Official ESCRS | European Society of Cataract & Refractive Surgeons


Changes in the intraocular pressure (IOP) readings and corneal biomechanics following small incision lenticule extraction (SMILE)

Search Title by author or title

Session Details

Session Title: Glaucoma Management

Session Date/Time: Monday 16/09/2019 | 16:30-18:00

Paper Time: 16:48

Venue: Free Paper Forum: Podium 4

First Author: : F.Abo Alhassan EGYPT

Co Author(s): :    M. Hosny   M. Salem   H. Alshewy                       

Abstract Details


To determine the accuracy of measuring the intraocular pressure after small incision lenticule extraction by the Goldmann applanation tonometer (GAT) and Ocular response analyser (ORA) and to determine the change in the corneal biomechanics and if they are related to the extracted lenticule thickness.


kasr alainy school of medicine and I Scan ophthalmology center


30 eyes of 15 myopic patients with refractive error ranging from -1.5 to -8.5 diopter underwent SMILE procedure at the interval between 3/2016 and 9/2016.The patients underwent meticulous ophthalmological examination and the IOP was measured by both the GAT and the ORA before the procedure and one month following it.


GAT recorded lower values than ORA values (IOPcc) preoperatively and postoperatively and the difference was statistically significant. The mean change in GAT was about - 5.3 mmHg and in the corneal compensated IOP measured bu ORA was - 2.9 mmHg. There was no statistically significant correlation between the GAT and ORA IOP drop and the lenticule thickness. Corneal biomechanics shows significant decline after the procedure. The postoperative decline in corneal biomechanical parameters was directly proportionate to the lenticule thickness.


The postoperative IOP measured (after SMILE surgery) by both methods is lower than the preoperative measurement with that of the GAT being lower than the ORA and is not related neither to the preoperative refraction nor the lenticule thickness, so we can’t predict the decrease of IOP after SMILE surgery. As regards the corneal biomechanics, both corneal hysteresis and corneal resistance factor decline following SMILE surgery. This drop correlates with the lenticule thickness.

Financial Disclosure:


Back to previous