AIM: To evaluate the change of retinal thickness and choroidal thickness in patients with diabetic macular edema or retinal vein occlusion-macular edema after intravitreal Ranibizumab injection using spectral domain-optical coherence tomography(SD-OCT), and to identify determinants for the change of different types of macular edema.

METHODS: Patients were recruited from March 2016 to July 2017 diagnosed with diabetic macular edema or retinal vein occlusion-macular edema. Subfoveal choroidal thickness(SFCT)and central retinal thickness(CRT)of all eyes were measured by SD-OCT preoperatively and at 1, 3, 6mo after operation. The change of retinal thickness and choroidal thickness after intravitreal ranibizumab injection for macular edema caused by different diseases were evaluated. Moreover, the potential determinants were studied about the change of retinal thickness and choroidal thickness.

RESULTS: Thirty-six eyes of 36 patents with macular edema were treated with intravitreal ranibizumab injection. After the intravitreal ranibizumab injection, the CRT and SFCT decreased, when compared with the CRT and SFCT preoperative. There was a significant difference in the change of CRT and SFCT in different time points of following-up(F_CRT=40.876, P_CRT<0.001; F_SFCT=46.319, P_SFCT<0.001). In diabetic macular edema group, the change of SFCT was associated with the preoperative SFCT, and the change of CRT was correlated with preoperative CRT and the fast blood glucose level. In retinal vein occlusion-macular edema group, the change of SFCT was associated with the preoperative SFCT, the change of CRT was associated with preoperative CRT, the obstructive positions and the onset time of disease.

CONCLUSION: Reduction of choroidal thickness and retinal thickness in macular edema caused by different diseases can be detected with SD-OCT after intravitreal injections of ranibizumab. The reduction of choroidal thickness was correlated with the preoperative choroidal thickness. In diabetic macular edema eyes, the reduction of retinal thickness was correlated with preoperative CRT and the fast blood glucose level. Whereas, in retinal vein occlusion-macular edema eyes, the reduction of retinal thickness was correlated with the preoperative CRT, the obstructive positions and the onset time.