Correlation between Macular GCIPL Thickness and Visual Acuity after Resolution of Diabetic Macular Edema

ABSTRACT

PURPOSE: To evaluate the peripapillary retinal nerve fiber layer (pRNFL) thickness and macular ganglion cell-inner plexiform layer (mGCIPL) thickness in eyes with resolved diabetic macular edema (DME). METHODS: Twenty eyes of diabetic retinopathy patients with resolved DME (DME group) after treatment, and 20 eyes of diabetic retinopathy patients without DME (no-DME group) were included in this study. The pRNFL thickness, mGCIPL thickness and central macular thickness (CMT) were measured using spectral-domain optical coherence tomography (SD-OCT). Analyses were performed to determine the correlation between the different thicknesses and the visual function. RESULTS: No significant difference in mean CMT was observed between the DME and no-DME groups. Average pRNFL thickness in the DME group was thicker than in the no-DME group (p = 0.003). Average mGCIPL thickness in the DME group was thinner than in the no-DME group (p = 0.030). Final visual acuity was significantly correlated with average mGCIPL thickness and minimum mGCIPL thickness, but not pRNFL thickness and CMT in the DME group. CONCLUSIONS: mGCIPL thickness decreased in the DME group compared with the no-DME group and was correlated with the visual acuity. These results suggested that inner retinal injury in patients with DME might lead to poor visual outcome after treatment.