Changes in Forward and Backward Light Scatter in Keratoconus Resulting From Corneal Cross-Linking

Abstract

Unlike TE-CXL, CXL increases the already-elevated stromal backscatter in keratoconus. Forward scatter increases equally for both techniques.

Corneal Densitometry in Keratoconus

“…1,16 High levels of corneal light backscatter can be seen even in corneas considered clinically clear. 18 In our study, we found an increase in light backscatter in the central cornea (6 mm in diameter) and total diameter in the KC group . 18 In our study, we found an increase in light backscatter in the central cornea (6 mm in diameter) and total diameter in the KC group .…”

Changes in straylight and densitometry values after corneal collagen crosslinking

“…The highest UVA intensities are in the center of its beam, and the irradiation intensity declines gradually toward the periphery. 27 The higher intensities in the center produce a deeper CXL effect in the central cornea. This explains why the demarcation line in the peripheral corneal regions typically is more shallow in eyes treated using this device.…”

Primary Outcomes of Accelerated Epithelium-Off Corneal Cross-Linking in Progressive Keratoconus in Children: A 1-Year Prospective Study

“…Kamaev et al found higher densitometry values in anterior stroma compared to middle and posterior stroma, as well as the central 6 mm zone compared to the more peripheral zones. The decline in riboflavin concentration, intensity of ultraviolet light, and oxygen concentration in deeper stromal layers explains the higher anterior stromal values [ 10 ], whereas the Gaussian beam profile of the conventional UVA-irradiation device with increased irradiation intensity at the center and gradual decline towards the periphery explains the more central haze distribution [ 11 ].…”