Analysis of densitometry of keratoconus / 眼科新进展

ABSTRACT

Objeetive To compare corneal densitometry measured by Pentacam in normal and keratoconic eyes,and assess the differences in densitometry values among the stages of keratoconus.Methods Densitometry values for 66 eyes (36 eyes from keratoconus group,30 eyes from control group) were obtained for the 0-2 mm,2-6 mm,and 6-10 mm zones of the anterior (up to 120 mm),posterior (posterior 60 mm),and central (between the anterior and posterior) cornea.The differences in densitometry values among the stages of keratoconus were compared.Pearson correlation analysis was used to access the relationship among Keratoconus optical density,cornea thickness and flat K values.1~l~ In total diameter,the corneal densitometry between keratoconus group (17.96 ± 3.23) and control group (17.39 ± 1.95) was not significant different(P =0.124),but there were significant differences between the groups for densitometry measurements in central 2.0 mm zones(anterior,central and total layers),annulus 2-6 mm(anterior layers) and anterior layers in total diameter (all P ＜0.05).Divided by different stage of keratoconus,the anterior layer in mild Keratoconus had no difference with control group(P ＞0.05),but therewere significant differences in moderate keratoconus group(all P ＜ 0.05).In severe Keratoconus group,a statistically significant difference was present at the 2 central annuli in total thickness and annulus 2-6 mm (anterior,central and total layers) with control group (P ＜ 0.05).The correlation between corneal densitometry and the other parameters,including cornea thickness and flat K values were significant (all P ＜ 0.05).Conelusion Compared with normal cornea,there is no change in mild keratoconus.The increase of corneal densitometry in moderate keratoconus group happens in the anterior layers of 0-2 mum zones.The anterior layers of 0-6 mm zones and central layers in 0-2 mm zones in severe keratoconus group are higher than those of control group.More advanced cases present a higher corneal densitometry.Corneal densitometry is an important characteristic of keratoconus,it can be used to detect the process and therapeutic effect of keratoconus.