Prognostic value of multifocal electroretinography and optical coherence tomography in eyes undergoing panretinal photocoagulation for diabetic retinopathy.

PURPOSE To investigate the prognostic utility on visual acuity of multifocal electroretinography (mfERG) and optical coherence tomography (OCT) in diabetic eyes receiving panretinal photocoagulation (PRP). METHODS Patients with severe nonproliferative diabetic retinopathy (NPDR) or early proliferative diabetic retinopathy (PDR) who needed PRP were included in this study. The mfERG and OCT data were recorded before PRP, and the final best-corrected visual acuity (BCVA) was recorded at 6 months after PRP. The correlation between pre-PRP data and post-PRP BCVA was analyzed using Pearson's correlation analysis and multivariate linear regression analysis. RESULTS Among the 42 eyes included, 31 eyes (73.8%) had improvement or remained stable in visual acuity, and 11 eyes (26.2%) had deterioration in BCVA. The final BCVA was significantly correlated with the amplitude and latency of mfERG in all nine sectors, and the amplitude had a stronger correlation than latency. The foveal ellipsoid zone of the photoreceptors and external limiting membrane (ELM) status, as well as the retinal thickness in most sectors, were also correlated with the final BCVA. In a multivariate linear regression model, age, pre-PRP BCVA, amplitude of mfERG in the central sector, and foveal ellipsoid zone status were significantly correlated with the final BCVA. The retinal thickness was correlated with the amplitude or latency of mfERG in some sectors, and the correlation was tighter in temporal and inferior sectors. CONCLUSIONS A lower amplitude of mfERG and disrupted foveal ellipsoid zone status were significantly correlated with a worse visual prognosis in diabetic eyes after PRP.