title: Pattern Visual Evoked Potentials in Patients with Type II Diabetes Mellitus.
abstract: OBJECTIVE
  To evaluate cortical and retinal activity by pattern visual evoked potentials (PVEP) in patients with type II diabetes mellitus.
  
  
  METHODS
  PVEP was recorded in 40 diabetic patients including 20 subjects with non-proliferative diabetic retinopathy (NPDR) and 20 others without any retinopathy on fundus photography, and compared to 40 age- and sex-matched normal non-diabetic controls.
  
  
  RESULTS
  P100 wave latency was significantly longer in diabetic patients as compared to normal controls (P<0.001); both diabetic subjects without retinopathy and those with NPDR had significantly longer P100 latency than controls (P<0.001 for both comparisons). There was significant reduction in N75 (P=0.037) and P100 (P=0.001) amplitudes in diabetic subjects. No correlation was observed between VEP amplitude or wave latency, and the level of glycemia or duration of diabetes mellitus.
  
  
  CONCLUSIONS
  Increased PVEP latency may be a sign of retinal ganglion cell damage which takes place before the appearance of the first ophthalmoscopically detectable signs of diabetic retinopathy. PVEP may be considered as a method for detecting prediabetic retinopathy and has the potential to reduce diabetic complications.
authors.affiliation: Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Heravian
authors.forename: Akram
authors.initials: A
authors.lastname: Ehyaei
authors.forename: Nasser
authors.initials: N
authors.lastname: Shoeibi
authors.forename: Abbass
authors.initials: A
authors.lastname: Azimi
authors.forename: Hadi
authors.initials: H
authors.lastname: Ostadi-Moghaddam
authors.forename: Abbas-Ali
authors.initials: AA
authors.lastname: Yekta
authors.forename: Mohamad Javad
authors.initials: MJ
authors.lastname: Khoshsima
authors.forename: Habbibolah
authors.initials: H
authors.lastname: Esmaily