Atropine reduces experimental myopia and eye enlargement via a nonaccommodative mechanism

Invest Ophthalmol Vis Sci. 1993 Jan;34(1):205-15.


Purpose: To determine whether the muscarinic antagonist atropine effectively reduces or prevents experimentally induced myopia via a nonaccommodative mechanism.

Methods: Chicks were monocularly deprived (MD) of pattern vision by placement of a translucent occluder over the left eye. In two of the three MD groups, chicks received a series of intravitreal injections of atropine (n = 8) or saline vehicle (n = 8) with MD. Control groups (n = 8) of chicks were employed to assess the effects of MD, intravitreal injections, and drug effects.

Results: In sham-injected or saline-injected MD chicks, 8 days of MD produced -18.5 D and -20.9 D of experimental myopia, respectively. In atropine-injected MD chicks, 8 days of MD produced only -2.8 D of experimental myopia. This significant reduction in experimentally induced myopia in atropine-injected MD chicks was associated with a marked reduction in the relative axial elongation of the deprived eye (0.21 mm) when compared to saline-injected or sham-injected MD chicks (1.04 mm and 1.00 mm). This reduction in axial length in atropine-injected MD chicks was predominantly the result of a reduction in vitreous chamber elongation, although a reduction in anterior segment depth also was observed. Mean equatorial diameter was significantly reduced in atropine-injected MD chicks compared to saline-injected and sham-injected MD chicks, although to a lesser extent. Control experiments demonstrated that intravitreally injected atropine did not reduce carbachol-induced accommodation or light-induced pupil constriction in the skeletal intraocular muscles of the chick eye.

Conclusions: These findings demonstrate that chronic administration of the muscarinic antagonist atropine prevents experimentally induced myopia in chick via a nonaccommodative mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Accommodation, Ocular*
  • Animals
  • Anthropometry
  • Atropine / therapeutic use*
  • Chickens
  • Choroid / pathology
  • Disease Models, Animal
  • Eye / pathology*
  • Hypertrophy / pathology
  • Hypertrophy / physiopathology
  • Hypertrophy / prevention & control
  • Injections
  • Light
  • Myopia / pathology
  • Myopia / physiopathology
  • Myopia / prevention & control*
  • Pupil / drug effects
  • Retina / ultrastructure
  • Sensory Deprivation
  • Vitreous Body


  • Atropine