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. 2019 May 6;8(3):12.
doi: 10.1167/tvst.8.3.12. eCollection 2019 May.

Correlation Between Corneal Topographic, Densitometry, and Biomechanical Parameters in Keratoconus Eyes

Yang Shen  1   2   3 , Tian Han  1   2   3 , Vishal Jhanji  4 , Jianmin Shang  1   2   3 , Jing Zhao  1   2   3 , Meiyan Li  1   2   3 , Xingtao Zhou  1   2   3
Affiliations

Correlation Between Corneal Topographic, Densitometry, and Biomechanical Parameters in Keratoconus Eyes

Yang Shen et al. Transl Vis Sci Technol. .

Abstract

Purpose: To investigate the correlation between corneal densitometry, corneal topographic parameters, and corneal biomechanical properties in keratoconus.

Methods: A total of 76 eyes of 76 keratoconus patients were enrolled in this cross-sectional study. Corneal densitometry and topography were measured using Pentacam HR. Corneal biomechanical properties were measured using CorVis ST.

Results: The corneal densitometry values of the anterior 0 to 2 and 2 to 6 mm layers significantly correlated with the maximum keratometry values (R = 0.373, P = 0.001 and R = 0.276, P = 0.016, respectively), thinnest corneal thickness values (R = -0.331, P = 0.003 and R = -0.234, P = 0.042, respectively), anterior corneal elevation (R = 0.392, P < 0.001 and R = 0.323, P = 0.004, respectively), and posterior corneal elevation (R = 0.450, P < 0.001 and R = 0.367, P = 0.001, respectively). The stiffness parameter-applanation time 1 (SP-A1) significantly correlated with the corneal densitometry values for the anterior 0 to 2 mm (R = -0.397, P < 0.001), anterior 2 to 6 mm (R = -0.331, P = 0.004), central 0 to 2 mm (R = -0.306, P = 0.007), central 2 to 6 mm (R = -0.228, P = 0.048), posterior 2 to 6 mm (R = -0.243, P = 0.035), total 0 to 2 mm (R = -0.291, P = 0.011), and total 2 to 6 mm (R = -0.295, P = 0.010) layers.

Conclusions: The corneal densitometry values correlated with the severity of keratoconus and the SP-A1 values.

Translational relevance: Corneal densitometry values may serve as markers to predict the severity of keratoconus.

Keywords: CorVis ST; Pentacam HR; biomechanics; corneal structure; keratoconus.

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Figures

Figure 1
Figure 1
The densitometric distribution from the anterior to the posterior layers over the annuli of 0 to 2 and 2 to 6 mm of a cornea with keratoconus.
Figure 2
Figure 2
(A) The correlations between the Kmax and corneal densitometry values obtained in the anterior layer over the annuli of 0 to 2 and 2 to 6 mm (R = 0.373, P = 0.001, and R = 0.276, P = 0.016, respectively). (B) The correlations between the thinnest corneal thickness values and the corneal densitometry values of the anterior 0 to 2 mm (R = −0.331, P = 0.003), anterior 2 to 6 mm (R = −0.234, P = 0.042), central 0 to 2 mm (−0.256, P = 0.026), and total 0 to 2 mm (R = −0.230, P = 0.045) layers. (C) The correlations between the anterior corneal elevation values and the corneal densitometry values of anterior 0 to 2 mm (R = 0.392, P < 0.001), anterior 2-6mm (R = 0.323, P = 0.004), central 0 to 2 mm (R = 0.232, P = 0.043), total 0 to 2 mm (R = 0.244, P = 0.033), and total 2 to 6 mm (R = 0.241, P = 0.036) layers. (D) The correlations between the posterior corneal elevation values and the corneal densitometry values of anterior 0 to 2 mm (R = 0.450, P < 0.001), anterior 2 to 6 mm (R = 0.323, P = 0.004), total 0 to 2 mm (R = 0.260, P = 0.023), and total 2 to 6 mm (R = 0.267, P = 0.020) layers.
Figure 3
Figure 3
The correlations between the stiffness parameter-applanation time 1 values and the corneal densitometry values obtained in the anterior layer over the annuli of 0 to 2 and 2 to 6 mm, the central layer over the annuli of 0 to 2 and 2 to 6 mm, the posterior layer over the annuli of 2 to 6 mm, and the total layer over the annuli of 0 to 2 and 2 to 6 mm (anterior 0–2 mm, R = −0.397, P < 0.001; anterior layer 2–6 mm, R = −0.331, P = 0.004; central layer 0–2 mm, R = −0.306, P = 0.007; central layer 2–6 mm, R = −0.228, P = 0.048; posterior layer 2–6 mm, R = −0.243, R = 0.035; total layer 0–2 mm, R = −0.291, P = 0.011, and total layer 2–6 mm, R = −0.295, P = 0.010, respectively).
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