Vehicle of triamcinolone acetonide is associated with retinal toxicity and transient increase of lens density

Background Intravitreal triamcinolone acetonide (TA) has been widely used as a therapeutic method for many ocular diseases, but a consensus on an appropriate safe therapeutic window of dosage for intravitreal injection, and whether vehicle of TA should be reduced or eliminated, has not yet been reached. The aim of this article is to investigate these issues.Methods Forty New Zealand white rabbits were divided into four experimental groups and one control group. Four or 25 mg TA, with vehicle either reduced or not, was injected into the vitreous cavity of rabbits in experimental groups. Rabbits in the control group received 0.2 ml intravitreal sterile saline solution. Intraocular pressures (IOP) were measured by a Tonopen tonometer. Values of lens density were measured by a Pentacam system. Soluble protein, total antioxidation capacity, reduced glutathione (GSH), glutathion peroxidase (GSH-px), and superoxide dismutase (SOD) in lens were measured by specific kits. ERG and pathological examinations, including light and electron microscopy of the retina, were also performed.Results Elevation of IOP was noted in all experimental groups after intravitreal TA (P<0.01, paired t-test). Significant increase of lens density was noticed at 1 week after intravitreal TA in the 25 mg vehicle-containing group (P<0.0001, paired t-test). Significant loss of GSH-px activity was noticed at the end of the study (P<0.05, paired t-test), while SOD activity increased (P<0.05, paired t-test). Amplitudes of ERG waves declined significantly in vehicle-containing groups (P<0.01, paired t-test) at the end of the study. Pathological examination showed obvious retinal toxicity in vehicle-containing groups.Conclusions Vehicle of TA should be eliminated or reduced before intravitreal injection to avoid potential retinal toxicity and transient increase in lens density.Presented at Chinese Academy of Fundus Disease Meeting, April, 2005.This study was supported by the 985 Fund of Peking University, Beijing.The authors have no financial interest in any instruments or drugs mentioned in this study.     

晶体玻璃体视网膜联合手术治疗复杂性视网膜脱离

目的探讨玻璃体视网膜手术（ｖｉｔｒｅｒｅｔｉｎａｌｓｕｒｇｅｒｙ，ＶＲ术）联合晶体切除／超声粉碎的效果。方法对８１例（８１只眼）应用晶体玻璃体视网膜联合手术（ｌｅｎｔｉｃｕｌａｒ－ｖｉｔｒｅｏｒｅｔｉｎａｌｓｕｒｇｅｒｙ，ＬＶＲ术）治疗的复杂性视网膜脱离进行回顾性分析。结果解剖性成功者６４只眼（７９．０１％），功能性成功者４５只眼（５５．５６％）；手术成功率显著降低的原因是前部增殖性玻璃体视网膜病变（ｐｒｏｌｉｆｅｒａｔｉｖｅｖｉｔｒｅｏ－ｒｅｔｉｎｏｐａｔｈｙ，ＰＶＲ）（成功率４２．８６％，Ｐ＜０．０１）和术中／术后眼内出血（成功率５８．８２％，Ｐ＜０．０２５）。结论ＬＶＲ术是治疗复杂性视网膜脱离的主要方法；显著影响手术预后的因素是前部ＰＶＲ和术中／术后眼内出血。     

电镜观察透明质酸酶对人眼晶状体上皮细胞作用

目的：探讨透明质酸酶是否可以溶解晶状体囊膜上皮细胞及其作用机制。方法。取人眼超声乳化白内障摘除术中撕下的前囊膜，对半切开，一半立即置于37℃水浴箱中的2ml平衡液中。另一半置于37℃水浴箱中的2ml平衡液 1500IU透明质酸酶中。分别放置5、1O、15min，然后立即放入4％戊二醛中固定，送透射电镜检查。结果：置于平衡液中5、10、15min的前囊膜，囊膜表面的晶状体上皮细胞之间的细胞连接完整;而置于透明质酸酶中5，10、15min的前囊膜，其表面的晶状体上皮细胞之间以及细胞与囊膜之间的缝隙随时间延长而增大。结论:透明质酸酶可以破坏晶状体上皮细胞之间以及细胞与囊膜之间的连接，从而使晶状体囊膜上的上皮细胞易于被清除。     

