An Analysis of mfERG in Early Diabetic Retinopathy

Objective:To investigate the characteristics of mfERG in diabetic retinopathy patients and to study the diagnostic sig- nificance of mfERG in early diabetic retinopathy.Methods:mfERG was examined on 40 eyes(24 patients)of diabetic retinopathy pa- tients and 40 eyes(27 persons)of normal control group with the RETIscan system(ROLAND Company,Germany).The whole record- ing process was divided into 12 periods of time,each of which was 47sec,and the result was recorded according to the first order re- sponse.Results:In diabetic group,the result from the mfERG showed that the vibration density of Plwave from ring 1 to 5 reduced grad- ually with acentric degree increasing,amplitude of vibration of wave P1 and N1 decreasing and the time of latency postponing.The den- sity and amplitude of vibration of wave P 1 and N 1 of all quadrants decreased while the time of latency postponed.Conclusions:Firstly, diabetic retinopathy takes place in macula area more frequently and the changes of function appear earlier than morphological changes do.Secondly,diabetic retinopathy and its earlier changes of function first appear on the posterior pole leaning to superior-temporal side. Lastly,diabetes patients without changes of diabetic retinopathy may already have severe damage in the outer layer of retina.