Validation of refraction and anterior segment parameters by a new multi-diagnostic platform (VX120) / Validación de los parámetros de refracción y segmento anterior mediante una nueva plataforma multi-diagnóstica (VX120)

Background: The VX120 (Visionix Luneau, France) is a novel multi-diagnostic platform that combines Hartmann-Shack based autorefraction, Placido-disk based corneal-topography and anterior segment measurements made with a stationary-Scheimpflug camera. We investigate the agreement between different parameters measured by the VX120 with accepted or gold-standard techniques to test if they are interchangeable, as well as to evaluate the repeatability and reproducibility. Methods: The right-eyes of healthy subjects were included in the study. Autorefraction of the X120 was compared to subjective refraction. Agreement of anterior segment parameters was compared to the Sirius (CSO, Italy) including autokeratometry, central corneal thickness (CCT), iridiocorneal angle (IA). Inter and intra-test repeatability of the above parameters was assessed. Results were analyzed using Bland and Altman analyses. Results: A total of 164 eyes were evaluated. The mean difference between VX120 autorefraction and subjective refraction for sphere, spherical equivalent (SE), and cylinder was 0.01 ± 0.43 D, 0.14 ± 0.47 D, and -0.26 ± 0.30 D, respectively and high correlation was found to all parameter (r > 0.75) except for J45 (r = 0.61). The mean difference between VX120 and the Sirius system for CCT, IA, and keratometry (k1 and k2) was -3.51 ± 8.64 μm, 7.6 ± 4.2°, 0.003 ± 0.06 mm and 0.004 ± 0.04 mm, respectively and high correlation was found to all parameter (r > 0.97) except for IA (r = 0.67). Intrasession repeatability of VX120 refraction, CCT, IA and keratometry yielded low within-subject standard deviations. Inter-session repeatability showed no statistically significant difference for most of the parameters measured. Conclusions: The VX120 provides consistent refraction and most anterior segment measurements in normal healthy eyes, with high levels of intra and inter-session repeatability

Antecedentes: VX120 (Visionix Luneau, Francia) es una plataforma multi-diagnóstico novedosa que combina la auto-refracción basada en Hartmann-Shack, la topografía corneal mediante discos de Plácido, y las mediciones del segmento anterior realizadas mediante cámara de Scheimpflug. Analizamos la concordancia entre los diferentes parámetros medidos por VX120 con las técnicas aceptadas o de referencia, para probar si eran intercambiables, y evaluamos la repetibilidad y reproducibilidad. Métodos: Se incluyeron en el estudio los ojos derechos de sujetos sanos. Se comparó la auto-refracción de VX120 con la refracción subjetiva. La concordancia de los parámetros del segmento anterior se comparó con la del sistema Sirius (CSO, Italia), incluyendo autoqueratometría, espesor corneal central (ECC) y ángulo iridiocorneal (AI). Se valoró la repetibilidad inter e intra-prueba de los parámetros anteriores. Los resultados se analizaron mediante el método de Bland-Altman. Resultados: Se evaluó un total de 164 ojos. La diferencia media entre la auto-refracción de VX120 y la refracción subjetiva para esfera, equivalente esférico (EE), y cilindro fue de 0,01 ± 0,43 D, 0,14± 0,47 D y -0,26 ± 0,3 D, respectivamente, encontrándose una elevada correlación entre todos los parámetros (r > 0,75) excepto para J45 (r = 0,61). La diferencia media entre VX120 y el sistema Sirius para ECC, AI, y queratometría (k1 y k2) fue de -3,51 ± 8,64 μm, 7,6 ± 4,2°, 0,003 ± 0,06 mm y 0,004 ± 0,04 mm, respectivamente, encontrándose una elevada correlación entre todos los parámetros (r > 0,97) excepto para AI (r = 0,67). La repetibilidad intra-sesión de la refracción VX120, ECC, AI y queratometría reflejó desviaciones estándar bajas entre sujetos. La repetibilidad inter-sesión no reflejó una diferencia significativa para la mayoría de los parámetros medidos. Conclusiones: VX120 aporta medidas consistentes de refracción y de la mayoría de las mediciones del segmento anterior en ojos sanos normales, con elevados niveles de repetibilidad intra e inter-sesión

Validation of refraction and anterior segment parameters by a new multi-diagnostic platform (VX120).

BACKGROUND: The VX120 (Visionix Luneau, France) is a novel multi-diagnostic platform that combines Hartmann-Shack based autorefraction, Placido-disk based corneal-topography and anterior segment measurements made with a stationary-Scheimpflug camera. We investigate the agreement between different parameters measured by the VX120 with accepted or gold-standard techniques to test if they are interchangeable, as well as to evaluate the repeatability and reproducibility. METHODS: The right-eyes of healthy subjects were included in the study. Autorefraction of the VX120 was compared to subjective refraction. Agreement of anterior segment parameters was compared to the Sirius (CSO, Italy) including autokeratometry, central corneal thickness (CCT), iridiocorneal angle (IA). Inter and intra-test repeatability of the above parameters was assessed. Results were analyzed using Bland and Altman analyses. RESULTS: A total of 164 eyes were evaluated. The mean difference between VX120 autorefraction and subjective refraction for sphere, spherical equivalent (SE), and cylinder was 0.01±0.43D, 0.14±0.47D, and -0.26±0.30D, respectively and high correlation was found to all parameter (r>0.75) except for J45 (r=0.61). The mean difference between VX120 and the Sirius system for CCT, IA, and keratometry (k1 and k2) was -3.51±8.64µm, 7.6±4.2°, 0.003±0.06mm and 0.004±0.04mm, respectively and high correlation was found to all parameter (r>0.97) except for IA (r=0.67). Intrasession repeatability of VX120 refraction, CCT, IA and keratometry yielded low within-subject standard deviations. Inter-session repeatability showed no statistically significant difference for most of the parameters measured. CONCLUSIONS: The VX120 provides consistent refraction and most anterior segment measurements in normal healthy eyes, with high levels of intra and inter-session repeatability.