Corneal Biomechanics After Lasik Hiperopya Versus Lasik Xtra®

To draw a long-term corneal biomechanics comparison between hyperopic Lasik and hyperopic Lasik Xtra® (corneal reinforcement with Riboflavin Vit B2 and UVA).

A prospective observational comparative study of a total of 28 eyes of consecutive patients who have been randomly selected from department of oftalmology, Oftalvist Clinic in Alicante database for laser hyperopia correction has been carried out.

The LASIK + CXL (Riboflabin +UVA) = LASIK Xtra® technique has been applied to a group of 15 eyes and the conventional LASIK technique has been applied to another group of 13 eyes.

The corneal parameters related to the biomechanical behavior of the cornea that have been studied with the Corvis ST instrument are: deformation amplitude, applanation lengths, applanation velocity, CBI (Biomechanical Index for Keratoconus detection, value between 0-1 being greater than 0.5 suspicious of corneal values ​​compatible with keratoconus), thickness and corneal keratometry in both groups.

For the analysis of the results we will use the statistical program Xcel for Windows.

The data analysis study was carried out on the total number of eyes included. The data analyzed are fron long-term corneal biomechanics.
When analysing variables with Corvist® ST, it is observed that:
1.- There are statistically significant differences for certain variables, such as CBI and the maximum corneal concavity radius
2.-Of the 28 eyes analysed, 3 of the 15 Lasik Xtra® eyes with thinner pachymetries have a smaller maximum corneal concavity radius compared to 2 of the 13 eyes with thinner pachymetries of Lasik patients despite similar values of amplitude deformation in both groups.
3.- A CBI value of less than 0.5 was obtained in 26.6% of the eyes operated with LASIK Xtra® and in 23.07% of the eyes operated with LASIK.

From the comparative study of the corneal biomechanics of the hyperopic Lasik Xtra® surgical techniques with respect to standard hyperopic Lasik measured with Corvist® ST, the general conclusion that can be drawn is that by reinforcing the collagen bonds with riboflavin in the Lasik Xtra® technique, a percentage of patients retain a more stable cornea over time and the cornea remains within the normal nomographic values.
This new device, despite being a novel instrument that needs further research, is considered a work tool with great potential that offers a wide range of parameters, which allow us to work on the analysis of biomechanical behaviour, being of great relevance to various fields of the clinical and research sector.