Objective To inverstingate the effect of perfluorohexyloctane(F6H8)to the retina of rabbit eyes. Methods Fifteen vitrectomized New Zealand white rabbits were injectedF6H8(experiment group,12 rabbits ) and BSS(control group,3 rabbits) into vitreous cavity.Slit-lamp biomicroscopy and indirect ophthalmoscopy were performed pre- and postoperatively in all the eyes.Histopathological examination was done after the rabbits were sacrificed at the end of the study. Results A large clear balb was formed after intravitreal injection of theF6H8 in the vitreous was injected and no retinal detachment and cataract were found.The OPL was edematous and then thinned out in 4th week in experimental group.Degenerating cells was found in inner and outer nuclear layers.Cellular vaculoar degeneration was present in TEM. ConclusionF6H8 in vitreous cavity may cause significant side effects on retina,we could not recommend it to be used as an intraocular temponade.
Objective To observe the effects on rabbit corneas and retinas after single intravitreal injection of voriconazole at different doses. Methods According to the randomization table, 25 healthy rabbits were randomly divided into control group, and voriconazole 50, 100, 200, and 400 μg groups. Therefore, there were 5 rabbits in each group. The eyes of control group received intravitreal injection of 0.1 ml balanced saline solution, and those treatment groups received 0.1 ml voriconazole injection of corresponding dose. Before the injection and 1, 7, and 14 days after the injection, endothelial cell counts and corneal thicknesses were measured; full-field electroretinogram were performed and b-wave amplitudes in maximal combined reaction (Max-R) were recorded. On 14 days after the injection, histologic structures were observed by light microscope and transmission electron microscope. Results There was no significant difference in endothelial cell counts (F=0.320, 0.291, 0.467, 0.649) and corneal thicknesses (F=0.214, 0.284, 0.360, 0.225) with those of control group at any time points (P > 0.05). Before and 1 day after the injection, b-wave amplitudes of each voriconazole group had no significant difference compared with those of control group (F=0.220, 0.106; P > 0.05). On 7 days after the injection, b-wave amplitudes decreased significantly at doses of 200 μg and 400 μg (P < 0.05). On 14 days after the injection, there was no significant difference between the the amplitude of 200 μg group and that of control group (P > 0.05). However, the amplitude of the 400 μg group decreased continuously and there was still significant difference (P < 0.05). Light microscopy did not reveal any corneal abnormality in both control group and voriconazole groups. The retinas were normal except that of the 400 μg group, which hadathinner and degenerated inner nuclear layer and disordered photoreceptor layer. Under transmission electron microscope, there were no ultrastructure damages of corneas in both control group and voriconazole groups, either. The rabbit retinas of the 50 μg and 200 μg group have normal inner nuclear layer and photoreceptor layer, but degrees of changes in both layers were observed in the eyes of 200 μg and 400 μg group. Conclusions There is no obvious effects on rabbit corneas and retinas after single intravitreal injection of voriconazole at he dose less than or equal 100 μg. There are no obvious effects on rabbit corneas at the dose of 200 μg and 400 μg, while there are damages to the retinas in both functions and histological structures.
Objective To investigate the effects of glycation pro ducts on growth and cytosoic free calcium (［Ca2+］i) of bovine retinal capillary pericytes. Methods The changes of growth and ［Ca2+］i of bovine retinal pericytes,which were cultured in early glycation products of bovine serum albumin (EG-BSA) and advanced glycation end products of bovine serum albumin (AGE-BSA),were studied by counting cell numbers,MTT colorimetric assay,［3H］thymidine incorporating,and fluorescent indicator fura-2 acetoxymeth1 ester (Fura-2AM). Results The number of alive pericytes in groups of EG-BSA and AGE-BSA were 17.87plusmn;2.36 and 14.77plusmn;3.72 which comparing with their control groups (20.54plusmn;0.82 and 20.31plusmn;0.93)were de creased 13．00% and 27．00% (Plt;0.01) by counting cell numbers on a counting plate after four days.The results were 0.4619plusmn;0.0946 and 0.3884plusmn;0.1031 which comparing with their control groups (0.5236plusmn;0.0539 and 0.5227plusmn;0.0519)were decreased 12．00% and 25.70% (Plt;0.01) by MTT colorimetric assay.Amount of ［3H］thymidine incorporating in groups of EG-BSA and AGE-BSA were 39450.16plusmn;887 0.68 and 33667.85plusmn;10581.70 which comparing with their control groups (56373.63plusmn;2317.97 and 56542.04plusmn;1961.23)were decreased 30．00% and 40.40% (Plt;0.01).The ［Ca2+］i concentration of pericytes in groups of EG-BSA and AGE-BSA were (129.55plusmn;30.41) nmol/L and (179.71plusmn;56.69) nmo l/L which comparing with their control groups ［(79.70plusmn;6.94) nmol/L and (83.plusmn;6.39) nmo l/L］ were increased to 163．00% and 214．00%. Conclusion Both EG-BSA and AGE-BSA can inhibit the proliferation and DNA syntheses of retinal capillary pericytes,and increased ［Ca2+］i concentration in pericytes,especially the AGE-BSA. (Chin J Ocul Fundus Dis，2000，16：139-212)
