ObjectiveTo investigate the effect of triamcinolone acetonide (TA) with different dosage and excipient on retina.MethodsThirty-two purebred New Zealand white rabbits randomly divided into 4 groups underwent intravitreous injection with TA. Group 1:4 mg TA without excipient; group 2:25 mg TA without excipient; group 3:4 mg TA with excipient; group 4:25 mg TA with excipient. Electroretinography (ERG) was performed on each rabbit before intravitreal injection, 1 week, 1 and 2 months after the injection. All the animals were killed and the eyeballs were extirpated 2 months after the injection, and pathological examinations including light and electron microscopy were performed.ResultsNo significant difference was found in the latent period of ERG at the points of time before and after the injection in all the groups, but the amplitudes of ERG waves was lower in groups containing excipient than that before the treatment (Plt; 0.01). The results of light and electron microscopy showed damages of tissue or structures of retina in various degrees in groups containing excipient.ConclusionIntravitreous injection of TA with the dosage of ≤25 mg without excipient does no harm to the retinal configuration and function, and excipient may lead to the change of retinal configuration and function.(Chin J Ocul Fundus Dis, 2005,21:229-232)
ObjectiveTo observe the therapeutic effect of intravitreous injection with triamcinolone acetonide (TA) on diffused diabetic macular edema.MethodsIntravitreous injection with TA was performed on 21 patients with diabetic macular edema who had undergone ocular-fundus examination, fundus fluorescein angiography (FFA), and optical coherence tomography (OCT). The followup duration was 1 month, 3, and 6 months. The visual acuity, intraocular pressure, and retinal thickness at the macular area before and after the treatment, examined by ETDRS eye chart, noncontact tonometer, and OCT respectively, were observed and compared.ResultsOne month, 3, and 6 months after the injection, the mean extent of improvement of visual acuity was 7.5, 9.1 (including 2-line improvement in 10 eyes which occupied 48%), and 5.1 letters respectively; while the decrease of retinal thickness at macula was 143 μm (decrease of 33%), 184 μm (decrease of 42%), and 151 μm (decrease of 35%) respectively.ConclusionsIntravitreous injection with TA is effective for diffused diabetic macular edema in a short term (about 3 months).(Chin J Ocul Fundus Dis, 2005,21:217-219)
ObjectiveTo observe the expression of inflammatory cytokines in diabetic rats received posterior sub-Tenon capsule injection of triamcinolone acetonide (TA) and pan-retinal photocoagulation. MethodsA total of 48 Brown Norway rats received intraperitoneal injection of streptozotocin to establish the diabetic model. Diabetic rats were randomly divided into experimental group (20 rats), control group (20 rats) and blank group (8 rats). 50 μl TA or saline was injected into the posterior sub-Tenon capsule immediately after the photocoagulation in the experimental group and the control group, respectively. The blank group received no treatment. The mRNA and protein expression level of retinal vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) and tumor necrosis fator-α (TNF-α) were measured by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) at 1, 3, 7 days after laser photocoagulation. ResultsThe mRNA and protein expression of VEGF, IL-6, TNF-α of the experimental group and control group were significantly higher than the blank group, the difference was statistically significant (P < 0.05). The mRNA and protein expression of VEGF, IL-6 and TNF-α of the experimental group were significantly lower than that of the control group. On day 1 after laser photocoagulation, the mRNA expression of VEGF was not statistically significant in the experimental group and control group (P > 0.05), the mRNA and protein expression of VEGF, IL-6, TNF-α of the two groups were statistically significant in the remaining observing time (P < 0.05). ConclusionPosterior sub-Tenon capsule injection of TA can effectively reduce retinal photocoagulation induced VEGF, IL-6, TNF-α expression.