Abnormalities of the oculomotor function in type 1 diabetes and diabetic neuropathy

Abstract

Aims: Abnormalities in the oculomotor system may represent an early sign of diabetic neuropathy and are currently poorly studied. We designed an eye-tracking-based test to evaluate oculomotor function in patients with type 1 diabetes.

Methods: We used the SRLab-Tobii TX300 Eye tracker®, an eye-tracking device, coupled with software that we developed to test abnormalities in the oculomotor system. The software consists of a series of eye-tracking tasks divided into 4 classes of parameters (Resistance, Wideness, Pursuit and Velocity) to evaluate both smooth and saccadic movement in different directions. We analyzed the oculomotor system in 34 healthy volunteers and in 34 patients with long-standing type 1 diabetes.

Results: Among the 474 parameters analyzed with the eye-tracking-based system, 11% were significantly altered in patients with type 1 diabetes (p < 0.05), with a higher proportion of abnormalities observed in the Wideness (24%) and Resistance (10%) parameters. Patients with type 1 diabetes without diabetic neuropathy showed more frequently anomalous measurements in the Resistance class (p = 0.02). The classes of Velocity and Pursuit were less frequently altered in patients with type 1 diabetes as compared to healthy subjects, with anomalous measurements mainly observed in patients with diabetic neuropathy.

Conclusions: Abnormalities in oculomotor system function can be detected in patients with type 1 diabetes using a novel eye-tracking-based test. A larger cohort study may further determine thresholds of normality and validate whether eye-tracking can be used to non-invasively characterize early signs of diabetic neuropathy.

Trial: NCT04608890.

Keywords: Diabetic neuropathy; Eye movement tracking; Oculomotor system; Type 1 diabetes.

Fig. 1

Cumulative distributions of all parameters analyzed using the eye-tracking-based test in healthy subjects and T1D patients with/without neuropathy. a Eye-tracking-based test and procedure. b Bar graphs depicting percentage of parameters analyzed in each class (Wideness, Resistance, Pursuit and Velocity) based on the statistically significant difference observed comparing CTRL versus T1D patients. White bars: % of parameters not altered (p > 0.05) when comparing T1D versus CTRL. Black bars: % of parameters altered when comparing T1D vs. CTRL (p < 0.05). c Bar graphs representing percentage of parameters altered (n = 50, p < 0.05) in patients with T1D and grouped by presence/absence of diabetic neuropathy. Black bars: % of parameters altered in T1D patients with neuropathy versus T1D patients without neuropathy (p < 0.05). d Summarizing score (1–5) evaluating proportion of altered parameters analyzed in each class (Wideness, Resistance, Pursuit and Velocity) in patients with T1D and grouped by presence/absence of diabetic neuropathy. CTRL, healthy subjects; T1D, patients with type 1 diabetes

Fig. 2

Cumulative distributions and proportions of all parameters analyzed using the eye-tracking-based test in healthy subjects and T1D patients grouped according to the presence/absence of diabetic neuropathy. a–d Bar graphs depicting number of parameters analyzed in the Wideness (a), Resistance (b), Pursuit (c) and Velocity (d) classes based on the statistically significant difference observed comparing CTRL versus T1D with/without neuropathy. CTRL, healthy subjects; T1D, patients with type 1 diabetes