantitatively, the signal intensity ratios in the PC of the treatment group of cats were statistically lower than the ratios of the control group of cats for the second set of T1WIs (p = 0.037). The AC and vitreous showed no statistically significant difference between the feline treatment group and control group (p > 0.05). CONCLUSION: Contrast-enhanced MR images revealed increased vascular permeability in the PC of the eye after infusion of triolein emulsion. Dexamethasone seems to decrease the breakdown of the blood-aqueous barrier in the PC.

Experimental Model for Research on the Blood-Ocular Barrier

PURPOSE: The eyeball has 2 blood-ocular barriers, i.e., the blood-retinal and blood-aqueous barriers. The purpose of this study was to evaluate if triolein emulsion could disrupt the barriers, and we wanted to suggest as an experimental model for future blood-ocular barrier studies. MATERIALS AND METHODS: The triolein emulsion was made of 0.1 ml triolein and 20 ml normal saline, and this was infused into the carotid artery of ten cats (the experimental group). As a control group, only normal saline was infused in another ten cats. Precontrast and postcontrast T1-weighted MR images were obtained at 30 minutes and 3 hours after embolization in both groups. The signal intensities were evaluated qualitatively and quantitatively in the anterior and posterior chambers and also in the vitreus fluid. Statistical analysis was performed by employing the Kruskal Wallist test, Dunn's Multiple Comparison test and the Wilcoxon signed rank test. RESULTS: In the control group, no contrast enhancement was demonstrated in the anterior or posterior chamber or in the vitreus fluid of the ipsilateral or contralateral eyeball on the 30 minutes MR images. The anterior chambers of the ipsilateral and contralateral eyeballs revealed delayed contrast enhancement on the 3 hour MR images. In the experimental group, the 30 minute-postembolization MR images were not different from those of the control group. The 30 minute-postembolization MR images demonstrated delayed contrast enhancement in the anterior chamber of the ipsilateral and contralateral eyeballs and in the posterior chamber of the ipsilateral eyeball. The delayed contrast enhancement of the posterior chamber of the ipsilateral eyeball was statistically significant (p<0.05). CONCLUSION: The present study demonstrated significant contrast enhancement in the posterior chamber with infusion of the triolein emulsion, and this can serve as a model for blood-aqueous barrier studies.

Estudo comparativo da flarefotometria em pacientes com melanoma maligno e nevo de coróide / Comparative study of flarephotometry in patients with malignant melanoma and choroidal nevus

Introduçäo: Os tumores malignos intra-oculares estäo associados com um aumento do flare na camara anterior, causado por uma quebra na barreira hemato-aquosa, que pode ocorrer por varios mecanismos. Estudos utilizando a flarefotometria confirmam o aumento do flare em olhos com tumores intra-oculares malignos e benignos. Objetivo: Avaliar a flarefotometria como auxiliar no diagnóstico diferencial de melanoma maligno e nevo de coróide, comparando-se com olhos contralaterais normais. Métodos: Foram avaliados olhos com melanoma maligno e olhos com nevo de coróide diagnosticados por meio de oftalmoscopia indireta e/ou ultrasonografia. Os olhos normais contralaterais foram utilizados como controles. A flarefotometria foi realizada em todos os pacientes, sob midriase bilateral, utilizando equipamento LaserFlare Meter (FC 500, Kowa). Foram aplicados os testes de Wilcoxon, Mann-Whitney, e Spearman para análise estatistica. Resultados: A média da flarefotometrianos olhos com melanoma maligno de coróide foi 17,1 ph/ms e nos olhos normais contralaterais foi 4,06 pb/ms. Nos olhos com nevo de coróide o valor da flarefotometria foi 6,12 ph/ms e nos olhos contralaterais normais foi 4,47 ph/ms. O valor da flarefotometria foi maior nos olhos com melanoma maligno e nevo quando comparado com os olhos contralaterais normais (p<0,001 e p<0,01). Nos olhos com melanoma maligno o valor da flarefotometria foi significantemente maior que nos olhos com nevo de coróide (p<0,001). Foi observada correlaçäo positiva entre a espessura do tumor e a flarefotometria (r=0,47). Conclusäo: A flarefotometria é um exame útil no diagnóstico diferencial entre melanoma maligno e nevo de coróide.

