While 1% atropine and 1% cyclopentolate are used to help diagnose refractive error, the impact of both remains unclear—and what we do know is controversial. Looking to clarify the effects of each cycloplegia agent, researchers recently found that cyclopentolate and atropine have different effects on ocular biometry, and atropine results in choroidal thickening.

The study included 207 myopic children between the ages of six and 12. All participants underwent comprehensive eye examinations before and after cyclopentolate, after which they randomly received 1% or 0.01% atropine once every night for a week.

The team observed decreased choroidal thickness (-3±9μm), elongation of axial length (9±16μm), loss of lens power (-0.14±0.37D) and a hyperopic shift (0.14±0.22D) after cycloplegia with cyclopentolate. As for atropine, they noted that ocular biometry differed between the 1% and 0.01% groups after one week of use. The 1% atropine group exhibited choroidal thickening (24±13μm) and reduced axial length (-30±27μm), with greater changes in lens power (0.50±0.37D) and spherical equivalent (0.52±0.23D). The 0.01% atropine showed a slight increase in choroidal thickness (6±9μm), but other biometric measures showed no significant changes.

The researchers conclude that, given the findings, the choroid may be a site of action for atropine.