Abstract
Purpose :
Keratoconus is defined as a non-inflammatory pathology of the cornea. Recent investigations have found a probable inflammatory role in the pathophysiology, but the amount of inflammatory component has not been clearly determined yet.
The aim of the study is to detect overexpression of inflammation and tissue damage markers in the corneal stroma of keratoconus compared with healthy corneal stroma.
Methods :
A comparative, cross-sectional and prospective study was carried out in Cornea and Refractive Surgery and Biomedical Research Center of the Fundación Hospital Nuestra Señora de la Luz in Mexico City. Proper informed consent was obtained, corneal tissue sample was collected from patients with advanced keratoconus who underwent penetrating keratoplasty (PK group), and as a control group, stromal lenticules were collected by ReLEx® SMILE (Carl Zeiss, VisuMax 2.0®) technique in patients undergoing refractive surgery; ectasic disease was ruled out (SMILE group). Both tissue samples were storaged in PBS tubes with lysis buffer inhibitor at -80 degrees Celsius.
Quantification of cytokines and tissue damage markers were performed with a protein array on nitrocellulose membranes using the Proteome Profiler Array-Human Angiogenesis kit (R&D Systems ®), following the manufacter’s instructions. Results were visualized with G-box imaging system, and analyzed the density of each point with the Vision Works LS software. Data were normalized relative to the positive and negative control. We considered as a biological significance more than 2-fold change.
Results :
Twenty-two patients were included, 7 from the PK group and 15 from the SMILE group. Significant overexpression of angiogenin (3-fold change), dipeptidyl peptidase IV (4-fold change), endostatin (6-fold change), fibroblast growth factor type 1( 3-fold change) and 2 (2-fold change), insulin-like growth factor type 2 (2-fold change), interleukin-8 (3-fold change), metalloproteinases-8 (5-fold change) and 9 (2-fold change), peptidase inhibitor-5 (3-fold change) and urokinase protein (2-fold change) were observed in the PK group compared to the SMILE group.
Conclusions :
An overexpression of inflammatory proteins in corneal tissue of patients with keratoconus was found compared with healthy corneal tissue. The more significant was endostatin, which has a role in scar formation. Any underexpressed inflammatory protein was found.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.