METHODS: In this prospective study, 53 patients with mild or moderate non-proliferative diabetic retinopathy(NPDR)without macular edema and 53 non-diabetic patients underwent uneventful phacoemulsification cataract surgery. Subfoveal choroidal thickness and central macular thickness were measured before and one month and three months after the surgery using enhanced depth imaging optical coherence tomography(EDI-OCT)and the changes of SFCT and CMT were compared between the two study groups.

RESULTS: In diabetic cases, the mean CMT at the baseline was 267±32 μm. The CMT significantly increased after surgery with a mean value of 291±77 μm at 1mo(P=0.034)and 293±75 μm at 3mo(P=0.047). The mean SFCT at the baseline was 199±72 μm. The SFCT significantly increased after surgery with a mean value of 231±73 μm at 1mo(P=0.035)and 248±91 μm at 3mo(P=0.026). In non-diabetic cases, the mean CMT at the baseline was 264±29 μm. The CMT significantly increased after surgery with a mean value of 278±42 μm at 1mo(P<0.001)and 276±56 μm at 3mo(P=0.028). The mean SFCT at the baseline was 236±60 μm. The SFCT significantly increased after surgery with a mean value of 265±64 μm at 1mo(P<0.001)and 240±60 μm at 3mo(P=0.234). The changes of CMT were not significantly different between the study groups(all P>0.05). Although the non-diabetic cases had thicker choroid at the baseline, the change of SFCT was not significantly different between study groups 1mo postoperative(P=0.97)and was borderline 3mo after surgery(P=0.05).

CONCLUSION: CMT and SFCT significantly increased post operatively in both groups. The changes of CMT and SFCT were not significantly different between diabetic and non-diabetic cases.