Study of the association between pupillary autonomic neuropathy and diabetic retinopathy in type 2 diabetic patients

Abstract

Pupillary alteration in diabetes is interpreted as a manifestation of autonomic neuropathy and microvascular injury, as reflected in abnormal fundoscopic findings. <em><strong>Objective:</strong></em> To describe the association between pupillary autonomic neuropathy and diabetic retinopathy in type 2 diabetic patients. Materials and <em><strong>Methods:</strong></em> Comparative analytical descriptive study. 76 subjects were included, divided into two groups: 46 type 2 diabetic patients, and 30 healthy (non-diabetic) subjects over 40 years. The diameter and speed of pupil response were measured with high resolution videoscopic camera, and the retina was evaluated with retinal camera. <em><strong>Results:</strong></em> There was a difference between the pupillary speed and HbA1c of the group of type 2 diabetic patients (0.512 mm/s SD 0.283, HbA1c 7.89% SD 1.88) and the group of healthy patients (3.5 mm SD 0.52; 0.785 mm/s SD 0.368; HbA1c 6.31 SD 0.59). The main fundoscopic findings localized in retina were neovascularization (78.26%), exudates (67.39%) and hemorrhages (60.87%). There was an association between HbA1c greater than 7.89% and pupillary speed less than 0.598 mm/s, and the presence of neovascularization and retinal hemorrhages. Conclusions: Evidence showed association between pupillary responses, HbA1c and retinal findings in type 2 diabetic patients.