White to white cornea diameter and mesopic pupil size in patients with keratoconus

Abstract

Objectives: Keratoconus is characterized by the abnormal cornea structure and it is manifested by changes in anterior segment parameters responsible for ocular high order spherical aberrations. The aim of the study is to investigate cornea horizontal white to white diameter and mesopic pupil size in patients with keratoconus. Methods: The medical records of each participant were reviewed. The horizontal white to white cornea diameter and the mesopic pupil size were measured with the Sirius Topography System in 215 eyes of 123 subjects. Two groups were formed, the first group included 113 eyes with keratoconus and the second group is composed of 102 healthy eyes. Differences in sex, age, cornea diameter and mesopic pupil size between two groups were analyzed statistically. Results: There were no statistically significant differences in sex and age distribution between the two groups (p>0.05). The average horizontal corneal diameter was 11.98±0.33 mm in the 1st group and 11.81±0.24 mm in group 2. It was significantly higher in patients with keratoconus than in healthy subjects. (p=0.04) The mean mesopic pupil size was 3.64±0.12 mm in group 1 and it was 3.73±0.14 mm in group 2. The mesopic pupil size was significantly higher in healthy subjects than in patients with keratoconus (p=0.03). Conclusion: This study showed that while the horizontal white to white diameter of the cornea increases in keratoconus, the mesopic pupil size decreases. In clinical practice, these two parameters should be considered in treatment procedures of patients with keratoconus.