Pupillometer-Based Objective Chromatic Perimetry in Normal Subjects and Glaucoma Patients

Abstract

Purpose: : Recently we have demonstrated significant results using Pupillary Light Reflex (PLR) as an objective chromatic perimetry in retinitis pigmentosa patients. In the current study we evaluated this novel system in glaucoma patients.

Methods: : We used a pupillometer [Ronald Consult, Germany] and standard automated perimetry in eight normal individuals and four Glaucoma patients. PLR were measured for three different stimuli: short wavelength stimuli (SWS) (peak 480nm) in two incremental light intensities (40cd/m²,100 cd/m²) in each of eleven different visual field points. In each point in the visual field the PLR amplitudes were calculated for each stimulus. The PLR ratio between the different stimuli was also calculated.

Results: : The averages of the PLR amplitudes for the normal subjects in response to low intensity SWS of the 11 points ranged between 0.89mm to 1.4mm and for the glaucoma patients ranged between 0.44mm to 1.04mm (P<0.001). The averages PLR amplitude for the high intensity SWS of the 11 points ranged between 1.19mm to 1.71mm in the normal subjects and between 0.5mm to 1.01mm for the glaucoma patients (P<0.001). The averages of the PLR ratio between the low and high intensity SWS was significantly higher in the glaucoma patients then in the normal subjects (P=0.02).

Conclusions: : Reduced pupil response to full field stimuli in high intensity SWS was previously found to be correlated with gangelion cell damage in glaucoma patient. This study demonstrated that high intensity SWS PLR in glaucoma patients was more reduced compare to normal subjects in different locations of the visual field. Pupillometer-based chromatic perimetry may possibly be used as an objective measure for visual field defects in gangelion cell damage.

Clinical Trial: : http://www.clinicaltrials.gov NCT01021982

Keywords: perimetry • pupillary reflex • visual fields