EyeCalc+ Ophthalmology Calculators

Parks Three Step

Localises the suspected isolated paretic cyclovertical muscle in acquired vertical diplopia.

References

• Parks MM. Isolated cyclovertical muscle palsy. AMA Arch Ophthalmol 1958.
• Bielschowsky A. Lectures on motor anomalies of the eyes: II. Paralysis of individual eye muscles. Arch Ophthalmol 1935.
• Kushner BJ. Errors in the three-step test in the diagnosis of vertical strabismus. Ophthalmology 1989.
• Manchandia AM, Demer JL. Sensitivity of the three-step test in diagnosis of superior oblique palsy. J AAPOS 2014.
• Triantafilou D, Suh DW, et al.. Three Step Test for Cyclovertical Muscle Palsy. EyeWiki (American Academy of Ophthalmology) 2026.

This tool is for informational and educational purposes only and is not a substitute for professional medical judgment.