ABSTRACT
PURPOSE: This study investigated the occurrence of keratoconus among first-degree relatives of patients with keratoconus and evaluated their refractive characteristics. METHOD: A cross-sectional observational study was conducted on 248 relatives of 52 patients with keratoconus in whom bilateral eye analysis was conducted. Corneal tomography was performed for all participants with a comprehensive analysis of various parameters, including K1, K2, Kmax, elevation, skewing, and thinnest location. In addition, the following data were also analyzed: uncorrected visual acuity, corrected distance visual acuity, refraction measurements alongside a slit-lamp examination, and fundus examination. RESULTS: Among 248 participants, 19 (7.7%) had keratoconus, 3.2% had forme fruste, and 15.3% had suspected keratoconus. Among all studied cases, 73.8% had normal corneas. Significant differences (P = 0.001) were found in the distribution of keratoconus prevalence among brothers, mothers, sons, and sisters (13.6%, 4.3%, 5.6%, and 12.1%, respectively). The presence of refractive errors also showed significant differences between the relatives (P = 0.03). CONCLUSIONS: Increased keratoconus prevalence among relatives of patients with keratoconus indicates the vulnerability of this population to the development of the disease, necessitating early screening of this group for detection of keratoconus as early as possible.
ABSTRACT
The initial contact with blood and its components, including plasma proteins and platelets, directs the body's response to foreign materials. Natural scaffolds of extracellular matrix or fibrin contain fibrils with nanoscale dimensions, but how platelets specifically respond to the topography and architecture of fibrous materials is still incompletely understood. Here, planar and nanofiber scaffolds are fabricated from native fibrinogen to characterize the morphology of adherent platelets and activation markers for phosphatidylserine exposure and α-granule secretion by confocal fluorescence microscopy and scanning electron microscopy. Different fibrinogen topographies equally support the spreading and α-granule secretion of washed platelets. In contrast, preincubation of the scaffolds with plasma diminishes platelet spreading on planar fibrinogen surfaces but not on nanofibers. The data show that the enhanced interactions of platelets with nanofibers result from a higher locally accessible surface area, effectively increasing the ligand density for integrin-mediated responses. Overall, fibrinogen nanofibers direct platelets toward robust adhesion formation and α-granule secretion while minimizing their procoagulant activity. Similar results on fibrinogen-coated polydimethylsiloxane substrates with micrometer-sized 3D features suggest that surface topography could be used more generally to steer blood-materials interactions on different length scales for enhancing the initial wound healing steps.