A Novel Computerized Portable Pupillometer Detects and Quantifies Relative Afferent Pupillary Defects

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Devices

Background:

• Relative afferent pupillary defects (RAPDs) are crucial indicators of optic nerve and retinal dysfunction.
• Accurate and objective quantification of RAPDs is essential for diagnosing and monitoring vision loss.
• Current methods for RAPD assessment can be subjective and operator-dependent.

Purpose of the Study:

• To validate a novel computerized portable pupillometer for detecting and quantifying RAPDs.
• To assess the device's correlation with expert clinical grading of RAPDs.
• To determine the sensitivity and specificity of the pupillometer in identifying clinically significant RAPDs.

Main Methods:

• Pupillary response curves were recorded in patients with clinically graded RAPDs (n=32) and normal subjects (n=31) with simulated RAPDs.
• Pupillary constriction amplitude (CA), velocity (CV), and onset latency (COL) were used to calculate RAPDs.
• Inter-visit variability was assessed in 14 normal subjects.

Main Results:

• The novel pupillometer demonstrated a strong correlation with expert clinical grading of RAPDs (r=0.81, p<0.0001).
• The device distinguished patients with RAPDs (≥0.5 LU) from normal subjects with 91% accuracy.
• Calculations using CA and CV showed stronger correlation with clinical grading than COL.

Conclusions:

• The computerized portable pupillometer is a reliable tool for objective RAPD assessment.
• The device exhibits high sensitivity and specificity for detecting clinically significant RAPDs.
• This pupillometer has potential as a valuable clinical tool for screening patients with vision loss.