Evaluation of Static and Dynamic Pupil and Light Sensitivity to a Single Drop of Various Concentrations of Low-Dose Atropine (0.01%, 0.025%, and 0.05%)
Abstract: This study aimed to evaluate the static and dynamic pupil changes, and light
sensitivity following a single dose of low-dose atropine at concentrations of 0.01%, 0.025%,
and 0.05% over a 24 h period. Healthy young adults (20–22 years; n = 25) participated
in this randomized, double-blind study. Each participant received one of three atropine
concentrations in a masked fashion. Baseline mesopic and dynamic pupil sizes were
measured at various post-instillation intervals (5 min, 30 min, 1 h, 2 h, 4 h, and 24 h).
A minimum 48 h washout period was observed between treatments. Subjective light
sensitivity was assessed using the Visual Light Sensitivity Questionnaire (VLSQ-8) at 24 h.
All atropine concentrations caused significant pupil dilation (p < 0.001), with the 0.05%
concentration producing the greatest dilation (peak mesopic size: 7.4 mm, p < 0.001) and
the slowest recovery at 24 h (6.4 mm, p < 0.001). The dynamic pupil constriction range was
most restricted with 0.05% (1.7 mm, p < 0.05), compared to 0.025% (2.2 mm) and 0.01%
(2.6 mm). Subjective symptoms, including light sensitivity and glare, followed a dose
dependent pattern (p < 0.05). In 60% participants, 0.05% caused the most symptoms, while
in 70% participants, 0.01% caused the least. Despite significant pupil dilation, the pupil
center coordinates did not shift significantly along the horizontal or vertical axes (p > 0.05).
Low-dose atropine induced dose-dependent pupil dilation and light sensitivity; 0.05%
atropine caused the most pronounced effects. These findings underscore the importance
of tailoring the atropine dosage to balance its efficacy and tolerability. Further studies
are needed to explore the long-term impact of repeated dosing on pupillary behavior and
subjective symptoms.
Keywords: low-dose atropine; pupil; light sensitivity; dynamic pupil
Abstract: This study aimed to evaluate the static and dynamic pupil changes, and light
sensitivity following a single dose of low-dose atropine at concentrations of 0.01%,…