AIM: To determine the association between subfoveal choroidal thickness before therapy and therapeutic activity in diabetic macular edema.

METHODS: The current study was a retrospective study, which included 32 patients(32 eyes)diagnosed with diabetic retinopathy and macular edema. All the patients were firstly treated with intravitreal injections of ranibizumab. Main outcome measures were included the subfoveal choroidal thickness, central macular thickness and best-corrected visual acuity(BCVA)at preoperation and postoperative visit at 3mo.

RESULTS: After 3 monthly intravitreal injections of ranibizumab, the BCVA was significantly higher than that before therapy and accompanied with significantly reduced thickness of subfoveal choroid and central fovea of macula. Spearman analysis was revealed that a greater baseline subfoveal choroidal thickness was associated with a better BCVA(r_s =0.544, P=0.036).

CONCLUSION: In the therapy of intravitreal injections of ranibizumab on diabetic macular edema, there seems to be a better BCVA in the patients with a greater baseline subfoveal choroidal thickness. Therefore, baseline subfoveal choroidal thickness may be a useful predictor for the therapy of diabetic macular edema.