Cycloplegic Myopia Control Treatment May Affect Ocular Biological Parameters

Cycloplegic myopia control treatments may produce different effects on ocular biological parameters in children of different ages, according to a study published in BMC Ophthalmology. While these effects are not statistically significant among pediatric patients of similar age groups, they are statistically significant when different types of cycloplegic drugs in children of different age groups are considered.  

Investigators enrolled 195 children in a prospective, observational study and stratified participants according to cycloplegic myopia control treatment and age. Participants aged 2 to 12 years received treatment with 1% atropine (n=55) or tropicamide (n=70), while all 70 patients aged 14 to 17 years underwent tropicamide treatment. The team administered atropine dosing 3 times daily for 3 days and tropicamide dosing 4 times in 1 day at 5-minute intervals and performed ocular biometric measurements, which included refractive state, axial length, axial position of corneal astigmatism, corneal curvature, central corneal thickness, anterior chamber depth (ACD), anterior chamber volume, and white to white diameter before and after cycloplegia. The team measured changes in the ophthalmic biological parameters before and after cycloplegia and evaluated the effects of the drugs on ciliary muscle paralysis.

A comparison of ocular biological parameters before and after cycloplegia in participants within the same age group did not yield any significant differences in value (P >.05), but there were significant differences in the corresponding values of axial length, flattest keratometry (K1), and ACD among the different age groups (P <.05).

Before cycloplegia, there were significant differences in axial length, K1, steepest keratometry, (K2) and ACD within the different age groups (P <.05), but these values did not maintain statistical significance following cycloplegia (P >.05).

Cycloplegic myopia control treatment created statistically significant differences in axial length and ACD following application among the different age groups, the report shows. Atropine treatment resulted in mean increases in axial length and ACD among children aged younger than 13 years (1.71 and 0.42 mm, respectively), while tropicamide treatment resulted in mean decreases for both parameters (-1.47 and -0.01 mm, respectively) in individuals aged older than 13 years.  

“This study demonstrated that atropine and tropicamide have different effects on cycloplegia in children of different ages,” according to the researchers. “The effects of these two drugs on children’s ocular biological parameters are also different, and both will lead to different changes in the parameters. The effects of atropine/tropicamide on ocular biological parameters should be fully considered when evaluating the refractive state before refractive surgery or calculating the degree of intraocular lens before cataract surgery.”

Study limitations include failure to include an atropine cycloplegic myopia control treatment group consisting of individuals aged older than 13 years.