[Optic neuropathy in diabetic patients]

Diabetes beyond the well described diabetic retinopathy symptoms leads also to other ophthalmology problems. Among them, there are less known neuropathies and other neuroophthalmological disorders. To determine whether optic neuropathy coexists with painful peripheral neuropathy.

50 patients (99 eyes) with diabetes (type one 21 patients and type two 29 patients) and painful neuropathy. Their mean age was 56.14 +/- 11.31 standard deviation (SD) and their glycosylated hemoglobin (HbA1c) was 8.12 +/- 1.46 SD. Mean duration of diabetes was 17.05 +/- 9.47 SD. 50 healthy (100 eyes) age- and sex-matched individuals were evaluated as a control group. In all patients the basic ophthalmological exam was performed. Visual field was tested with Humphrey perimeter (Carl Zeiss Meditec HFA II 745); the mean defect (MD) and pattern standard deviation (PSD) parameters were counted. Optic disc tomography was determined by Heidelberg retina tomograph II; the cup/disk area ratio (C/D) and mean retinal nerve fiber layer (RNFL) thickness were considered.

Diabetic eyes had significantly lower results of MD and RNFL thickness. Mean MD = -8.83 +/- 8.5 SD and mean RNFL thickness = 0.29 +/- 0.13 SD whereas PSD = 4.1 +/- 3.27 SD significantly different values (p < 0.001; p < 0.05; p < 0.05 respectively). There was no statistically significant increase in C/D = 0.24 +/- 0.14 SD versus control subjects (p = 0.1). We observed general reduction of retinal sensitivity and glaucoma-like changes in visual field as vell as diminished mean RNFL thickness.

The results of our study suggest that in diabetic patients with peripheral painful neuropathy not only peripheral nerves but also optic nerve are damaged.