Assessment of corneal biomechanical changes after one month of SMILE using Scheimpflug-based dynamic tonometry

Session Details

Session Title: Corneal Biomechanics

Session Date/Time: Tuesday 13/09/2016 | 16:30-18:00

Paper Time: 17:18

Venue: Auditorium C6

First Author: : J.Fernández SPAIN

Co Author(s): :    J. Martinez   A. Tauste   M. Rodriguez-Vallejo              

Abstract Details

Purpose:

To evaluate the changes produced in the most reliable parameters of CorvisST (CST) by SMILE at one month after surgery.

Setting:

Qvision, Ophthalmology Department of Virgen del Mar Hospital (Spain)

Methods:

73 eyes (subjects), mean age 31.3 ± 6.5, were measured with the CST before SMILE (cap thickness of 140 microns) and one month later. All eyes with a subjective astigmatism under 2.25D and a mean spherical equivalent of -3.76 ± 1.56D ranging from -1.00D to -7.25D. Times at first, second applanation, and highest concavity (AT1, AT2 and HCT) were included in the study. Pre and post ATs were compared with paired t-tests (AT1 pre-post vs AT2 post-pre). The IOP and the SMILE surgery were considered as predictors of the DA and they were analyzed through a linear multiple regression model.

Results:

A mean decrease after SMILE of 0.33 ms was obtained for AT1 (p<0.001) and an increase of 0.26 ms for AT2 (p=0.006), however the difference between AT1 and AT2 changes due to SMILE was not significant (p=0.453). HCT was near the same pre-SMILE 17.17 +/- 0.49 ms than pos-SMILE 17.21 +/- 0.56 ms (p = 0.620). The slope of the linear fit for IOP versus DA remained constant after the procedure and a multiple linear regression model resulted in no differences for the change of slope due to the SMILE procedure.

Conclusions:

SMILE produces changes in ATs but these are similar for AT1 and AT2, this means there was not change in viscoelasticity or if there were any change, it could not be detected by Corvis ST. The constant slope for the relation between IOP and DA before and after the procedure suggests that corneal stiffness remains unaltered after SMILE procedure.

Financial Disclosure:

... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented