ObjectiveTo evaluate the effect of intravitreous injection with triamcinolone acetonide (TA) on macular edema.MothodHaving been examined by ophthalmoscopy, optic coherent tomography (OCT), retinal thickness analyzer (RTA), and fundus fluorescein angiography (FFA), 33 patients (37 eyes) with diffused and (or) cystoid macular edema caused by diabetes and retinal venous occlusion were intravitreously injected with 0.1 ml triamcinolone acetonide (40 mg/ml). During 1-9 month followup period, the visual acuity, intraocular pressure, inflammatory extent, manifestation of lens and fundus were observed, the retinal thickness was examined by OCT and RTA, and vascular leakage were detected by FFA.ResultsMacular thickness was (244.07±118.80), (195.53±57.70), and (181.42±54.79) μm respectively 1, 2, 3 months after treatment; while macular thickness was (724.35±227.41) μm before the treatment. The difference was statistically significant （t =10.72, 12.84, 13.90; P lt;0.001）. The visual acuity was 0.39±0.19, 0.45±0.24, and 0.43±0.21 respectively, comparing with the visual acuity before the treatment (0.20±0.16), the difference was statistically significant （t =4.445, 4.349, 3.474; P lt;0.001, lt;0.001, 0.03）；The result of FFA showed less leakage of fluorescein and proliferative lesion. Four pateints had the ocular pressure ≥25 mm Hg (1 mm Hg=0.133 kPa) in 9 who had ≥20 mm Hg. Recurrence of macular edema was found in 4 eyes of 3 patients 4 and 6 months after the treatment, respectively. No infection or aggravation of lenticular turbidness occurred.ConclusionIntravitreous injection with TA can be used to treat macular edema due to diabetes and retinal venous occlusion, and recurrence of macular edema or increase of intraocular pressure may occur in some patients.(Chin J Ocul Fundus Dis, 2005,21:205-208)