Abstract
Purpose :
Purpose: Keratoconus is a corneal disease that profoundly impact on patients’ visual acuity and quality of life. There is a lack of understanding about its pathophysiological mechanisms and familial associations. Recent studies have shown implication of inflammatory pathways with altered cytokine and proteinase levels in tear film and corneal tissue. The present observational study intends to expand the current knowledge about keratoconus through a detailed investigation which comprises corneal tomography and tear film evaluation of patients from the Cornea and External Disease Ambulatory, Department of Ophthalmology, UNICAMP, their family members and age/sex-matched control group.
Methods :
Methods: corneal tomographic Scheimpflug images with Pentacam were obtained from all study subjects: 38 keratoconus, 29 family members and 20 controls. Tear samples were collected for multiplex assay analysis (IL-6, IL-10, IL-4, TNF-alpha, and IFN-gamma). We also conducted a pilot proteomic essay in tear samples from 6 keratoconus subjects and 4 controls.
Results :
Results: Comparing patients’ relatives and control group, we found significant differences in the following Pentacam indices: Kmax (45.36 vs 44.27, p=0.019), thinnest pachymetry (524.20 vs 540.6, p=0.023), ARTmax (376.55 vs 415.75, p=0.05), Belin-Ambrosio indices Dt (0.43 vs -0.05, p=0.023), Da (1.02 vs 0.66, p=0.049) and D (1.64 vs 1.15, p=0.023). Tear film cytokine levels showed no differences between family members and the control group. Comparing keratoconus subjects, we found significant differences for TNF-alpha (15.82 vs 5.41, p=0.038) and INF-gamma (46.94 vs 13.89, p=0.029) levels. The proteomic analysis showed 7 differentially expressed proteins: immunoglobulin heavy variable 3 and 5, immunoglobulin heavy constant mu, proline-rich protein 27, histone H2B, keratin type 1 cytoskeletal 13, and neutrophil defensin.
Conclusions :
Conclusions: patients’ relatives showed altered tomographic indices in comparison to healthy controls. We also found different cytokine levels and proteomic profile in tear film samples between keratoconus subjects and controls. These findings may help further research in keratoconus pathophysiology and identification of possible biomarkers.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.