Comparative regional pupillography as a noninvasive biosensor screening method for diabetic retinopathy

Area of Science:

• Ophthalmology
• Medical Imaging
• Diabetic Retinopathy Research

Background:

• Diabetic retinopathy (DR) is a leading cause of vision loss.
• Assessing midperipheral retinal ischemia in DR is crucial for patient management.
• Current methods for evaluating peripheral retinal function can be invasive or subjective.

Purpose of the Study:

• To introduce infrared regional pupillometry as an objective method for assessing midperipheral to central retinal sensitivity.
• To correlate pupillometry findings with the severity of midperipheral retinal ischemia in diabetic subjects.

Main Methods:

• Bilateral infrared pupillometry was performed on 12 normal and 17 diabetic subjects.
• Diabetic subjects were categorized by non-proliferative diabetic retinopathy (NPDR) severity.
• Central and annular stimuli of varying intensities were used, measuring pupillary amplitude and constriction velocity.
• Ratio of central to peripheral responses (Q values) was calculated and regressed with stimulus strength.

Main Results:

• Statistically significant differences in pupillary amplitude (Q(A)) and constriction velocity (Q(CV)) were found between control and moderate/severe NPDR groups.
• Significant differences in Q(A) and Q(CV) were also observed between control and mild NPDR groups.
• Q(A) and Q(CV) showed significant differences between moderate/severe NPDR cases and those without or with mild NPDR.

Conclusions:

• Pupillary response ratios (Q(A) and Q(CV)) strongly correlate with the severity of diabetic retinopathy.
• These pupillometry-derived metrics do not correlate with the duration of diabetes.