Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Oct;69(10):2650-2656.
doi: 10.4103/ijo.IJO_3365_20.

Short term changes in corneal stress-strain index and other corneal biomechanical parameters post-laser in situ keratomileusis

Vaishal P Kenia  1 , Raj V Kenia  2 , Onkar H Pirdankar  3
Affiliations

Short term changes in corneal stress-strain index and other corneal biomechanical parameters post-laser in situ keratomileusis

Vaishal P Kenia et al. Indian J Ophthalmol. 2021 Oct.

Abstract

Purpose: To report the short-term changes in a corneal stress-strain index (SSI) and other corneal biomechanical parameters post-laser in situ keratomileusis (LASIK) surgery.

Methods: A retrospective study was conducted at a tertiary eye care center wherein patients who had undergone LASIK (microkeratome blade and femtosecond bladeless LASIK) between July and December 2019 were enrolled. Patients of age group 20-40 years, best-corrected visual acuity of 20/20, intraocular pressure (IOP) <22 mmHg, pre-LASIK pachymetry >500 microns, and corneal astigmatism ≤3.00 D were included. Subjects with a prior history of refractive surgery, any other ocular or systemic disease, poor-quality scans, intraoperative complications, and missing data were excluded. Corneal biomechanical properties including SSI were analyzed using Corvis ST and compared using the Paired T-test for each group separately at pre-LASIK, and 1-month post-operatively.

Results: Overall, 202 eyes were reviewed, and 79 eyes fulfilled the inclusion criteria. Forty-three and 36 eyes had undergone Microkeratome Blade LASIK (Group I) and Femto LASIK (Group II), respectively. Overall, 29 and 26 corneal biomechanical parameters out of 33 changed significantly post-Microkeratome Blade LASIK and Femto LASIK, respectively. Statistically significant changes were noted in all the parameters at A1, maximum and Vinciguerra screening parameters (P < 0.001), however, no changes were noted in SSI in both the groups when compared with the pre-surgery data.

Conclusion: Though the reduction in SSI was not statistically significant, other biomechanical parameters showed significant biomechanical changes pre- and post-LASIK surgeries in both the groups. However, a long-term study with a larger sample size would be required to understand the changes and stability in SSI post-refractive surgery.

Keywords: Corneal biomechanics; Corneal stress-strain index (SSI); LASIK.

PubMed Disclaimer

Conflict of interest statement

None

Comment in

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Pesudovs K, Garamendi E, Elliott DB. The Quality of life impact of refractive correction (QIRC) questionnaire:Development and validation. Optom Vis Sci. 2004;81:769–77. - PubMed
    1. Pesudovs K, Garamendi E, Elliott DB. A quality of life comparison of people wearing spectacles or contact lenses or having undergone refractive surgery. J Refract Surg. 2006;22:19–27. - PubMed
    1. Bohac M, Koncarevic M, Pasalic A, Biscevic A, Merlak M, Gabric N, et al. Incidence and clinical characteristics of post-LASIK ectasia:A review of over 30,000 LASIK cases. Semin Ophthalmol. 2018;33:869–77. - PubMed
    1. Wolle M, Randleman JB, Woodward M. Complications of refractive surgery:Ectasia after refractive surgery. Int Ophthalmol Clin. 2016;56:129–41. - PMC - PubMed
    1. Siganos CS, Kymionis GD, Astyrakakis N, Pallikaris IG. Management of corneal ectasia after laser in situ keratomileusis with intacs. J Refract Surg. 2002;18:43–6. - PubMed