Abstract
Purpose:
Retinopathy and neuropathy are well known complication of diabetes, but the pathophysiology of neuro-retinopathy in diabetes is not clearly established. This study was to evaluate the correlation of segmented retinal thickness with peripheral nerve conduction and autonomic nerve function in diabetic patients.
Methods:
The medical records, including spectral-domain optical coherence tomography (Cirrus HD-OCT), peripheral nerve conduction study and autonomic nerve function test, of 160 patients with diabetes who presented no diabetic retinopathy or mild non-proliferative diabetic retinopathy were retrospectively reviewed. The mean retinal thickness of parafoveal area within 1-3mm and ganglion cell/inner plexiform layer (GC-IPL) thickness in macular 6 regions were measured using custom-built algorithm with OCT. Peripheral nerve conduction study was performed at peroneal, post. tibial motor nerve and sural sensory nerve. The autonomic nerve function test was scored with assessment of Valsalva maneuver, lying heart rate, interval change of heart rate, postural hypotension, and sustained handgrip. The patients were classified into 3 groups by severity of peripheral neuropathy and autonomic dysfunction, analyzing correlations with macular GC-IPL thickness and mean retinal thickness respectively.
Results:
The mean age was 63.61±12.52. The mean macular GC-IPL thickness was 79.89±4.70㎛ and mean retinal thickness of parafovea was 315.05±12.70㎛. Macular GC-IPL thickness showed significant correlation with both peripheral nerve conduction (No peripheral neuropathy vs definite peripheral neuropathy: 80.8±5.8㎛ vs 77.2±4.2㎛, p=0.001) and autonomic nerve function (No or mild dysfunction vs Severe dysfunction: 81.2±6.6㎛ vs 77.6±5.9㎛, p=0.005). Retinal thickness of parafovea decreased without statistical significance according to the peripheral nerve conduction (p=0.873) nor autonomic nerve function (p=0.674).
Conclusions:
The decrease of GC-IPL thickness positively correlated with peripheral nerve conduction and autonomic nerve function in diabetes who presented no diabetic retinopathy or mild non-proliferative diabetic retinopathy.