Evaluation of posterior corneal astigmatism changes in femtosecond LASIK and SMILE

Session Details

Session Title: Corneal Refractive Surgery

Session Date/Time: Tuesday 17/09/2019 | 14:00-16:00

Paper Time: 15:03

Venue: Free Paper Forum: Podium 3

First Author: : A.Sharma INDIA

Co Author(s): :    M. Vanathi   N. Gupta   R. Tandon   S. Khokhar                    

Abstract Details

Purpose:

To evaluate the posterior corneal astigmatism in myopic femtosecond (FS) flap LASIK and SMILE surgeries.

Setting:

Cornea & Refractive Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India

Methods:

In a prospective longitudinal observational study of data of 22 eyes (mean age 25±5 years) undergoing myopic FS-flap LASIK and 22 eyes (mean age 25 ± 5 years) undergoing SMILE, preoperative & first-postoperative month data: mean refractive spherical equivalent (MRSE), ablation depth (AD), flap thickness (FT), percent tissue altered (PTA), corneal curvature [anterior, posterior and total corneal astigmatism with Cassini Technologies & Scheimpflug imaging - Pentacam) were noted. Patients <18 years, pregnancy/lactation, history of glaucoma, uveitis, auto-immune diseases, unstable refractive error & other ocular comorbidities were excluded. The primary outcome measure evaluated was the change in posterior corneal astigmatism.

Results:

LASIK [mean AD 67.27 ± 21.94µm, RSBT 347.99±23.15µm, PTA 33.53 ± 3.49] for MRSE -4.87 ± 1.77D showed a change in mean preoperative anterior corneal astigmatism from 0.93±0.49D to 0.67 ± 0.39D, mean posterior corneal astigmatism from -0.30±0.15D to -0.37 ± 0.27D; SMILE [Mean AD 61.90 ± 13.56µm, RSBT 353.19 ± 27.56µm, PTA 32.88 ± 3.10] for MRSE of -4.73 ± 1.07D showed a change in mean preoperative anterior corneal astigmatism from 0.77 ± 0.44D to 0.75 ± 0.28D and mean posterior corneal astigmatism from -0.27 ± 0.13D to -0.30 ± 0.15D at first postoperative month with Cassini imaging.

Conclusions:

This preliminary study of posterior corneal astigmatism with Cassini imaging shows that both myopic LASIK and SMILE surgery influence the posterior corneal astigmatism.

Financial Disclosure:

None