Abstract
Purpose: :
To evaluate the pupillary response to light stimulation in patients with glaucoma at different stages by the use of computerized pupillometry.
Methods: :
A retrospective study was conducted on a group of 48 patients with glaucoma that undergone visual field test (Humphrey Sita Standard 24-2) and dynamic monocular pupillometry (MonCV3 Metrovision) in both eyes. For the study, the subjects were classified into 6 stages according to visual field damage using the glaucoma staging system 2 (Brusini et al. 2006). A group of 8 healthy subjects homogeneous for age and sex was used as control. From each exam the following parameters have been considered: latency and duration of contraction, latency and duration of dilatation; the initial, the maximum, and the mean pupil diameter; the minimum amplitude of contraction and dilatation; the rate of contraction and dilatation of the pupil.
Results: :
One-way analysis of variance (ANOVA) of the response times, namely the latency and duration of contraction, and latency and duration of dilatation, showed no significant differences between the groups (p>0.05). A similar result has been found by comparing the values of the maximum, the mean pupil diameters, and the amplitude of contraction. In contrast, ANOVA test revealed a significant difference between the groups when contraction (p=0,0004) and dilatation (p<0.0001) speed, and minimum pupil diameters (p=0,0065) were considered. Even more, linear regression analysis showed a significant inverse correlation when comparing the contraction (p=0.0272, r=-0.81) and dilatation (p=0.0074, r=-0.889) speed with progression of glaucoma stage.
Conclusions: :
The study showed that glaucoma damage is associated with altered values of pupillary response to light. This event may be the consequence of the progressive loss of retinal ganglion cells and their axons induced by glaucoma.
Keywords: pupillary reflex • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • pupil