The Combined Effect of Tropicamide and Phenylephrine on Corneal Astigmatism Axis

José María Sánchez-González (Coresponding Author), David Flikier, Salvador Nebro-Cobos, Francisco Zamorano-Martín, Rahul Rachwani-Anil, María García-Lorente, Davide Borroni, Jorge Peraza-Nieves, Carlos Rocha-de-Lossada

    Research output: Contribution to journalArticlepeer-review

    1 Citation (Scopus)


    Purpose: To analyze astigmatism axis changes after tropicamide and phenylephrine combined instillation. Method: One hundred and thirty-one eyes from 66 patients enrolled this cross-sectional study. An extensive ocular examination was carried out prior to tropicamide and phenylephrine instillation. Power and axis value from flat, steep, and mean keratometry were calculated using an Auto Kerato-Refractometer (AKR). Later, topography and tomography maps were evaluated with Pentacam HR® (Oculus, Wetzlar, Germany). Subsequently, a single drop of tropicamide 1% and phenylephrine hydrochloride 10% were instilled twice, with a five-minute gap between each instillation. After 30 minutes, the AKR and Pentacam HR® tests were repeated. Results: Incyclotorsion was found in 59 eyes (45.1%) and mean absolute incyclotorsion change was 3.91 ± 3.62 degrees (0.10 to 14.20). Excyclotorsion was found in 72 eyes (54.9%) and mean excyclotorsion change was 4.99 ± 5.94 degrees (0.20 to 36.20). We observed that 74.6% and 68.1% of eyes experienced incyclotorsion and excyclotorsion within 0 to 5 degrees, respectively. Fewer patients experienced incyclotorsion and excyclotorsion changes within 5 to 10 degrees, precisely 11.8% and 19.4%, respectively. Eyes that experienced over 10 degrees of incyclotorsion and excyclotorsion were 13.6% and 12.5%, respectively. Conclusion: Astigmatism axis could change after combined tropicamide and phenylephrine instillation. Reference axis marking in astigmatism correction surgery should be performed under the same circumstances as the astigmatism axis has been measured.

    Original languageEnglish
    Pages (from-to)179-186
    Number of pages8
    JournalCurrent Eye Research
    Issue number2
    Publication statusPublished - Feb 2022


    • astigmatism
    • axis
    • phenylephrine
    • Tropicamide

    Field of Science*

    • 3.2 Clinical medicine

    Publication Type*

    • 1.1. Scientific article indexed in Web of Science and/or Scopus database


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