AIM: To observe the changes of retina and choroid in macular region using EDI SD-OCT before and after phacoemulsification, and study the intervention and prevention effect of triamcinolone acetonide(TA)on macular edema.

METHODS: In a prospective randomized clinical trial, selected the cataract patients with NPDR in our hospital. They were randomly divided into two groups. The experimental group(group 1)received Tenon's injection of TA 40mg during phacoemulsification, while the control group(group 2)only received phacoemulsification. The changes of best corrected visual acuity(BCVA), intraocular pressure(IOP), central macular retinal thickness(CMT), subfoveal choroidal thickness(SFCT)before and after surgery were observed.

RESULTS: There were significant differences in BCVA between the two groups before and after operation(P<0.05); at 1wk after operation, the SFCT of the control group was thicker than that of the experimental group(t=2.165, P<0.05); at 2wk after operation, there were significant differences between the CMT and SFCT groups(P<0.05). There were significant differences in BCVA and CMT between the two groups(P<0.05), and no significant difference in IOP(P>0.05).The incidence of diabetic macular edema(DME)after surgery was 0 in group 1 and 11% in group 2.

CONCLUSION: Posterior subfascial injection of TA in NPDR patients during phacoemulsification may have a positive preventive effect on the occurrence of DME.