Correlation analysis between corneal biomechanics and aberrations of the anterior, posterior surface in myopic eyes which underwent small incision lenticule extraction (SMILE)

Session Details

Session Title: Corneal Biomechanics

Session Date/Time: Monday 15/09/2014 | 17:00-18:30

Paper Time: 18:06

Venue: Capital Hall A

First Author: : Y.Wang CHINA

Co Author(s): :    W. Wu              

Abstract Details

Purpose:

To investigate the correlations between corneal biomechanics and the anterior, posterior and total corneal aberrations in myopic eyes underwent small incision lenticule extraction (SMILE).

Setting:

Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology Tianjin Medical University, Tianjin China

Methods:

Sixty myopic eyes of 60 subjects were enrolled in this prospective study. The anterior, posterior and total corneal aberrations in the central 6mm zone from the third to the forth Zernike order were compared pre and post SMILE. Multivariate linear regression analysis was ap¬plied to determine correlations between the postoperative high order aberrations (HOAs) and the corneal hysteresis (CH) and corneal resistance factor (CRF). The magnitude of the refractive correction, ablation depth, incision width, postoperative central corneal thickness, and intraocular pressure were also investigated in this regression analysis.

Results:

The corneal total high order aberrations(μm) significantly increased after SMILE, from0.35±0.09 to 0.80±0.26 for the anterior(P<0.001), and from 0.18±0.03 to 0.19±0.03 for the posterior cornea(P=0.014), from 0.35 to 0.09 to 0.83 ±0.29 for the whole cornea(P<0.001). The spherical aberration significantly increased from 0.24±0.08,0.20±0.08 to 0.49±0.12, 0.45±0.14 for the anterior and total cornea respectively(P<0.001), the vertical coma significantly increased from -0.07±0.16, 0.00±0.04,-0.09±0.16 to -0.44±0.37, 0.01±0.04,-0.46±0.38 μm for the anterior, posterior and total cornea(P<0.001,P=0.013,P<0.001 respectively). Multivariate analysis showed the postoperative corneal total HOAs associated with the sphere (β=-0.425, P <0.001; β=-0.433, P <0.001for the anterior and whole cornea), CRF (β=-0.248, P =0.031; β=-0.243, P =0.033 for the anterior and whole cornea) and incision width (β=-0.239, P =0.035; β=-0.249, P =0.028for the anterior and whole cornea). The determinants of the anterior vertical coma were CRF (β=0.279, P =0.022) and incision width (β=0.322, P =0.007). CH significantly associated with the posterior spherical aberration (β=-0.316, P =0.014).

Conclusions:

This study suggested that the anterior, posterior and whole corneal aberrations increased after SMILE and mainly the vertical coma and spherical aberration .The significant correlations were found between the CRF and vertical coma for the anterior cornea that might be related to the corneal incision in SMILE procedure. CH also significantly correlated with spherical aberration for posterior cornea which may be related to the corneal biomechanical response. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Financial Interest:

NONE