Objective To investigate the correlation of ascorbic acid distribution and retinal susceptibility to iron toxicity of the retina.Methods Autoclaved iron particles of 5 mg and 15 mg were implanted into the vitreous cavities of 32 Spragu-Dawley (SD) rats and 9 rabbits, respectively. The retinal sections of rats and rabbits were examined after hemotoxylin-eosin (HE) staining. Apoptos is of rabbits′retinal neurons was investigated by TdT-mediated dUTP-biotin nick-end labeling (TUNEL). Chinoy′s method was used to observe the distribution of as corbic acid in the retinae of the 2 kinds of animals.Results In rats, histological and structural densification was observed only in the photoreceptor cells after implantation of the iron particles. In rabbits, however, histological and structural destruction as well as TUNEL-positive nuclei were observed in all neuronal layers of the retina 3 days after the implantation of the iron particles. Silver granules reduced by ascorbic acid from silver nitrate were observed only in the outer nuclear layer in normal rats retinae, while they were observed evenly throu ghout all layers of rabbits′retinae. Conclusions The suscept ibility of retina to iron toxicity is correlated to the distribution of ascorbic acid in retina. (Chin J Ocul Fundus Dis，2003，19：269-332)
Objective To investigate the effects of advanced glycation endproducts (AGEs) on proliferation of pericytes of bovine retinal capillary vessels and expression of transforming growth factor beta;(TGF-beta;). Methods The proliferation of pericytes detected by methyl thiazolyl tetrazolium (MTT) colorimetric assay, cellular cycle of pericytes was analyzed by flow cytometry was used to analyze cell, and TGF-beta; protein expression of pericytes was observed by immunofluorescent staining. Results AGEs inhibited the proliferation of pericytes of bovine retinal capillary vessels, stopped the cellular cycle of pericytes in synthesis phase (S phase), increased the number of apoptotic cells obviously (Plt;0.01), and promoted the expression of TGF-beta; proteinof perycytes. Conclusions AGEs may promote the apoptosis of pericytes by inhibiting the proliferation of pericytes to lead the decrease of pericytes number, and may accelerate diabetic retinopathy by promoting the expression of TGF-beta; protein of pericytes. (Chin J Ocul Fundus Dis, 2006, 22: 20-23)
ObjectiveTo evaluate the security of intravitreal injection with ciproflaxacin to retina.MethodsTweenty-four rabbits were randomly divided into 4 groups with 6 rabbits in each group. 0.1 ml ciproflaxacin in doses of 2 500,5 000,and 10 000 μg was intravitreally injected into the rabbits eyes, retrospectively. And 0.1 ml saline solution was injected into the vitreous body of the rats in the control group. Indirect microscope, light microscope and electroretinogram (ERG) were used to observe the changes of ocular fundus.ResultsNormal results of light microscopy and ultrastructure were found in 250 μg and 500 μg groups; irregularly arranged outer and inner nuclear layers, dropsical or even lost ganglion cells, and ultrastructural changes were in 1 000 μg group. There was no apparent difference of ERG′s a and b amplitudes before and after intravitreal injection with ciproflaxacin in each group.ConclusionIntravitreal injection with ciproflaxacin is safe, and 500 μg or less is the secure dosage in rabbits' eyes. (Chin J Ocul Fundus Dis, 2005,21:180-182)
ObjectiveTo investigate the protective effect and mechanism of betaxolol on optic nerves after experimental retinal ischemia-reperfused injury.MethodsRetinal ischemia was induced in SD rats by increasing intraocular pressure through intracameral infusion. Sixty-eight rats were randomly divided into 3 groups: normal control (eight rats), 0.25% betaxolol treatment (thirty rats) and saline control group (thirty rats). The latter two groups were subdivided into group 1 day, 3 and 7 days after reperfusion, respectively, with 10 rats in each group. Betaxolol and normal saline was applied to the right eyes of the rats in the treatment group and to the ones in normal saline control group, respectively. The amplitude of bwave of electron retinograph (ERG) was observed and the histological and ultrastructural changes were detected by light and electron microscopy. The expression of neural nitrogen oxide synthase (nNOS) was detected by immunohistochemistry. The content of malonyldialdehyde (MDA) and the superoxide dismutase (SOD) activity were measured by spectrophotometer.ResultsBegan from the first day after reperfusion, in saline control group, the amplitudes of ERG bwave reduced continuously, the histopathological damages of retina were aggravating, the expression of nNOS increased, MDA level increased and SOD level decreased persistently, which significantly differed from the normal control group （P＜0.01）; in contrast to the saline control group, the amplitudes of bwave of ERG in betaxolol treatment group after reperfusion got right obviously（P＜0.01）, with alleviated histopathological damages, decreased nNOS positive neurons（P＜0.01）, decreased MDA content（P＜0.01）, and increased SOD activity （P＜0.01）, in which no statistical significance of nNOS positive neurons was found between the treatment group and normal control group （P＞0.01）. ConclusionBetaxolol, by reducing intracellular overfreight ofCa2+, inhibiting production of NO and elevating the ability of anti-oxidation in rat retina, can protect retinal neurons from ischemiareperfused injury.(Chin J Ocul Fundus Dis, 2005,21:249-252)