Changes of choroidal thickness after treatment for diabetic retinopathy

To investigate the choroidal thickness changes after intravitreal bevacizumab injection (IVB), panretinal photocoagulation (PRP) or both for diabetic retinopathy treatment.

The study included 31 eyes (31 patients) in the IVB group, 35 eyes (35 patients) in the PRP group and 35 eyes (35 patients) in the IVB-PRP group. Enhanced depth imaging optical coherence tomography (EDI-OCT) was performed before and 1 month after each treatment to measure subfoveal and extrafoveal (500 and 1000 μm) choroidal thicknesses. The best-corrected visual acuity (BCVA) and central macular thickness (CMT) were also measured.

The choroidal thickness at all locations significantly decreased after treatment in all groups, but there was no significant difference in the amount of change among the three groups. The subfoveal choroidal thickness and CMT significantly decreased after treatment in the IVB and IVB-PRP groups. In the PRP group, the CMT significantly increased, while the choroidal thickness significantly decreased after treatment. The subfoveal choroidal thickness and CMT were significantly reduced after IVB, but there was no significant correlation between their changes. The BCVA was improved significantly in the IVB and IVB-PRP group, but not in the PRP group.

The choroidal thickness decreased after all treatments, suggesting that IVB or PRP rapidly reduced choroidal vascular permeability.