To evaluate changes in subfoveal choroidal thickness (SFCT) after patterned panretinal photocoagulation (PRP) using pattern scan laser (PASCAL) in patients with diabetic retinopathy.

This study included 39 patients (50 eyes) treated with patterned PRP using PASCAL and who were followed for at least 3 months. Patients were classified into 2 groups according to severity: severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy. SFCT was measured by enhanced depth imaging of spectral-domain optical coherence tomography. The change in SFCT was analyzed at 1 and 3 months after PRP.

SFCT was 270.42 ± 61.44 µm before PRP, 264.52 ± 60.78 µm at 1 month, and 255.74 ± 56.89 µm at 3 months after PRP. Significant change of SFCT was found at 3 months after PRP. Central macular thickness was 275.56 ± 50.61 µm before PRP and increased to 295.18 ± 52.80 µm and 293.10 ± 57.24 µm at 1 and 3 months post-treatment, respectively. There were no significant differences between groups in SFCT at baseline or in the amount of change in SFCT after PRP.

SFCT significantly decreased after patterned PRP using PASCAL.