Purpose
The aim was to assess early functional and structural changes in the neural retina in
type 2 diabetic patients with no clinical signs of diabetic retinopathy (DR).
Patients and methods
A total of 92 eyes of 48 patients were included, which were divided into the following
groups: 30 eyes of 16 participants with type 2 diabetes mellitus without clinical DR,
with a mean age of 48.75±3.09 years, as group 1; 30 eyes of 16 participants with
type 2 diabetes mellitus with DR, with a mean age of 51.75±2.86 years, as group 2;
and a control group of 32 eyes of 16 healthy age-matched and sex-matched
participants, with a mean age of 49.88±4.26 years. After full ophthalmologic
examination, spectral-domain optical coherence tomography scans, multifocal
electroretinogram (Mf-ERG), pattern electroretinogram (PERG), and
photonegative response (PhNR) were tested for all participants. Statistical
analysis was performed to compare ganglion cell complex (GCC) thicknesses,
multifocal electroretinogram, PERG, and phNR values between the groups.
Results
There were no statistically significant differences between the studied groups
regarding age, sex, refraction, or intraocular pressure (P=0.056,0.72, 0.16, and
0.35, respectively). There were significant differences of total GCC thickness
values among group 1 (107.13±7.04 μm), group 2 (97.27±10.97 μm), and control
group (113.81±5.26 μm) (P