Development of dynamic pupillometry for evaluation of autonomic functions in diabetic patients

Abstract

Diabetes is a chronic non-communicable disease leading to various microvascular and macrovascular complications Autonomic dysfunction is one of the complications of diabetes that goes undetected The quantitative Pupillary light reflex is a sensitive indicator of autonomic failure Hence the current study aimed to develop an indigenous dynamic pupillometry that quantifies pupil light reflex that reflects an individuals autonomic status A cost effective Dynamic Pupillometer was built from a standard web camera to record the pupil light reflex using infrared videography The methodology for pupil diameter assessment was established using image analysis The system characterization was verified for its validity and reliability The study was conducted in 400 participants divided into the diabetic group n equal to 200 and healthy volunteer group n equal to 200 A robust methodology was established to obtain pupil diameter using image analysis and intraobserver and interobserver variability was assessed good association was obtained between the novel method PLR and the gold standard method HRV All PLR variables including parasympathetic variables sympathetic variables were statistically significant between the diabetic patients and healthy participants. All the HRV parameters were within the normative data range as per the Taskforce guidelines 1996 The RMSSD NN50 were significantly different between the two groups The current study findings indicate autonomic dysfunction in diabetic patients compared to healthy participants evaluated by PLR Parasympathetic dysfunction was detected which delays the constriction phase identified from the PLR variables Thus, evaluation of PLR helps to detect autonomic dysfunction and the extent of parasympathetic and sympathetic contribution to inadequate PLR response newline