Progression of amiodarone induced cataracts

Amiodarone hydrochloride is a potent antiarrhythmic agent recently approved for use by the Food and Drug Administration. Anterior subcapsular lens opacities were observed in seven of fourteen patients treated with moderate to high doses of amiodarone at the Veterans Administration Medical Center in San Francisco in 1982. The present report summarizes the present status of these same fourteen patients ten years later. Anterior subcapsular lens opacities developed or progressed in all patients continuing treatment with this antiarrhythmic agent during the following ten year interval. Although Snellen visual acuities are not decreased, subtle visual impairment is present as measured by contrast sensitivity measurements with and without glare. This decrease in visual acuity is not a contraindication for therapy with this potentially life saving drug.     

无晶状体眼二期前房型人工晶状体植入后的临床观察

目的　探讨无晶状体眼二期植入弹性开放襻一体式前房型人工晶状体的有效性和安全性。方法　 37例 37眼白内障术后无晶状体眼在表面麻醉下经巩膜隧道式切口二期植入新型弹性开放襻一体式前房型人工晶状体 ,并联合周边虹膜切除术。术后随访 5～ 2 8个月 ,平均 18.4个月。结果　 37只无晶状体眼均顺利植入新型弹性开放襻一体式前房型人工晶状体。术前矫正视力为 0 .1～ 0 .6 ,术后 3个月达 0 .2～ 0 .8,2 7眼≥ 0 .5(73.0 % ) ,35眼 (94 .6 % )达到术前最佳矫正视力以上。术前角膜内皮细胞计数平均为 (194 7± 5 81)个 /mm2 ,术后 3个月平均为 (1871± 4 6 2 )个 /mm2 ,手术前、后的差异无显著性 (P >0 .0 5 )。术后常见并发症为角膜水肿、葡萄膜炎、一过性高眼压。结论　无晶状体眼二期植入新型弹性开放襻一体式前房型人工晶状体是一种简便、安全、有效的手术方法     

Effect of Bendazac Lysine on lens and retina in diabetics

The possible beneficial effects on the lens and retina which Bendazac Lysine may have in the treatment of adult diabetic patients were investigated. Twenty patients, ranging in age from 54.80 ± 5.86 years old, were studied. The average duration of the diabetes was 11.32 ± 4.10 years. Thirteen patients had background retinopathy. The metabolic controls carried out during the study were satisfactory (HbA1<11%). Bendazac Lysine (500 mg three times a day) was administered for 6 months. Blood-retinal barrier permeability (VPR and VPRt) and lens transmittance (t) were evaluated prior to and 6 months after treatment by fluorophotometry. No statistically significant differences between the pre- and post-treatment values of the retina permeability were observed, however, there was a statistically significant improvement (p<0.05) (initial value: t= 0.813 ± 0.040 and final value: t=0.823 ± 0.037) in the lens transmittance. The authors conclude that Bendazac Lysine has a beneficial effect on the lens in the diabetic adult although no improvement in the permeability of the blood-retinal barrier has been observed.     

