To evaluate the changes in choroidal thickness and superficial vascular density of the macula and optic disc using optical coherence tomography angiography after laser photocoagulation. Methods

We conducted a retrospective chart review of 25 eyes of diabetic retinopathy patients who underwent panretinal photocoagulation. The macula and optic disc were divided into nine areas, and the vascular density of each area was quantitatively measured using optical coherence tomography angiography. The changes in vascular density and choroidal thickness were analyzed before laser photocoagulation and at 1 week after, 1 month after, and 3 months after treatment. Results

In the panretinal photocoagulation group, the average vascular densities of the macula were 13.5 ± 3.6 mm⁻¹ before treatment, and 14.7 ± 3.1 mm⁻¹ after 1 week, 13.7 ± 2.6 mm⁻¹ after 1 month, and 12.8 ± 3.8 mm⁻¹ after 3 months of treatment. The average vascular densities of the optic disc were 14.7 ± 5.2 mm⁻¹ before treatment, and 14.1 ± 4.7 mm⁻¹ after 1 week, 14.8 ± 5.3 mm⁻¹ after 1 month, and 15.0 ± 4.7 mm⁻¹ after 3 months of treatment. The average subfoveal choroidal thicknesses were 327.5 ± 57.9 µm before treatment, and 334.4 ± 52.5 µm after 1 week, 291.2 ± 52.9 µm after 1 month, and 286.3 ± 44.4 µm after 3 months of treatment. Conclusions

The vascular density of the macula increased temporarily after 1 week of treatment but decreased afterwards. The vascular density of the optic disc decreased after 1 week of laser treatment but increased over time. The subfoveal choroidal thickness increased after 1 week of laser treatment but decreased afterwards.