Technologic advances in the field of vision care have led to the development of multidiagnostic platforms that integrate, in the same device, several technologies to measure different anatomical and optical parameters of the eye.1 This type of diagnostic platform allows a complete characterisation of the corneal structure, including the analysis of the shape and optical aberrations of the two corneal surfaces, distribution of thickness and even a volumetric analysis of the cornea.1
One of the main features of these devices is the clinical characterisation of the ocular optics, providing measurement of objective refraction and ocular aberrations.2,3 Likewise, these instruments provide a complete geometric analysis of the cornea.
The combination of Scheimpflug imaging and Placido disk technologies has been shown to be a good option to obtain consistent curvature and elevation data in normal healthy and even in keratoconus eyes.4-8 Finally, multidiagnostic platforms allow the clinician to obtain different anatomical dimensions of anterior segment structures, which are crucial for ocular pathology screening and to perform a comprehensive monitoring of ocular diseases.
Recently, a new multidiagnostic platform (Figure 1) has been developed that enables tangential and axial curvature data of the anterior corneal surface to be obtained, as well as a biometric estimation of various anterior segment structures; measurement of corneal, internal and ocular wavefront aberrations; visual quality simulations; corneal pachymetry maps; and IOP measurements.
Specifically, this system (VX120, Visionix-Luneau Technologies) (Figure 2) combines a Hartmann-Shack aberrometer; a Placido disk corneal topographer; a Scheimpflug imaging-based system; and an air tonometer. The Hartmann-Shack aberrometer measures 1,500 points in 0.2 seconds in an area ranging from 2 to 7 mm in diameter.
The Scheimpflug imaging-based system uses monochromatic blue light of 455 nm to obtain pachymetric measurements with a resolution of ± 1 µm and iridocorneal angle measurements with a resolution of ± 1º. The Placido disk system projects 24 rings on the corneal surface, measuring more than 100,000 points.
Recently, some improvements have been introduced in the Scheimpflug photography system included in the VX120 system that allows, additionally, the characterisation of the posterior corneal topographic profile and the generation of corneal pachymetric maps, which has given rise to the VX130 system.