To unveil the etiology, pathogenic mechanism and the clinical significance of the corneal iron line through various clinical aspects of the corneal iron line.

This study included 45 eyes of 39 patients who visited the Department of Ophthalmology in Chungnam National University Hospital between April 2011 and March 2014. Anterior segment of the eye was photographed during the diagnostic process. The medical history of the patient was investigated and corneal topography was performed to discover the relationship between the position of the corneal iron line and the curvature of the corneal surface.

The corneal iron line was identified in various corneal diseases such as herpetic stromal keratitis and; corneal ulcer. The average age of patients was 57.8 years. Corneal topography was performed in 12 patients and a connection was found between the curvature of the corneal surface and the position of corneal iron line at 75%. During the research period, corneal disease progressed and associated corneal iron line became clearer in 2 eyes. However, there was no repositioning or new appearance in different areas. The corneal iron line was not associated with visual acuity and the shape varied in accordance with the accompanying corneal disorder. The location where the tears repeatedly accumulate was associated with corneal surface.

Based on the occurrence location and the shape of the corneal iron line, we could understand that the occurrence of corneal iron line is associated with the past and current corneal surface irregularities, which verified the validity of the tear pooling hypothesis. Therefore, this result can aid in establishing the diagnosis and treatment plan when the corneal iron line is discovered during clinical practice.