Publication
Multifocal electroretinogram responses in Nepalese diabetic patients without retinopathy
Publisher:
Springer Science and Business Media LLC
Date:
05-06-2014
DOI:
10.1007/S10633-014-9447-9
Abstract: To determine neuroretinal function with multifocal electroretinogram (mfERG) in diabetic subjects without retinopathy. Multifocal electroretinogram (mfERG) was performed in 18 eyes of 18 diabetic subjects without retinopathy and 17 eyes of 17 age and gender-matched healthy control participants. Among 18 diabetic subjects, two had type 1 and 16 had type 2 diabetes. MfERG responses were averaged by the retinal areas of six concentric rings and four quadrants, and 103 retinal locations N1-P1 litude and P1-implicit time were analysed. Average mfERG N1-P1 litude (in nv/deg(2)) of 103 retinal locations was 56.3 ± 17.2 (mean ± SD) in type 1 diabetic subjects, 47.2 ± 9.3 in type 2 diabetic subjects and 71.5 ± 12.7 in controls. Average P1-implicit time (in ms) was 43.0 ± 1.3 in type 1 diabetic subjects, 43.9 ± 2.3 in type 2 diabetic subjects and 41.9 ± 2.1 in controls. There was significant reduction in average N1-P1 litude and delay in P1-implicit time in type 2 diabetic subjects in comparison to controls. mfERG litude did not show any significant correlation with diabetes duration and blood sugar level. However, implicit time showed a positive correlation with diabetes duration in type 2 diabetic subjects with diabetes duration ≥5 years. This is the first study in a Nepalese population with diabetes using multifocal electroretinography. We present novel findings that mfERG N1-P1 litude is markedly reduced along with delay in P1-implicit time in type 2 diabetic subjects without retinopathy. These findings indicate that there might be significant dysfunction of inner retina before the development of diabetic retinopathy in the study population, which have higher prevalence of diabetes than the global estimate and uncontrolled blood sugar level.