A Comparison of the Responses to Diode and Argon Laser Irradiation of the Iris in Rabbits

We compared the effects of diode laser (DL) irradiation of the iris with those of argon laser (AL). Histopathologic examination of laser-induced lesion, measurements of aqueous flare and prostaglandin (PG) E2 were performed. DL was applied in one eye of each animal and the fellow eye received ALwith the same parameters in 49 pigmented rabbits. At 1 hour after irradiation, the mean flare count was higher in the DL-treated eyes than in AL-treated eyes(p0.05). On histopathologic examinations, iris defect by DL was wider and shallower than that by AL. The extent of coagulation of the iris tissue was more extensive in the DL-irradiated iris. Our results suggest that the DL irradiation may be more harmful to the blood-aqueous barrier and iris tissue than AL. Further development of the laser equipment or the treatment regimen for diode laser iridotomy may be necessary.

Observation of Damage to the Blood-Aqueous Barrier after Trabeculectomy with Mitomycin C

We observed the breakdown of the blood-aqueous barrier after trabeculectomy with mitomycin C by using laser flaremeter. There were 20 patients (25 eyes) of which 9 patients(11 eyes) were applied 0.02% MMC for 3minutes during the trabeculectomy and 11 patients (14 eyes) were not applied MMC. All patients were diagnosed as primary open angle glaucoma and underwent trabeculectomy. The preoperative, postoperative 1 day and 3 months aqueous flare intensity were 10.8+/- 5.05, 15.6+/- 5.32, 10.1+/- 4.55(photon count/msec)in group with MMC and 10.6+/-4.04,15.9+/-3.30, 9.2+/-3.94(photon count/msec) in group without MMC Anterior chamber flares were highest on the first postoperative day, declining rapidly in the first week with more gradual recovery to preoperative level by 1 month postoperatively, which shows the breakdown of blood-aqueous barrier by surgery. There was no statistically significant difference between the two groups in postsurgical aqueous flare intensity. 0.02% MMC does not appear.

Soluçäo salina balanceada resfriada e a inflamaçäo pós-operatória em facoemulsificaçäo / Cold balanced saline solution and the postoperative inflammation in phacoemulsification

Cirurgiöes admitem, empiricamente, que a infusäo resfriada de soluçäo salina balanceada durante a facoemulsificaçäo diminui o processo inflamatório após o procedimento cirúrgico. Avaliou-se assim, o possível papel protetor da barreira hemato-aquosa por essa soluçäo, quando utilizada à temperatura mais baixa. Vinte olhos de 20 pacientes com catarata, sendo doze do sexo masculino e oito do sexo feminino, com idade entre 42 e 81 anos, foram divididos em dois grupos. O primeiro recebeu soluçäo salina balanceada à temperatura ambiente e o segundo, à temperatura de 4§C durante a facoemulsificaçäo. A inflamaçäo intra-ocualr foi quantificada pelo "Kowa laser flare meter", no pré-operatório, primeiro e sétimo dias pós-operatórios. A média pré-operatória foi inferior a 7,6 fotóns/mseg em todos os casos e, nesse tempo do experimento, os grupos 1 e 2 foram comparáveis (näo se observou diferença entre eles). Näo houve diferença estatisticamente significante entre os dois grupos no primeiro e sétimo dias pós-operatórios (P<0,001). Assim, foi possível observar que a infusäo resfriada durante a facoemulsificaçäo näo atuou como fator protetor sobre o componente de barreira hemato-aquosa da inflamaçäo.

