Which medication is used for cycloplegic refractions?

• A. Cyclopentolate 1%, 2%
• B. Homatropine 2%
• C. Atropine 1%
• D. Tropicamide 1%

Answer: (A)

When performing cycloplegic refractions, the goal is to temporarily paralyze accommodation so the eye’s true refractive error can be measured without the stimulus of focusing. Cyclopentolate at 1% or 2% is the medication most commonly used for this purpose because it provides reliable and sufficient cycloplegia with a practical onset and duration. It blocks the muscarinic receptors in the ciliary muscle, producing accommodation paralysis quickly (about 30–60 minutes) and lasting for roughly a day, which is long enough to get an accurate refraction but short enough to minimize inconvenience.

Other options exist for different situations, but they are not as well suited for standard cycloplegic refraction. Tropicamide acts quickly and dilates the pupil but often yields only mild or incomplete cycloplegia, especially in children. Atropine causes very long-lasting cycloplegia, taking days to weeks, which makes it impractical for routine refractions. Homatropine can produce cycloplegia as well, but its onset and duration are more variable and often longer than cyclopentolate, making it less ideal as a first-line choice.