J Korean Ophthalmol Soc.  2020 Aug;61(8):882-889. 10.3341/jkos.2020.61.8.882.

Clinical Reliability of the Topolyzer Vario Instrument for Measurement of Corneal Refractive Power

• Surl D
• Jun I
• Lee HK
• Kim EK
• Seo KY
• Kim TI

• KMID: 2505307
• DOI: http://doi.org/10.3341/jkos.2020.61.8.882

Abstract

Purpose
To evaluate the clinical reliability of the Topolyzer Vario (Wavelight-Alcon, Erlangen, Germany), we compared threedifferent corneal topographers in terms of corneal refractive power.
Methods
The medical records of patients who visited Severance Hospital for corneal refractive surgery were retrospectivelyreviewed. Keratometric data of patients who underwent evaluations using the Pentacam HR (Oculus, Wetzlar, Germany),ORBscan II (Bausch & Lomb, Rochester, NY, USA), and Topolyzer Vario instruments on the same day were obtained. Flat keratometry(K_f), steep keratometry (K_s), mean keratometry (K_m), astigmatism keratometry (K_astig), Cartesian astigmatism (J₀), andoblique astigmatism (J₄₅) values were calculated. The measurement values of the three devices were subjected to Pearson’scorrelation analysis and repeated measures analysis of variance (with Bonferroni correction); a Bland-Altman plot was alsocreated.
Results
The keratometric data of 80 eyes were included in the analysis and all of the keratometric measurements obtained bythe three devices showed significant correlations, i.e., good agreement. The K_f and K_m measurements of the Pentacam HR wereflatter than those of the ORBscan II, and the K_f, K_m, K_s, and J₄₅ measurements were flatter than those of the Topolyzer Vario.However, there was no significant difference in keratometric values between the ORBscan II and Topolyzer Vario. Furthermore,the difference in corneal refractive power between the Pentacam HR and Topolyzer Vario was not clinically significant.
Conclusions
When measuring the corneal refractive power of patients without any history of corneal disorder or ocular surgery,the Topolyzer Vario is a clinically reliable device that shows similar performance to the ORBscan II and Pentacam HR.

Keyword

Corneal refractive power; Keratometry; Topographer; Topolyzer vario