Effect of 5-fluorouracil and Mitomycin-C on Blood Aqueous Barrier

The adjunctive use of 5-fluorouracil and mitomycin C remarkably improves the success rate of glaucoma filtering surgery, but these antiproliferative agents may be toxic to other ocular tissues. The authors evaluated the effect of 5-FU and MMC on the blood-aqueous barrier. Sixteen pigmented rabbits were used, 7 for 5-FU group and 9 for MMC group. Five milligrams of 5-FU(0.1ml) was injected subconjunctivally in one eye of each animal in 5-FU group. In MMC group, we made limbus-based conjunctival flap on superotemporal area and applied MMC(0.4 mg/ml) soaked Week-cell sponge on subconjunctival-scleral space for 5 minutes and irrigated with 200 ml of normal saline. The contralateral eyes of each animal in both groups were used for control. We measured protein concentration in anterior chamber with the laser flare-cell meter(Kowa, FM-500). At 7 hours after operation, protein concentration in anterior chamber was significantly higher in 5-FU injected eyes(11.22 +/- 1.98 photons/msec, mean +/- S.D.) than control eyes(7.78 +/- 0.96 photons/msec) in the 5-FU group. There was no difference between MMC treated eyes and control eyes. MMC soaking is thought to be less harmful on the blood-aqueous barrier than 5-FU subconjunctival injection.

Experimental Study on the Effect of the Flow Rate and Blood Aqueous Barrier After Cyclocryotherapy in the Rabbits

The purpose of the study is to investigate the changes of the blood aqueous barrier, the flow rate and IOP after cyclocryotherapy in the white rabbits. After cyclocryotherapy we injected intravenously a dose of 25mg/kg of fluorescein sodium and sampled the aqueous humor at 1 and 2 hour and measured the concentration of flouorescein sodium by means of HPLC(High Performance Liquid Chromatography). By the comparision study among the control group, 4 times cyclocryotherapy application group and 8 times cyclocryotherapy applications group during experimental period, the results were summarized as follows. 1. In the control group, the mean aqueous amount was 0.297+0.020ml, the flow rate was 3.282+0.426 ul/min. 2. In the cyclocryotherapy group, IOP was significantly decreased during experimental period. It was found that the IOP in the 8 times cyclocryotherapy application group was more decreased than that in the times cyclocryotherapy application group after 2 weeks. 3. There was marked increase of the concentration of fluorescein sodium in aqueous humour after acute cyclocryotherapy, but it was decreased to normal level at 4 weeks. The difference between the two groups was not found. 4. The flow rate was markedly decreased after acute cycrocryotherapy and was almost back to normal 4 weeks in two groups. There was difference between the two groups. 5. In Electron microscopic study, many wide intercellular gaps between the nonpigmented and pigmented epithelium are observed but the nucleus of the nonpigmented and pigmented epithelium are well preserved on the day of experiment. From 7 days the nucleus, and both nonpigmented and pigmented epithelium are markedly decreased in number. By 28 days the cytoplasm is shrunken, nucleus has disappeared, and a capillary near pig-ment epithelium obstructed but the basement membrane of thest cells is well pres-erved. 6. After cyclocryotherapy, The IOP decreased progressively during experimental period, but the flow rate was almost back to normal at 4 weeks. From the result we can deduce the outflow facility was not influenced by cyclocryotherapy. And so it was suggested from electron microscopic study that IOP lowering effect of cyclocryotherapy was due to quantitiative destruction of aqueous production.

Tne effets of anti-inflammatory ageets on bloed-aqueous-barrier in experimental uveitis

The purpose of this paper is to study the effects of anti-inflammatory agents on the blood-aqueous-berrier in experimentally induced uveitis. 10% solution of sodium fluorescein was injection intravenously in the ear vein of rabbits (0.25 ml/kg) and fluorescein curve was drawn after the method of Amsler and Huber. Experimental uveitis was induced by the injection of 0.2 ml of human serwn into the vitreous body. After uveitis had been induced. three kinds of anti-inflammatory agents-Prednisolone, Benzyron and Methotrexate-were Biven oralIy. In control animals in which no uveitis was induced, no changes in fluorescein curve were demonstrated before and after the administrations of drugs. In animals with uveitis, maked increases of the blood-aqueous barrier were noted. When Benoyron and Prednisolone were given to these animals, normaliration of the fluorescein curves were demonstrated. Methotrexate had no effects on the fluorescein curves in uveitis animals, showing no improvements in the permeability of uveal vessela. This ineffectiveness seemed to be due to the resistance of rabbits to methotrexate.