Longitudinal changes in each retinal layer thickness in diabetic retinopathy patients treated with pan-retinal photocoagulation.

BACKGROUND/

OBJECTIVES

To identify longitudinal changes in each retinal layer thickness in diabetic retinopathy (DR) patients who underwent pan-retinal photocoagulation (PRP).

SUBJECTS/

METHODS

The subjects were divided into three groups: type 2 diabetes patients without DR (DM group), those with DR (DR group), and those who underwent PRP ≥ 6 months earlier (PRP group). Following the baseline visit, patients underwent three additional assessments at 1-year intervals.

RESULTS

In total, 297 eyes were included: 87, 124, and 76 in the DM, DR, and PRP groups, respectively. The baseline ganglion cell complex (GCC) thickness was 110.4 ± 13.4, 112.5 ± 13.2, and 116.1 ± 17.6 μm in the DM, DR, and PRP groups, respectively (P = 0.047). The baseline thickness of inner nuclear layer (P = 0.026) and outer plexiform layer (P = 0.002) differed significantly, which was significantly thicker in the PRP group. The photoreceptor layer and retinal pigment epithelium thicknesses differed significantly among the groups (both P < 0.001), and those in the PRP group were significantly thinner than in the other groups. In the PRP group, there were significant decreases in GCC and outer nuclear layer (ONL) thickness over time, while the other layers did not change significantly. The GCC (estimate = -0.15, P = 0.012) and ONL (estimate = -0.16, P = 0.019) thicknesses were significantly associated with changes in best-corrected visual acuity.

CONCLUSIONS

The thickness of each retinal layer of patients who underwent PRP changed differently over time, and these changes were significantly associated with changes in visual acuity.