Abstract: Objective To observe and analyze the effect of intravitreal triamcinolone acetonide (IVTA) on the anatomical structure and visual function of the macular area after the operation of idiopathic anterior macular membrane (IMEM). Design Case-control study. Participants 74 patients (74 eyes) with IMEM underwent surgery in the Second Hospital of Hebei Medical University from January 2017 to December 2019. Methods The patients were randomly divided into vitrectomy combined with IVTA group (38 cases, 38 eyes) and vitrectomy group (35 cases, 35 eyes). Vitrectomy was performed to remove the epimacular membrane and internal limiting membrane in the two groups, and IVTA 2 mg/0.05 ml was performed in IVTA group. The patients were followed up for at least 12 months. The best corrected visual acuity (BCVA), macular fovea thickness (CMT), ectopic inner foveal layers (EIFL) + outer plexiform layer thickness and intraocular pressure（IOP） were observed before and 1, 3, 6 and 12 months after operation. Pearson correlation analysis, multiple linear regression equation and generalized estimation equation were used for statistical analysis. Main Outcome Measures BCVA, CMT, EIFL+outer plexiform layer thickness. Results The preoperative BCVA was closely related to the thickness of EIFL+ outer plexiform layer (r=0.934, P=0.005). The BCVAs of IVTA group and the control group were significantly improved after operation (χ2=3428.83，P＜0.001； χ2=445.67，P＜0.001）； At 3, 6 and 12 months after operation, the difference of BCVA between the two groups was statistically significant (χ2=8.31，P=0.004； χ2=11.31，P=0.001； χ2=22.54, P<0. 001). The BCVA of the IVTA group was significantly better than that of the control group. The CMT of IVTA group and the control group were significantly decreased after surgery (χ2=1121.82，P<0.001; χ2=355.92，P<0.001）. There was significant difference in CMT between the two groups at 3, 6 and 12 months after operation (χ2=12.47，P＜0.001； χ2=21.15，P＜0.001； χ2=28. 88, P＜0. 001). The CMT in the IVTA group was significantly lower than that in the control group. The EIFL+outer plexiform layer thickness of IVTA group and the control group decreased significantly after operation (χ2=842.68，P<0.001; χ2=246.40，P<0.001）. At 3, 6 and 12 months after operation, there was significant difference in EIFL+outer plexiform layer thickness between the two groups (χ2=11.25，P=0.001； χ2=15.93，P＜0.001； χ2=11.98, P=0. 001). The EIFL+outer plexiform layer thickness in the IVTA group was significantly lower than that in the control group. Conclusion IVTA at the end of surgery can assist in the recovery of macular anatomy and visual function after vitrectomy in patients with idiopathic epimacular membrane. (Ophthalmol CHN, 2021, 30: 453-459)

Key words: idiopathic epimacular membrane, triamcinolone acetonide, vitrectomy, ectopic inner foveal layers