Efficacy of tropicamide 1% versus cyclopentolate 1% for cycloplegic refraction in the paediatric population of Eastern India: A crossover randomized clinical trial

Cycloplegic refraction is regarded as the gold standard procedure for prescribing glasses in children. Inadequate cycloplegic effect results in an under-plus or over-minus refractive correction. Additionally, procedure time is a crucial factor in determining the ideal cycloplegic agent. Children typically have fluctuating accommodation, which can lead to errors in the objective estimation of refractive errors. Therefore, cycloplegia is needed to relax accommodation, which is achieved by instilling cycloplegic agents. A high amplitude of accommodation is the primary cause of variability in pediatric subjects. Hypermetropic refractive errors vary more than myopia and emmetropia. Inhibition of the acetylcholine present in the ciliary body causes paralysis of the ciliary muscles, cycloplegia, and dilation of the pupil, known as mydriasis. The clinician selects different cycloplegic agents based on factors such as the presence or absence of strabismus, type of refractive error, previous history of drug allergies, and the age of the subjects. 1% Cyclopentolate is a cycloplegic agent that requires sixty minutes of waiting time to have its effect, which can last up to seventy-two hours. In contrast, tropicamide requires a waiting time of forty minutes, and its effect lasts for up to 4-5 hours.  Post-cycloplegia with cyclopentolate, a child’s academic activities may be hampered for 3-4 days. Cyclopentolate has several side effects, such as nausea, problems with coordination, mental confusion, seizures, fever, and dry mouth, while tropicamide has fewer side effects.  Our study aims to compare the post-cycloplegic refractive error for the same subject on two separate visits using 1% cyclopentolate and 1% tropicamide in a two-week interval for the Eastern Indian population aged between 6 and 18 years.