الفهرس 
Aldose reductase and vasoproliferativ
Procedures of visual evoked potentialsOnly 14 pages are availabe for public view
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Abstract
In diabetes mellitus, visual deficit appears to result from both vascular disease and metabolic abnormalities, which can affect the retina, optic nerve and visual pathways. Visual evoked potentials assessemet is used to evaluate optic neuropathy in diabetic patients. Measurement of evoked potentials is a simple, sensitive and objective technique for evaluating impulse conduction along the central nerves pathways
The aim of this work was to evaluate the effect of type 1 diabetes mellitus on CNS by visual evoked potentials assessment in type 1 diabetic children and adolescents and to correlate these abnormalities with age, duration of diabetes, glycemic control, presence or absence of peripheral neuropathy and other diabetic microvascular complications.
The present study was conducted upon a group of 40 diabetic children and adolescents(16 males and 24females, mean age was 13.3±2 years) suffering from type1 diabetes mellitus following up in the pediatric Diabetes Clinic, Children’s Hospital, Ain Shams University, Cairo, Egypt from September 2008 till February 2010 who were subdivided into twenty diabetic patients with known evidence of microvascular complications (9 males and 11 females, mean age was 14±1.82 years) and twenty diabetic patients without evidence of microvascular complications (7 males and 13females, mean age was 12.55±2 years). Twenty healthy age and sex matched children were included as a control group (8 males and 12 females, mean age was 12.8±2.16 years).
The studied patients in this study were subjected to complete history taking with special stress on age of onset of diabetes, duration of disease and visual or neural complaints such as blurring of vision, tingling and numbness of the upper and the lower extremities.
Complete physical examination was carried out with special emphasis on anthropometric measurements (body weight, height, and Body mass index), blood pressure and fundus examination.
Laboratory investigations were performed including RBG, HbA1c, and determination of urinary microalbuminuria. Mean RBG and mean HbA1c were calculated over the last 2 years from the patients files.
Electrophysiological studies including visual evoked potential studies, sensory and motor nerve conduction studies for median and common peroneal nerves.
The patients and controls were matched as regards age, sex and anthropometric measures.
Mean age, duration of disease, visual, neurological symptoms, abnormal fundus, mean RBG, HbA1c and microalbuminuria were significantly higher in patients with known microvascular complications than in patients without microvascular complications. Mean age of onset of diabetes was significantly lower in patients with microvascular complications.
Presence of abnormal P100 amplitude and latency in right and left eyes were significantly higher in diabetic patients than controls and in patients with microvascular complications compared to patients without microvascular complications.
There was a positive correlation between right eye VEP latency and both RBG, HbA1c in diabetic patients and a significant negative correlation between diabetic patients’ right, left eyes VEP amplitude and both RBG, HbA1c. There was a positive correlation between right eye VEP amplitude and age of onset of diabetes mellitus and a significant positive correlation between patients’ right and left eyes VEP latency and sensory, motor CPN latency.
Diabetic patients were significantly higher than controls as regards the presence of abnormal sensory CPN and MN latencies. Diabetic patients with known microvascular complications were significantly higher as regards the presence of abnormal motor CPN, MN latencies and velocities compared to diabetic patients without microvascular complications.
In diabetic patients; there was a significant positive correlation between motor and sensory CPN latency and HbA1c. A significant negative correlation between motor CPN velocity and both RBG, HbA1c.
Diabetic patients with abnormal fundus examination (15% of studied patients) showed lower mean age of onset, higher mean duration of disease, RBG and HbA1c than patients with normal fundus examination and also had a significantly higher mean right and left eyes latencies.
Diabetic patients with micro-albuminuria showed lower mean age of onset, higher mean age, mean duration of disease, RBG and HbA1c than patients with normoalbuminuria. Also micro-albuminuric patients showed significantly higher right, left eyes amplitude and latency, motor CPN, MN latency and velocity compared to normoalbuminuric patients.
Diabetic patients with visual symptoms (25 patients) showed significant lower mean age of onset, right, left eyes amplitudes than patients without visual symptoms and also had significant higher frequency of abnormal right, left eyes latency.
Thus, we concluded that visual evoked potential is commonly affected in type 1 diabetic children and adolescents particularly in diabetic patients with microvascular complications. Visual evoked potential abnormalities are closely related to age of onset of diabetes mellitus, glycemic control, sensory and motor peripheral neuropathy. Visual evoked potential can detect abnormalities in the visual pathway early prior to any visual symptoms or change in fundus examination.