Changes in tear biomarkers in keratoconus after cross-linking

Session Details

Session Title: Cross-Linking

Session Date/Time: Tuesday 25/09/2018 | 14:00-16:00

Paper Time: 14:12

Venue: Room A3, Podium 3

First Author: : J.Recalde SPAIN

Co Author(s): :    J. Duran   I. Rodriguez-Agirrete   J. Soria   M. Sanchez-Tena   T. Suarez   A. Acera     

Abstract Details

Purpose:

The purpose of this work was to analyze the expression of matrix metalloproteinase 9 (MMP-9), calcyclin (S100A6), and cystatin 4 (CST4) in the tears of keratoconus patients. The correlation between the expression of these proteins and the values of various ocular surface parameters was examined after accelerated corneal cross-linking with pulsed ultraviolet light (A-CXL).

Setting:

Instituto Clinico-Quirurgico de Oftalmologia, Bilbao, Spain.

Methods:

This prospective, observational study enrolled 20 patients (24 eyes) with different grades of keratoconus, scheduled to undergo the A-CXL procedure. Tear samples were analyzed employing customized antibody microarray assays for MMP-9, S100A6, and CST4 proteins. Keratometry readings at the corneal apex (Kmax) and the mean keratometry (SimK) values were obtained to examine the postoperative evolution of corneal topography. The state of the ocular surface was evaluated using the results of the Ocular Surface Disease Index (OSDI) questionnaire, tear osmolarity (OSM) tests, Schirmer test (SCH), tear film breakup time (TBUT), tear clearance (CLR), fluorescein (FLUO) and lissamine green (LG) corneal staining.

Results:

Eventually, 18 patients (22 eyes) were studied. The concentration of MMP-9 decreased from 104.5 ± 78.98 ng/ml before the surgery to 48.7 ± 24.20 ng/ml after 12 months of follow-up. The concentration of S100A6 decreased from 350.20 ± 478.08 ng/ml to 55.70 ± 103.62 ng/ml. There were no changes in the CST4 concentration after 12 months of follow-up (2231.05 ± 2863.70 vs. 2139.60 ± 2719.89 ng/ml). Although at the end of the study none of the studied clinical variables showed significant changes in comparison with the baseline, a good correlation between the biochemical and clinical parameters was observed.

Conclusions:

A-CXL promoted a decrease in the concentration of MMP-9 and S100A6 in the tear film. This effect may be related to the restoration of corneal homeostasis and the consequent repair of the tissue damage caused by keratoconus. Moreover, the A-CXL treatment did not produce lasting alterations in the ocular surface, and the values of the evaluated clinical parameters did not change significantly.

Financial Disclosure:

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