The Effects of 0.01% Atropine on Adult Myopes' Contrast Sensitivity

Abstract

Purpose: Atropine at a low concentration is considered a safe and effective treatment to mitigate myopia progression. However, the potential unwanted side effects of administering atropine at a low dose on visual functions other than best corrected visual acuity has not been investigated. In this study, we investigate the short-term (12,16, and 20 h) and long-term (1, 2, and 4 weeks) effects of 0.01% atropine (i.e., 0.1 mg/ml) on contrast sensitivity (CS) in patients with myopia.

Methods: Thirty adults (23.33 ± 2.93 years old) with myopia between -1.00 and -6.00 diopters (D), astigmatism of -1.50 D or less, and anisometropia of 1.00 D or less, participated in this prospective, masked, placebo-controlled, randomized study. The participants were randomly assigned to receive 0.01% atropine or polyvinyl alcohol eye drops once nightly to both eyes for four weeks. CS was measured binocularly at baseline and 12, 16, 20 h, 1, 2, and 4 weeks after the first use of the eye drops.

Results: There was no statistically significant differences of CS found between atropine and placebo-controlled groups in both short-term and long-term. There was no statistically significant interaction effect found between the time and group.

Conclusion: We demonstrated no significant deleterious effect of 0.01% atropine on adult myopes' CS.

Keywords: atropine; contrast sensitivity; myopia; myopia control; visual perception.

FIGURE 1

A flow chart illustrating the study procedure.

FIGURE 2

An illustration of the test. The stimulus was a sinusoidal grating of vertical or horizontal orientation with spatial frequency of 1.5, 3, 6, 12, 18, 24 cycles per degree. A 0.5-degree Gaussian ramp was added around the stimulus to reduce the edge effect.

FIGURE 3

Contrast sensitivity function of the two groups following short-term (A) and long-term (B) administration of 0.01% atropine or polyvinyl alcohol. There was no significant effect of time in the polyvinyl alcohol group and the atropine group (respectively, P = 0.444, P = 0.123 at short-term; P = 0.094, P = 0.656 at long-term). There was no significant difference between the polyvinyl alcohol group and the atropine group (P = 0.924 and P = 0.724 for short- and long-term, respectively).

FIGURE 4

Boxplots of AULCSF following short-term (A) and long-term (B) administration of polyvinyl alcohol (Blue) and atropine (red). The black solid line within each box represents the median. The box represents the interquartile range (IQR) of the data (25th to the 75th percentile). The whisker represents 1.5 × IQR either above the third quartile or below the first quartile. Crosses represent outliers.