Purpose: The aim of this study was to evaluate the changes in thickness of each macular retinal layer, the peripapillary retinal nerve fiber layer (RNFL), and central macular thickness (CMT) after 577-nm pattern scanning
laser (PASCAL) photocoagulation in patients with diabetic retinopathy.
Methods: This retrospective study included 33 eyes with diabetic retinopathy that underwent 577-nm PASCAL photocoagulation. Each retinal layer thickness, peripapillary RNFL thickness, and CMT were measured by
spectral-domain optical coherence tomography before 577-nm PASCAL photocoagulation, as well as at 1, 6, and 12 months after 577-nm PASCAL photocoagulation. Computerized intraretinal segmentation of optical coherence tomography was performed to identify the thickness of each retinal layer.
Results: The average thickness of the RNFL, ganglion cell layer, inner plexiform layer, inner nuclear layer, inner retinal layer, and CMT at each follow-up increased significantly from baseline (p < 0.001), whereas that of the
retinal pigment epithelium at each follow-up decreased significantly from baseline (p < 0.001). The average
thickness of the peripapillary RNFL increased significantly at one month (p < 0.001). This thickness subsequently
recovered to 7.48 μm, and there were no significant changes at six or 12 months compared to baseline(p > 0.05).
Conclusions: Each macular retinal layer and CMT had a tendency to increase for one year after 577-nm PASCAL
photocoagulation, whereas the average thickness of retinal pigment epithelium decreased at one-year
follow-up compared to the baseline. Although an increase in peripapillary RNFL thickness was observed one
month after 577-nm PASCAL photocoagulation, there were no significant changes at the one-year follow-up compared to the baseline.