Effect of corneal cross-linking surgery on corneal densitometry in patients with keratoconus

Abstract

Objective To obtain and analyze the effect of corneal collagen crosslinking (CXL) on corneal densitometry (CD) in patients with keratoconus (KC) by using the Pentacam 3D anterior segment analysis system. Methods Twenty-eight KC patients who visited the Chinese PLA General Hospital and underwent CXL from January 2017 to December 2019 were subjected and included in the KC-CD group. There were 14 patients who underwent monocular CXL, and the operated eyes were included in the CXL group and the non-operated eyes in the non-CXL group. CD values and data of corneal morphology, and the thinnest corneal thickness (TCT) were obtained and analyzed before and in 1 and 3 months, and 1 year after the CXL using the Pentacam 3D anterior segment analysis system. Nonparametric test, one-way Chi-square analysis, paired t-test and other statistical analyses were applied to compare CD before and after surgery in a cross-sectional and longitudinal manner. Results The CD values of 0~2 mm and 2~6 mm zones in the anterior, central, and posterior layers as well as in the total cornea were significantly higher (P 2~6 mm zones of the anterior layer, the central layer, the posterior layer, and the total layer. Compared with the Non-CXL group, the CD values of the above-mentioned layer of CXL group were still higher at 3 months after surgery (P < 0.05), but their mean CD values were decreased at 1 month after CXL. At 1 year after undergoing CXL, there were no significant changes in CD values in each layer between the CXL and non-CXL groups. Conclusion CXL causes an increase in CD value in KC patients with keratoconus, which peaks at 1 month postoperatively and then gradually decreased to normal level at 1 year after surgery.

Keywords

• pentacam
• corneal densitometry
• keratoconus
• corneal cross-linking