Correlation of retinal neurodegeneration with measures of peripheral autonomic neuropathy in type 1 diabetes

Abstract

PurposeTo evaluate the relationship of neuroretinal layer thickness with sensitive measures of cardiovascular autonomic neuropathy in diabetic patients with non‐proliferative diabetic retinopathy (NPDR).MethodsTwenty‐seven eyes of 27 patients with type 1 diabetes presenting with mild‐to‐moderate NPDR were compared to 27 healthy control (HC) eyes matched for age and gender. The total macular volume (TMV) and the volumes of individual neurosensory layers in the macula were analysed from spectral domain optical coherence tomography using automated layer segmentation. Cardiovascular autonomic regulation was assessed by short‐term power spectrum analysis of heart rate variability (HRV) before, during and after an orthostatic challenge.ResultsThe patients had an age of 46 ± 12 years and diabetes since 28 ± 9 years. Diastolic and mean arterial pressure was lower in the patients compared to HCs. TMV (r = 0.58, p = 0.002), inner plexiform layer volume (IPLV; r = 0.39, p = 0.047) and inner nuclear layer volume (INLV; r = 0.60, p = 0.001) were associated with reduced recovery of low‐frequency (LF) spectral power of HRV after orthostatic load in diabetic patients but not in HCs. The response of LF spectral power during the orthostatic manoeuvre was blunted in patients compared to HCs (p = 0.02). Diabetes duration was negatively associated with TMV and INLV, whereas IPLV was significantly reduced in eyes with moderate NPDR compared to HCs.ConclusionThe results indicate a correlation between inner retinal tissue loss and diminished autonomic regulation in type 1 diabetic patients with mild‐to‐moderate NPDR. The observed changes can be interpreted as congruent early signs of retinal and systemic neuropathy in diabetes.

Short‐time effect of intravitreal injections on retinal vascular oxygenation and vessel diameter in patients with diabetic macular oedema or neovascular age‐related macular degeneration

“…The increased blood oxygenation levels in retinal veins have been attributed to several disease-specific changes in diabetic retinopathy leading to a reduced oxygen consumption in retinal tissue: Predominantly, diabetes-induced microvascular changes such as basement membrane thickening, reduced capillary density and shunt vessel formation may lead to reduced tissue perfusion and hence limit oxygen uptake and distribution in the retina (Pemp & Schmetterer 2008;Czak o et al 2018). In addition, neuroretinal tissue loss mainly of the inner retinal layers, which increases with diabetes duration (Pemp et al 2018), could also reduce retinal oxygen consumption. Increased total retinal blood flow in diabetic retinopathy and the higher affinity of oxygen to glycosylated haemoglobin, which is elevated in diabetes patients, may as well account for an oxygenation increase in retinal veins and also in retinal arteries (Bek 2013;Klefter et al 2015).…”

Open carpal tunnel release and diabetes: a retrospective study using PROMs and national quality registries

“…Mechanisms affecting peripheral nerves in diabetes are many, including microangiopathy, hypoxia and metabolic factors,12 rendering the diabetic nerve more sensitive to compression 13. Retinopathy is a frequent complication seen in diabetes, and there is an association between retinopathy and diabetic neuropathy,14 15 as well as between ocular neurodegenerative changes and diabetic neuropathy 16 17. Retinopathy might hence be used as a proxy variable for neuropathy.…”

Optical coherence tomography in the investigation of systemic neurologic disease

“…Choi et al observed that retinal nerve fibre layer thickness and ganglion cell–inner plexiform layer thicknesses are independently associated with cardiac autonomic function, assessed by heart rate variability (with deep breathing and a change in posture from lying to standing position). Total macular and inner retinal layer volumes have also been reported to be associated with heart rate variability (a measure of autonomic neuropathy) in individuals with diabetes …”