The ciliary muscle exhibited an inward-forward contraction during accommodation, resulting in a significant thickening of the anterior area of the ciliary muscle. In addition to ultrasound biomicroscope (UBM), anterior segment optical coherence tomography (AS-OCT) is also commonly used to study morphological changes in the ciliary muscle. Studies using AS-OCT revealed that the posterior area of the ciliary muscle thinned during accommodation.~The morphology of the ciliary muscles differs in individuals with refractive errors. Many researchers found that the ciliary muscle became thicker with an increase of axial length (AL) Some studies suggested that myopia primarily affected the posterior area of the ciliary muscle.~Atropine has a ciliary muscle-paralysing effect and causes hyperopic drift. Besides, atropine has been proven to slow the progression of myopia. Many studies have suggested that atropine can increase the thickness of the choroid. However, few studies have discussed changes in the ciliary muscle after treatment with atropine or other cycloplegic agents.~This study aimed to assess the difference in ciliary muscle morphology before and after two different cycloplegic agents and to analyze the correlation between the changes of ciliary muscle biological parameters and the changes of eye axis, spherical equivalent, lens diopter, choroidal thickness, etc. One hundred and forty-four children would be randomly assigned 1:1 to the 1% atropine group and the tropicamide group. This study might provide clinical evidence for the role of regulatory factors in the occurrence and development of myopia.
Atropine has a ciliary muscle-paralysing effect and causes hyperopic drift. Besides, atropine has been proven to slow the progression of myopia. Many studies have suggested that atropine can increase the thickness of the choroid. However, few studies have discussed changes in the ciliary muscle after treatment with atropine or other cycloplegic agents.~This study aimed to assess the difference in ciliary muscle morphology before and after two different cycloplegic agents and to analyze the correlation between the changes of ciliary muscle biological parameters and the changes of eye axis, spherical equivalent, lens diopter, choroidal thickness, etc. One hundred and forty-four children would be randomly assigned 1:1 to the 1% atropine group and the tropicamide group. This study might provide clinical evidence for the role of regulatory factors in the occurrence and development of myopia.