Are posterior corneal changes significant related to visual quality in corneal intrastromal ring implant?

Session Details

Session Title: Presented Poster Session: Refractive Surgery New Techniques/Instrumentation/Devices II

Venue: Poster Village: Pod 2

First Author: : C.Peris Martínez SPAIN

Co Author(s): :    M. Garcia-Carabal   M. Diez-Ajenjo   M. Garcia-Domene                 

Abstract Details

Purpose:

To assess if posterior corneal changes related to corneal intrastromal ring implant produce significant changes in patients visual quality. To assess if anterior corneal aberrometers are useful to evaluate visual quality of intrastromal ring implant patients

Setting:

FISABIO Oftalmología Médica, Bifurcación Pío Baroja-General Avilés, s/n. E-46015 Valencia (Spain)

Methods:

126 eyes of 104 patients (38 women/66 men) with intrastromal corneal ring segment (ICRS) implant were evaluated. Prior to surgery, we measured best corrected visual acuity (BCVA), corneal topography and low order aberrations (n=2) with Pentacam. All patients were implanted with Kearing intrastromal ring. After 6 months postoperative, we also measured BCVA, corneal topography and low order aberrations. We use SPSS 24.0 program to analyze the results obtained, with a Kolmogorov- Smirnov test with Lilliefors correction, and a paired t-test.

Results:

Preoperative BCVA was 0.22±020logMAR. Queratometry was K1 45±5D and K2 50±5D. Total Zernike values (in µm) were Z(0,2) 46±16, Z(-2,2) -5±5, Z(2,2) 4±10. For posterior surface, they were Z(0,2) 82±9 Z(-2,2) -3±3, Z(2,2) 3±6. 6 moths after surgery, BCVA was 0.10±0.15logMAR, queratometry was K1 45±5D and K2 48±5D. Total Zernike coefficients were Z(0,2) 142±15, Z(-2,2) -2±5, Z(2,2) 2±6. For posterior surface, Z(0,2) 81±10, Z(-2,2) -1.16±4.05, Z(2,2) 1.6±4.6. All coefficients were statistically significant between pre and post surgery except for Z(2,2) total value.

Conclusions:

ICRS implant also modified corneal posterior surface. These modifications produced significant changes in Zernike coefficients, and consecuently, these changes affected to visual quality of the patients. With an anterior corneal surface aberrometer we can not appreciate appropriately the visual changes and visual quality of patients with ICRS implants, because we can not estimate corneal posterior contribution to visual quality of these patients.

Financial Disclosure:

None