The effect of single and repeated UVB radiation on rabbit cornea

Background Cumulative effect of ultraviolet radiation (UVR) is an important aspect of UV corneal damage. The purpose of this study was to apply high resolution magic angle spinning proton nuclear magnetic resonance (HR-MAS ¹H NMR) spectroscopy to evaluate the effect of single and repeated UV radiation exposure of the same overall dose on the rabbit cornea.Methods Corneal surfaces of 24 normal rabbit eyes were examined for the effects of UVB exposure (312 nm). In the first group (UVB1), animals were irradiated with a single dose (3.12 J/cm²; 21 min) of UVB radiation. The animals in the second group (UVB2) were irradiated three times for 7 min every other day (dose of 1.04 J/cm²; days 1, 3, 5) to give the same overall dose (3.12 J/cm²). The third group served as an untreated control group. One day after the last irradiation, the animals were sacrificed, and the corneas were removed and frozen. HR-MAS ¹H NMR spectra from intact corneas were obtained. Special grouping patterns among the tissue samples and the relative percentage changes in particular metabolite concentrations were evaluated using modern statistical methods (multivariate analysis, one-way ANOVA).Results The metabolic profile of both groups of UVB-irradiated samples was significantly different from the control corneas. Substantial decreases in taurine, hypo-taurine and choline-derivatives concentrations and substantial elevation in glucose and betaine levels were observed following the UVR exposure. There was no significant difference between the effect of a single and repeated UVB irradiation of the same overall dose.Conclusions For the first time, the effects of single and repeated UVR doses on the metabolic profile of the rabbit cornea were analysed and compared. The combination of HR-MAS ¹H NMR spectroscopy and modern statistical methods (multivariate analysis, one-way ANOVA) proved suitable to assess the overall view of the metabolic alterations in the rabbit corneal tissue following UVB radiation exposure.     

碱性成纤维细胞生长因子受体基因在牛眼晶体上皮细胞内的表达

目的探讨碱性成纤维细胞生长因子（ｂａｓｉｃｆｉｂｒｏｂｌａｓｔｇｒｏｗｔｈｆａｃｔｏｒ，ｂＦＧＦ）对晶体上皮细胞促增殖作用的机理。方法从培养的第二代牛眼晶体上皮细胞提取ＲＮＡ，经逆转录反应合成ｃＤＮＡ。借助从人体胎盘纤维细胞ｂＦＧＦ受体序列合成的寡核苷酸引物，聚合酶链反应体外扩增ｃＤＮＡ。扩增的ｃＤＮＡ片段克隆后，Ｓａｎｇｅｒ双脱氧链终止法测定其序列。结果探测出牛眼晶体上皮细胞ｂＦＧＦ受体的ｍＲＮＡ，测序后发现其氨基酸序列片段中仅３个氨基酸与人体不同。结论晶体上皮细胞存在ｂＦＧＦ受体，当ｂＦＧＦ与其受体结合后，对促进晶体上皮细胞的增殖以及白内障术后后囊混浊具有重要作用。     

应用激光扫描共聚焦显微镜观察晶体上皮细胞中的游离钙

目的用钙的荧光指示剂ｆｌｕｏ－３和激光扫描共聚焦显微镜（ｌａｓｅｒｓｃａｎｎｉｎｇｃｏｎｆｏｃａｌｍｉｃｒｏｓｃｏｐｙ，ＬＳＣＭ）观察大白鼠的晶体上皮细胞（ｌｅｎｓｅｐｉｔｈｅｌｉａｌｃｅｌ，ＬＥＣ）中的游离钙。方法ｆｌｕｏ－３着染细胞后，应用ＬＳＣＭ观察细胞内ｆｌｕｏ－３与钙螯合后的荧光分布，最后用钙离子载体Ａ２３１８７和重金属离子Ｍｎ＋＋作校正，将ｆｌｕｏ－３与钙结合显示的荧光强度转换为［Ｃａ＋＋］ｉ值。结果ＬＥＣ中的游离钙主要分布在细胞核中。大白鼠晶体上皮细胞中的［Ｃａ＋＋］ｉ为２５９．７９±４９．２４ｎｍｏｌ／Ｌ。结论ｆｌｕｏ－３与ＬＥＣ孵育后能着染细胞。用ＬＳＣＭ能直观地观察细胞内钙的分布，并能通过校正得到细胞内游离钙的绝对值。这种成熟的方法，为进一步对ＬＥＣ中游离Ｃａ＋＋的研究提供技术准备