Associations of peripheral sensory, autonomic and anatomic neural characteristics and proliferative retinopathy in persons with type 1 diabetes

Abstract

Purpose : Diabetes affects many of the body’s organ systems including microvascular function and neural systems. This study describes the relationships of neuropathies and retinal microcirculatory characteristics in participants of the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) with long duration T1D.

Methods : From 2012-2014, 351 WESDR participants completed a standardized examination and interview. Sensory neuropathy was defined as a loss of sensation, numbness or tingling in hands or feet. Autonomic neuropathy was defined via postural hypotension (systolic blood pressure drop) and two-time domain heart rate variability measures (root mean square of the successive differences in RR intervals (RMSD)) and the standard deviation of successive RR intervals (SDNN). Diabetic retinopathy severity was ascertained from fundus photographs graded per standard protocol. Macular edema was graded from SD-OCT images defined by at least two cysts in the macular area (excluding other causes) using a standardized grading scheme. Visual impairment was defined as 20/40 or worse in the better seeing eye after refraction.

Results : Adjusting for A1C and duration of diabetes, the presence of sensory neuropathy (OR=2.16, CI 1.32, 3.54), heart rate variability (OR=.70, CI.58, .85 for RMSD and .69 CI .58, .83 for SDNN/5 unit change in each) and postural hypotension (OR=2.22, CI1.06, 4.64 presence vs. absence) were significantly associated with prevalent proliferative diabetic retinopathy. Sensory neuropathy was significantly associated with macular edema (OR=2.08, CI1.01, 4.25), but autonomic neuropathy was not. We found a significant association of sensory neuropathy with visual impairment (3.96, CI. 1.22,12.81). Autonomic neuropathy was not associated. Retinal thickness and visual outcome associations will be presented.

Conclusions : Some markers of neuropathy are associated cross-sectionally with proliferative diabetic retinopathy and visual impairment. Sensory neuropathy is associated with macular edema. These observations confirm that neuropathies and diabetic retinal pathology are at least co-morbid phenomena but do not inform whether there is a temporal sequence of events. We also cannot state a causal association. Finer measures of neural and sensory pathology, including in the retina, are needed to investigate these questions.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.