Inner and Outer Retinal Thickness Mapping of Nonproliferative Diabetic Retinopathy by Spectral-Domain Optical Coherence Tomography

BACKGROUND AND OBJECTIVE: To report inner retinal thickness (IRT), outer retinal thickness (ORT), and total retinal thickness (TRT) mapping of nonproliferative diabetic retinopathy (DR). PATIENTS AND METHODS: Spectral-domain optical coherence tomography (SD-OCT) images were obtained in 31 study participants with nonproliferative DR. Semi-automated software generated IRT, ORT, and TRT maps. IRT, ORT, and TRT in each macular subfield were compared between groups with and without increased central subfield thickness. RESULTS: There were statistically significant differences in IRT, ORT, and TRT between groups (P < .007). In participants with nonproliferative DR with increased central subfield thickness, TRT was significantly increased in parafoveal and perifoveal inferior subfields (P < .001). In these subfields, both IRT and ORT were significantly increased (P < .007) compared to those in participants without increased central subfield thickness. CONCLUSION: Mapping of inner and outer retinal thickness shows promise for monitoring depthspecific thickness alterations by macular subfields due to DR.