A NEW APPROACH TO KERATOCONUS DIAGNOSTICS USING MATRIX METALLOPROTEINASE-9 MARKER.

In spite of numerous studies, the exact mechanism of the keratoconus development remains unknown. Nowadays, it is considered to be a multifactorial disorder, caused by a combination of both genetic and environmental factors. Some recent studies have indicated that IL-6 and matrix metalloproteinase-9 take crucial part in disease development. The study aims to test the association of keratoconus with elevated Matrix Metalloproteinase-9 levels in the lacrimal fluid of patients. In controlled, cross-sectional, double-masked study, the patients were examined as they attended the clinic; this method approximated random sampling. The study took place in "Shengavit" Medical Center (Yerevan). The study procedures were carried out in a standard examination room. The level of Matrix Metalloproteinase-9 was assessed using immunochromatographic analyses. In addition, a Shirmer's test was performed on all patients. In total, 90 patients (one eye of every patient) were examined. Three groups were distinguished: I (control) group - patients without any ocular pathology (n=30); II - patients with subclinical keratoconus (n=30); III - patients in the first, second, and third stages of keratoconus (n=30). In the third group (patients with obvious keratoconus), elevated levels of Matrix Metalloproteinase-9 were observed in 27 out of 30 eyes (90%). In the second group (patients with subclinical keratoconus), high levels of Matrix Metalloproteinase-9 were observed in 25 out of 30 eyes (83.33%). In the control group, only one eye out of 30 had an elevated level of Matrix Metalloproteinase-9 (3.33%). The results of the study demonstrate that the tear fluids of patients in the first to third stages of keratoconus or with subclinical keratoconus contain elevated levels of Matrix Metalloproteinase-9 as compared to the control group. Consequently, the detection of Matrix Metalloproteinase-9 in tear fluid can be used in the diagnostics of keratoconus.